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Background: Dynamic knee valgus (DKV) is a risk factor for non-contact anterior cruciate ligament (ACL) injuries. Understanding the changes in the electromyographic activity of the lower extremity muscles in individuals with DKV helps trainers design ACL injury prevention exercises. Therefore, the present meta-analysis aimed to investigate the muscle activation of the lower limb muscles in individuals with DKV during single-leg and overhead squats. Methods: Articles with titles, abstracts, and full texts were searched and screened independently by two reviewers in the Web of Science, Scopus, PubMed, and Google Scholar databases, without restrictions on publication date and in English using specified keywords from their inception to January 5, 2024. The quality of articles was evaluated using a modified version of the Downs and Black quality checklist. This meta-analysis used mean difference (MD) to compare the muscle activity patterns between individual with DKV and healthy individuals. Heterogeneity was detected using I-square (I2) test. Results: In total, four papers with 130 participants were included in the study. Evidence showed a significant difference between the DKV group and the healthy group regarding the activities of the adductor magnus (MD: 6.25, P < 0.001), vastus medialis (MD: 13.23, P = 0.002), vastus lateralis (MD: 11.71, P = 0.004), biceps femoris (MD: 3.06, P = 0.003), and tibialis anterior muscles (MD: 8.21, P = 0.02). Additionally, muscle activity in the DKV group was higher than that in the healthy group. Conclusions: This meta-analysis reveals distinct muscle activation patterns in individuals with dynamic knee valgus (DKV), with increased activity in key muscles suggesting compensatory responses. These findings underscore the need for targeted rehabilitation to address muscle imbalances and improve knee stability. [ABSTRACT FROM AUTHOR]

Abstract Background Dynamic knee valgus (DKV) is a risk factor for non-contact anterior cruciate ligament (ACL) injuries. Understanding the changes in the electromyographic activity of the lower extremity muscles in individuals with DKV helps trainers design ACL injury prevention exercises. Therefore, the present meta-analysis aimed to investigate the muscle activation of the lower limb muscles in individuals with DKV during single-leg and overhead squats. Methods Articles with titles, abstracts, and full texts were searched and screened independently by two reviewers in the Web of Science, Scopus, PubMed, and Google Scholar databases, without restrictions on publication date and in English using specified keywords from their inception to January 5, 2024. The quality of articles was evaluated using a modified version of the Downs and Black quality checklist. This meta-analysis used mean difference (MD) to compare the muscle activity patterns between individual with DKV and healthy individuals. Heterogeneity was detected using I-square (I 2) test. Results In total, four papers with 130 participants were included in the study. Evidence showed a significant difference between the DKV group and the healthy group regarding the activities of the adductor magnus (MD: 6.25, P

Purpose: Past research supports the hypothesis that the position of basketball players affects their susceptibility to injury; however, there is disagreement among researchers regarding which positions are at greater risk of injury. The current study compares the lower limb joint angles in basketball players with dynamic knee valgus deficiency across different positions. Methods: In this study, 27 basketball players with dynamic knee valgus deficiency were purposefully selected in three groups as follows: Guards (mean age=19.77±2.68 years, mean height=1.77±0.04 cm, and mean weight=63.40±5.10 kg), forwards (mean age=20.22±2.90 years, mean height=187±0.04 cm, and mean weight=76.80±2.94 kg ) and centers (mean age=22.33±3.27years, mean height=1.99±0.04 cm, and mean weight=98.84±18.42 kg), within the age range of 16 to 26 years. The anthropometric characteristics of the players, including height, weight, shoulder width, hip width, anterior superior iliac spine distance, lower limb length, Q angle, knee width, and ankle width, were measured. To evaluate the lower limb angles in the sagittal and frontal planes, imaging was performed using two digital cameras at a distance of 366 cm and a height of 105 cm relative to the subject, and the subjects performed three countermovement jumps. The analysis was conducted using the Kinovea software. To compare the mean variables of the study, mixed-design analysis of variance (2×3), one-way analysis of variance, and the Bonferroni post hoc tests were utilized. All hypothesis tests were conducted at a significance level of P≤0.05. Results: There was no significant difference in the initial contact angle of the hip joint (P=0.537), maximum hip flexion (P=0.891), initial contact angle of the knee joint (P=0.264), maximum knee flexion (P=0.321), initial contact angle of the ankle joint (P=0.116), and maximum ankle flexion (P=0.393) among the three groups. Additionally, there was no significant difference in the initial contact angle of the knee joint in dominant (P=0.059) and non-dominant (P=0.490) legs, as well as in the maximum knee flexion in dominant (P=0.872) and non-dominant (P=0.552) legs. Conclusion: No significant differences were observed in the lower limb joint angles among the three groups of guards, forwards, and centers. Therefore, different basketball positions may not be a significant risk factor for non-contact anterior cruciate ligament injuries.

Objective Deficient movement patterns can alter the kinematics of lower limb during landing jump tasks, potentially leading to non-contact anterior cruciate ligament injuries. The aim of this study is to investigate the impact of an eight-week kinematic feedback training program on male athletes exhibiting selected movement control issues during jumping tasks. Methods This study is a randomized clinical trial conducted before and after the intervention. Thirty-four male recreational athletes with movement control deficiencies were chosen based on predetermined criteria and randomly assigned to either a control or feedback group in a 1:1 ratio. Kinematic variables were recorded in the sagittal and frontal planes while participants performed jumping and landing tasks before and after a two-month jump training program, with feedback provided to the feedback group and not to the control group. Data analysis utilized two-way analysis of variance and Bonferroni tests for each movement task, with significance set at P < 0.05. Results Results from the statistical analysis revealed that the eight-week feedback training program significantly influenced hip, knee, and ankle kinematics in athletes with motor control deficiencies during jump-landing tasks. Additionally, feedback was effective in reducing knee valgus. Conclusion The findings demonstrate that feedback effectively impacts kinematic parameters in both sagittal and frontal planes, suggesting its potential utility in correcting incomplete movement patterns during jump-landing tasks.

