Jump-landing Task Research Articles

Lower limbs kinematic analysis during a jump landing task in soccer players with unilateral anterior cruciate ligament reconstruction

BackgroundFatigue leads to an acute decline in muscle strength, altered patterns of lower extremity muscle activation, changes in hip and knee kinematics. In terms of the effects of fatigue on knee joint kinematics during plyometric training, there is still a lack of knowledge regarding kinematic differences between athletes who passed the ACL reconstructions rehabilitation period and healthy athletes. Therefore, this study aimed to compare lower limb joint kinematic parameters between reconstructed cruciate ligament and healthy control soccer players during jump landing in a fatigued setting.MethodsLower limb kinematic parameters were recorded in 20 professional soccer players (age, 24.95 ± 2.92 years; body mass, 77.20 ± 12.88 kg; height, 1.77 ± 3.19 m) during jump landing task before and after the fatigue protocol. The control group consisted of healthy subjects and the experimental group consisted of subjects with ACL reconstruction by thigh transplantation. Kinematic data was recorded with 4 cameras to measure lower limb angles at first foot contact and maximum range of motion.ResultsThe results showed that before fatigue, there was only a significant difference between the two groups in the maximum range of motion of the non-involved hip joint (P = 0.022) and angle of the involved hip at first contact (P = 0.049). In other data on joint range of motion or initial contact angle, no significant difference was observed between the two groups (P > 0.05). After fatigue protocol, there was a significant difference in initial foot contact in non-involved (P = 0.030), and involved (P = 0.020) hip joint angles between the two groups. However, no significant difference in initial contact angle or range of motion of other joints was observed between the groups.ConclusionsThis study shows that plyometric fatigue does not contribute to numerous changes in contact angles and range of motion in lower extremity joints in healthy soccer players and those with a history of cruciate ligament repairs.

The Influence of Ankle Mobility and Foot Stability on Jumping Ability and Landing Mechanics: A Cross-Sectional Study.

Practicing physical activities or sports that involve frequent jumping and landing can strain the muscles and joints of the lower limbs, especially in those who do not have adequate physical preparation. The objective of this study was to (a) determine the correlation between ankle range of motion (ROM) and landing stability following jumps; (b) assess the association between the jump height in a counter-movement jump (CMJ) test and ankle ROM; and (c) examine the connection between stabilometry during specific jumps movements present in many sports and in ankle stabilization. Sixty-two healthy amateur volleyball players participated in the study (age: thirty-seven females and twenty-five males; age (years): 16.5 ± 4.25; height (cm): 166 ± 11.4; weight (Kg): 61.6 ± 13.7). Participants were recruited for the study in collaboration with student sports associations. The evaluations encompassed the measurement of ankle joint mobility for both lower limbs using an inertial sensor, a static baropodometric and stabilometric analysis using a pressure platform, and the CMJ test using the Microgate system. After the assessments, participants performed a "specific jump landing task". Significant correlations were found between foot range of motion (ROM) and counter-movement jump (CMJ) performance. Specifically, the ROM of the right foot had a strong correlation with the CMJ (r = 0.81, p < 0.001), while the left foot ROM showed a moderate correlation (r = 0.46, p < 0.001). The specific jump task revealed substantial changes in stabilometry parameters, particularly during forward hops compared to lateral jumps. Dorsiflexion ROM significantly impacts jumping ability. Evaluating landing patterns and stabilometry during targeted activities can help optimize training, improve dynamic balance, and reduce ankle injury risk.

Movement Quality Assessment of Army Reserve Officers' Training Corps Cadets: A Report of Validity and Normative Data.

