Background Osteosarcoma patients who have undergone prosthetic lower limb reconstruction following tumour resection walk at a slower preferred speed than healthy controls. In addition, they demonstrate lower peak isokinetic knee extension torques, which may explain the observed differences in sagittal plane knee joint kinematics during walking. However, mechanisms for this and the associated knee joint kinetics are not well understood, particularly at matched walking speeds. Methods This observational case-control study compared sagittal plane lower limb walking gait characteristics between patients who have undergone prosthetic reconstruction and matched healthy controls across their preferred and matched walking speeds. Data were collected from 18 control participants and 17 patients while walking on a force-instrumented treadmill at the different speeds. Spatiotemporal variables, peak knee flexion angle, peak knee extensor moments (torques), and peak knee joint power were compared between groups. Results Patients walked with a slower preferred speed than the control group. When comparing lower limb gait mechanics at matched speeds, patients demonstrated lower magnitude peak knee extensor moments than the control group, and these differences were greater at faster speeds. At the fastest walking speed, patients also displayed lower peak knee joint power compared to the control group. The differences in knee joint kinetics observed between groups may be due to an inability amongst patients to generate the magnitudes of knee extensor force that the control group can generate.

Advanced footwear technology distance running shoes (AFTs) have been shown to reduce the oxygen cost of running at a given speed compared to traditional distance running shoes. This may be at least partly driven by the compliant, resilient midsole properties of AFTs. Increasing the compliance of AFT midsoles may further improve running economy but may also result in increased frontal plane motion and therefore instability. This study quantified frontal plane kinematics and kinetics during running with one type of advanced footwear technology running shoe with three different midsole properties. The three shoe conditions had Asker C compliance values of C-55, C-45 and C-25. Twenty-one male and female runners ran at two speeds in each of the shoe conditions on a force-instrumented treadmill whilst kinematics were synchronously recorded. Frontal plane ground reaction forces and rearfoot, knee and hip kinematics and kinetics were compared between conditions. Peak rearfoot eversion angle and range of motion were not different between footwear conditions, whereas peak eversion velocity was 12% and 17% slower in the most compliant shoe than the control shoe and least compliant shoe respectively. Peak knee and hip adduction range of motion were both lower in the most compliant shoe. Peak lateral ground reaction forces and center of pressure excursion were also lower in the most compliant shoe. The reduced frontal plane motion and forces when running in a shoe with a highly compliant midsole may be influenced by the rapid deformation of the midsole and an increased frontal plane rearfoot joint stiffness.

Anterior cruciate ligament (ACL) injuries are common in many sports and impose substantial performance and long-term health burdens. A quantitative synthesis of real-world, video-identified game situations can inform sport-specific prevention methods. The aim of the study was to identify game situations and movement patterns leading to ACL injury in different sports. Systematic review with meta-analysis. PubMed, Google Scholar, Web of Science, and Scopus were searched for studies analyzing video recordings of ACL injuries sustained by athletes of any sex during training or competition. Random effects meta-analyses of prevalence and moderator analyses (sport as a factor) were performed. In total, 39 articles (1551 video-verified ACL injuries) of on-average moderate quality (Quality Appraisal for Sports Injury Video Analysis Studies [QA-SIVAS]) scale mean 66

OBJECTIVE: To assess whether a 9-week intervention combining cutting technique retraining and hip/calf resistance exercises reduced knee abduction moment (KAM) in young female handball players. STUDY DESIGN: Controlled laboratory study. METHODS: Forty female players (aged 15-18 years) were assigned to an intervention group (IG; n = 20) or control group (CG; n = 20). KAM during sidestep cutting and isometric strength were assessed preintervention and postintervention. The IG completed a twice-weekly program integrated into team practice. RESULTS: Group × time interaction was not significant for KAM ( P = .366) or foot strike angle (FSA; P = .171). Both groups reduced KAM ( P = .002; IG: 0.68 ± 0.16 to 0.59 ± 0.21 Nm/kg*m; CG: 0.68 ± 0.31 to 0.53 ± 0.22 Nm/kg*m) and increased FSA ( P = .040). Knee valgus angle showed no significant interaction ( P = .462) or main effects ( P = .148, P = .080). There was no interaction for hip external rotation, hip abduction, or ankle plantarflexion strength ( P≥.05). Hip abduction strength increased over time ( P = .046) without group differences. CONCLUSION: The intervention did not significantly improve KAM or strength versus standard training, though trends suggest possible effects on cutting mechanics. JOSPT Open 2025;3(4):473-482. Epub 20 August 2025. doi:10.2519/josptopen.2025.0144

