Search

Background Professional soccer teams are often required to compete with ≤ 4 days recovery between matches. Since congested schedules reduce recovery time between matches, players are possibly at an increased injury risk. To date, there are no published systematic reviews on the impact of match congestion on injuries during professional male soccer. Objective The aim of this systematic review was to assess the effects of fixture congestion on injuries during professional soccer. Methods Following pre-registration on the Open Science Framework (https://osf.io/86m25/) and conforming with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, systematic searches of four electronic databases (PubMed, Scopus, SPORTDiscus, and Web of Science) were conducted by independent researchers from inception until February 2022. Articles were included if they were original articles written in English and contained relevant time-loss injury data (injury that results in unavailability for training and/or match-play) for male professional soccer players regarding periods of fixture congestion (a minimum of two matches with ≤ 4 days recovery). Results A total of eight articles were included in the review. Five studies identified that congested fixture schedules expose players to increased match injury incidence, although layoff duration was typically lower during congested periods. Two studies identified that training and overall injury incidence were higher during congested periods, with another study identifying a lower training injury incidence during congested periods. Conclusion Injury risk is, overall, increased during fixture-congested periods; however, the layoff duration is typically shorter. The current findings have implications for practitioners regarding the management, periodisation, monitoring, and design of training and competition schedules.

Fatigue alters rearfoot kinematics on an individual basis and may offer a means of functionally grouping runners. This proof of concept study aimed to determine whether fatigue related changes in rearfoot eversion could be used to functionally group runners. Sixteen male recreational runners had their frontal plane rearfoot kinematics recorded by a three-dimensional motion capture system before and after a 5km run. The magnitude of change in frontal plane rearfoot kinematics pre- to post-fatigue was calculated and K-means clustering used to identify functional groups based upon these changes.

Background: Total hip arthroplasty (THA) patients have been shown to not achieve normal sagittal plane hip kinematics. However, previous studies have only conducted group level analysis and as such lack the sensitivity to highlight whether individual patients do achieve normal hip kinematics. As such this study looked to determine whether some patients with well-functioning THA achieve typical sagittal plane hip kinematics. Methods: Sagittal plane hip kinematics were collected on 11 well-functioning THA patients (Oxford Hip Score = 46 ± 3) and 10 asymptomatic controls using a 3-dimensional motion analysis system during self-paced walking. High-functioning THA patients were identified as those who displayed sagittal plane hip kinematics that were within the variance of the control group on average, and low-functioning patients as those who did not. Results: 5 THA patients were identified as high-functioning, displaying hip kinematics within the variance of the control group. High-functioning THA patients displayed peak hip flexion and extension values more closely aligned to asymptomatic control group than low-functioning patients. However, hip range of motion was comparable between high- and low-functioning total hip arthroplasty patients and reduced compared to controls. Conclusion: The presence of high-functioning THA patients who display comparable sagittal plane hip kinematics to controls suggests these patients do achieve normative function and challenges the conclusions of previous group level analysis. Understanding why some patients achieve better function post-operatively will aid pre- and post-operative practices to maximise functional recovery.

Background The conventional gait model (CGM) is commonly utilised within clinical motion analysis but has a number of inherent limitations. To overcome some of these limitations modifications have been made to the CGM and six-degrees of freedom models (6DoF) have been developed. Research Question How comparable are lower limb kinematics calculated using modified CGM and 6DoF models and what is the error associated with the output of each model during walking? Methods Ten healthy males attended two gait analysis sessions, in which they walked at a self-selected pace, while a 10-camera motion capture system recorded lower limb kinematics. Hip, knee and ankle joint kinematics in all three anatomical planes were calculated using a modified CGM, with medial anatomical markers and a three-dimensional foot added, and 6DoF. Mean absolute differences were calculated on a point-by-point basis over the walking gait cycle and interpreted relative to a 5° threshold to explore the comparability of model outputs. The standard error of the measurement (SEM) was also calculated on a point-by-point basis over the walking gait cycle for each model. Results Mean absolute differences above 5° were reported between the two model outputs in 58–86% of the walking gait cycle at the knee in the frontal plane, and over the entire walking gait cycle at the hip and knee in the transverse plane. SEM was typically larger for the modified CGM compared to the 6DoF, with the highest SEM values reported at the knee in the frontal plane, and the hip and the knee in the transverse plane. Significance Caution should be taken when looking to compare findings between studies utilising modified CGM and 6DoF outside of the sagittal plane, especially at the hip and knee. The reduced SEM associated with the 6DoF suggests this modelling approach may be preferable.

