Publications by category
Journal articles
Brailey G, Metcalf B, Lear R, Price L, Cumming S, Stiles V (In Press). A comparison of the associations between bone health and three different intensities of accelerometer-derived habitual physical activity in children and adolescents: a systematic review. Osteoporosis International
Rowlands AV, Sherar LB, Fairclough SJ, Yates T, Edwardson CL, Harrington DM, Davies MJ, Munir F, Khunti K, Stiles VH, et al (In Press). A data-driven, meaningful, easy to interpret, standardised accelerometer outcome variable for global surveillance. Journal of Science and Medicine in Sport
Rowlands A, Fairclough S, Yates T, Edwardson C, Davies M, Munir F, Khunti K, Stiles VH (In Press). Activity intensity, volume & norms: Utility & interpretation of accelerometer metrics. Medicine and Science in Sports and Exercise
Lilley KL, Stiles, VH, Dixon SJ (In Press). The influence of motion control shoes on the running gait of mature and young females. Gait and Posture
Jones HSR, Stiles VH, Verheul J, Moore IS (2022). Angular Velocities and Linear Accelerations Derived from Inertial Measurement Units can be Used as Proxy Measures of Knee Variables Associated with ACL Injury.
Sensors,
22(23), 9286-9286.
Abstract:
Angular Velocities and Linear Accelerations Derived from Inertial Measurement Units can be Used as Proxy Measures of Knee Variables Associated with ACL Injury
Given the high rates of both primary and secondary anterior cruciate ligament (ACL) injuries in multidirectional field sports, there is a need to develop easily accessible methods for practitioners to monitor ACL injury risk. Field-based methods to assess knee variables associated with ACL injury are of particular interest to practitioners for monitoring injury risk in applied sports settings. Knee variables or proxy measures derived from wearable inertial measurement units (IMUs) may thus provide a powerful tool for efficient injury risk management. Therefore, the aim of this study was to identify whether there were correlations between laboratory-derived knee variables (knee range of motion (RoM), change in knee moment, and knee stiffness) and metrics derived from IMUs (angular velocities and accelerations) placed on the tibia and thigh, across a range of movements performed in practitioner assessments used to monitor ACL injury risk. Ground reaction forces, three-dimensional kinematics, and triaxial IMU data were recorded from nineteen healthy male participants performing bilateral and unilateral drop jumps, and a 90° cutting task. Spearman’s correlations were used to examine the correlations between knee variables and IMU-derived metrics. A significant strong positive correlation was observed between knee RoM and the area under the tibia angular velocity curve in all movements. Significant strong correlations were also observed in the unilateral drop jump between knee RoM, change in knee moment, and knee stiffness, and the area under the tibia acceleration curve (rs = 0.776, rs = −0.712, and rs = −0.765, respectively). A significant moderate correlation was observed between both knee RoM and knee stiffness, and the area under the thigh angular velocity curve (rs = 0.682 and rs = −0.641, respectively). The findings from this study suggest that it may be feasible to use IMU-derived angular velocities and acceleration measurements as proxy measures of knee variables in movements included in practitioner assessments used to monitor ACL injury risk.
Abstract.
Lilley K, Stiles V, Dixon S (2022). The influence of design variations in footwear medial-lateral support on the running biomechanics of older female runners.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART P-JOURNAL OF SPORTS ENGINEERING AND TECHNOLOGY,
236(1), 53-59.
Author URL.
Watson PJ, Fieldsend JE, Stiles VH (2021). A scoping review using social network analysis techniques to summarise the prevalance of methods used to acquire data for athlete survelliance in sport.
International Journal of Computer Science in Sport,
20(2), 175-197.
Abstract:
A scoping review using social network analysis techniques to summarise the prevalance of methods used to acquire data for athlete survelliance in sport
Abstract
. To aid the implementation of athlete surveillance systems relative to logistical circumstances, easy-to-access information that summarises the extent to which methods of acquiring data are used in practice to monitor athletes is required. In this scoping review, Social Network Analysis and Mining (SNAM) techniques were used to summarise and identify the most prevalent combinations of methods used to monitor athletes in research studying team, individual, field- and court-based sports (357 articles; SPORTDiscus, MEDLINE, CINHAL, and WebOfScience; 2014-2018 inc.). The most prevalent combination in team and field-based sports were HR and/or sRPE (internal) and GPS, whereas in individual and court-based sports, internal methods (e.g. HR and sRPE) were most prevalent. In court-based sports, where external methods were occasionally collected in combination with internal methods of acquiring data, the use of accelerometers or inertial measuring units (ACC/IMU) were most prevalent. Whilst individual and court-based sports are less researched, this SNAM-based summary reveals that court-based sports may lead the way in using ACC/IMU to monitor athletes. Questionnaires and self-reported methods of acquiring data are common in all categories of sport. This scoping review provides coaches, sport-scientists and researchers with a data-driven visual resource to aid the selection of methods of acquiring data from athletes in all categories of sport relative to logistical circumstances. A guide on how to practically implement a surveillance system based on the visual summaries provided herein, is also presented.
Abstract.
Jones HSR, Moore IS, King E, Stiles VH, Laudani L, McCarthy‐Ryan M, McFadden C, Daniels KAJ (2021). Movement strategy correspondence across jumping and cutting tasks after anterior cruciate ligament reconstruction. Scandinavian Journal of Medicine & Science in Sports, 32(3), 612-621.
Bitchell CL, Varley-Campbell J, Robinson G, Stiles V, Mathema P, Moore IS (2020). Recurrent and Subsequent Injuries in Professional and Elite Sport: a Systematic Review.
Sports Medicine - Open,
6(1).
Abstract:
Recurrent and Subsequent Injuries in Professional and Elite Sport: a Systematic Review
Background: Injury surveillance in professional sport categorises injuries as either “new” or “recurrent”. In an attempt to make categorisation more specific, subsequent injury categorisation models have been developed, but it is not known how often these models are used. The aim was to assess how recurrent and subsequent injuries are reported within professional and elite sport. Methods: Online databases were searched using a search strategy. Studies needed to prospectively report injury rates within professional or elite sports that have published consensus statements for injury surveillance. Results: a total of 1322 titles and abstract were identified and screened. One hundred and ninety-nine studies were screened at full text resulting in 81 eligible studies. Thirty studies did not report recurrent injuries and were excluded from data extraction. Within the studies that reported recurrent injuries, 21 reported the number and percentage; 13 reported only the proportion within all injuries; three reported only the number; five reported the number, percentage and incidence; and two only reported the incidence. Seven studies used subsequent injury terminology, with three reporting subsequent injury following concussion, one using an amended subsequent injury model and three using specific subsequent injury categorisation models. The majority of subsequent injuries (ranging from 51 to 80%) were categorised as different and unrelated to the index injury. The proportion of recurrent injuries (exact same body area and nature related to index injury) ranged from 5 to 21%. Conclusions: Reporting recurrent or subsequent injuries remains inconsistent, and few studies have utilised subsequent injury models. There is limited understanding of subsequent injury risk, which may affect the development of injury prevention strategies. Trial Registration: CRD42019119264
Abstract.
Dean S, Poltawski L, Warmoth K, Goodwin V, Stiles V, Taylor R (2019). Independently Getting Off the floor (IGO): a feasibility study of teaching people with stroke to get up after a fall. International Journal of Therapy and Rehabilitation, 26
Dixon S, Nunns M, House C, Rice H, Mostazir M, Stiles V, Davey T, Fallowfield J, Allsopp A (2019). Prospective study of biomechanical risk factors for second and third metatarsal stress fractures in military recruits.
Journal of Science and Medicine in Sport,
22(2), 135-139.
Abstract:
Prospective study of biomechanical risk factors for second and third metatarsal stress fractures in military recruits
Objectives: This prospective study investigated anatomical and biomechanical risk factors for second and third metatarsal stress fractures in military recruits during training. Design: Prospective cohort study. Methods: Anatomical and biomechanical measures were taken for 1065 Royal Marines recruits at the start of training when injury-free. Data included passive range of ankle dorsi-flexion, dynamic peak ankle dorsi-flexion and plantar pressures during barefoot running. Separate univariate regression models were developed to identify differences between recruits who developed second (n = 7) or third (n = 14) metatarsal stress fracture and a cohort of recruits completing training with no injury (n = 150) (p < 0.05). A multinomial logistic regression model was developed to predict the risk of injury for the two sites compared with the no-injury group. Multinomial logistic regression results were back transformed from log scale and presented in Relative Risk Ratios (RRR) with 95% confidence intervals (CI). Results: Lower dynamic arch index (high arch) (RRR: 0.75, CI: 0.63–0.89, p < 0.01) and lower foot abduction (RRR: 0.87, CI: 0.80–0.96, p < 0.01) were identified as increasing risk for second metatarsal stress fracture, while younger age (RRR: 0.78, CI: 0.61–0.99, p < 0.05) and later peak pressure at the second metatarsal head area (RRR: 1.19, CI: 1.04–1.35, p < 0.01) were identified as risk factors for third metatarsal stress fracture. Conclusions: for second metatarsal stress fracture, aspects of foot type have been identified as influencing injury risk. For third metatarsal stress fracture, a delayed forefoot loading increases injury risk. Identification of these different injury mechanisms can inform development of interventions for treatment and prevention.