Since the introduction of advanced footwear technology(AFT),distance running performances have improved significantly,as evidenced by a series of world records and general improve-ments in both elite and recreational running performances.1 In their recent systematic review and meta-analysis,Stephen et al.2 synthesize evidence on how AFT as a whole,as well as longitudinal bending stiffness(LBS)and midsole energy return as key constructional features,affect running economy(RE)and ankle mechanics during running.2 Their systematic review demonstrates that AFT improves RE by～2.7％at an average running speed of 14.5 km/h.In contrast,their synthesis of the currently available literature suggests that neither LBS nor energy return alone significantly improves oxygen consumption or alters ankle mechanics.

OBJECTIVES:Neuromuscular activation and peak external knee abduction moments (pKAM) are risk factors for anterior cruciate ligament injuries during sidestep cutting. This study aimed to: 1) compare thigh muscle activity between preplanned and unplanned sidestep cuts, 2) assess rank correlations of mean thigh muscle pre-activity in both cuts, 3) investigate the relationship between pKAM and thigh muscle activity in 31 experienced female handball players. METHODS:Four-component (vastus medialis, vastus lateralis, semitendinosus, biceps femoris) electromyogram vector fields were compared from 100 ms before ground contact until toe-off using Statistical Parametric Mapping. Spearman's rank correlation coefficient was used to assess rank correlations of mean pre-activity of individual muscles between cuts. Relationships between pKAM and the four-component electromyogram vector fields were assessed using Canonical Correlation Analysis. RESULTS:Four-component muscle activity differed before ground contact and push-off, mostly due to activity differences in muscle pairs. Individual analyses showed lower vastus medialis activity in unplanned cuts right before ground contact. High pre-activity rank correlations were found for vastus medialis and lateralis, moderate for semitendinosus, and none for biceps femoris between preplanned and unplanned cuts. Canonical correlation analyses indicated no relationship between muscle activity and pKAM. CONCLUSION:The knee might be more vulnerable to injury in unplanned tasks due to lower muscular pre-activity. Muscle activity does not vary with pKAM, suggesting passive structures must absorb higher loads with increasing pKAM. Differences in vastus medialis pre-activity and inconsistencies in biceps femoris pre-activity ranking highlight areas for targeted neuromuscular training to better protect the knee against external loads.

In a randomized controlled cross-over study ten male runners (26.7 ± 4.9 years; recent 5-km time: 18:37 ± 1:07 min:s) performed an incremental treadmill test (ITT) and a 3-km time trial (3-km TT) on a treadmill while wearing either carbon fiber insoles with downwards curvature or insoles made of butyl rubber (control condition) in light road racing shoes (Saucony Fastwitch 9). Oxygen uptake, respiratory exchange ratio, heart rate, blood lactate concentration, stride frequency, stride length and time to exhaustion were assessed during ITT. After ITT, all runners rated their perceived exertion, perceived shoe comfort and perceived shoe performance. Running time, heart rate, blood lactate levels, stride frequency and stride length were recorded during, and shoe comfort and shoe performance after, the 3-km TT. All parameters obtained during or after the ITT did not differ between the two conditions [range: p = 0.188 to 0.948 (alpha value: 0.05); Cohen's d = 0.021 to 0.479] despite the rating of shoe comfort showing better scores for the control insoles (p = 0.001; d = −1.646). All parameters during and after the 3-km TT showed no differences (p = 0.200 to 1.000; d = 0.000 to 0.501) between both conditions except for shoe comfort showing better scores for control insoles (p = 0.017; d = −0.919). Running with carbon fiber insoles with downwards curvature did not change running performance or any submaximal or maximal physiological or biomechanical parameter and perceived exertion compared to control condition. Shoe comfort is impaired while running with carbon fiber insoles. Wearing carbon fiber insoles with downwards curvature during treadmill running is not beneficial when compared to running with control insoles.