Purpose: Past research supports the hypothesis that the position of basketball players affects their susceptibility to injury; however, there is disagreement among researchers regarding which positions are at greater risk of injury. The current study compares the lower limb joint angles in basketball players with dynamic knee valgus deficiency across... [ABSTRACT FROM AUTHOR]

Purpose: The risk of anterior cruciate ligament (ACL) injuries in childhood has increased in recent decades and could be a major threat to a child's sports career. An increased risk of ACL injury is associated with dynamic knee valgus (DKV). Therefore, this study aimed to analyze the effect of an ACL injury protocol on the LESS, proprioception, and DKV of child soccer players. Methods: In this study, thirty male football players with DKV (mean ± SD: age 11.40 ± .72 years, weight 36.62 ± 4.68 kg, height 141.10 ± 3.98 m) were randomly assigned into two groups: control (n=15) and training (n=15). Single-leg landing, LESS, and knee joint proprioception tests were administered before and after the implementation of the training protocol. After identifying the variables, the training group performed the injury proprioception program for eight weeks, with three training sessions each lasting 20–25 minutes per week. The control group continued their normal warm-up routine. To examine the difference between the pre-test and post-test, repeated measures ANOVA was conducted using SPSS 26 software with a significance level of 0.05. Results: The results of the research showed that after eight weeks of the injury prevention program, there was a significant improvement in reducing the valgus angle of the knee (p=0.005, F=9.369, η²=0.251), reducing the LESS scores (p=0.002, F=12.374, η²=0.306) and improving proprioception (p=0.003, F=10.251, η²=0.268). Conclusion: According to the results of the research, it can be concluded that Stop-X injury prevention program can lead to improvements in knee valgus pattern, LESS and proprioception in child soccer players. Using the results of this research is recommended to soccer coaches and training experts.

Neuromuscular deficits at the proximal or distal to the knee may contribute to knee valgus and anterior cruciate ligament (ACL) injury. A valgus or abducted position of the knee greater than 12° for females is suggested to be an indicator of the risk of lower extremity injuries. However, there is a lack of examination regarding neuromuscular patterns in both proximal and distal kinetic chains. The purpose of this study was to investigate the effect of 8 weeks of neuromuscular training on knee valgus and co‐activation of the hip and ankle muscles during a countermovement jump in female athletes with a high risk of ACL injury. Twenty‐eight female athletes, with knee valgus greater than 12°, were randomly assigned into two groups: training (n = 14) and control (n = 14). The following measurements were taken before and after the intervention: co‐activation of Gluteus Maximus‐Tensor Fasciae Latae (GMax‐TFL), Gluteus Medius‐Adductor Longus (GMed‐AL), Tibialis Anterior‐Medial Gastrocnemius (TA‐MG), Tibialis Anterior‐Lateral Gastrocnemius (TA‐LG), Medial Gastrocnemius‐Lateral Gastrocnemius (MG‐LG) muscles, and DKV angle during single‐leg countermovement jump task. Following the intervention, the training group demonstrated increased co‐activation of muscles (except TA‐LG) (P < 0.05). The knee valgus angle in the training group decreased by 5.9° (P = 0.001). Our results demonstrated that neuromuscular training alters muscle activity patterns and the neuromuscular group demonstrated a clinically meaningful and statistical reduction in knee valgus. Highlights: Dynamic knee valgus (DKV) is a risk factor for identifying women with a risk of lower extremity injuries.Muscle activity patterns of the hip and ankle, such as DKV, may be modifiable through neuromuscular training.Neuromuscular training with feedback could reduce excessive DKV at a clinically meaningful level. [ABSTRACT FROM AUTHOR]

Background and Aims Dynamic knee valgus (DKV) and impaired static and dynamic balances are the risk factors of the anterior cruciate ligament injuries in football players. This study aims to investigate the effect of the knee control program on knee valgus angle and static and dynamic balances in young male football players with DKV. Methods This is a quasi-experimental study. Of 156 young male football players, 48 with DKV were recruited and randomly assigned to intervention group (n=24, Mean age=12.70±0.62 years, height=1.52±0.07 m, weight=48.87±6.67 kg, BMI=21.10±2.18 kg/m2) and control group (n=24, mean age=12.58±0.65 years, height= 1.52±0.08 m, weight= 50.45±6.79 kg, BMI=21.88±2.92 kg/m2). The drop-jump test, Stork test, and Y balance test were used to measure dynamic knee valgus angle, static balance, and dynamic balance, respectively. The intervention group received the knee control program as a warm-up exercise for 8 weeks, while the control group performed their routine warm-up exercises during this time. Analysis of covariance and the paired t-test were used to evaluate differences in the study variables. Results In the intervention group, there was a significant reduction in knee valgus angle (P=0.001) and significant improvements in static balance (P=0.001) and dynamic balance (P=0.001) in the post-test phase compared to the pre-test phase, but there were no significant differences in the control group (P>0.05). Moreover, the results showed significant differences between the two groups in knee valgus angle (P=0.001), static balance (P=0.001) and dynamic balance (P=0.002). Conclusion The knee control program is effective in reducing dynamic knee valgus angle and improving static and dynamic balances in young football players with DKV. Thus, it seems that this program can reduce the risk of anterior cruciate ligament injuries in young male football players. [ABSTRACT FROM AUTHOR]