Abstract.
Stiles VH, Pearce M, Moore I, Langford J, Rowlands A (2018). Wrist-worn accelerometry for runners: Objective quantification of training load. Medicine and Science in Sports and Exercise, 50, 2277-2284.
Stiles VH, Metcalf BS, Knapp KM, Rowlands AV (2017). A small amount of precisely measured high-intensity habitual physical activity predicts bone health in pre- and post-menopausal women in UK Biobank.
International Journal of Epidemiology,
46(6), 1847-1856.
Abstract:
A small amount of precisely measured high-intensity habitual physical activity predicts bone health in pre- and post-menopausal women in UK Biobank
Background: Physical inactivity is a highly modifiable risk factor for the development of osteoporosis but, due to a lack of research that has precisely and objectively meaured physical activity (PA) relevant to bone, the specific contribution that PA can make to bone health is poorly understood. This study examined whether a more precise measure of PA relelvant to bone was associated with meaures of bone health in pre- and postmenopausal women in UK Biobank. Methods: Time spent at intensities specific to bone health [≥750 milli-gravitational units (mg) and ≥1000 mg] were analysed from raw tri-axial acceleration data averaged over 1-second epochs from 7-day monitoring of habitual PA using accelerometry-based activity monitors (100 Hz; AX3, Axivity, UK) of 1218 pre- and 1316 post-menopausal healthy women. In a cross-sectional analysis, associations between categories of time ( < 1, 1-2 and ≥2minutes) spent above the intensity thresholds and calcaneal quantitative ultrasound measures of bone health (bone mineral density T-score, BMDT-score; speed of sound, SOS; and broadband ultrasound attenuation, BUA) were examined. Results: Compared with < 1minute, spending 1-2 or ≥2minutes/day at intensities ≥1000mg in pre-menopausal and ≥750mg in post-menopausal women was positively associated with BMDT-score, SOS and BUA. Conclusion: Brief bursts of high-intensity PA relevant to bone health can be captured by applying bone-specific thresholds of intensity to raw tri-axial accelerations averaged over 1-second epochs. Accumulating 1-2 minutes/day of high-intensity PA, equivalent to running in pre-menopausal women and slow jogging in post-menopausal women, is associated with better bone health.
Abstract.
Starbuck C, Stiles V, Urà D, Carré M, Dixon S (2017). Biomechanical responses to changes in friction on a clay court surface.
J Sci Med Sport,
20(5), 459-463.
Abstract:
Biomechanical responses to changes in friction on a clay court surface.
OBJECTIVES: to examine the influence of clay court frictional properties on tennis players' biomechanical response. DESIGN: Repeated measures. METHODS: Lower limb kinematic and force data were collected on sixteen university tennis players during 10×180° turns (running approach speed 3.9±0.20ms-1) on a synthetic clay surface of varying friction levels. To adjust friction levels the volume of sand infill above the force plate was altered (kg per m2 surface area; 12, 16 and 20kgm-2). Repeated measures ANOVA and Bonferroni's corrected alpha post-hoc analyses were conducted to identify significant differences in lower limb biomechanics between friction levels. RESULTS: Greater sliding distances (ηp2=0.355, p=0.008) were observed for the lowest friction condition (20kgm-2) compared to the 12 and 16kgm-2 conditions. No differences in ankle joint kinematics and knee flexion angles were observed. Later peak knee flexion occurred on the 20kgm-2 condition compared to the 12kgm-2 (ηp2=0.270, p=0.023). Lower vertical (ηp2=0.345, p=0.027) and shear (ηp2=0.396, p=0.016) loading rates occurred for the 20kgm2 condition compared to the 16kgm2. CONCLUSIONS: Lower loading rates and greater sliding distances when clay surface friction was reduced suggests load was more evenly distributed over time reducing players' injury risks. The greater sliding distances reported were accompanied with later occurrence of peak knee flexion, suggesting longer time spent braking and a greater requirement for muscular control increasing the likelihood of fatigue.
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Nunns M, Stiles V, Fulford J, Dixon S (2017). Estimated third metatarsal bending stresses are highly susceptible to variations in bone geometry.
Footwear Science,
9(3), 127-137.
Abstract:
Estimated third metatarsal bending stresses are highly susceptible to variations in bone geometry
Background: Third metatarsal stress fractures are relatively common during Royal Marines recruit training; however, their aetiology is poorly understood. Mathematical modelling of the third metatarsal may aid in understanding risk factors for stress fracture, particularly if the influence of footwear on peak bending stresses can be determined. This study built on previous models of metatarsal bending stress by integrating individual metatarsal geometry and gait data. Methods: Data from five males with size 11 (UK) feet were acquired. MRI images were digitised to determine cross-sectional bone parameters. Gait variables included vertical ground reaction forces, plantar pressure and foot orientation. The magnitude and location of peak bending stresses were calculated for barefoot running, before standard issue combat boots and trainers were compared. Findings: Estimated peak compressive, tensile and torsional stresses were greater in combat assault boots than in trainers (p < 0.05) with medium effect sizes but wide confidence intervals. However, differences in bone geometry between individuals had a much greater influence on estimated peak stresses. Interpretation: Results suggest that bone geometry has a greater influence on third metatarsal stress fracture risk than footwear. Future bone stress simulations should account for bone geometry. Further development of the model in a variety of participants should proceed to verify these suggestions.
Abstract.
Nunns MP, House CM, Rice H, Mostazir M, Davey P, Stiles V, Fallowfield J, Allsopp A, Dixon SJ (2016). Four biomechanical and anthropometric measures predict tibial stress fracture:. A prospective study of 1065 Royal Marines.
British Journal of Sports MedicineAbstract:
Four biomechanical and anthropometric measures predict tibial stress fracture:. A prospective study of 1065 Royal Marines
Background: Tibial stress fractures cause a significant burden to Royal Marines recruits. No prospective running gait analyses have previously been performed in military settings.
Aim: We aimed to identify biomechanical gait factors and anthropometric variables associated with increased risk of TSF.
Methods: 1065 Royal Marines recruits were assessed in week-2 of training. Bilateral plantar pressure and 3D lower limb kinematics were obtained for barefoot running at 3.6 m.s-1, providing dynamic arch index, peak heel pressure and lower limb joint angles. Age, bimalleolar breadth, calf girth, passive hip internal/external range of motion and body mass index (BMI) were also recorded. Ten recruits who sustained a TSF during training were compared with 120 recruits who completed training injury-free using a binary logistic regression model to identify injury risk factors.
Results: Four variables significantly (p
Abstract.
Starbuck C, Damm L, Clarke J, Carré M, Capel-Davis J, Miller S, Stiles V, Dixon S (2016). The influence of tennis court surfaces on player perceptions and biomechanical response.
J Sports Sci,
34(17), 1627-1636.
Abstract:
The influence of tennis court surfaces on player perceptions and biomechanical response.
This study aimed to examine player perceptions and biomechanical responses to tennis surfaces and to evaluate the influence of prior clay court experience. Two groups with different clay experiences (experience group, n = 5 and low-experience group, n = 5) performed a 180° turning movement. Three-dimensional ankle and knee movements (50 Hz), plantar pressure of the turning step (100 Hz) and perception data (visual analogue scale questionnaire) were collected for two tennis courts (acrylic and clay). Greater initial knee flexion (acrylic 20. 8 ± 11.2° and clay 32.5 ± 9.4°) and a more upright position were reported on the clay compared to the acrylic court (P
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Rowlands AV, Fraysse F, Catt M, Stiles VH, Stanley RM, Eston RG, Olds TS (2015). Comparability of measured acceleration from accelerometry-based activity monitors.
Med Sci Sports Exerc,
47(1), 201-210.
Abstract:
Comparability of measured acceleration from accelerometry-based activity monitors.