Background Non-contact anterior cruciate ligament injuries during sidestep cutting typically occur rapidly after contact between the foot and the ground with little time for athletes to correct movement patterns. Technique feedback aiming at safe posture at initial ground contact might prove valuable in reducing frontal plane knee joint loading. Objective To assess the immediate effects of individualized technique feedback during sidestep cutting on selected technique variables and peak external knee abduction moments. Design Interventional study. Setting Biomechanical laboratory. Participants 48 adolescent female elite handball players. Interventions Players performed three preplanned handball-specific sidestep cuts on each leg while 3D biomechanics were recorded. Following these cuts, players received tailored technique feedback on their foot strike angle, knee valgus angle, or vertical impact velocity based on cut-off values drawn from an existing data set. If multiple technique variables exceeded their cut-off, variable selection was based on its established relation with performance. Following feedback, three more cuts on each leg were performed. Main Outcome Measurements Peak external knee abduction moment and selected technique variables. Results Feedback aimed at pronounced forefoot landings and reduced knee valgus angles improved technique immediately (+12.7°, p < .001, Figure a and +1.5°, p = .022, Figure b, respectively) and reduced peak external knee abduction moments (-13.4%, p = .003, Figure d and -17.1%, p = .020, Figure e, respectively). Feedback aimed at reduced vertical impact velocities improved technique immediately (-19.0%, p = .010; Figure c); however, peak external knee abduction moments were unaffected (p = .328; Figure f), owing to the variable's unclear relation with technique and therefore lowest priority and smallest sample size. Conclusions Individualized feedback can induce sidestep cutting technique changes immediately, thereby successfully decreasing peak external knee abduction moments and potentially injury risk. Improving technique without sacrificing performance might prove attractive to coaches and players alike.

OBJECTIVE: To compare knee abduction moment (KAM) magnitudes between a generic 180° pivot turn (modified 505 change-of-direction test; m505) and a handball-specific sidestep cut, and to assess ranking consistency. Additionally, to examine the resultant ground reaction force (GRF) and its frontal plane moment arm to the knee to comprehend their contributions to KAM. STUDY DESIGN: Observational laboratory study. METHODS: High-level female handball players (n = 45) performed the m505 and handball-specific sidestep cut. Resultant GRF, its frontal plane moment arm to the knee, and KAM were obtained and subsequently compared between the tasks. Rank correlation coefficients were employed to assess if variables of both tasks are related. RESULTS: Peak KAM was similar for the m505 and the sidestep cut (1.79 (0.95 – 3.53) Nm/kg vs. 1.64 (0.34 – 3.60) Nm/kg; rB = .25; p = .14). The ranking of the players' peak KAM differed substantially ( rS = 0.26, p = .084), suggesting that different tasks could classify the same player with different injury risk. The m505 generated lower resultant GRF (24 ± 4 N/kg, 95% CI [23, 24] vs. 33 ± 9 N/kg, 95% CI [31, 35]; d = 1.30; p < .001) but longer frontal plane moment arms (7.8 ± 1.8 cm, 95% CI [7.3, 8.4] vs. 5.4 ± 1.5 cm, 95% CI: [5.0, 5.8]; d = 1.36; p < .001) than the sidestep cut. CONCLUSION: A difference in individual ACL injury risk assessment depending on movement type was revealed. While KAM magnitudes were similar across direction-change tasks, player rankings differed. The contributions of resultant GRF and frontal plane moment arms to peak KAM varied between tasks, underscoring the importance of task-specific and individualized injury prevention.