Medial tibial stress syndrome (MTSS) is a common running-related injury. Alterations in movement patterns and movement coordination patterns have been linked to the development of overuse injuries. The aim of this study was to compare transverse plane tibial and frontal plane rearfoot motion and the coordination of these movements between runners with MTSS and healthy controls. A total of 10 recreational runners with MTSS and 10 healthy controls ran at 11 km/h on a treadmill. A 3-camera motion analysis system operating at 200 Hz was used to calculate tibia and rearfoot motion. Stance phase motion patterns were compared between groups using multivariate analysis, specifically, Hotelling T2 test with statistical parametric mapping. A modified vector coding technique was used to classify the coordination of transverse plane tibial and frontal plane rearfoot motion. The frequency of each coordination pattern displayed by each group was compared using independent samples t tests. Individuals with MTSS displayed significantly (P = .037, d = 1.00) more antiphase coordination (tibial internal rotation with rearfoot inversion) despite no significant (P > .05) differences in stance phase kinematics. The increased antiphase movement may increase the torsional stress placed upon the medial aspect of the tibia, contributing to the development of MTSS.

The premise behind static foot classification suggests structure dictate's function. However, the validity of this has been challenged, as weak association between static foot type and dynamic motion exists. This has led to calls for dynamic assessments and classification of feet based on functional motion, yet methods to do this have been seldom explored.Within a group of runners do homogenous sub-groups of ankle joint complex (AJC) frontal plane motion exist?A k means clustering analysis was conducted on the frontal plane AJC motion patterns of a group of healthy adults running barefoot (n = 42) to identify functional movement groups. Once identified, statistical parametric mapping was employed to determine the differences between clusters across stance. The identified clusters were used to determine dynamic foot type; an agreement analysis was conducted between the newly defined foot types and the Foot Posture Index (FPI-6).Two distinct clusters were identified. Waveform analysis identified that cluster 1 displayed significantly (p 0.001) less AJC eversion between 0% and 97% of the stance phase compared to cluster 2, with the differences between clusters associated with large effect sizes (g1). Based on the displayed kinematic profiles, cluster 1 was defined as a Neutral Dynamic Foot Type (NeutralWe demonstrated a protocol to classify a runner's foot type derived directly from AJC motion during running. Poor agreement between the dynamic and static classification measures further evidence that these assessments are not analogous. Our results question the validity of static classification when looking to characterise the foot during running, suggesting dynamic assessments are more appropriate to reflect the foots functional response.

In footwear research, footwear comfort has become an increasingly popular topic. Commonly used assessment tools include the visual analogue scale, the Likert scale and self-reported ranking (Lindor...

Objectives: Describe hamstring injury incidence across competition formats, activity at time of injury, and time of season, facilitating the identification of injury risk factors in elite men's senior First-Class County Cricket. Design: Prospective cohort. Methods: Hamstring time loss injury incidence (between format, activity, and time of season) calculated for elite men's senior First-Class County Cricket seasons 2010 to 2019. Results: The diagnosis with the highest seasonal incidence was ‘Biceps femoris strain grade 1–2’ (2.5 injuries/100 players). Hamstring injury incidence was highest in One-Day cricket (mean 27.2 injuries/1000 team days). Running between wickets when batting was the activity associated with the highest incidence in the shorter competition formats (8.4 and 4.8 injuries/1000 team days for One-Day and T20, respectively). Bowling delivery stride or follow through was the activity with the highest incidence for longer multi-day Test format (mean 2.3 injuries/1000 team days), although similar incidence was observed across all formats for this activity. Most injuries were sustained at the start of the season (April; 22.7 injuries/1000 team days), with significantly fewer injuries at end of the season (September; 4.1 injuries/1000 team days). Conclusions: Similar bowling injury incidence across formats suggests hamstring injury risk is associated more with the activity itself, whereas injury risk when batting was susceptible to changes in match intensity. The notably higher (albeit non-significant) incidence in April may allude to a lack of preparedness to meet the physical demands of the start of the season. The findings have practical relevance for practitioners, identifying potential opportunities for preventative strategies.