Background and Aims: Dynamic knee valgus (DKV) is an abnormal pattern of movement or abnormal alignment of the lower limb that causes changes in lower limb function in the frontal plane and absorption of excessive reaction force by the knee ligaments during sports activities, which can increase the risk of anterior cruciate ligament injury. This study aims to compare the balance, strength, and range of motion (ROM) of hip and ankle joints in volleyball players with and without DKV. Methods: This is a quasi-experimental and causal-comparative study. Participants were 60 volleyball players (30 with DKV and 30 without DKV). The tuck jump test was used to evaluate their DKV. The ROM of knee and ankle joints was measured using a goniometer, while the isometric strength of the hip and ankle muscles was determined using a hand dynamometer. Then static and dynamic balances were evaluated by the Stork test and the Y balance test, respectively. Independent t-test was used to compare the means of variables between the two groups in SPSS software, version 24. Results: The results showed a significant difference in static balance (P=0.005), dynamic balance (P≤0.05), hip abduction strength (P=0.03), hip external rotation strength (P=0.01), and ROM of ankle dorsiflexion (P=0.03) between the two groups, where those without DKV performed better. The difference in other variables was not significant between the two groups. Conclusion: The results indicate the importance of improving hip abduction and hip external rotation strength as well as the ROM of ankle dorsiflexion for reducing the DKV, which should be considered in designing training protocols. [ABSTRACT FROM AUTHOR]

Background and Aims The present study aims to investigate the effect of a neuromuscular training program on knee valgus angle, and range of motion (ROM) and muscle strength of hip and ankle in male adolescent football players with dynamic knee valgus (DKV). Valgus knee is one of the most common neuromuscular abnormalities that is involved in causing non-contact damage to the anterior cruciate ligament (ACL).Methods This is a quasi-experimental study. Participants were 25 adolescent male football players with DKV who were purposefully selected from Shahin Football Academy in Amol, Iran and randomly divided into two groups of control and training. The existence of DKV was assessed by Squats test and the valgus angle were assessed by jump-landing test and Kinovea software. The abduction and external rotation strength and ROM of hip and the dorsiflexion and plantarflexion strength and ROM of ankle were evaluated with Manual Muscle Testing and a goniometer, respectively. After performing the pre-test assessments, the subjects in the training group performed neuromuscular training for 8 weeks, while the control group also participated in the physical fitness program of Shahin Football Academy. At the end, assessments were performed again in two groups. To examine the differences, repeated measures analysis of variance and Bonferroni post hoc test were used in SPSS software, version 24. The significance level was set at 0.05. Results The results showed a significant difference in knee valgus angle (P=0.001), abduction ROM of hip (P=0.01), external rotation ROM of hip (P=0.01), dorsiflexion ROM of ankle with knee extension (P=0.001), dorsiflexion ROM of ankle with knee flexion (P=0.001), hip abduction strength (P=0.002), hip external rotation strength (P=0.01), and plantarflexion strength of ankle (P=0.03) between the control and training groups. However, the results showed no significant difference in plantarflexion ROM of ankle and dorsiflexion strength of ankle (P>0.05). After one month, the results showed the sustainability of the effect of training on abduction and external rotation ROM of hip, dorsiflexion ROM of ankle with knee extension and flexion, and dorsiflexion and plantarflexion strength of ankle.Conclusion The neuromuscular training can reduce the risk of non-contact ACL injury in male football players with DKV by improving strength and ROM of hip and ankle.

Background and Aims Dynamic knee valgus, as a poor movement pattern, may increase the risk of injury in the knee joint. This condition, which is related to a deviation in the lower limb alignment, can cause serious damage to the knee joint during tasks such as jump-landing, especially when bearing weight. The present study aims to investigate the role of dynamic knee valgus (DKV) in occurrence of knee injuries.Methods This is a review study. A search was conducted for the related articles published in English or Persian using the keywords Dynamic Knee Alignment, Dynamic Knee Valgus, Knee Joint Kinematics, Medial Collapse, Medial Knee Displacement, Frontal Plane Knee Excursion, Projection Angle, Dynamic Lower Extremity Valgus and Knee Injury in Science Direct, Scopus, PEDro, Google Scholar, PubMed, SID, ISC, Medlib, MagIran and IranDoc databases published from 2005 to May 2021. Initial search yielded 230 articles. After examining their full texts, 67 related articles were remained. Finally, 34 articles in the field of the role of DKV in occurrence of common knee injuries were selected for the review. Results Most of the studies were conducted on women and young people (aged 16-25 years). The DKV cause knee injuries such as anterior cruciate ligament injury (21 studies), patellofemoral pain syndrome (7 studies), tibiofemoral osteoarthritis (4 studies) and patellofemoral osteoarthritis (one study) as well as other cases such as osteoarthritis of the inner knee, chronic pain injuries in the hip and knee joints, and cartilage injuries. Conclusion DKV, as a poor movement pattern, put a person at risk of lower limb injuries. Muscle imbalance, muscle weakness, and impairment in the static alignment and its effect on dynamic alignment are among the most important mechanisms of DKV. Due to the structural and biomechanical characteristics, the most injuries caused by DKV occur in women.