Running footwear is continuously being modified and improved; however, running-related overuse injury rates remain high. Nevertheless, novel manufacturing processes enable the production of individualized running shoes that can fit the individual needs of runners, with the potential to reduce injury risk. For this reason, it is essential to investigate functional groups of runners, a collective of runners who respond similarly to a footwear intervention. Therefore, the objective of this study was to develop a framework to identify functional groups based on their individual footwear response regarding injury-specific running-related risk factors for Achilles tendinopathy, Tibial stress fractures, Medial tibial stress syndrome, and Patellofemoral pain syndrome. In this work, we quantified the footwear response patterns of 73 female and male participants when running in three different footwear conditions using unsupervised learning (k-means clustering). For each functional group, we identified the footwear conditions minimizing the injury-specific risk factors. We described differences in the functional groups regarding their running style, anthropometric, footwear perception, and demographics. The results implied that most functional groups showed a tendency for a single footwear condition to reduce most biomechanical risk factors for a specific overuse injury. Functional groups often differed in their hip and pelvis kinematics as well as their subjective rating of the footwear conditions. The footwear intervention only partially affected biomechanical risk factors attributed to more proximal joints. Due to its adaptive nature, the framework could be applied to other footwear interventions or performance-related biomechanical variables.

Background Sidestep cutting technique is highly individual and has been shown to influence knee joint loading. However, studies assessing whether individualized technique feedback improves technique and ACL injury-relevant knee joint loads instantly in a sport-specific task are lacking. Purpose To determine the instant effects of individualized augmented technique feedback and instructions on technique and the peak external knee abduction moment (pKAM) in a handball-specific sidestep cut. Additionally, to determine the effects of technique modifications on the resultant ground reaction force and its frontal plane moment arm to the knee joint center. Study Design Controlled laboratory cohort study Methods Three-dimensional biomechanics of 48 adolescent female handball players were recorded during a handball-specific sidestep cut. Following baseline cuts to each side, leg-specific visual and verbal technique feedback on foot strike angle, knee valgus motion, or vertical impact velocity using a hierarchically organized structure accounting for the variables’ association with performance was provided. Subsequently, sidestep cuts were performed again while verbal instructions were provided to guide technique modifications. Combined effects of feedback and instructions on technique and pKAM as well as on the resultant ground reaction force and its frontal plane moment arm to the knee joint center were assessed. Results On average, each targeted technique variable improved following feedback and instructions, leading to instant reductions in pKAM of 13.4% to 17.1%. High inter-individual differences in response to feedback-instruction combinations were observed. These differences were evident in both the adherence to instructions and the impact on pKAM and its components. Conclusion Most players were able to instantly adapt their technique and decrease ACL injury-relevant knee joint loads through individualized augmented technique feedback, thereby potentially reducing the risk of injury. More research is needed to assess the retention of these adaptations and move towards on-field technique assessments using low-cost equipment. Level of Evidence: Level 3

Objectives We aimed to investigate the effects of ankle taping on lower extremity biomechanics related to injury development and how these effects change after sports-specific use. Design Randomized, repeated measures design with three conditions: Barefoot, tape applied fresh, and tape after sports-specific use (between-subject factor: sex). Methods Twenty-five healthy participants (ten female) performed sports-specific movements, including running, drop jumping, and 180° change of direction, under the three conditions. Kinetic and kinematic data were collected using 3D motion capturing and force platforms. Results Tape applied fresh and tape after sports-specific use significantly reduced peak ankle inversion. Biomechanical risk factors for anterior cruciate ligament or running overuse injuries were either unchanged or decreased with tape applied fresh, except for the peak loading rate of the resultant ground reaction force, which increased between 4% and 18% between movement types. After 15 minutes of sports-specific use of the tape, the alterations induced by tape applied fresh remained for some biomechanical risk factors while they became closer to barefoot again for others, indicating a differential response to prolonged use of taping for different biomechanical variables. Conclusions Ankle taping protects the ankle joint by reducing biomechanical risk factors associated with ankle sprains, and most biomechanical risk factors for anterior cruciate ligament or running overuse injuries are not increased. Further research is needed to explore the duration of protective effects, variations across sports, and its impact on patients with chronic ankle instability, contributing to a more comprehensive understanding of ankle taping's influence on lower extremity biomechanics.