Background The pelvis is commonly tracked during three-dimensional motion analysis using markers located on the anterior and posterior superior iliac spines. However, these markers are prone to soft tissue artefact and marker occlusion, highlighting the need for alternative technical marker sets. Research question How comparable are hip joint kinematics calculated using two alternative pelvic technical marker sets and a conventionally modelled pelvis? Methods Fourteen participants undertook 3D gait analysis, walking overground at a self-selected pace (1.38 ± 0.14 m·s−1), barefoot. Hip joint kinematics were compared using root mean square error (RMSE) between a conventionally tracked pelvis and two alternative technical marker sets; (1) posterior cluster and (2) additional iliac crest markers. Results The average RMSE in the sagittal, frontal and transverse planes was 2.5° ± 2.8°, 1.6° ± 0.4° and 0.8° ± 0.4°, respectively for the posterior cluster, and 1.3° ± 0.7°, 0.8° ± 0.3° and 1.4° ± 0.5° for the iliac crest marker set. The RMSE was significantly larger for the posterior cluster compared to the iliac crest model in the sagittal (p = .05, d = .28) and frontal planes (p Significance The findings of this study suggest that either a posterior cluster or additional iliac crest markers offer means of accurately calculating hip joint kinematics within 3° of the conventional pelvic model. Therefore, either technical marker set offers a viable alternative to the conventional pelvic model for calculating hip joint kinematics.

To date there is a paucity of information about how different types of conventional running shoes influence lower limb kinematics. The aim of the study was to determine the influence of motion control, neutral, and cushioned running shoes upon lower limb kinematics. Twenty-eight active males completed one test session running in standardized motion control, neutral, and cushioned running shoes on a treadmill at a self-selected pace (2.9 [0.6] m·s

This study aimed to compare the physical demands of contact small sided game (CSSG), non-contact small sided game (NCSSG) and match play, in female rugby union. Fifteen female rugby union players participated within this study. Participants completed two testing sessions. Session one involved two 20-minute small sided games (contact and non-contact). Session two involved a competitive rugby union game. Movement characteristics, heart rate, PlayerLoadTM and tackles were recorded using GPS units and heart rate monitors. No significant differences were identified between conditions in relation to average heart rate or time spent in different heart rate zones. Significant differences were identified between conditions for distance, normalised PlayerLoadTM and tackles. Distance covered was significantly higher in the non-contact small sided game, while normalised PlayerLoadTM and tackles were significantly lower in this condition. These findings suggest that the physiological stress, in terms of heart rate, is comparable between the match and both small sided games. Thus both small sided games seem to elicit an appropriate internal training response. However, the reductions in tackles and normalised PlayerLoadTM in the non-contact small sided game are likely to reduce injury risk, while the increase in distance covered may enhance the training stimuli provided in this condition.

The aim of this study was to determine the influence of motion control, neutral and cushioned running shoes upon inter-segmental foot kinematics. Twenty-eight active males completed one testing session, in which they ran in standardised motion control, neutral and cushioned running shoes on a treadmill at a self-selected pace (2.9 ± 0.6 m·s−1). Incisions were made within the shoes to enable the motion of the foot to be tracked using a motion analysis system and inter-segmental foot kinematics calculated using the Istituti Ortopedici Rizzoli foot model. Discrete parameters associated with midfoot–rearfoot, forefoot–rearfoot, forefoot–midfoot and medial longitudinal arch motion were compared between footwear conditions. Midfoot–rearfoot eversion upon initial contact and peak medial longitudinal arch angles (MLAA) were significantly lower in the motion control shoe compared to the neutral and cushioned shoes. The reductions in midfoot–rearfoot eversion and medial longitudinal arch deformation in the motion control running shoe may be due to increased medial posting and torsional control systems in this shoe. However, these changes in midfoot kinematics may be offset by significant increases in sagittal plane midfoot–rearfoot and forefoot–rearfoot range of motion, particularly during mid-stance.