Abstract Background Dynamic knee valgus (DKV) is a multi-planar faulty movement pattern that can cause faulty postural control. The primary objective of this study is to investigate the differences in postural sway (PS) between individuals aged 18–30 years old diagnosed with and without DKV. Methods In this cross-sectional study, 62 students (39 males and 23 females) with and without DKV (age: 24.58 ± 2.63 years) were selected and assigned to two groups by conducting the single-leg squat test in the screening stage. The Biodex balance system was then employed to compare the two groups in PS. Mann–Whitney U test was conducted to compare the groups in PS (p ≤ 0.05). Results The study’s findings indicate that individuals with DKV did not exhibit any significant differences, compared to those without, about the anterior-posterior stability index (with p values for both static and dynamic situations at 0.309 and 0.198, respectively), medial-lateral stability index (with p values for both static and dynamic situations at 0.883 and 0.500, respectively), and overall stability index (with p values for both static and dynamic situations at 0.277 and 0.086, respectively). Conclusion Though several possible factors could contribute to the lack of significant differences in postural sway between individuals with and without DKV, such as measurement tool differences, variable sensitivity in postural stability tests, and differences in movement variability and test stance, we recommend analyzing postural sway in more functional tasks and with different methodological patterns in future studies. Such research could help develop targeted interventions for individuals with DKV and offer a better understanding of the relationship between postural control and DKV.

ObjectivesFatigue can decrease knee stability and increase the injury risk. However, fatigue is rarely being applied throughout movement analysis. The aim of this study was to investigate if the knee stability throughout SLDLs differ between cyclic and acyclic sports, before and after fatigue in general, and between the dominant and non-dominant leg of soccer players.MethodsA total of 43 active male (n = 34) and female (n = 9) athletes (age: 26.5 ± 7.2) participated in this study with a pre-post-design. Subjects performed a single leg drop landing (SLDL) from a plyobox. For each leg, the two-dimensional frontal plane projection angle (FPPA) was analyzed. After pretesting the shuttle run test was performed until exhaustion, before repeating the measurements.ResultsANOVA with repeated measures was applied and identified no significance difference for the FPPA between cyclic and acyclic sports (F = 0.98, p = 0.33), a significant difference before and after fatigue (F = 12.49, p = 0.002) and no significant difference between the dominant and non dominant leg of soccer players (F = 4.35, p = 0.26).DiscussionFatigue seems to be able to have a significant influence on knee stability in the frontal axis. Therefore, fatigue should be included in motion analysis for injury prevention and return to play tests because during this physical state most injuries happen.

Background: Dynamic knee valgus (DKV) is a multi-planar faulty movement pattern that can cause faulty postural control. The primary objective of this study is to investigate the differences in postural sway (PS) between individuals aged 18–30 years old diagnosed with and without DKV. Methods: In this cross-sectional study, 62 students (39 males and 23 females) with and without DKV (age: 24.58 ± 2.63 years) were selected and assigned to two groups by conducting the single-leg squat test in the screening stage. The Biodex balance system was then employed to compare the two groups in PS. Mann–Whitney U test was conducted to compare the groups in PS (p ≤ 0.05). Results: The study's findings indicate that individuals with DKV did not exhibit any significant differences, compared to those without, about the anterior-posterior stability index (with p values for both static and dynamic situations at 0.309 and 0.198, respectively), medial-lateral stability index (with p values for both static and dynamic situations at 0.883 and 0.500, respectively), and overall stability index (with p values for both static and dynamic situations at 0.277 and 0.086, respectively). Conclusion: Though several possible factors could contribute to the lack of significant differences in postural sway between individuals with and without DKV, such as measurement tool differences, variable sensitivity in postural stability tests, and differences in movement variability and test stance, we recommend analyzing postural sway in more functional tasks and with different methodological patterns in future studies. Such research could help develop targeted interventions for individuals with DKV and offer a better understanding of the relationship between postural control and DKV. [ABSTRACT FROM AUTHOR]

Abstract Background The performing of jump and landing in futsal simultaneous with divided attention is one of the most common mechanisms of non-contact anterior cruciate ligament (ACL) injury. Neuromuscular training has effectively reduced the risk of ACL injury, but the effect of neurocognitive training has received less attention. This study investigated the effect of combining 8 weeks of neuromuscular training with dual cognitive tasks on the landing mechanics of futsal players with knee ligament dominance defects. Methods Thirty male futsal players (mean ± SD: age: 21.86 ± 3.27 years) with knee ligament dominance defects were purposefully identified by the tuck jump test and were randomly divided into the intervention and the control group. The intervention group performed dual task (DT) training for three weekly sessions for 8 weeks and 60 min each, while the control group only did activities of daily living. During the drop vertical jump test, 2D landing kinematics in two moments of initial contact (IC) and full flexion (FF) were assessed. Data were analyzed by means of 2 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of (α ≤ 0.05). Results A significant improvement was observed in the intervention group compared to the control group for the dynamic knee valgus at IC (F1,28 = 6.33; P = 0.02, ES = 0.31) and FF (F1,28 = 13.47; P = 0.003, ES = 0.49), knee flexion at IC (F1,28 = 20.08; P = 0.001, ES = 0.41) and FF (F1,28 = 13.67; P = 0.001, ES = 0.32), ankle dorsiflexion at IC (F1,28 = 37.17; P = 0.001, ES = 0.72) and FF (F1,28 = 14.52; P = 0.002, ES = 0.50), and trunk flexion at FF (F1,28 = 20.48; P = 0.001, ES = 0.59) angles. Changes in the trunk flexion at IC (F1,28 = 0.54; P = 0.47, ES = 0.03) and trunk lateral flexion at IC (F1,28 = 0.006; P = 0.93, ES = 0.00) and FF (F1,28 = 2.44; P = 0.141, ES = 0.148) angles were not statistically significant. Conclusions DT training compared to the control group improved landing mechanics in futsal players with knee ligament dominance defects. Trial registration: Current Controlled Trials using the IRCT website with ID number IRCT20210602051477N1 prospectively registered on 20/06/2021.

Highlights The CCEP can improve lower extremity kinematics and muscle strength in people with DKV. Proximal and distal segments should be considered simultaneously for improving DKV. The CCEP is recommended to improve DKV.