Tibial stress injuries are problematic among runners. The loading magnitude is the most important mechanical contributor to bone damage accumulation, but loading quantity is also important, and faster runners require fewer loading cycles to complete a given distance than slower runners. This study estimated tibial loading and damage accumulation throughout a demanding 10-km run in recreational (RR) and competitive runners (CR). Male runners reporting a 10-km season-best run slower than 47:30 min (RR) or faster than 37:30 min (CR) completed a 10-km treadmill running protocol at 105% of their season's best time. Tibial loading was estimated from bending moments at the distal 1/3rd of the tibia by ensuring static equilibrium at each 1% of stance. Peak loading was obtained, and cumulative damage per kilometer was estimated using a tissue-dependent weighting factor. Peak tibial loading and damage accumulation per kilometer significantly decreased throughout the run, by 5% and 4%, respectively. Peak loading was significantly higher (31%) in CR than RR, and there was an indication (p = 0.058 and large effect size) of a greater rate of damage accumulation in CR than RR. Tibial loading per step and the rate of accumulation per kilometer decreased throughout a demanding 10-km run suggesting that changes in running mechanics as a result of prolonged running may not be a primary mechanism for stress injury development. Competitive runners experience greater peak tibial loading and possibly greater cumulative tibial damage when they complete 10 km faster than recreational runners. Peak tibial loading per step and the rate of damage accumulation decreased throughout a demanding 10-km run in both recreational and competitive runners. Running-induced changes in gait mechanics may not be a predominant mechanism for the development of tibial stress injuries. Completing a 10-km run at a faster speed requires fewer loading cycles, but this does not result in reduced tibial damage accumulation due to the greater loading magnitude.

Background Anterior cruciate ligament injury (ACL) prevention programs lack game specificity, and the effect on knee loading and movement technique during sport-specific cutting tasks has rarely been investigated. Objective To determine the effect of a handball-specific ACL injury prevention program in reducing knee joint loading and optimizing cutting techniques. Design Pre-posttest control group design. Setting Biomechanical laboratory. Participant 40 young female elite handball players were assigned to an intervention (INT) group (n = 20) and a control (CON) group (n = 20). Interventions Players performed handball-specific fake-cuts while 3D biomechanics were recorded before (T0) and after nine weeks (T1). The INT performed neuromuscular training, including hip and calf muscle strength exercises and handball cutting technique training, focusing on forefoot landing and avoiding knee valgus. Mixed rANOVAs (group x time) were conducted. Main Outcome Measurements The external peak knee abduction moment (KAM). We furthermore assessed knee valgus angle at initial ground contact, foot strike angle, as well as cutting angle and approach speed. Results Both groups reduced KAM from T0 to T1 (Table, Figure). The knee valgus angle was similar between groups and unchanged over time. Both groups adapted a forefoot landing from T0 to T1. Both groups decreased the approach speed but increased their cutting angle from T0 to T1. There were no interaction effects, indicating similar changes over time in both groups. Conclusions The handball-specific prevention program failed to reduce KAM in the INT. A longer intervention period or different intervention content might be required to induce reductions in KAM and further improve the cutting technique.

BACKGROUND:Internal tibial loading is influenced by modifiable factors with implications for the risk of stress injury. Runners encounter varied surface steepness (gradients) when running outdoors and may adapt their speed according to the gradient. This study aimed to quantify tibial bending moments and stress at the anterior and posterior peripheries when running at different speeds on surfaces of different gradients. METHODS:Twenty recreational runners ran on a treadmill at 3 different speeds (2.5 m/s, 3.0 m/s, and 3.5 m/s) and gradients (level: 0%; uphill: +5%, +10%, and +15%; downhill: -5%, -10%, and -15%). Force and marker data were collected synchronously throughout. Bending moments were estimated at the distal third centroid of the tibia about the medial-lateral axis by ensuring static equilibrium at each 1% of stance. Stress was derived from bending moments at the anterior and posterior peripheries by modeling the tibia as a hollow ellipse. Two-way repeated-measures analysis of variance were conducted using both functional and discrete statistical analyses. RESULTS:There were significant main effects for running speed and gradient on peak bending moments and peak anterior and posterior stress. Higher running speeds resulted in greater tibial loading. Running uphill at +10% and +15% resulted in greater tibial loading than level running. Running downhill at -10% and -15% resulted in reduced tibial loading compared to level running. There was no difference between +5% or -5% and level running. CONCLUSION:Running at faster speeds and uphill on gradients ≥+10% increased internal tibial loading, whereas slower running and downhill running on gradients ≥-10% reduced internal loading. Adapting running speed according to the gradient could be a protective mechanism, providing runners with a strategy to minimize the risk of tibial stress injuries.