Movement quality screening in early-career military populations, like Army Reserve Officers' Training Corps (AROTC) cadets, could decrease the negative impact of musculoskeletal injury observed within the military. Movement quality screening techniques should be valid before being pursued in the field. Normative data describing movement quality of AROTC cadets are also needed. Therefore, the aims of this study were to determine criterion validity of several movement quality assessments and report normative jump-landing kinematics of AROTC cadets. This cross-sectional research was approved by the Institutional Review Board. As part of a larger study, 20 AROTC cadets (21.3 ± 3.4 years; 1.7 ± 0.1 m; 73.8 ± 14.8 kg) had 3-dimensional (3D) and 2-dimensional (2D) kinematic data collected simultaneously while performing a jump-landing task. Variables of interest were 3D hip and knee sagittal, frontal, and transverse joint angles at maximum knee flexion. An experienced rater calculated sagittal and frontal 2D joint angles at maximum knee flexion. Averages of 2D and 3D angles were calculated to describe normative data and for further data analysis. Bivariate correlations between 3D and 2D variables were used to determine criterion validity. Moderate correlations were found between 2D and 3D hip frontal plane angles (P = .05, r =-0.33), 2D and 3D knee sagittal plane angles (P = .04, r = 0.35), and 2D and 3D knee frontal plane angles (P = .03, r = -0.36). Normative values of knee and hip kinematics demonstrated averages of 17.58° of knee adduction, 16.48° of knee external rotation, 11.57° of hip abduction, 10.76° of hip internal rotation, and 103.47° of knee flexion during landings. However, ranges demonstrated that landing patterns vary within AROTC cadets. The normative values of 3D jump-landing kinematic data indicate that movement quality varies greatly within AROTC cadets, and some cadets display potentially injurious movements. Therefore, screening movement quality could be beneficial to determine musculoskeletal injury risk in AROTC cadets. Based on the correlations discovered in this study, we recommend the 2D techniques used in this study be researched further as they may serve as alternatives to expensive, timely 3D techniques that could be better utilized in military environments.

The relationship between ankle landing kinematics, isokinetic strength, muscle activity, and the prevalence of lower extremity injuries in university-level netball players during a single season.

Safe landing in netball is fundamental. Research on the biomechanics of multidirectional landings is lacking, especially among netball players. Furthermore, few studies reporting the associations between ankle kinematics, isokinetic ankle muscle strength, muscle activities, and injury prevalence in South African netball have been undertaken. To determine the relationships between ankle kinematics, kinetics, isokinetic strength, and muscle activity during jump-landing tasks, as well as the prevalence of lower extremity injuries in university-level netball players during a single season. This cross-sectional repeated-measure study consisted of ten university-level female netball players. The injury prevalence data was collected during the 2022 netball season. The ankle muscle activity, kinematic, and kinetic data were collected during multidirectional single-leg landing and muscle strength was collected from plantar- and dorsiflexion trials. Netball players' ankle strength was generally below average. There was evidence of negative correlations between the ankle range of motion (ROM), isokinetic strength, and muscle activity amplitudes. A lack of evidence prevented the conclusion that lower extremity dominance predisposed players to injury, and that any specific body part was more likely to be injured among netball players. Landing forces and muscle activity are direction-dependent, especially for the dominant limb. Lower extremity strength and neuromuscular control (NMC) across multiple jump-landing directions should be an area of focus for female netball players.

COMPARISON OF INTER-SESSION, INTRA-RATER AND INTER-RATER RELIABILITY OF SINGLE AND DOUBLE LEG LANDING ERROR SCORING SYSTEM USING DIFFERENT CALCULATION METHODS

INTRODUCTION &amp; AIMS The Landing Error Scoring System (LESS) is used for screening noncontact anterior cruciate ligament (ACL) injury risk. The LESS is deemed a valid and reliable indicator of landing biomechanics that predict noncontact ACL injuries. We have sought to validate a Single-Leg Landing Error Scoring System (SLESS) against the established LESS. There are seven distinct calculation methods for final LESS scores, adding variability to the original version and the risk of misinterpreting results. This study used different calculation methods to investigate the inter-session, intra-rater and inter-rater reliability of the SLESS and LESS scores. METHODS Thirty-five team sports players performed four drop jump landing variations (dominant leg, non-dominant leg, double-leg and cognitive loading drill with double-leg) over three sessions. Sessions 1 and 2 were conducted on the same day, with Session 3 a week later. Video footage from frontal and sagittal views captured all landings. Three professionals scored recorded trials using standard SLESS and LESS protocols. One scorer assessed intra-session and inter-session reliability, while three evaluated inter-rater reliability. The final SLESS and LESS scores were calculated using original version/OG, average of 3 trials-AV, worst trial/WT, best score/BS, first trial/FT, last trial/LT, error present in at least two of three trials/TT). Reliability was assessed using intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV) with 95% confidence intervals. RESULTS The study observed acceptable inter-session reliability across single-leg and double-leg drop jump landing tasks using all seven calculation methods (SLESS: ICC=0.80-0.91, SEM=1.07-1.10, CV=6.5-10.1%; LESS: ICC=0.63-0.90, SEM=1.06-1.11, CV=5.7-11.5%). The study also demonstrated acceptable intra-rater reliability for all tasks using all calculation methods (SLESS: ICC=0.86-0.94, SEM=1.05-1.08, CV=5.0-8.5%; LESS: ICC=0.74-0.93, SEM=1.04-1.08, CV=4.2-8.5%). In addition, acceptable inter-rater reliability was shown for all tasks using all calculation methods (SLESS: ICC=0.69-0.83, SEM=1.11-1.18, CV=10.5-18.0%; LESS: ICC=0.54-0.82, SEM=1.10-1.20, CV=10.3-20.3%). CONCLUSION The study indicates the reliability of all seven calculation methods for SLESS and LESS scores. Precise specification of the chosen calculation method is crucial for practitioners and researchers.