The aim of this study was to compare the muscle activity of the gluteus medius (GMe), gluteus maximus (GMa), biceps femoris (BF), vastus lateralis (VL), vastus medialis (VM) and erector spinae (ES) as well as medial knee displacement (MKD) while using varying stiffness resistance bands (red: 1.68 kg; black: 3.31 kg; gold: 6.44 kg) during a barbell back squat (BBS) among males and females. A total of 23 (females: 11) resistance trained people were recruited for this study. Muscle activity was measured using electromyography, and motion capture cameras tracked lower-limb kinematics and MKD. Three resistance bands were placed at the distal end of the femur while performing a BBS at their 85% repetition maximum (RM). Parametric and non-parametric statistical analyses were conducted with the alpha level of 0.05. The gold resistance band resulted in a smaller knee-width-index value (i.e., greater MKD) compared to other bands (p < 0.01). Males exhibited less MKD compared to females during the BBS for each resistance band (p = 0.04). Males produced greater VL activity when using the black and gold resistance bands during the BBS (p = 0.03). When using a gold resistance band, the GMe muscle activation was higher compared to other resistance bands (p < 0.01). VM muscle activity was reduced when using a gold resistance band compared to no band condition (p < 0.01). BF (p = 0.39) and ES (p = 0.88) muscle activity did not change when using different resistance bands. As a result, females may be at a biomechanical disadvantage when using resistance bands compared to males while performing the BBS hindering them from optimal performance. [ABSTRACT FROM AUTHOR]

Background: The performing of jump and landing in futsal simultaneous with divided attention is one of the most common mechanisms of non-contact anterior cruciate ligament (ACL) injury. Neuromuscular training has effectively reduced the risk of ACL injury, but the effect of neurocognitive training has received less attention. This study investigated the effect of combining 8 weeks of neuromuscular training with dual cognitive tasks on the landing mechanics of futsal players with knee ligament dominance defects. Methods: Thirty male futsal players (mean ± SD: age: 21.86 ± 3.27 years) with knee ligament dominance defects were purposefully identified by the tuck jump test and were randomly divided into the intervention and the control group. The intervention group performed dual task (DT) training for three weekly sessions for 8 weeks and 60 min each, while the control group only did activities of daily living. During the drop vertical jump test, 2D landing kinematics in two moments of initial contact (IC) and full flexion (FF) were assessed. Data were analyzed by means of 2 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of (α ≤ 0.05). Results: A significant improvement was observed in the intervention group compared to the control group for the dynamic knee valgus at IC (F1,28 = 6.33; P = 0.02, ES = 0.31) and FF (F1,28 = 13.47; P = 0.003, ES = 0.49), knee flexion at IC (F1,28 = 20.08; P = 0.001, ES = 0.41) and FF (F1,28 = 13.67; P = 0.001, ES = 0.32), ankle dorsiflexion at IC (F1,28 = 37.17; P = 0.001, ES = 0.72) and FF (F1,28 = 14.52; P = 0.002, ES = 0.50), and trunk flexion at FF (F1,28 = 20.48; P = 0.001, ES = 0.59) angles. Changes in the trunk flexion at IC (F1,28 = 0.54; P = 0.47, ES = 0.03) and trunk lateral flexion at IC (F1,28 = 0.006; P = 0.93, ES = 0.00) and FF (F1,28 = 2.44; P = 0.141, ES = 0.148) angles were not statistically significant. Conclusions: DT training compared to the control group improved landing mechanics in futsal players with knee ligament dominance defects. Trial registration: Current Controlled Trials using the IRCT website with ID number IRCT20210602051477N1 prospectively registered on 20/06/2021. [ABSTRACT FROM AUTHOR]

Introduction: The analysis of movement quality is important for better exercise prescription. This study tested the reproducibility of a protocol for remote assessment of dynamic knee alignment using images taken by patients. Methods: Thirteen women filmed themselves performing single-leg squats on two days at a 15-day interval. Three raters measured the knee frontal plane projection angle using the resultant images. Results: Two participants (15.4%) were excluded for not performing the protocol correctly. The intraclass correlation coefficient was between 0.880 and 0.999 for the intra-rater comparison, and between 0.817 and 0.987 for the inter-rater comparison. Discussion: The success of the protocol in 84.6% of participants and the excellent reproducibility suggest that the methodology of analyzing patient-captured cell phone images might be a plausible alternative for remote evaluation of dynamic knee alignment.

Purpose: One of the most significant contributors to lower extremity degeneration alterations and its effects on balance and sports performance is dynamic knee valgus (DKV) as a faulty movement pattern. Different exercise interventions have been conducted to improve DKV. Extensive research and meta-objective analysis were conducted to assess how exercise interventions affected people with lower extremity functional indicators of DKV. Methods: The electronic databases Scopus, Web of Science (WoS), PubMed, Google Scholar, and Iranian databases SID and Magiran were systematically searched from inception to September 2021. Only full-text articles published in English/Persian peer-reviewed journals that met this study criterion were tracked. Two researchers evaluated the methodological quality of research findings separately, employing the Downs and Black Checklist. After collecting significant data from eligible studies, the results were integrated by applying a random-effects meta-analysis approach. Results: The final systematic review and meta-analysis comprised seven of the 3470 papers deemed potentially relevant. The outcome illustrates that different exercise interventions may be effective in improving dynamic balance (SD=0.93 degrees, 95%CI: 0.54-1.32, P<0.001) and functional performance (Hedge's g=1.695, 95% CI=1.22-2.17, Z=6.99, P<0.001) in 250 DKV participants. Conclusion: Exercise interventions appear to be an effective method to enhance dynamic balance and functional performance in individuals experiencing DKV; nevertheless, these results should be regarded as preliminary due to the limited number of studies and their limitations. [ABSTRACT FROM AUTHOR]