Advanced footwear technology (AFT) is currently being debated in sports. There is a direct evidence that distance running in AFT improves running economy. In addition, there is indirect evidence from competition performance for improved running performance from using AFTs in middle- and long-distance running and sprinting events. However, the extent to which world-class performance is affected across the full range of track and road racing events between genders has not been systematically analyzed. This study examined publicly available performance datasets of annual best track and road performances for evidence of potential systematic performance effects following the introduction of AFT. The analysis was based on the 100 best performances per year for men and women in outdoor events from 2010 to 2022, provided by the world governing body of athletics (World Athletics). We found evidence of progressing improvements in track and road running performances after the introduction of AFT for road races in 2016 and AFT for track racing in 2019. This evidence is more pronounced for distances longer than 1500 m in women and longer than 5000 m in men. Women seem to benefit more from AFT in distance running events than men. For the sprint events (100 m to 400 m hurdles), the peak performance gains in 2021 and 2022 compared to the pre-AFT period ranged from 0.6 to 1.1% and from 0.4 to 0.7% for women and men, respectively. For middle-distance events (400 m to 3000 m steeplechase), peak performance gains ranged from 0.6 to 1.9% and from 0.6 to 0.7% for women and men, respectively. For distances from 5000 m to the marathon, performance gains ranged from 2.2% to 3.5% and 0.7% to 1.4% for women and men, respectively. While the observational study design limits causal inference, this study provides a database on potential systematic performance effects after introducing advanced shoes/spikes in track and road running events in world-class athletes. Further research is needed to examine the underlying mechanisms and, in particular, potential gender differences in the performance effects of AFT.

Lateral ankle sprains are the most common injuries in indoor and court sports, with ankle inversion being a primary injury driver. Stabilising the ankle during multidirectional changes is crucial for injury prevention. Conversely, increased shoe stiffness has been hypothesised to influence the magnitude of ankle inversion and may raise the risk for ankle injuries. Therefore, the purpose of this study was to investigate the influence of shoe longitudinal bending stiffness on ankle biomechanics during indoor and court sport-specific cutting movements. Biomechanical data from 19 participants were collected using a motion capture system and force plate. A jump-cut protocol with two different cutting directions after landing was performed in indoor shoes with and without carbon plate inserts of varying stiffness. Ankle kinematics and kinetics were analysed with statistical parametric mapping and repeated measures analysis of variance. A significant increase in ankle inversion during the 180 degrees cut and a reduction in forefoot inversion (foot torsion) for stiffer footwear conditions during both the 45 degrees and 180 degrees cut were observed. While dorsiflexion moments differed during the last 10% of ground contact, ankle inversion moments did not significantly diverge between shoe conditions. Furthermore, a noteworthy correlation between footwear longitudinal bending stiffness and torsional stiffness was identified. In conclusion, increased bending stiffness significantly affected ankle and foot kinematics. The ankle compensated for restricted mobility and higher demands during high-degree jump-cuts, while foot torsion played a more prominent role in low-degree cuts. The heightened ankle inversion during high-degree cuts may induce an elevated risk for lateral ankle sprains. Further longitudinal studies are necessary to comprehensively understand injury incidence and the role of shoe stiffness in injury prevention.