Jump Landing Kinematics: Establishing Normative Ranges For Male And Female Athletes.

Lower extremity joint (LE) kinematics during landing tasks are important predictors of injury risk and performance outcomes in athletes. To establish sex-related differences and normative ranges for LE kinematics during the jump-landing task in a large cohort of healthy military service academy cadets. Cross-Sectional Study. US Air Force, Naval, and Military Academies. 5308 cadets (2062 females [38.8%]). Sex-related differences in LE kinematics were analyzed using independent samples t-tests. Mean differences (MD) and effect sizes (d) were reported for interpretability. Normative ranges for hip and knee joint angles were established separately for males and females at initial contact (IC) and 50% of the stance phase. Compared to males, moderate effect sizes (d ≥ .5) were observed for knee external rotation (negative value) where females displayed greater motion at IC and at 50% stance (MD: - 3.9˚ and -5.0˚, respectively, p < .001). The following findings were of small effect size (.2 ≥ d > .5). Females exhibited less knee and hip flexion at IC (MD: -1.8˚ and -0.5˚, respectively, p < .001) and at 50% stance (MD: -4.1˚ and -4.6˚, respectfully, p < .001). This was accompanied by females having greater knee valgus (negative value) and hip adduction at IC (MD: -2.2˚ and 1.06˚, respectively, p < .001) and at 50% stance (MD: -3.2˚ and 1.8˚, respectfully, p < .001). This study establishes normative ranges for LE kinematics during the jump-landing task in a large cohort of healthy military service academy cadets entering their first year. Sex- related differences in LE kinematics were observed, highlighting the importance of considering sex as a factor in the evaluation of lower extremity movement quality and management of injury risk.

Chronic ankle instability affects the association between knee joint angle and loading: musculoskeletal simulation study

The purpose of this study was to calculate and compare (1) knee loads, (2) muscle-specific contributions to knee loads, and (3) effects of knee flexion angle on knee loads and muscle-specific load contributions during a forward jump-landing task in people with and without chronic ankle instability (CAI). Eight CAI patients and seven healthy controls performed a forward jump-landing task. We collected 3D kinematics, ground reaction force, and muscle activation and used musculoskeletal modeling. The results showed that only healthy controls exhibited an association between knee flexion angle and knee compressive impulse (r = 0.854, p = .014). The lack of association in CAI group may lead to knee instability and increase knee injury risk in people with CAI.

Comparison of the Effects of Exercises with and without Feedback on Lower Extremity Kinematics During Jump Landing Tasks in Men with Selected Motor Control Defects: A Randomized Clinical Trial

Comparison of the Effects of Exercises with and without Feedback on Lower Extremity Kinematics During Jump Landing Tasks in Men with Selected Motor Control Defects: A Randomized Clinical Trial

Biomechanical risk factors for ACL injury differ between the sexes when performing a high-intensive exergame