BACKGROUND: Accelerometers that provide triaxial measured acceleration data are now available. However, equivalence of output between brands cannot be assumed and testing is necessary to determine whether features of the acceleration signal are interchangeable. PURPOSE: This study aimed to establish the equivalence of output between two brands of monitor in a laboratory and in a free-living environment. METHODS: for part 1, 38 adults performed nine laboratory-based activities while wearing an ActiGraph GT3X+ and GENEActiv (Gravity Estimator of Normal Everyday Activity) at the hip. For part 2, 58 children age 10-12 yr wore a GT3X+ and GENEActiv at the hip for 7 d in a free-living setting. RESULTS: for part 1, the magnitude of time domain features from the GENEActiv was greater than that from the GT3X+. However, frequency domain features compared well, with perfect agreement of the dominant frequency for 97%-100% of participants for most activities. For part 2, mean daily acceleration measured by the two brands was correlated (r = 0.93, P < 0.001, respectively) but the magnitude was approximately 15% lower for the GT3X+ than that for the GENEActiv at the hip. CONCLUSIONS: Frequency domain-based classification algorithms should be transferable between monitors, and it should be possible to apply time domain-based classification algorithms developed for one device to the other by applying an affine conversion on the measured acceleration values. The strong relation between accelerations measured by the two brands suggests that habitual activity level and activity patterns assessed by the GENE and GT3X+ may compare well if analyzed appropriately.
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Rowlands AV, Schuna JM, Stiles VH, Tudor-Locke C (2013). Cadence, peak vertical acceleration and peak loading rate during ambulatory activities: Implications for activity prescription for bone health.
Journal of Physical Activity and HealthAbstract:
Cadence, peak vertical acceleration and peak loading rate during ambulatory activities: Implications for activity prescription for bone health
Background: Previous research has reported thresholds to identify activities associated with bone mineral density (BMD). Such thresholds are typically expressed in units of body weights or acceleration, which are hard to translate into meaningful recommendations for physical activity. Cadence (steps/min) is a more readily interpretable measure of ambulatory activity. Objective: to examine relationships between cadence, acceleration and ground reaction force (GRF) during ambulation and identify the cadence associated with previously reported bone-beneficial thresholds from vertical acceleration and GRF data. Methods: Ten participants completed eight trials each of: slow walking, brisk walking, slow running, and fast running. Acceleration data were captured using a GT3X+ worn at the hip. Measures of GRF were collected via a force plate. Results: Strong relationships were identified between cadence and peak vertical acceleration (r=0.96, p
Abstract.
Stiles VH, Katene WH (2013). Improving physical education student teachers' knowledge and understanding of applied biomechanical principles through peer collaboration. Physical Education and Sport Pedagogy, 18(3), 235-255.
Lilley K, Stiles VH, Dixon S (2013). The influence of motion control shoes on the running gait of mature and young females.
Gait and Posture,
37(3), 331-335.
Abstract:
The influence of motion control shoes on the running gait of mature and young females
Background
This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm.
Methods
15 mature (40–60 years) and 15 young (18–25 years) females performed 10 running trials at 3.5 m s−1 ± 5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics.
Findings
In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p < 0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p < 0.05). No between shoe differences in knee external adductor moment were observed.
Interpretation
A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment.
Abstract.
Stiles VH, Griew PJ, Rowlands AV (2013). Use of accelerometry to classify activity beneficial to bone in premenopausal women.
Med Sci Sports Exerc,
45(12), 2353-2361.
Abstract:
Use of accelerometry to classify activity beneficial to bone in premenopausal women.
PURPOSE: the aims of this study were to quantify the relation between ground reaction force (GRF) and peak acceleration from hip- and wrist-worn accelerometers and determine peak acceleration cut-points associated with a loading rate previously demonstrated as beneficial to bone (43 body weights (BW)·s⁻¹) in premenopausal women. METHODS: Forty-seven premenopausal women (age, 39.2 ± 5.6 yr; mass, 65.9 ± 11.0 kg; height, 1.67 ± 0.06 m) performed walking (slow, fast, and with bag), floor sweeping, running (slow and fast), jumping (low, 5 cm), and box drop (20 cm) trials. Peak accelerations were sampled at 100 Hz by GENEActiv and ActiGraph GT3X+ accelerometers (ActiGraph LLC, Pensacola, FL) worn at the hip (vertical and resultant) and the wrist (resultant). A force plate (960 Hz, AMTI) was used to assess peak vertical GRF and peak loading rate for eight steps per activity. Receiver operating characteristic curves were used to determine the optimal peak acceleration cut-points associated with a loading rate of 43 BW·s⁻¹ in 37 participants, and these cut-points were cross-validated in the remaining 10 participants. RESULTS: for all activities combined, peak accelerations were positively and significantly (P < 0.001) correlated with peak vertical GRF (hip r > 0.8, wrist r > 0.7) and peak loading rate (hip r > 0.7, wrist r > 0.57). Irrespective of monitor type and wear site, peak acceleration discriminated between loading rates above and below 43 BW·s⁻¹ with high levels of accuracy (area under the curve >0.92, P < 0.001). Overall classification agreement was >85% for both monitors worn at either the wrist or hip in the cross-validation sample. CONCLUSION: GENEActiv and ActiGraph GT3X+ accelerometers worn at the wrist or hip can be used as an unobtrusive tool to identify the occurrence of loading rates likely beneficial to bone in premenopausal women during their daily activity.
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Rowlands AV, Stiles VH (2012). Accelerometer counts and raw acceleration output in relation to mechanical loading.
Journal of Biomechanics,
45(3), 448-454.
Abstract:
Accelerometer counts and raw acceleration output in relation to mechanical loading
The purpose of this study was to assess the relationship of accelerometer output, in counts (ActiGraph GT1M) and as raw accelerations (ActiGraph GT3X+ and GENEA), with ground reaction force (GRF) in adults. Ten participants (age: 29.4±8.2 y, mass: 74.3±9.8 kg, height: 1.76±0.09 m) performed eight trials each of: slow walking, brisk walking, slow running, faster running and box drops. GRF data were collected for one step per trial (walking and running) using a force plate. Low jumps and higher jumps (one per second) were performed for 20 s each on the force plate. For box drops, participants dropped from a 20 cm box onto the force plate. Throughout, three accelerometers were worn at the hip: GT1M, GT3X+ and GENEA. A further GT3X+ and GENEA were worn on the left and right wrist, respectively. GT1M counts correlated with peak impact force (r = 0.85, p
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Lilley K, Stiles V, Dixon SJ (2011). A Biomechanical Comparison of the Running Gait of Mature and Young Females.
Gait and Posture,
43, 496-500.
Abstract:
A Biomechanical Comparison of the Running Gait of Mature and Young Females
Background. Due to health and social advantages, the popularity of running as a sport among mature female runners is expanding steadily. However, the incidence of running injuries and associated conditions is vast among this group. The purpose of this study was to quantify gait parameters of mature and younger female runners to assess whether certain running characteristics predispose to debilitating conditions. It was hypothesised that mature females would exhibit greater rearfoot eversion, knee internal rotation, knee external adductor moments and loading rate of ground reaction force when compared to younger runners. Methods. 15 mature (40-60 years) and 15 young (18-24 years) females performed 10 running trials at 3.5 m.s-1 in the biomechanics laboratory. Both kinematic and ground reaction force data were collected. Signs of osteoarthritis and knee injuries were assessed using the KOOS scale. Findings. Mature females produced significantly higher peak rearfoot eversion, knee internal rotation, external adductor moment and loading rate of ground reaction force. compared to the young participants (p"lt;0.05). Interpretations. Although all participants recorded “symptom free” on the KOOS scale, all variables of gait found higher among the mature group have previously been associated with development of overuse injuries and debilitating conditions, suggesting a possible predisposition towards these conditions among the mature group.
Abstract.
Stiles VH, Guisasola IN, James IT, Dixon SJ (2011). Biomechanical Response to Changes in Natural Turf during Running and Turning.
Journal of Applied Biomechanics,
27(1), 54-63.
Abstract:
Biomechanical Response to Changes in Natural Turf during Running and Turning
Integrated biomechanical and engineering assessments were used to determine how humans responded to variations in turf during running and turning. Ground reaction force (AMTI, 960 Hz) and kinematic data (Vicon Peak Motus, 120 Hz) were collected from eight participants during running (3.83 m/s) and turning (10 trials per condition) on three natural turf surfaces in the laboratory. Surface hardness (Clegg hammer) and shear strength (cruciform shear vane) were measured before and after participant testing. Peak loading rate during running was significantly higher (p <. 05) on the least hard surface (sandy; 101.48 BW/s ± 23.3) compared with clay (84.67 BW/s ± 22.9). There were no significant differences in running kinematics. Compared with the “medium” condition, fifth MTP impact velocities during turning were significantly (RM-ANOVA, p <. 05) lower on clay (resultant: 2.30 m/s [± 0.68] compared with 2.64 m/s [± 0.70]), which was significantly (p <. 05) harder “after” and had the greatest shear strength both “before” and “after” participant testing. This unique finding suggests that further study of foot impact velocities are important to increase understanding of overuse injury mechanisms.