The aim of this study was to assess the influence of a half-time (HT) re-warm up (RWU) strategy on measures of performance and the physical and perceptual response to soccer-specific activity. Ten male soccer players completed a control (CON) and RWU trial, in which participants completed 60 min (4 x 15-min periods with a 15-min HT interspersing the third and fourth periods) of a soccer-specific exercise protocol. The CON trial comprised a passive 15-min HT, whilst the RWU trial comprised a passive 12-min period, followed by a 3-min RWU. The RWU elicited an improvement in 20 m sprint times (

Objectives This study primarily aimed to explore injury incidence rates in the three main domestic competition formats in England and Wales (First-Class, One-Day and Twenty20 [T20]). For the first time, the study also describes the epidemiology of elite men’s domestic cricket injuries across nine seasons (2010–2018 inclusive). Design Prospective cohort analysis. Methods Injury incidence and prevalence from all injuries calculated according to the updated international consensus statement on injury surveillance in cricket, with statistical process control charts (SPC) used to detect trends in the data. Results The average match injury incidence was 102 injuries/1000 days of play, with highest incidence in One-Day (254 injuries/1000 days of play), followed by T20 (136 injuries/1000 days of play) and First-Class Cricket (68 injuries/1000 days of play). Most match injuries were sustained during bowling (41.6 injuries/1000 days of play), followed by fielding (26.8 injuries/1000 days of play) and batting (22.3 injuries/1000 days of play). The thigh was the body area most commonly injured (7.4 injuries/100 players per season), with lumbar spine injuries the most prevalent (1.3% of players unavailable on any given day during the season). On average, 7.5% of players were unavailable on any given day during the domestic season when all injuries were considered (match and training). The SPC charts showed relatively consistent match injury incidence for all competitions, reproduced across all nine seasons. Conclusion These findings provide a robust empirical base for the extent of the injury problem in domestic cricket played in England and Wales, with similar injury profiles across the three formats.

Context: The influence of playing surface on injury risk in soccer is contentious, and contemporary technologies permit an in vivo assessment of mechanical loading on the player. Objective: To quantify the influence of playing surface on the PlayerLoad elicited during soccer-specific activity. Design: Repeated measures, field-based design. Setting: Regulation soccer pitches. Participants: Fifteen amateur soccer players (22.1 [2.4] y), injury free with ≥6 years competitive experience. Interventions: Each player completed randomized order trials of a soccer-specific field test on natural turf, astroturf, and third-generation artificial turf. GPS units were located at C7 and the mid-tibia of each leg to measure triaxial acceleration (100 Hz). Main Outcome Measures: Total accumulated PlayerLoad in each movement plane was calculated for each trial. Ratings of perceived exertion and visual analog scales assessing lower-limb muscle soreness were measured as markers of fatigue. Results: Analysis of variance revealed no significant main effect for playing surface on total PlayerLoad (P = .55), distance covered (P = .75), or postexercise measures of ratings of perceived exertion (P = .98) and visual analog scales (P = .61). There was a significant main effect for GPS location (P P .001), but with no difference between limbs (P = .70). There was no unit placement × surface interaction (P = .98). There was also a significant main effect for GPS location on the relative planar contributions to loading (P Conclusions: PlayerLoad metrics suggest that playing surface does not influence mechanical loading during soccer-specific activity (not including tackling). Clinical reasoning should consider that PlayerLoad magnitude and axial contributions were sensitive to unit placement, highlighting opportunities in the objective monitoring of load during rehabilitation.

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects (benefits and harms) of running shoes for preventing lower‐limb running injuries in adult runners.