Introduction: The analysis of movement quality is important for better exercise prescription. This study tested the reproducibility of a protocol for remote assessment of dynamic knee alignment using images taken by patients. Methods: Thirteen women filmed themselves performing single-leg squats on two days at a 15-day interval. Three raters measured the knee frontal plane projection angle using the resultant images. Results: Two participants (15.4%) were excluded for not performing the protocol correctly. The intraclass correlation coefficient was between 0.880 and 0.999 for the intra-rater comparison, and between 0.817 and 0.987 for the inter-rater comparison. Discussion: The success of the protocol in 84.6% of participants and the excellent reproducibility suggest that the methodology of analyzing patient-captured cell phone images might be a plausible alternative for remote evaluation of dynamic knee alignment. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament (ACL) injuries are caused by both contact and non-contact injuries. However, it can be claimed that non-contact ones account approximately for 70% of all cases. Thus, several authors have emphasized the role of reduction of muscle strength as a modifiable risk factor referred to non-contact ACL injury, with the latter being targeted by specific training interventions. The present paper wants to review the available literature specifically on the relationship between dynamic knee valgus, gluteal muscles (GM) strength, apart from the potential correlation regarding ACL injury. After a research based on MEDLINE via PubMed, Google scholar, and Web of Science, a total of 29 articles were collected and thus included. Additionally, this review highlights the crucial role of gluteal muscles in maintaining a correct knee position in the coronal plane during different exercises, namely walking, running, jumping and landing. [ABSTRACT FROM AUTHOR]

Objective: Dynamic Knee Valgus (DKV) causes many acute and chronic knee injuries during deceleration and landing in sports activities and can affect the athletes’ specific skills. This study aims to investigate the effect of 6 weeks of progressive jump-landing training on jump shooting accuracy and knee valgus angle in male basketball players with DKV. Methods: This is a quasi-experimental study conducted on 24 male basketball players with DKV in Mazandaran, who were selected purposefully. They were randomly divided into training and control groups. Their jump shooting accuracy was assessed by Boddington’s Basketball Jump Shooting Accuracy Test, and their DKV angle was measured by a two-dimensional evaluation method in Quinoa software. In addition to their routine exercises, the training group performed the jump-landing training for 6 weeks at 3 sessions per week, while the control group performed their usual exercises only. In order to compare the two study groups, ANCOVA was used. Results: The progressive jump-landing program had a significant effect on jump shooting accuracy (P=0.001) and DKV angle (P=0.001). Conclusion: Six weeks of progressive jump-landing training can improve the jump shooting accuracy and knee valgus angle in basketball players with DKV. Therefore, jump landing exercises are recommended for improving the jump shooting skill and knee alignment in these athletes.

Background: Dynamic knee valgus (DKV) is a prevalent movement impairment widely regarded as a risk factor for lower extremity disorders such as patellofemoral pain syndrome. The present study aimed to investigate the effectiveness of the comprehensive corrective exercise program (CCEP) on kinematics and strength of lower extremities in males with DKV.Methods: Thirty asymptomatic young men with DKV between the ages of 18 and 28 years participated in this study. They were randomly assigned to the intervention (n = 15) and control groups (n = 15). The intervention group performed the CCEP for three sessions per week for eight weeks, while the control group only did activities of daily living. Hip external rotator and abductor muscle strength and three-dimensional lower extremity kinematics consisting of knee varus/valgus, femur adduction/abduction, femur medial/lateral rotation, and tibial medial/lateral rotation were measured at the baseline and post-test. The data were analyzed using the analysis of covariance (ANCOVA).Results: There were significant improvements in all kinematics variables in the intervention group after the 8-week CCEP. Moreover, the strength of abductor and external rotator muscle improved in the intervention group (P < 0.05).Conclusions: The CCEP led to substantial improvements in the selected variables of lower extremity kinematics and muscle strength in participants with DKV during a single-leg squat. These results imply that practitioners should adopt a comprehensive approach to pay simultaneous attention to both proximal and distal segments for improving DKV.Trial Registration: The protocol has been approved in the Registry of Clinical Trials (Registration N: IRCT20180821040843N1 ) on 2018-12-30. [ABSTRACT FROM AUTHOR]

In physiotherapy, there is still a lack of practical measurement options to track the progress of therapy or rehabilitation following injuries to the lower limbs objectively and reproducibly yet simply and with minimal effort and time. We aim at filling this gap with the design of an IMU (inertial measurement unit) system with only one sensor placed on the tibia edge. In our study, the IMU system evaluated a set of 10 motion tests by a score value for each test and stored them in a database for a more reliable longitudinal assessment of the progress. The sensor analyzed the different motion patterns and obtained characteristic physiological parameters, such as angle ranges, and spatial and angular displacements, such as knee valgus under load. The scores represent the patient's coordination, stability, strength and speed. To validate the IMU system, these scores were compared to corresponding values from a simultaneously recorded marker-based 3D video motion analysis of the measurements from five healthy volunteers. Score differences between the two systems were almost always within 1–3 degrees for angle measurements. Timing-related measurements were nearly completely identical. The tests on the valgus stability of the knee showed equally small deviations but should nevertheless be repeated with patients, because the healthy subjects showed no signs of instability. [ABSTRACT FROM AUTHOR]