Abstract.
Nunns M, Stiles V, Dixon S (2011). The effects of standard issue Royal Marine footwear on risk factors associated with third metatarsal stress fractures. Footwear Science, 3(sup1), S124-S125.
Guisasola I, James I, Stiles V, Dixon S (2010). Dynamic behaviour of soils used for natural turf sports surfaces.
Sports Engineering,
12(3), 111-122.
Abstract:
Dynamic behaviour of soils used for natural turf sports surfaces
The modulus and damping properties of soils in compression are a function of soil type, water content, stress history and loading rate. To model human–surface interaction with natural turf sports surfaces, stiffness and damping properties must be determined at dynamic loading rates. Two contrasting soil types, a Sand and a Clay Loam, commonly used in sports surfaces were loaded uniaxially to 2 kN at loading rates between 0.6 and 6 kN s−1 in modified dynamic soil testing apparatus. Soils were compacted prior to loading but initial cycles resulted in viscoplastic deformation, with strain accumulation with repeated cycles of loading. Ultimately a resilient, viscoelastic steady-state equilibrium with loading was established. Resilient modulus and damping ratio varied with soil type, water content, stress history and increased significantly with loading rate. The resilient modulus of the Sand soil, typical of modern free-draining sand construction natural turf sports surfaces, was significantly greater than that of a Clay Loam soil more characteristic of traditional natural turf surfaces; reducing water content caused an increase in modulus and a decrease in damping ratio in the Clay Loam soil. Determination of these properties provides initial data for the modelling natural turf surface behaviour in terms of both ball and human interactions, with further research required to determine the effect of both grass roots and leaves on mechanical behaviour.
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Guisasola I, James I, Llewellyn C, Stiles V, Dixon S (2010). Quasi-static mechanical behaviour of soils used for natural turf sports surfaces and stud force prediction.
Sports Engineering,
12(2), 99-109.
Abstract:
Quasi-static mechanical behaviour of soils used for natural turf sports surfaces and stud force prediction
The quasi-static testing of soils used in natural turf pitches yields key parameters in soil modelling,including elastic moduli, Poisson’s ratio and Mohr–Coulomb parameters for shearing resistance and cohesion in soil. The bulk strength of a Sand soil used in the construction of elite sports surfaces was found to increase initially and then decrease with increasing water content due to apparent cohesion effects. For a Clay Loam soil,
more common in recreational facilities, shear strength decreased with water content. Reducing density resulted in a reduction of shear strength and elastic moduli in both soils due to reduced packing of particles reducing particle–particle contact surface area. The effect of roots on the shear strength of a Sand soil was not significant but reduced elastic moduli significantly. Horizontal forces measured during running and turning in a biomechanics laboratory were in good agreement with forces predicted using a simple quasi-static soil model for coarse-grained (Sand) soils although this was not the case with the Clay Loam soil.
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Stiles VH, James IT, Dixon SJ, Guisasola IN (2009). Natural turf surfaces: the case for continued research.
Sports Med,
39(1), 65-84.
Abstract:
Natural turf surfaces: the case for continued research.
It is well documented that health and social benefits can be attained through participation in sport and exercise. Participation, particularly in sports, benefits from appropriate surface provisions that are safe, affordable and high quality preferably across the recreational to elite continuum. Investment, construction and research into artificial sports surfaces have increased to meet this provision. However, not all sports (e.g. golf, rugby and cricket) are suited to training and match-play on artificial turf without compromising some playing characteristics of the games. Therefore, full sport surface provision cannot be met without the use of natural turf surfaces, which also have an important role as green spaces in the built environment. Furthermore, a significant number of people participate in outdoor sport on natural turf pitches, although this is a declining trend as the number of synthetic turf surfaces increases. Despite natural turf being a common playing surface for popular sports such as soccer, rugby and cricket, few biomechanical studies have been performed using natural turf conditions. It is proposed that if natural turf surfaces are to help meet the provision of sports surfaces, advancement in the construction and sustainability of natural turf surface design is required. The design of a natural turf surface should also be informed by knowledge of surface-related overuse injury risk factors. This article reviews biomechanical, engineering, soil mechanics, turfgrass science, sports medicine and injury-related literature with a view to proposing a multidisciplinary approach to engineering a more sustainable natural turf sport surface. The present article concludes that an integrated approach incorporating an engineering and biomechanical analysis of the effects of variations in natural turf media on human movement and the effects of variations in human movement on natural turf is primarily required to address the longer-term development of sustainable natural turf playing surfaces. It also recommends that the use of 'natural turf' as a catch-all categorization in injury studies masks the spatial and temporal variation within and among such surfaces, which could be important.
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Stiles VH, Dixon, S.J. (2007). Biomechanical response to systematic changes in impact interface cushioning properties while performing a tennis specific movement.
Journal of Sports Sciences,
25(11), 1229-1239.
Abstract:
Biomechanical response to systematic changes in impact interface cushioning properties while performing a tennis specific movement.
It is currently not known whether human responses across typical sports surfaces are dependent on cushioning or frictional
properties of the interface. The present study assessed systematic changes in surface cushioning (baseline acrylic, rubber,
thin foam, and thick foam) as participants performed tennis running forehand foot plants wearing a basic neutral shoe
(plimsolls). It was hypothesized that systematic decreases in peak rates of loading, heel pressures, and perceived hardness
would be yielded as surface cushioning increased (impact test device). A common acrylic top surface provided consistent
frictional properties across surfaces. Kinetics (AMTI, 960 Hz and Footscan Pressure Insoles, 500 Hz), kinematics (Peak
MOTUS, 120 Hz), and cushioning perception were assessed. Peak and mean loading rates of vertical ground reaction force,
peak horizontal force, peak heel pressure, and rates of loading demonstrated significant correlations (P50.05) with the
participants’ perceived levels of cushioning and matched mechanical rankings of surface cushioning. In contrast, peak impact
force was lowest on the least cushioned surface. Kinematic responses were not significantly different between surfaces.
Present evidence supports ‘‘peak rate of loading’’ as a more suitable indicator of surface cushioning than peak impact force.
Although cautionary, biomechanical support is also provided for mechanical methods of surface cushioning assessment.
Abstract.
Stiles VH, Dixon SJ (2007). Biomechanical response to systematic changes in impact interface cushioning while performing a tennis specific movement. Journal of Sport Sciences, 25(11), 1229-1239.
Stiles VH, Dixon SJ (2006). The influence of different playing surfaces on the biomechanics of a tennis forehand foot plant. Journal of Applied Biomechanics, 22(1), 14-24.
Dixon SJ, Stiles VH (2003). Impact absorption of tennis shoe-surface combinations. Sports Engineering, 6(1), 1-10.
Chapters
Damm L, Stiles V, Dixon S (In Press). Human-shoe-surface interaction. In Dixon S, Fleming P, James I, Carre M (Eds.) The Science and Engineering of Sport Surfaces, Oxon: Routledge, 135-157.
Stiles VH, Dixon S (In Press). Sports surfaces, biomechanics and injury. In Dixon S, Fleming P, James I, Carre M (Eds.) The Science and Engineering of Sport Surfaces, Oxon: Routledge, 70-97.
Stiles V, Knapp K (2022). Bone Health. In Scott A, Broom D (Eds.)
Exercise Management for Referred Medical Conditions, Oxon: Routledge, 421-446.
Abstract:
Bone Health
Abstract.
Conferences
Nunns M, Stiles V (2015). The influence of variable medial–lateral stiffness footwear on frontal plane kinematics and joint moments at the knee and ankle in healthy young males.
Nunns M, Stiles V (2015). The influence of variations in heel and forefoot midsole stiffness on sagittal plane kinematics and joint moments at the knee and ankle.
Nunns M, Rice H, House C, Fallowfield J, Allsopp A, Stiles V, Dixon S (2013). A prospective study identifying risk factors for tibial stress fracture in Royal Marine recruits: initial findings.
Dixon S, Nunns M, House C, Rice H, Stiles V (2013). Ankle joint kinematics influence risk of third metatarsal stress fracture in military recruits.
Dean S, Goodwin VA, Poltawski L, Stiles VH, Taylor R (2013). The IGO study: a 'before and after' case series to assess the safety and teaching of a technique designed for people with stroke to Independently Get up Off the floor.
Author URL.
Nunns M, Stiles V, Dixon S (2012). The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures.
Abstract:
The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures
Abstract.
Nunns MPI, Stiles VH, Dixon SJ (2012). The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures.