Introduction&#x0D; Incidence rates in anterior cruciate ligament (ACL) injuries, which are linked to multiple factors, are higher in females than males (Sutton &amp; Bullock, 2013). However, the main contributors to the difference in risk are biomechanical factors such as increased knee valgus (KV), knee internal rotation (KIR), or decreased hip flexion (HF; Seyedahmadi et al., 2022). Returning back to sports after an injury requires extensive rehabilitation as well as training of dual-task situations in order to be physically and cognitively prepared. Exergaming represents a dual task including a cognitive and a motor component and may be used as training modality during rehabilitation. It is known that performing a dual-task leads to altered landing movement patterns in healthy athletes (Dai et al., 2018). Before an exergame for rehabilitation after ACL injury can be implemented and tailored to the specific needs of female and male athletes, the movement patterns of males and females need to be understood. Therefore, the aim of this study was to identify biomechanical differences between males and females when performing a high-intensive exergame.&#x0D; Methods&#x0D; Using 3D-motion capture (Vicon) kinematics were measured in 18 healthy athletes (9 male, 9 female) during a 25-min exergame (Sphery Racer, ExerCube). The exergame included nine different exercises of which 8 were used for analysis. The exercises were separated into neutral (squat, jump, burpee) and side-specific exercises (low-touch, mid-touch, high-touch, punch, lunge). For analysis, the maximal KV, maximal KIR, and the minimal HF were extracted during 10-30° knee flexion. These maximal values were then compared between the sexes, the exercises, and both legs with a linear mixed model, for each the neutral and the side-specific exercises.&#x0D; Results&#x0D; A main effect of sex was only found for side-specific exercises in KIR (F(1, 16) = 6.1, p = .02) with females exhibiting higher values. For KV and HF in side-specific exercises as well as all variables in neutral exercises, no significant main effect for sex was found. However, there was a main effect of exercise in KV; KIR, and HF in neutral (p &lt; .001) as well as in side-specific exercises (p &lt; .001).&#x0D; Discussion/Conclusion&#x0D; Differences in KIR between males and females primarily exist during touches and punches. Therefore, exergames should incorporate this fact to counteract increased risk for knee injuries in females.&#x0D; References&#x0D; Dai, B., Cook, R. F., Meyer, E. A., Sciascia, Y., Hinshaw, T. J., Wang, C., &amp; Zhu, Q. (2018). The effect of a secondary cognitive task on landing mechanics and jump performance. Sports Biomechanics, 17(2), 192–205. https://doi.org/10.1080/14763141.2016.1265579&#x0D; Seyedahmadi, M., Minoonejad, H., Karimizadeh Ardakani, M., Heidari, Z., Bayattork, M., &amp; Akbari, H. (2022). What are gender differences in lower limb muscle activity during jump-landing tasks? A systematic review and meta-analysis. BMC Sports Science, Medicine &amp; Rehabilitation, 14(1), Article 77. https://doi.org/10.1186/s13102-022-00469-3&#x0D; Sutton, K. M., &amp; Bullock, J. M. (2013). Anterior cruciate ligament rupture: Differences between males and females. The Journal of the American Academy of Orthopaedic Surgeons, 21(1), 41–50. https://doi.org/10.5435/jaaos-21-01-41

The influence of jump-landing direction on dynamic postural stability following anterior cruciate ligament reconstruction

BackgroundTraditional testing prior to return to sport following anterior cruciate ligament reconstruction typically involves jump-landing tasks in the forward direction. As injury is most likely the result of multiplanar neuromuscular control deficits, assessment of dynamic postural stability using landing tasks that require multiplanar stabilization may be more appropriate. The purpose of this study was to examine how dynamic postural stability is affected when performing jump-landing tasks in three different directions. MethodsFifteen athletes [11 females (18.0 ± 3.0 years) and 4 males (18.5 ± 3.1 years)] following anterior cruciate ligament reconstruction performed a series of single-limb jump-landing tasks in 3 directions. Individual directional stability indices and a composite dynamic postural stability index were calculated using ground reaction force data and were compared using separate one-way repeated measures ANOVAs. FindingsAll directional stability indices demonstrated a significant main effect for jump-landing direction (medial-lateral P < 0.001, η2p = 0.95; anterior-posterior P < 0.001, η2p = 0.97; vertical P = 0.021, η2p = 0.24). The diagonal jump-landing direction produced increased medial-lateral stability and vertical stability scores, while the forward and diagonal jump-landing directions produced increased anterior-posterior stability scores. There was no significant effect for the composite dynamic stability index score. InterpretationJump-landing direction affects dynamic postural stability in all 3 planes of movement in athletes following anterior cruciate ligament reconstruction. Results indicate the potential need to incorporate multiple jump-landing directions to better assess dynamic postural stability prior to return to sport.