Context: Contemporary synthetic playing surfaces have been associated with an increased risk of ankle injury in the various types of football. Triaxial accelerometers facilitate in vivo assessment of planar mechanical loading on the player. Objective: To quantify the influence of playing surface on the PlayerLoad elicited during footwork and plyometric drills focused on the mechanism of ankle injury. Design: Repeated-measures, field-based design. Setting: Regulation soccer pitches. Participants: A total of 15 amateur soccer players (22.1 [2.4] y), injury free with ≥6 years competitive experience. Interventions: Each player completed a test battery comprising 3 footwork drills (anterior, lateral, and diagonal) and 4 plyometric drills (anterior hop, inversion hop, eversion hop, and diagonal hop) on natural turf (NT), third-generation artificial turf (3G), and AstroTurf. Global positioning system sensors were located at C7 and the mid-tibia of each leg to measure triaxial acceleration (100 Hz). Main Outcome Measures: PlayerLoad in each axial plane was calculated for each drill on each surface and at each global positioning system location. Results: Analysis of variance revealed a significant main effect for sensor location in all drills, with PlayerLoad higher at mid-tibia than at C7 in all movement planes. AstroTurf elicited significantly higher PlayerLoad in the mediolateral and anteroposterior planes, with typically no difference between NT and 3G. In isolated inversion and eversion hopping trials, the 3G surface also elicited lower PlayerLoad than NT. Conclusions: PlayerLoad magnitude was sensitive to unit placement, advocating measurement with greater anatomical relevance when using microelectromechanical systems technology to monitor training or rehabilitation load. AstroTurf elicited higher PlayerLoad across all planes and drills and should be avoided for rehabilitative purposes, whereas 3G elicited a similar mechanical response to NT.

Cricket was the first sport to publish recommended methods for injury surveillance in 2005. Since then, there have been changes to the nature of both cricket and injury surveillance. Researchers representing the major cricket playing nations met to propose changes to the previous recommendations, with an agreed voting block of 14. It was decided that 10 of 14 votes (70%) were required to add a new definition element and 11 of 14 (80%) were required to amend a previous definition. In addition to the previously agreed 'Match time-loss' injury, definitions of 'General time-loss', 'Medical presentation', 'Player-reported' and 'Imaging-abnormality' injuries are now provided. Further, new injury incidence units of match injuries per 1000 player days, and annual injuries per 100 players per year are recommended. There was a shift towards recommending a greater number of possible definitions, due to differing contexts and foci of cricket research (eg, professional vs amateur; injury surveillance systems vs specific injury category studies). It is recommended that researchers use and report as many of the definitions as possible to assist both comparisons between studies within cricket and with those from other sports.

Background The aim of this study was to determine the level of agreement between common clinical foot classification measures. Methods Static foot assessment was undertaken using the Foot Posture Index (FPI-6), rearfoot angle (RFA), medial longitudinal arch angle (MLAA) and navicular drop (ND) in 30 participants (29 ± 6 years, 1.72 ± 0.08 m, 75 ± 18 kg). The right foot was measured on two occasions by one rater within the same test environment. Agreement between the test sessions was initially determined for each measure using the Weighted Kappa. Agreement between the measures was determined using Fleiss Kappa. Results Foot classification across the two test occasions was almost perfect for MLAA (Kw = .92) and FPI-6 (Kw = .92), moderate for RFA (Kw = .60) and fair for ND (Kw = .40) for comparison within the measures. Overall agreement between the measures for foot classification was moderate (Kf = .58). Conclusion The findings reported in this study highlight discrepancies between the chosen foot classification measures. The FPI-6 was a reliable multi-planar measure whereas navicular drop emerged as an unreliable measure with only fair agreement across test sessions. The use of this measure for foot assessment is discouraged. The lack of strong consensus between measures for foot classification underpins the need for a consensus on appropriate clinical measures of foot structure.

Footwear biomechanics research typically focuses on the assessment of frontal plane rearfoot (RF) motion when determining the influence of footwear on foot motion (Cheung & Ng, 2007; Lilley, Stiles...