Publications by year
In Press
Brailey G, Metcalf B, Lear R, Price L, Cumming S, Stiles V (In Press). A comparison of the associations between bone health and three different intensities of accelerometer-derived habitual physical activity in children and adolescents: a systematic review. Osteoporosis International
Rowlands AV, Sherar LB, Fairclough SJ, Yates T, Edwardson CL, Harrington DM, Davies MJ, Munir F, Khunti K, Stiles VH, et al (In Press). A data-driven, meaningful, easy to interpret, standardised accelerometer outcome variable for global surveillance. Journal of Science and Medicine in Sport
Rowlands A, Fairclough S, Yates T, Edwardson C, Davies M, Munir F, Khunti K, Stiles VH (In Press). Activity intensity, volume & norms: Utility & interpretation of accelerometer metrics. Medicine and Science in Sports and Exercise
Damm L, Stiles V, Dixon S (In Press). Human-shoe-surface interaction. In Dixon S, Fleming P, James I, Carre M (Eds.) The Science and Engineering of Sport Surfaces, Oxon: Routledge, 135-157.
Stiles VH, Dixon S (In Press). Sports surfaces, biomechanics and injury. In Dixon S, Fleming P, James I, Carre M (Eds.) The Science and Engineering of Sport Surfaces, Oxon: Routledge, 70-97.
Lilley KL, Stiles, VH, Dixon SJ (In Press). The influence of motion control shoes on the running gait of mature and young females. Gait and Posture
2022
Jones HSR, Stiles VH, Verheul J, Moore IS (2022). Angular Velocities and Linear Accelerations Derived from Inertial Measurement Units can be Used as Proxy Measures of Knee Variables Associated with ACL Injury.
Sensors,
22(23), 9286-9286.
Abstract:
Angular Velocities and Linear Accelerations Derived from Inertial Measurement Units can be Used as Proxy Measures of Knee Variables Associated with ACL Injury
Given the high rates of both primary and secondary anterior cruciate ligament (ACL) injuries in multidirectional field sports, there is a need to develop easily accessible methods for practitioners to monitor ACL injury risk. Field-based methods to assess knee variables associated with ACL injury are of particular interest to practitioners for monitoring injury risk in applied sports settings. Knee variables or proxy measures derived from wearable inertial measurement units (IMUs) may thus provide a powerful tool for efficient injury risk management. Therefore, the aim of this study was to identify whether there were correlations between laboratory-derived knee variables (knee range of motion (RoM), change in knee moment, and knee stiffness) and metrics derived from IMUs (angular velocities and accelerations) placed on the tibia and thigh, across a range of movements performed in practitioner assessments used to monitor ACL injury risk. Ground reaction forces, three-dimensional kinematics, and triaxial IMU data were recorded from nineteen healthy male participants performing bilateral and unilateral drop jumps, and a 90° cutting task. Spearman’s correlations were used to examine the correlations between knee variables and IMU-derived metrics. A significant strong positive correlation was observed between knee RoM and the area under the tibia angular velocity curve in all movements. Significant strong correlations were also observed in the unilateral drop jump between knee RoM, change in knee moment, and knee stiffness, and the area under the tibia acceleration curve (rs = 0.776, rs = −0.712, and rs = −0.765, respectively). A significant moderate correlation was observed between both knee RoM and knee stiffness, and the area under the thigh angular velocity curve (rs = 0.682 and rs = −0.641, respectively). The findings from this study suggest that it may be feasible to use IMU-derived angular velocities and acceleration measurements as proxy measures of knee variables in movements included in practitioner assessments used to monitor ACL injury risk.
Abstract.
Stiles V, Knapp K (2022). Bone Health. In Scott A, Broom D (Eds.)
Exercise Management for Referred Medical Conditions, Oxon: Routledge, 421-446.
Abstract:
Bone Health
Abstract.
Lilley K, Stiles V, Dixon S (2022). The influence of design variations in footwear medial-lateral support on the running biomechanics of older female runners.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART P-JOURNAL OF SPORTS ENGINEERING AND TECHNOLOGY,
236(1), 53-59.
Author URL.
2021
Watson PJ, Fieldsend JE, Stiles VH (2021). A scoping review using social network analysis techniques to summarise the prevalance of methods used to acquire data for athlete survelliance in sport.
International Journal of Computer Science in Sport,
20(2), 175-197.
Abstract:
A scoping review using social network analysis techniques to summarise the prevalance of methods used to acquire data for athlete survelliance in sport
Abstract
. To aid the implementation of athlete surveillance systems relative to logistical circumstances, easy-to-access information that summarises the extent to which methods of acquiring data are used in practice to monitor athletes is required. In this scoping review, Social Network Analysis and Mining (SNAM) techniques were used to summarise and identify the most prevalent combinations of methods used to monitor athletes in research studying team, individual, field- and court-based sports (357 articles; SPORTDiscus, MEDLINE, CINHAL, and WebOfScience; 2014-2018 inc.). The most prevalent combination in team and field-based sports were HR and/or sRPE (internal) and GPS, whereas in individual and court-based sports, internal methods (e.g. HR and sRPE) were most prevalent. In court-based sports, where external methods were occasionally collected in combination with internal methods of acquiring data, the use of accelerometers or inertial measuring units (ACC/IMU) were most prevalent. Whilst individual and court-based sports are less researched, this SNAM-based summary reveals that court-based sports may lead the way in using ACC/IMU to monitor athletes. Questionnaires and self-reported methods of acquiring data are common in all categories of sport. This scoping review provides coaches, sport-scientists and researchers with a data-driven visual resource to aid the selection of methods of acquiring data from athletes in all categories of sport relative to logistical circumstances. A guide on how to practically implement a surveillance system based on the visual summaries provided herein, is also presented.
Abstract.
Jones HSR, Moore IS, King E, Stiles VH, Laudani L, McCarthy‐Ryan M, McFadden C, Daniels KAJ (2021). Movement strategy correspondence across jumping and cutting tasks after anterior cruciate ligament reconstruction. Scandinavian Journal of Medicine & Science in Sports, 32(3), 612-621.
2020
Bitchell CL, Varley-Campbell J, Robinson G, Stiles V, Mathema P, Moore IS (2020). Recurrent and Subsequent Injuries in Professional and Elite Sport: a Systematic Review.
Sports Medicine - Open,
6(1).
Abstract:
Recurrent and Subsequent Injuries in Professional and Elite Sport: a Systematic Review
Background: Injury surveillance in professional sport categorises injuries as either “new” or “recurrent”. In an attempt to make categorisation more specific, subsequent injury categorisation models have been developed, but it is not known how often these models are used. The aim was to assess how recurrent and subsequent injuries are reported within professional and elite sport. Methods: Online databases were searched using a search strategy. Studies needed to prospectively report injury rates within professional or elite sports that have published consensus statements for injury surveillance. Results: a total of 1322 titles and abstract were identified and screened. One hundred and ninety-nine studies were screened at full text resulting in 81 eligible studies. Thirty studies did not report recurrent injuries and were excluded from data extraction. Within the studies that reported recurrent injuries, 21 reported the number and percentage; 13 reported only the proportion within all injuries; three reported only the number; five reported the number, percentage and incidence; and two only reported the incidence. Seven studies used subsequent injury terminology, with three reporting subsequent injury following concussion, one using an amended subsequent injury model and three using specific subsequent injury categorisation models. The majority of subsequent injuries (ranging from 51 to 80%) were categorised as different and unrelated to the index injury. The proportion of recurrent injuries (exact same body area and nature related to index injury) ranged from 5 to 21%. Conclusions: Reporting recurrent or subsequent injuries remains inconsistent, and few studies have utilised subsequent injury models. There is limited understanding of subsequent injury risk, which may affect the development of injury prevention strategies. Trial Registration: CRD42019119264
Abstract.
2019
Dean S, Poltawski L, Warmoth K, Goodwin V, Stiles V, Taylor R (2019). Independently Getting Off the floor (IGO): a feasibility study of teaching people with stroke to get up after a fall. International Journal of Therapy and Rehabilitation, 26
Dixon S, Nunns M, House C, Rice H, Mostazir M, Stiles V, Davey T, Fallowfield J, Allsopp A (2019). Prospective study of biomechanical risk factors for second and third metatarsal stress fractures in military recruits.
Journal of Science and Medicine in Sport,
22(2), 135-139.