Greater Core Endurance Identifies Improved Mechanics During Jump Landing in Female Youth Soccer Athletes

Female soccer athletes are at greater risk for anterior cruciate ligament injury compared with males. Risk factors include altered landing biomechanics and diminished core neuromuscular control, measured using advanced laboratory equipment. There is a need for a clinical measure of core muscle function to better understand kinesiological factors within a female, youth athlete population. The purpose was to determine whether sagittal and frontal plane kinematics during a jump landing task differ based on levels of core endurance in female youth soccer athletes. Participants included healthy, female soccer athletes ages 8–17 years (M = 12.3 years, SD = 2.4 years), height (M = 1.52 m, SD = 0.16 m), and body mass (M = 46.0 kg, SD = 13.7 kg). A quantitative data descriptive laboratory study in a field-based setting was conducted. Sixty-six participants performed the side plank test for time to failure. Three-dimensional biomechanics were collected, and initial contact and peak trunk, hip, and knee joint angles were identified during the deceleration phase of a double-leg jump-landing task. The group with the lowest side plank time displayed decreased knee flexion at initial contact (p = .02) and peak knee flexion (p = .03) and decreased peak hip flexion angles (p = .01). There were no additional statistically significant differences among groups (p &gt; .05). Female youth soccer athletes who have reduced core endurance also display decreased hip and knee flexion, which may place them at risk for anterior cruciate ligament injury.

Establishing Phase Definitions for Jump and Drop Landings and an Exploratory Assessment of Performance-Related Metrics to Monitor During Testing.

Harry, JR, Simms, A, and Hite, M. Establishing phase definitions for jump and drop landings and an exploratory assessment of performance-related metrics to monitor during testing. J Strength Cond Res 38(2): e62-e71, 2024-Landing is a common task performed in research, physical training, and competitive sporting scenarios. However, few have attempted to explore landing mechanics beyond its hypothesized link to injury potential, which ignores the key performance qualities that contribute to performance, or how quickly a landing can be completed. This is because a lack of (a) established landing phases from which important performance and injury risk metrics can be extracted and (b) metrics known to have a correlation with performance. As such, this article had 2 purposes. The first purpose was to use force platform data to identify easily extractable and understandable landing phases that contain metrics linked to both task performance and overuse injury potential. The second purpose was to explore performance-related metrics to monitor during testing. Both purposes were pursued using force platform data for the landing portion of 270 jump-landing trials performed by a sample of 14 NCAA Division 1 men's basketball players (1.98 ± 0.07 m; 94.73 ± 8.01 kg). The proposed phases can separate both jump-landing and drop-landing tasks into loading, attenuation, and control phases that consider the way vertical ground reaction force (GRF) is purposefully manipulated by the athlete, which current phase definitions fail to consider. For the second purpose, Pearson's correlation coefficients, the corresponding statistical probabilities ( α = 0.05), and a standardized strength interpretation scale for correlation coefficients (0 < trivial ≤ 0.1 < small ≤ 0.3 < moderate ≤ 0.5 < large ≤ 0.7 < very large) were used for both the group average (i.e., all individual averages pooled together) and individual data (i.e., each individual's trials pooled together). Results revealed that landing time, attenuation phase time, average vertical GRF during landing, average vertical GRF during the attenuation phase, average vertical GRF during the control phase, vertical GRF attenuation rate, and the amortization GRF (i.e., GRF at zero velocity) significantly correlated with landing performance, defined as the ratio of landing height and landing time ( R ≥ ± 0.58; p < 0.05), such that favorable changes in those metrics were associated with better performance. This work provides practitioners with 2 abilities. First, practitioners currently assess jump capacity using jump-landing tests (e.g., countermovement jump) with an analysis strategy that makes use of landing data. Second, this work provides preliminary data to guide others when initially exploring landing test results before identifying metrics chosen for their own analysis.

Sex-Based Differences in Lower Extremity Kinematics During Dynamic Jump Landing Tasks After Neuromuscular Fatigue of the Hip Extensors and Knee Flexors.