BACKGROUND:Trunk lean angle is an underrepresented biomechanical variable for modulating and redistributing lower extremity joint loading and potentially reducing the risk of running-related overuse injuries. The purpose of this study was to systematically alter the trunk lean angle in distance running using an auditory real-time feedback approach and to derive dose-response relationships between sagittal plane trunk lean angle and lower extremity (cumulative) joint loading to guide overuse load management in clinical practice. METHODS:Thirty recreational runners (15 males and 15 females) ran at a constant speed of 2.5 m/s at 5 systematically varied trunk lean conditions on a force-instrumented treadmill while kinematic and kinetic data were captured. RESULTS:A change in trunk lean angle from -2° (extension) to 28° (flexion) resulted in a systematic increase in stance phase angular impulse, cumulative impulse, and peak moment at the hip joint in the sagittal and transversal plane. In contrast, a systematic decrease in these parameters at the knee joint in the sagittal plane and the hip joint in the frontal plane was found (p < 0.001). Linear fitting revealed that with every degree of anterior trunk leaning, the cumulative hip joint extension loading increases by 3.26 Nm·s/kg/1000 m, while simultaneously decreasing knee joint extension loading by 1.08 Nm·s/kg/1000 m. CONCLUSION:Trunk leaning can reduce knee joint loading and hip joint abduction loading, at the cost of hip joint loading in the sagittal and transversal planes during distance running. Modulating lower extremity joint loading by altering trunk lean angle is an effective strategy to redistribute joint load between/within the knee and hip joints. When implementing anterior trunk leaning in clinical practice, the increased demands on the hip musculature, dynamic stability, and the potential trade-off with running economy should be considered.

Biomechanical measurements of accidental ankle sprain injuries are rare but make important contributions to a more detailed understanding of the injury mechanism. In this case study, we present the kinematics and kinetics of a lateral ankle sprain of a female athlete performing handball-specific fake-and-cut manoeuvres. Three-dimensional kinematics and kinetics were recorded and six previously performed trials were used as reference. Plantarflexion, inversion, and internal rotation angles were substantially larger than the reference trials and peaked between 190 and 200 ms after initial ground contact. We observed a highly increased inversion and internal rotation moment. However, compared to the non-injury trials the data also revealed a reduction in the second dorsiflexion moment peak. Ground reaction forces were lower throughout the injury trial. Other parameters at initial ground contact including ankle and hip position, step length, and the traction coefficient indicate that a preparatory maladjustment occurred. This study adds valuable contributions to the understanding of lateral ankle sprains by building upon previously published reports and considering the shoe-surface interaction as an important factor for injury.

PurposeThe purpose of this study was to investigate the impact of sex on knee function, activity and quality of life following meniscus surgery using data from the German Arthroscopy Registry.MethodsThis is a retrospective cohort study with data collected between 2017 and 2022. Patient-reported outcome measures (PROMs), namely Knee Injury and Osteoarthritis Outcome Score (KOOS), EuroQol Visual Analogue Scale (EQ Scale), and Marx Activity Rating Scale (MARS), were collected preoperatively and at 6, 12 and 24 months postoperatively. Data were analysed to examine differences between male and female patients regarding PROMs, pre-existing conditions, meniscus lesion types and surgical treatments.ResultsA total of 1106 female (36.6%) and 1945 male patients (63.7%) were included. Males were significantly younger than females and had a higher body mass index. Overall, there were four times more medial meniscus lesions (MMLs) (77.5%) than lateral meniscus lesions (LMLs) (27.9%). Degenerative LMLs were more frequent in females, while traumatic LMLs were more common in males. Frequencies of traumatic and degenerative MMLs were similar among males and females. Males had higher absolute KOOS irrespective of treatment or meniscus lesion type. Meniscus repair resulted in similar improvements in Delta KOOS for both sexes, while meniscus resection exhibited higher absolute KOOS for males at each time point. Males generally had higher EQ Scale and MARS than females.ConclusionGreater improvements in knee function, activity and quality of life were observed in males. While MMLs appear to be comparable among sexes, the nature of LML differed significantly. These results may help surgeons to refine patient selection for specific treatments to improve overall clinical outcomes.Level of EvidenceLevel III.