Abstract:
Prospective study of biomechanical risk factors for second and third metatarsal stress fractures in military recruits
Objectives: This prospective study investigated anatomical and biomechanical risk factors for second and third metatarsal stress fractures in military recruits during training. Design: Prospective cohort study. Methods: Anatomical and biomechanical measures were taken for 1065 Royal Marines recruits at the start of training when injury-free. Data included passive range of ankle dorsi-flexion, dynamic peak ankle dorsi-flexion and plantar pressures during barefoot running. Separate univariate regression models were developed to identify differences between recruits who developed second (n = 7) or third (n = 14) metatarsal stress fracture and a cohort of recruits completing training with no injury (n = 150) (p < 0.05). A multinomial logistic regression model was developed to predict the risk of injury for the two sites compared with the no-injury group. Multinomial logistic regression results were back transformed from log scale and presented in Relative Risk Ratios (RRR) with 95% confidence intervals (CI). Results: Lower dynamic arch index (high arch) (RRR: 0.75, CI: 0.63–0.89, p < 0.01) and lower foot abduction (RRR: 0.87, CI: 0.80–0.96, p < 0.01) were identified as increasing risk for second metatarsal stress fracture, while younger age (RRR: 0.78, CI: 0.61–0.99, p < 0.05) and later peak pressure at the second metatarsal head area (RRR: 1.19, CI: 1.04–1.35, p < 0.01) were identified as risk factors for third metatarsal stress fracture. Conclusions: for second metatarsal stress fracture, aspects of foot type have been identified as influencing injury risk. For third metatarsal stress fracture, a delayed forefoot loading increases injury risk. Identification of these different injury mechanisms can inform development of interventions for treatment and prevention.
Abstract.
2018
Stiles VH, Pearce M, Moore I, Langford J, Rowlands A (2018). Wrist-worn accelerometry for runners: Objective quantification of training load. Medicine and Science in Sports and Exercise, 50, 2277-2284.
2017
Stiles VH, Metcalf BS, Knapp KM, Rowlands AV (2017). A small amount of precisely measured high-intensity habitual physical activity predicts bone health in pre- and post-menopausal women in UK Biobank.
International Journal of Epidemiology,
46(6), 1847-1856.
Abstract:
A small amount of precisely measured high-intensity habitual physical activity predicts bone health in pre- and post-menopausal women in UK Biobank
Background: Physical inactivity is a highly modifiable risk factor for the development of osteoporosis but, due to a lack of research that has precisely and objectively meaured physical activity (PA) relevant to bone, the specific contribution that PA can make to bone health is poorly understood. This study examined whether a more precise measure of PA relelvant to bone was associated with meaures of bone health in pre- and postmenopausal women in UK Biobank. Methods: Time spent at intensities specific to bone health [≥750 milli-gravitational units (mg) and ≥1000 mg] were analysed from raw tri-axial acceleration data averaged over 1-second epochs from 7-day monitoring of habitual PA using accelerometry-based activity monitors (100 Hz; AX3, Axivity, UK) of 1218 pre- and 1316 post-menopausal healthy women. In a cross-sectional analysis, associations between categories of time ( < 1, 1-2 and ≥2minutes) spent above the intensity thresholds and calcaneal quantitative ultrasound measures of bone health (bone mineral density T-score, BMDT-score; speed of sound, SOS; and broadband ultrasound attenuation, BUA) were examined. Results: Compared with < 1minute, spending 1-2 or ≥2minutes/day at intensities ≥1000mg in pre-menopausal and ≥750mg in post-menopausal women was positively associated with BMDT-score, SOS and BUA. Conclusion: Brief bursts of high-intensity PA relevant to bone health can be captured by applying bone-specific thresholds of intensity to raw tri-axial accelerations averaged over 1-second epochs. Accumulating 1-2 minutes/day of high-intensity PA, equivalent to running in pre-menopausal women and slow jogging in post-menopausal women, is associated with better bone health.
Abstract.
Starbuck C, Stiles V, Urà D, Carré M, Dixon S (2017). Biomechanical responses to changes in friction on a clay court surface.
J Sci Med Sport,
20(5), 459-463.
Abstract:
Biomechanical responses to changes in friction on a clay court surface.
OBJECTIVES: to examine the influence of clay court frictional properties on tennis players' biomechanical response. DESIGN: Repeated measures. METHODS: Lower limb kinematic and force data were collected on sixteen university tennis players during 10×180° turns (running approach speed 3.9±0.20ms-1) on a synthetic clay surface of varying friction levels. To adjust friction levels the volume of sand infill above the force plate was altered (kg per m2 surface area; 12, 16 and 20kgm-2). Repeated measures ANOVA and Bonferroni's corrected alpha post-hoc analyses were conducted to identify significant differences in lower limb biomechanics between friction levels. RESULTS: Greater sliding distances (ηp2=0.355, p=0.008) were observed for the lowest friction condition (20kgm-2) compared to the 12 and 16kgm-2 conditions. No differences in ankle joint kinematics and knee flexion angles were observed. Later peak knee flexion occurred on the 20kgm-2 condition compared to the 12kgm-2 (ηp2=0.270, p=0.023). Lower vertical (ηp2=0.345, p=0.027) and shear (ηp2=0.396, p=0.016) loading rates occurred for the 20kgm2 condition compared to the 16kgm2. CONCLUSIONS: Lower loading rates and greater sliding distances when clay surface friction was reduced suggests load was more evenly distributed over time reducing players' injury risks. The greater sliding distances reported were accompanied with later occurrence of peak knee flexion, suggesting longer time spent braking and a greater requirement for muscular control increasing the likelihood of fatigue.
Abstract.
Author URL.
Nunns M, Stiles V, Fulford J, Dixon S (2017). Estimated third metatarsal bending stresses are highly susceptible to variations in bone geometry.
Footwear Science,
9(3), 127-137.
Abstract:
Estimated third metatarsal bending stresses are highly susceptible to variations in bone geometry
Background: Third metatarsal stress fractures are relatively common during Royal Marines recruit training; however, their aetiology is poorly understood. Mathematical modelling of the third metatarsal may aid in understanding risk factors for stress fracture, particularly if the influence of footwear on peak bending stresses can be determined. This study built on previous models of metatarsal bending stress by integrating individual metatarsal geometry and gait data. Methods: Data from five males with size 11 (UK) feet were acquired. MRI images were digitised to determine cross-sectional bone parameters. Gait variables included vertical ground reaction forces, plantar pressure and foot orientation. The magnitude and location of peak bending stresses were calculated for barefoot running, before standard issue combat boots and trainers were compared. Findings: Estimated peak compressive, tensile and torsional stresses were greater in combat assault boots than in trainers (p < 0.05) with medium effect sizes but wide confidence intervals. However, differences in bone geometry between individuals had a much greater influence on estimated peak stresses. Interpretation: Results suggest that bone geometry has a greater influence on third metatarsal stress fracture risk than footwear. Future bone stress simulations should account for bone geometry. Further development of the model in a variety of participants should proceed to verify these suggestions.
Abstract.
2016
Nunns MP, House CM, Rice H, Mostazir M, Davey P, Stiles V, Fallowfield J, Allsopp A, Dixon SJ (2016). Four biomechanical and anthropometric measures predict tibial stress fracture:. A prospective study of 1065 Royal Marines.
British Journal of Sports MedicineAbstract:
Four biomechanical and anthropometric measures predict tibial stress fracture:. A prospective study of 1065 Royal Marines
Background: Tibial stress fractures cause a significant burden to Royal Marines recruits. No prospective running gait analyses have previously been performed in military settings.
Aim: We aimed to identify biomechanical gait factors and anthropometric variables associated with increased risk of TSF.
Methods: 1065 Royal Marines recruits were assessed in week-2 of training. Bilateral plantar pressure and 3D lower limb kinematics were obtained for barefoot running at 3.6 m.s-1, providing dynamic arch index, peak heel pressure and lower limb joint angles. Age, bimalleolar breadth, calf girth, passive hip internal/external range of motion and body mass index (BMI) were also recorded. Ten recruits who sustained a TSF during training were compared with 120 recruits who completed training injury-free using a binary logistic regression model to identify injury risk factors.
Results: Four variables significantly (p
Abstract.
Starbuck C, Damm L, Clarke J, Carré M, Capel-Davis J, Miller S, Stiles V, Dixon S (2016). The influence of tennis court surfaces on player perceptions and biomechanical response.
J Sports Sci,
34(17), 1627-1636.
Abstract:
The influence of tennis court surfaces on player perceptions and biomechanical response.
This study aimed to examine player perceptions and biomechanical responses to tennis surfaces and to evaluate the influence of prior clay court experience. Two groups with different clay experiences (experience group, n = 5 and low-experience group, n = 5) performed a 180° turning movement. Three-dimensional ankle and knee movements (50 Hz), plantar pressure of the turning step (100 Hz) and perception data (visual analogue scale questionnaire) were collected for two tennis courts (acrylic and clay). Greater initial knee flexion (acrylic 20. 8 ± 11.2° and clay 32.5 ± 9.4°) and a more upright position were reported on the clay compared to the acrylic court (P
Abstract.
Author URL.
2015
Rowlands AV, Fraysse F, Catt M, Stiles VH, Stanley RM, Eston RG, Olds TS (2015). Comparability of measured acceleration from accelerometry-based activity monitors.