Neuromuscular fatigue can increase the activation of antagonist muscles, thereby reducing the moment produced by the agonist. During the deceleration phase of landing, hip extensor and knee flexor muscles contract eccentrically to counteract the external hip flexion moment. Decreased hip flexion is associated with greater knee extensor moments and risk of injury. To investigate sex-based differences in kinematics and muscle activity after neuromuscular fatigue of the hip extensors and knee flexors during dynamic single-leg tasks. Controlled laboratory study. In this study, 9 female (age, 22.3 ± 3.4 years) and 7 male participants (age, 21.3 ± 2.6 years) completed the triple hop (THop) for distance and single-leg drop-jump (SJump) tasks before and after a fatigue protocol consisting of eccentric hip extension and knee flexion. Motion capture and electromyography were used to compare lower extremity kinematics and muscular activation between the sexes. During the THop, neuromuscular fatigue resulted in significantly decreased maximum hip flexion angles (P = .01), maximum knee flexion angles (P = .039), and an effect of sex on all hip flexion angles, where both sexes saw decreased hip flexion postfatigue (P = .033). A significant interaction of fatigue and sex on hip flexion angular velocity was observed during the SJump, indicating that men experienced an increase while women experienced a decrease in hip flexion angular velocities due to fatigue (P = .03). Gluteus maximus activation was increased, and erector spinae activation was decreased postfatigue in women during the THop (P = .053 and P = .023, respectively). Results indicate that men and women compensated differently after fatigue of the hip extensors and knee flexors. Women more commonly assumed an erect landing posture associated with increased injury risk after fatigue of the hip extensors and knee flexors.

Evaluation of the Anterior Cruciate Ligament Injury Risk During a Jump-Landing Task Using 3-Dimensional Kinematic Analysis Versus the Landing Error Scoring System.

The Landing Error Scoring System (LESS) has been utilized on the field or in the clinic to identify patients with an increased risk for anterior cruciate ligament (ACL) injuries; however, its validity and efficacy have not been fully confirmed. To assess the efficacy of the LESS in identifying the ACL injury risk by examining the correlation between the LESS score and motion patterns on 3-dimensional kinematic analysis. Controlled laboratory study. The jump-landing motion was analyzed for 16 female basketball or badminton players who volunteered to participate in the study. All study participants were aged 19 or 20 years. The sequence of motion was evaluated with the LESS, while kinematic data were simultaneously acquired with a 3-dimensional motion analysis system utilizing the point cluster method. The correlation between the LESS score and knee kinematics was statistically analyzed. When a LESS score ≥6 was defined to be a risk factor for ACL injuries, 7 of the 16 participants (43.8%) were found to exhibit risky motion patterns. Significant correlations were noted between the LESS score and knee valgus (r = 0.87; P < .0001) and internal tibial rotation (r = 0.57; P = .02) at landing. By contrast, a substantial variability was present in knee flexion, showing no correlation with the LESS score. Significant correlations were found between the LESS score and knee valgus and internal tibial rotation during a jump-landing task. The LESS can be regarded as an effective measure to identify risky motion patterns that may increase the likelihood of ACL injuries.

Inter-session, intra-rater and inter-rater reliability of single-leg drop jump landing tasks using the SLESS and compared to the double-leg drop jump landing tasks using theLESS

Inter-session, intra-rater and inter-rater reliability of single-leg drop jump landing tasks using the SLESS and compared to the double-leg drop jump landing tasks using theLESS

The Relationship between Ankle Joint Kinematics and Impact Forces during Unilateral Jump-Landing Tasks in University-Level Netball Players: A Pilot Study

Netball is a sport that involves multiplane- and multidirectional landings, which results in a high proportion of injuries, particularly to the ankle joint. The purpose of this study was to analyse the ankle kinematics in multiple planes during multidirectional single-leg landings in high-level netball players. A total of ten (n = 10) netball players voluntarily participated in the study. All netball players performed 25 single-leg jump landing maneuvers per leg (dominant and non-dominant) from a 0.30 m high platform, landing onto a 0.70 m away force plate platform. Their ankle kinematic, landing kinetic and time to stabilisation (TTS) data were collected in sagittal-, frontal- and transverse planes. Netball players showed mean differences in peak landing forces (F (8,91) = 2.68, p = 0.009) but not in TTS (F (8,91) = 2.27, p = 0.260). There was evidence of differences in ankle kinematics across all three planes [Sagittal: (F (9,81) = 3.48, p = 0.001); Frontal: (F (9,81) = 8.01, p &lt; 0.001); Transverse: (F (9,81) = 8.80, p &lt; 0.001)]. Furthermore, small to large negative (r = −0.55) correlations were observed between ankle range of motion (ROM) and peak landing forces. Associated landing forces can be moderated by greater sagittal plane ankle ROM during multidirectional landings to minimise the risk of ankle injuries in netball.

Association of Dynamic Knee Valgus and Bone Stress Injury in US Military Academy Cadets.