Introduction Multi-segmental foot modelling (MSFM) during shod activity has the potential to enhance our understanding of how footwear influences foot motion. Recent work by Bishop et al. (2015) and Shultz & Jenkyn (2012) has validated the incision parameters to accommodate surface mounted markers for two alternative MSFMs, requiring 7 and 5 incisions respectively, within the shoe. These MSFMs have been sparsely used in contrast to 3DFoot model (Leardini et al. 2007) which would require 10 incisions and has not been used previously to assess in-shoe foot motion. Purpose of the study To determine the influence of incisions to accommodate Jenkyn and Nicol (JN) and 3DFoot MSFMs upon the structural integrity of neutral running shoes. Methods Two procedures were applied to assess shoe deformation. A) Eight males (30±8yrs, 1.78±0.05m, 84±7kg) completed 2 testing sessions. Participants ran at a self-selected pace (3±0.5m.s-1) in standard ASICS running shoes. Baseline shoe deformation data was collected during the first session. Prior to session 2, 25mm incisions were made to accommodate MSFMs: 3DFoot (left shoe) and JN (right shoe). Kinematic data were recorded using a 3D motion analysis system (VICON, Oxford, England) at 200Hz. Three retro-reflective markers (Figure 1) were used to measure as shoe distance and shoe angle at initial contact (IC), heel rise (HR) and toe off (TO). Shoe deformation measures were compared using paired t-tests. B) Material strain of the shoe upper was assessed in 1 male participant (26yrs, 1.80m, 80kgs) using ARAMIS optical system. Material strain patterns were compared between intact and cut conditions using Trend symmetry (TS) analysis (Crenshaw & Richards, 2006). Here Figure 1. Results No significant differences (p > 0.05) in shoe distance were recorded between intact and cut conditions but significant differences (p < 0.05) were reported in shoe angle at all three events of running gait (Table 1). Material strain assessment showed lower TS scores for the lateral aspect of the shoe (TS = 0.81 ± 0.11) than the medial aspect (TS = 0.89 ± 0.12). Symmetry was greater between the intact and JN shoe (TS= 0.88 ± 0.10) than the intact and 3DFoot shoe (TS = 0.82 ± 0.13). Here Table 1. Discussion and Conclusion Analysis of kinematic shoe deformation measures revealed individual responses to incisions made within the upper of a running shoe to accommodate MSFMs. Significant (p < 0.05) changes in shoe angles were noted between the intact and cut conditions at IC and TO for the JN incisions and HR for the 3DFoot incisions. However, while the changes in shoe angle were significant, the mean difference was small (≤ 5°). This value is lower than the minimal important difference proposed by Nester et al. (2007) for comparison of gait kinematics. Thus, it may be argued that the differences in shoes angles between intact and cut conditions were negligible and the results support the use of either MSFM to assess shod foot motion. While the use of kinematic measures to infer the shoes structural integrity have been used previously (Shultz and Jenkyn, 2012), no validation of these measure has been undertaken. The small and non-systematic findings reported in both this study and that of Shultz and Jenkyn (2012), particularly for shoe distance measures; question the sensitivity of kinematic shoe deformation measures to detect changes in structural integrity. Material strain analysis was used to further explore area specific alterations in the running shoes structural integrity from the different incision sets. The material strain analysis supported the use of the JN foot model to assess in-shoe foot kinematics, due to higher symmetry scores and smaller mean differences between the intact and JN shoes. Further exploration of additional means of assessing the influence of incisions to accommodate MSFM upon the shoes structural integrity is warranted. References Bishop, C. et al. (2015). Gait Posture, 41 (1), 295-299. Crenshaw, S. and Richards, J. (2006) Gait Posture, 24 (4), 515-521. Jenkyn, T. and Nicol, A. (2007). J Biomech, 40 (14), 3271-3278. Leardini, A. et al. (2007). Gait Posture, 25 (3), 453-462. Nester, C. et al. (2007). J Biomech, 40 (15), 3412-3423. Shultz, R. and Jenkyn, T. (2012). Med Eng Phys, 34 (1), 118-122.