Med Sci Sports Exerc,
47(1), 201-210.
Abstract:
Comparability of measured acceleration from accelerometry-based activity monitors.
BACKGROUND: Accelerometers that provide triaxial measured acceleration data are now available. However, equivalence of output between brands cannot be assumed and testing is necessary to determine whether features of the acceleration signal are interchangeable. PURPOSE: This study aimed to establish the equivalence of output between two brands of monitor in a laboratory and in a free-living environment. METHODS: for part 1, 38 adults performed nine laboratory-based activities while wearing an ActiGraph GT3X+ and GENEActiv (Gravity Estimator of Normal Everyday Activity) at the hip. For part 2, 58 children age 10-12 yr wore a GT3X+ and GENEActiv at the hip for 7 d in a free-living setting. RESULTS: for part 1, the magnitude of time domain features from the GENEActiv was greater than that from the GT3X+. However, frequency domain features compared well, with perfect agreement of the dominant frequency for 97%-100% of participants for most activities. For part 2, mean daily acceleration measured by the two brands was correlated (r = 0.93, P < 0.001, respectively) but the magnitude was approximately 15% lower for the GT3X+ than that for the GENEActiv at the hip. CONCLUSIONS: Frequency domain-based classification algorithms should be transferable between monitors, and it should be possible to apply time domain-based classification algorithms developed for one device to the other by applying an affine conversion on the measured acceleration values. The strong relation between accelerations measured by the two brands suggests that habitual activity level and activity patterns assessed by the GENE and GT3X+ may compare well if analyzed appropriately.
Abstract.
Author URL.
Nunns M, Stiles V (2015). The influence of variable medial–lateral stiffness footwear on frontal plane kinematics and joint moments at the knee and ankle in healthy young males.
Nunns M, Stiles V (2015). The influence of variations in heel and forefoot midsole stiffness on sagittal plane kinematics and joint moments at the knee and ankle.
2013
Nunns M, Rice H, House C, Fallowfield J, Allsopp A, Stiles V, Dixon S (2013). A prospective study identifying risk factors for tibial stress fracture in Royal Marine recruits: initial findings.
Dixon S, Nunns M, House C, Rice H, Stiles V (2013). Ankle joint kinematics influence risk of third metatarsal stress fracture in military recruits.
Rowlands AV, Schuna JM, Stiles VH, Tudor-Locke C (2013). Cadence, peak vertical acceleration and peak loading rate during ambulatory activities: Implications for activity prescription for bone health.
Journal of Physical Activity and HealthAbstract:
Cadence, peak vertical acceleration and peak loading rate during ambulatory activities: Implications for activity prescription for bone health
Background: Previous research has reported thresholds to identify activities associated with bone mineral density (BMD). Such thresholds are typically expressed in units of body weights or acceleration, which are hard to translate into meaningful recommendations for physical activity. Cadence (steps/min) is a more readily interpretable measure of ambulatory activity. Objective: to examine relationships between cadence, acceleration and ground reaction force (GRF) during ambulation and identify the cadence associated with previously reported bone-beneficial thresholds from vertical acceleration and GRF data. Methods: Ten participants completed eight trials each of: slow walking, brisk walking, slow running, and fast running. Acceleration data were captured using a GT3X+ worn at the hip. Measures of GRF were collected via a force plate. Results: Strong relationships were identified between cadence and peak vertical acceleration (r=0.96, p
Abstract.
Stiles VH, Katene WH (2013). Improving physical education student teachers' knowledge and understanding of applied biomechanical principles through peer collaboration. Physical Education and Sport Pedagogy, 18(3), 235-255.
Dean S, Goodwin VA, Poltawski L, Stiles VH, Taylor R (2013). The IGO study: a 'before and after' case series to assess the safety and teaching of a technique designed for people with stroke to Independently Get up Off the floor.
Author URL.
Lilley K, Stiles VH, Dixon S (2013). The influence of motion control shoes on the running gait of mature and young females.
Gait and Posture,
37(3), 331-335.
Abstract:
The influence of motion control shoes on the running gait of mature and young females
Background
This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm.
Methods
15 mature (40–60 years) and 15 young (18–25 years) females performed 10 running trials at 3.5 m s−1 ± 5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics.
Findings
In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p < 0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p < 0.05). No between shoe differences in knee external adductor moment were observed.
Interpretation
A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment.
Abstract.
Stiles VH, Griew PJ, Rowlands AV (2013). Use of accelerometry to classify activity beneficial to bone in premenopausal women.
Med Sci Sports Exerc,
45(12), 2353-2361.
Abstract:
Use of accelerometry to classify activity beneficial to bone in premenopausal women.
PURPOSE: the aims of this study were to quantify the relation between ground reaction force (GRF) and peak acceleration from hip- and wrist-worn accelerometers and determine peak acceleration cut-points associated with a loading rate previously demonstrated as beneficial to bone (43 body weights (BW)·s⁻¹) in premenopausal women. METHODS: Forty-seven premenopausal women (age, 39.2 ± 5.6 yr; mass, 65.9 ± 11.0 kg; height, 1.67 ± 0.06 m) performed walking (slow, fast, and with bag), floor sweeping, running (slow and fast), jumping (low, 5 cm), and box drop (20 cm) trials. Peak accelerations were sampled at 100 Hz by GENEActiv and ActiGraph GT3X+ accelerometers (ActiGraph LLC, Pensacola, FL) worn at the hip (vertical and resultant) and the wrist (resultant). A force plate (960 Hz, AMTI) was used to assess peak vertical GRF and peak loading rate for eight steps per activity. Receiver operating characteristic curves were used to determine the optimal peak acceleration cut-points associated with a loading rate of 43 BW·s⁻¹ in 37 participants, and these cut-points were cross-validated in the remaining 10 participants. RESULTS: for all activities combined, peak accelerations were positively and significantly (P < 0.001) correlated with peak vertical GRF (hip r > 0.8, wrist r > 0.7) and peak loading rate (hip r > 0.7, wrist r > 0.57). Irrespective of monitor type and wear site, peak acceleration discriminated between loading rates above and below 43 BW·s⁻¹ with high levels of accuracy (area under the curve >0.92, P < 0.001). Overall classification agreement was >85% for both monitors worn at either the wrist or hip in the cross-validation sample. CONCLUSION: GENEActiv and ActiGraph GT3X+ accelerometers worn at the wrist or hip can be used as an unobtrusive tool to identify the occurrence of loading rates likely beneficial to bone in premenopausal women during their daily activity.
Abstract.
Author URL.
2012
Rowlands AV, Stiles VH (2012). Accelerometer counts and raw acceleration output in relation to mechanical loading.
Journal of Biomechanics,
45(3), 448-454.
Abstract:
Accelerometer counts and raw acceleration output in relation to mechanical loading
The purpose of this study was to assess the relationship of accelerometer output, in counts (ActiGraph GT1M) and as raw accelerations (ActiGraph GT3X+ and GENEA), with ground reaction force (GRF) in adults. Ten participants (age: 29.4±8.2 y, mass: 74.3±9.8 kg, height: 1.76±0.09 m) performed eight trials each of: slow walking, brisk walking, slow running, faster running and box drops. GRF data were collected for one step per trial (walking and running) using a force plate. Low jumps and higher jumps (one per second) were performed for 20 s each on the force plate. For box drops, participants dropped from a 20 cm box onto the force plate. Throughout, three accelerometers were worn at the hip: GT1M, GT3X+ and GENEA. A further GT3X+ and GENEA were worn on the left and right wrist, respectively. GT1M counts correlated with peak impact force (r = 0.85, p
Abstract.
Nunns M, Stiles V, Dixon S (2012). The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures.
Abstract:
The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures
Abstract.
Nunns MPI, Stiles VH, Dixon SJ (2012). The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures.
2011
Lilley K, Stiles V, Dixon SJ (2011). A Biomechanical Comparison of the Running Gait of Mature and Young Females.
Gait and Posture,
43, 496-500.
Abstract:
A Biomechanical Comparison of the Running Gait of Mature and Young Females
Background. Due to health and social advantages, the popularity of running as a sport among mature female runners is expanding steadily. However, the incidence of running injuries and associated conditions is vast among this group. The purpose of this study was to quantify gait parameters of mature and younger female runners to assess whether certain running characteristics predispose to debilitating conditions. It was hypothesised that mature females would exhibit greater rearfoot eversion, knee internal rotation, knee external adductor moments and loading rate of ground reaction force when compared to younger runners. Methods. 15 mature (40-60 years) and 15 young (18-24 years) females performed 10 running trials at 3.5 m.s-1 in the biomechanics laboratory. Both kinematic and ground reaction force data were collected. Signs of osteoarthritis and knee injuries were assessed using the KOOS scale. Findings. Mature females produced significantly higher peak rearfoot eversion, knee internal rotation, external adductor moment and loading rate of ground reaction force. compared to the young participants (p"lt;0.05). Interpretations. Although all participants recorded “symptom free” on the KOOS scale, all variables of gait found higher among the mature group have previously been associated with development of overuse injuries and debilitating conditions, suggesting a possible predisposition towards these conditions among the mature group.