Objective: Dynamic Knee Valgus is a common risk factor for acute lower extremity injuries and overuse. Studies on new training methods to improve motor function and strengthen the knee and thigh joint muscles are also ongoing. The purpose of this study was to compare the effect of conventional resistance training with and without Methods: This study was quasi-experimental. The present study’s statistical population consisted of active women with dynamic valgus deformity of the knee in Chalous (Mazandaran Province, Iran) aged 18-28. Thirty-six women with dynamic knee valgus were purposefully selected as the research Participants. Subjects were evaluated for patellar orientation with a goniometer, static and dynamic balance through stork and y tests, and lower limb strength with the Sargent jump test. Subjects were randomly divided into three groups: control, conventional resistance training without restricting blood flow, and traditional resistance training restricting blood flow. They also gave training sessions for 8 weeks in three sessions per week. Results: The results showed a positive effect of exercise programs on static balance (P=0.001), dynamic balance (P=0.001), patellar alignment, and lower limb strength (P=0.001) in women with dynamic knee defects. Also, the results of covariance analysis showed a significant difference between control and training groups. Conclusion: The present study results show a significant effect of the strength training program with and without restricting blood flow on improving patellar direction, static and dynamic balance, and lower limb strength of active women. It seems that active women can use these exercise programs to improve performance and reduce injury risk.

The purpose of this study was to test the hypothesis that Dynamic Knee Valgus (DKV) decreased performance in the Countermovement Jump (CMJ) and the Squat Jump (SJ) in judo athletes. Anthropometric measurements of body mass and height were collected, the DKV was analyzed during the Step-Down Test, and the power of the lower limbs was assessed using a contact platform during the CMJ and the SJ. The sample consisted of 39 male judo athletes of which 61.5% had DKV. In the analysis of the maximum height reached between the CMJ and the SJ in the group without DKV, significant differences (P<0.05) and a large effect size (Cohen's d = 1.55) were observed. In the group with DKV, no significant differences were found (P>0.05), in addition to a small effect size (Cohen's d = 0.47). In muscle power, significant differences were observed in the intergroup CMJ (P<0.05) and between the CMJ and the SJ in the group without DKV (P<0.05). Hence, it appears that DKV does not reduce performance in the countermovement jump and the squat jump. [ABSTRACT FROM AUTHOR]

Introduction: Patellofemoral pain syndrome (PFPS) is a common problem that particularly affects active young people. In these patients, dynamic knee valgus causes hip and knee kinematic changes. Therefore, the reduction of dynamic valgus angle is one of the rehabilitation strategies in people with PFPS. The objective of this study was to evaluate the immediate effect of a medial wedge insole and knee orthosis on the knee pain and knee movement during walking and squat on involved side in people with PFPS.Materials and Methods: 15 volunteers with PFPS participated in this crossover clinical study. All participants signed the consent form and then were evaluated in four random conditions (without orthosis, medial wedge, medial wedge in combination with knee brace, and knee brace). The kinematics and kinetics of the lower limb were studied during walking and single-leg squat. Data analysis was performed using repeated measures statistical analysis of variance (ANOVA).Results: The knee brace, knee brace with medial wedge, and medial wedge significantly reduced the pain of affected leg after single-leg squat (P = 0.001). The walking speed (P = 0.067) and dynamic knee valgus angle (P = 0.490) did not significantly change in four different modalities of intervention. The peak moment of the knee in frontal plane was significantly increased in three conditions [medial wedge (P = 0.001), knee brace (P = 0.008), and knee brace in combination with medial wedge (P = 0.033)] compared with the control condition.Conclusion: Use of medial wedge and neoprene knee brace can decrease pain and improve the biomechanical performance of people with PFPS. The use of these interventions can cause positive biomechanical effects on the lower limb.

Abstract Anterior cruciate ligament (ACL) injuries are caused by both contact and non‐contact injuries. However, it can be claimed that non‐contact ones account approximately for 70% of all cases. Thus, several authors have emphasized the role of reduction of muscle strength as a modifiable risk factor referred to non‐contact ACL injury, with the latter being targeted by specific training interventions. The present paper wants to review the available literature specifically on the relationship between dynamic knee valgus, gluteal muscles (GM) strength, apart from the potential correlation regarding ACL injury. After a research based on MEDLINE via PubMed, Google scholar, and Web of Science, a total of 29 articles were collected and thus included. Additionally, this review highlights the crucial role of gluteal muscles in maintaining a correct knee position in the coronal plane during different exercises, namely walking, running, jumping and landing.

Three-dimensional (3D) motion capture systems have been used to identify athletes in high risk of injury, but due to their cost, lack of portability and qualified technicians, an alternative is needed, such as two-dimensional (2D) systems. The purpose of this study was to examine the criterion-related validity of three measures of frontal plane knee alignment (Frontal plane projection angle [FPPA], knee-to-ankle separation ratio [KASR] and knee medial displacement [KMD]) and two sagittal plane measures (hip and knee flexion ranges of motion [ROMs]), recorded simultaneously using a 2D video analysis procedure and a 3D motion analysis system. Twenty-nine male futsal players had frontal and sagittal plane kinematics assessed while performing bilateral drop vertical jumps (DVJ). The criterion-related validity of the frontal and sagittal plane kinematic measures obtained using the 2D video analysis procedure and 3D motion system was determined through the estimation equation, typical error of the estimate (TEEST) and validity correlation (r). Kappa correlations were also calculated to determine the agreement between the 2D and 3D kinematic approaches. The results showed poor validity for the FPPA measure (standardized TEEST = 1.34 [large], r = 0.60) and moderate validity for KASR (standardized TEEST = 0.88 [moderate], r = 0.77), KMD (standardized TEEST = 0.53 [small], r = 0.88), hip flexion ROM (standardized TEEST = 0.62 [moderate], r = 0.85) and knee flexion ROM (standardized TEEST = 0.56 [small], r = 0.87) measures. However, only the KMD and knee flexion ROM measures showed high levels of agreement (kappa > 0.7). Therefore, the KMD and knee flexion ROM measures calculated during a bilateral DVJ and using a 2D video analysis procedure might be considered as valid and feasible alternatives to their respective 3D criterion to quantify knee kinematics and to detect futsal players who demonstrated aberrant movement patterns in the frontal and sagittal planes, respectively.