Early identification of incoming military personnel at elevated odds for bone stress injury (BSI) is important for the health and readiness of the US military. Prospective cohort study. Knee kinematic data of the incoming US Military Academy cadets were collected while performing a jump-landing task (The Landing Error Scoring System) using a markerless motion capture system and depth camera. Data on incidence of lower-extremity injury, including BSI, were collected throughout the study period. A total of 1905 participants (452 females, 23.7%) were examined for knee valgus and BSI status. A total of 50 BSI occurred during the study period (incidence proportion = 2.6%). The unadjusted odds ratio for BSI at initial contact was 1.03 (95% confidence interval [CI], 0.94-1.14; P = .49). Adjusted for sex, the odds ratio for BSI at initial contact was 0.97 (95% CI, 0.87-1.06; P = .47). At the instant of maximum knee-flexion angle, the unadjusted odds ratio was 1.06 (95% CI, 1.02-1.10; P = .01), and the odds ratio was 1.02 (95% CI, 0.98-1.07; P = .29) after adjusting for sex. This suggests that there was not a significant enough association for an increase in the odds of BSI based on either degree of knee valgus. Our results did not demonstrate an association between knee valgus angle data during a jump-landing task and future increased odds of BSI in a military training population. Further analysis is warranted, but the results suggests the association between kinematics and BSI cannot be effectively screened by knee valgus angle data in isolation.

Does prior concussion lead to biomechanical alterations associated with lateral ankle sprain and anterior cruciate ligament injury? A systematic review and meta-analysis

ObjectiveTo determine whether individuals with a prior concussion exhibit biomechanical alterations in balance, gait and jump-landing tasks with and without cognitive demands that are associated with risk of lateral ankle...

The Relationship Between Kinematical Parameters of Trunk and Knee Injuries in Male Judo Players

Background and Aims The knee joint injury in judokas mostly occurs in the standing position. This study aims to investigate the relationship between kinematic variables of trunk and the occurrence of knee injuries in male judokas. Methods In this study, 15 male judokas aged 20-30 years (7 with a history of knee joint injury and 8 controls) were selected based on the inclusion and exclusion criteria. Then, after installing markers on their body, they were asked to stand on a 30-cm box and, after a jump upwards, land on the ground on one foot (the support foot). Cameras were used to measure the angles of the knee and trunk joints during the jump landing task. Shapiro-Wilk test was used to examine the normality of data distribution. ANCOVA was used to compare the groups. The ssignificance level was set at 0.05. Results Healthy judokas had lower knee flexion angle and higher knee valgus angle. Moreover, they had lower trunk flexion angle, higher internal knee rotation, and higher relative rotation speed between femur and tibia compared to the injured group (P&lt;0.05). Conclusion Male Judo players with a history of knee injury have lower knee flexion and greater knee valgus, lower trunk flexion, higher internal knee rotation, and higher relative rotation between femur and tibia compared to their healthy peers. Professionals and coaches need to design injury prevention exercises for this group of athletes.

Effect of Taping on Feedforward Activity of the Non-dominant Leg Muscles in Elite Volleyball Players With Chronic Ankle Instability During A Single-leg Jump-landing Task

Background and Aims Although volleyball is a contact sport, there are a high number of injuries in volleyball during training or competitions. Since many jumps are performed during training, it is not surprising that a high number of injuries are caused by jumping and landing. The present study aims to investigate the effect of taping on the feedforward activity of non-dominant leg muscles during single-leg jump-landing in professional volleyball players with chronic ankle instability. Methods In this study, participants were 13 volleyball players with chronic ankle instability who were selected by a purposive sampling method. Electromyographic activity of peroneus longus, anterior tibialis, gastrocnemius, vastus lateralis, gluteus medius, and rectus femoris muscles of the non-dominant leg during a single-leg jump-landing task following a spike shot before and after taping was evaluated. Root mean square was used to calculate muscle activity before and after taping. The data were analyzed using paired t-test. The significance level was set at 0.05. Results The findings showed the significant effect of taping only on maximum feedforward activity (P=0.02) and average feedforward activity (P=0.03) of the peroneus longus muscle. The effect was not statistically significant for other muscles (P&gt;0.05). Conclusion It seems that taping is not useful for improving the feedforward activity of muscles in volleyball players with chronic ankle instability during single-leg jump-landing. Hence, other exercises or methods are recommended for these players during recovery or training.