Abstract.
Stiles VH, Guisasola IN, James IT, Dixon SJ (2011). Biomechanical Response to Changes in Natural Turf during Running and Turning.
Journal of Applied Biomechanics,
27(1), 54-63.
Abstract:
Biomechanical Response to Changes in Natural Turf during Running and Turning
Integrated biomechanical and engineering assessments were used to determine how humans responded to variations in turf during running and turning. Ground reaction force (AMTI, 960 Hz) and kinematic data (Vicon Peak Motus, 120 Hz) were collected from eight participants during running (3.83 m/s) and turning (10 trials per condition) on three natural turf surfaces in the laboratory. Surface hardness (Clegg hammer) and shear strength (cruciform shear vane) were measured before and after participant testing. Peak loading rate during running was significantly higher (p <. 05) on the least hard surface (sandy; 101.48 BW/s ± 23.3) compared with clay (84.67 BW/s ± 22.9). There were no significant differences in running kinematics. Compared with the “medium” condition, fifth MTP impact velocities during turning were significantly (RM-ANOVA, p <. 05) lower on clay (resultant: 2.30 m/s [± 0.68] compared with 2.64 m/s [± 0.70]), which was significantly (p <. 05) harder “after” and had the greatest shear strength both “before” and “after” participant testing. This unique finding suggests that further study of foot impact velocities are important to increase understanding of overuse injury mechanisms.
Abstract.
Nunns M, Stiles V, Dixon S (2011). The effects of standard issue Royal Marine footwear on risk factors associated with third metatarsal stress fractures. Footwear Science, 3(sup1), S124-S125.
2010
Guisasola I, James I, Stiles V, Dixon S (2010). Dynamic behaviour of soils used for natural turf sports surfaces.
Sports Engineering,
12(3), 111-122.
Abstract:
Dynamic behaviour of soils used for natural turf sports surfaces
The modulus and damping properties of soils in compression are a function of soil type, water content, stress history and loading rate. To model human–surface interaction with natural turf sports surfaces, stiffness and damping properties must be determined at dynamic loading rates. Two contrasting soil types, a Sand and a Clay Loam, commonly used in sports surfaces were loaded uniaxially to 2 kN at loading rates between 0.6 and 6 kN s−1 in modified dynamic soil testing apparatus. Soils were compacted prior to loading but initial cycles resulted in viscoplastic deformation, with strain accumulation with repeated cycles of loading. Ultimately a resilient, viscoelastic steady-state equilibrium with loading was established. Resilient modulus and damping ratio varied with soil type, water content, stress history and increased significantly with loading rate. The resilient modulus of the Sand soil, typical of modern free-draining sand construction natural turf sports surfaces, was significantly greater than that of a Clay Loam soil more characteristic of traditional natural turf surfaces; reducing water content caused an increase in modulus and a decrease in damping ratio in the Clay Loam soil. Determination of these properties provides initial data for the modelling natural turf surface behaviour in terms of both ball and human interactions, with further research required to determine the effect of both grass roots and leaves on mechanical behaviour.
Abstract.
Guisasola I, James I, Llewellyn C, Stiles V, Dixon S (2010). Quasi-static mechanical behaviour of soils used for natural turf sports surfaces and stud force prediction.
Sports Engineering,
12(2), 99-109.
Abstract:
Quasi-static mechanical behaviour of soils used for natural turf sports surfaces and stud force prediction
The quasi-static testing of soils used in natural turf pitches yields key parameters in soil modelling,including elastic moduli, Poisson’s ratio and Mohr–Coulomb parameters for shearing resistance and cohesion in soil. The bulk strength of a Sand soil used in the construction of elite sports surfaces was found to increase initially and then decrease with increasing water content due to apparent cohesion effects. For a Clay Loam soil,
more common in recreational facilities, shear strength decreased with water content. Reducing density resulted in a reduction of shear strength and elastic moduli in both soils due to reduced packing of particles reducing particle–particle contact surface area. The effect of roots on the shear strength of a Sand soil was not significant but reduced elastic moduli significantly. Horizontal forces measured during running and turning in a biomechanics laboratory were in good agreement with forces predicted using a simple quasi-static soil model for coarse-grained (Sand) soils although this was not the case with the Clay Loam soil.
Abstract.
2009
Stiles VH, James IT, Dixon SJ, Guisasola IN (2009). Natural turf surfaces: the case for continued research.
Sports Med,
39(1), 65-84.
Abstract:
Natural turf surfaces: the case for continued research.
It is well documented that health and social benefits can be attained through participation in sport and exercise. Participation, particularly in sports, benefits from appropriate surface provisions that are safe, affordable and high quality preferably across the recreational to elite continuum. Investment, construction and research into artificial sports surfaces have increased to meet this provision. However, not all sports (e.g. golf, rugby and cricket) are suited to training and match-play on artificial turf without compromising some playing characteristics of the games. Therefore, full sport surface provision cannot be met without the use of natural turf surfaces, which also have an important role as green spaces in the built environment. Furthermore, a significant number of people participate in outdoor sport on natural turf pitches, although this is a declining trend as the number of synthetic turf surfaces increases. Despite natural turf being a common playing surface for popular sports such as soccer, rugby and cricket, few biomechanical studies have been performed using natural turf conditions. It is proposed that if natural turf surfaces are to help meet the provision of sports surfaces, advancement in the construction and sustainability of natural turf surface design is required. The design of a natural turf surface should also be informed by knowledge of surface-related overuse injury risk factors. This article reviews biomechanical, engineering, soil mechanics, turfgrass science, sports medicine and injury-related literature with a view to proposing a multidisciplinary approach to engineering a more sustainable natural turf sport surface. The present article concludes that an integrated approach incorporating an engineering and biomechanical analysis of the effects of variations in natural turf media on human movement and the effects of variations in human movement on natural turf is primarily required to address the longer-term development of sustainable natural turf playing surfaces. It also recommends that the use of 'natural turf' as a catch-all categorization in injury studies masks the spatial and temporal variation within and among such surfaces, which could be important.
Abstract.
Author URL.
2007
Stiles VH, Dixon, S.J. (2007). Biomechanical response to systematic changes in impact interface cushioning properties while performing a tennis specific movement.
Journal of Sports Sciences,
25(11), 1229-1239.
Abstract:
Biomechanical response to systematic changes in impact interface cushioning properties while performing a tennis specific movement.
It is currently not known whether human responses across typical sports surfaces are dependent on cushioning or frictional
properties of the interface. The present study assessed systematic changes in surface cushioning (baseline acrylic, rubber,
thin foam, and thick foam) as participants performed tennis running forehand foot plants wearing a basic neutral shoe
(plimsolls). It was hypothesized that systematic decreases in peak rates of loading, heel pressures, and perceived hardness
would be yielded as surface cushioning increased (impact test device). A common acrylic top surface provided consistent
frictional properties across surfaces. Kinetics (AMTI, 960 Hz and Footscan Pressure Insoles, 500 Hz), kinematics (Peak
MOTUS, 120 Hz), and cushioning perception were assessed. Peak and mean loading rates of vertical ground reaction force,
peak horizontal force, peak heel pressure, and rates of loading demonstrated significant correlations (P50.05) with the
participants’ perceived levels of cushioning and matched mechanical rankings of surface cushioning. In contrast, peak impact
force was lowest on the least cushioned surface. Kinematic responses were not significantly different between surfaces.
Present evidence supports ‘‘peak rate of loading’’ as a more suitable indicator of surface cushioning than peak impact force.
Although cautionary, biomechanical support is also provided for mechanical methods of surface cushioning assessment.
Abstract.
Stiles VH, Dixon SJ (2007). Biomechanical response to systematic changes in impact interface cushioning while performing a tennis specific movement. Journal of Sport Sciences, 25(11), 1229-1239.
VStil, Dixon SJ (2007). Biomechanical response to systematic changes in impact interface cushioning while performing a tennis specific movement .
2006
Stiles VH, Dixon SJ (2006). The influence of different playing surfaces on the biomechanics of a tennis forehand foot plant. Journal of Applied Biomechanics, 22(1), 14-24.
2003
Dixon SJ, Stiles VH (2003). Impact absorption of tennis shoe-surface combinations. Sports Engineering, 6(1), 1-10.