Squats, ascending and descending stairs, and lunges are three functional movements popularly used in clinical rehabilitation. This study aimed to analyze the validity of the Kinect v2 for assessing the kinematics of three functional knee movements. An intelligent program was developed for real-time kinematic evaluation of the knee joint using the Kinect v2 system. Based on image recognition technology, images from the Kinect v2 depth camera were used to develop a kinematic evaluation program for knee joint movements. The kinematics of 30 healthy volunteers during stair ascent and descent, squatting, and lunging movements were collected synchronously with both VICON and Kinect systems. The peak knee angles in the sagittal and coronal planes were extracted and analyzed. A paired samples t-test and the relative coefficient within the groups were used for statistical analysis of the validity of the Kinect compared to the VICON. There was no significant difference (p ​> ​0.05) in bilateral knee flexion angle when lunging. No significant difference (p ​> ​0.05) was found in left knee flexion during squatting exercises. Although the Kinect generally underestimated knee flexion and valgus, it displayed excellent consistency and good to excellent agreement with the VICON motion analysis system. The results demonstrated that the Kinect based measurement tool for analyzing knee kinematics has the potential to be an effective clinical training device for maintaining knee alignment during exercise.

Three-dimensional (3D) motion capture systems have been used to identify athletes in high risk of injury, but due to their cost, lack of portability and qualified technicians, an alternative is needed, such as two-dimensional (2D) systems. The purpose of this study was to examine the criterion-related validity of three measures of frontal plane knee alignment (frontal plane projection angle [FPPA], knee-to-ankle separation ratio [KASR] and knee medial displacement [KMD]) and three sagittal plane measures (hip, knee and ankle flexion ranges of motion [RoMs]), recorded simultaneously using a 2D video analysis procedure and a 3D motion analysis system. Twenty-nine male futsal players had frontal and sagittal plane kinematics assessed while performing bilateral drop vertical jumps (DVJ). The criterion-related validity of the frontal and sagittal plane kinematic measures obtained using the 2D video analysis procedure and 3D motion system was determined through the estimation equation, typical error of the estimate (TEEST) and validity correlation (r). Kappa correlations were also calculated to determine the agreement between the 2D and 3D kinematic approaches. The results showed poor validity for the FPPA measure (standardized TEEST = 1.57 [large], r = 0.54) and ankle flexion RoM (standardized TEEST = 2.48 [large], r = 0.37) and moderate validity for KASR (standardized TEEST = 0.88 [moderate], r = 0.77), KMD (standardized TEEST = 0.44 [small], r = 0.91), hip flexion RoM (standardized TEEST = 0.67 [moderate], r = 0.83) and knee flexion RoM (standardized TEEST = 0.58 [small], r = 0.87) measures. However, only the KMD and knee flexion RoM measures showed high levels of agreement (kappa > 0.7). Therefore, the KMD and knee flexion RoM measures calculated during a bilateral DVJ and using a 2D video analysis procedure might be considered as valid and feasible alternatives to their respective 3D criterion to quantify knee kinematics and to detect futsal players who demonstrated aberrant movement patterns in the frontal and sagittal planes, respectively. [ABSTRACT FROM AUTHOR]

Featured Application: Lateral disposition of the knee under load in the single-leg squat (SLS) test is widely used for screening functional instabilities of the knee under load, which is associated with elevated risk of lower limb injuries and early onset of osteoarthritis. We identified that approximation of the Quadriceps angle at the lowest point of squat is error-prone and not suitable for comparing patients or monitoring progress, as it is highly dependent on squat depth and muscle strength. The current study shows that the Kinect Azure–based Dynaknee software is able to simultaneously measure squat depth and the dynamic valgus position of the knee. We suggest that valgus shift, measured at 15% squat depth and expressed in percentage of lower limb length, may be a more reliable parameter for evaluating dynamic valgus in an orthopedic or physical therapy office. (1) Dynamic knee valgus is a predisposing factor for anterior cruciate ligament rupture and osteoarthritis. The single-leg squat (SLS) test is a widely used movement pattern test in clinical practice that helps to assess the risk of lower-limb injury. We aimed to quantify the SLS test using a marker-less optical system. (2) Kinect validity and accuracy during SLS were established by marker-based OptiTrack and MVN Xsens motion capture systems. Then, 22 individuals with moderate knee symptoms during sports activities (Tegner > 4, Lysholm > 60) performed SLS, and this was recorded and analyzed with a Kinect Azure camera and the Dynaknee software. (3) An optical sensor coupled to an artificial-intelligence-based joint recognition algorithm gave a comparable result to traditional marker-based motion capture devices. The dynamic valgus sign quantified by the Q-angle at the lowest point of the squat is highly dependent on squat depth, which severely limits its comparability among subjects. In contrast, the medio-lateral shift of the knee midpoint at a fixed squat depth, expressed in the percentage of lower limb length, is more suitable to quantify dynamic valgus and compare values among individual patients. (4) The current study identified a new and reliable way of evaluating dynamic valgus of the knee joint by measuring the medial shift of the knee-over-foot at a standardized squat depth. Using a marker-less optical system widens the possibilities of evaluating lower limb functional instabilities for medical professionals. [ABSTRACT FROM AUTHOR]

In physiotherapy, there is still a lack of practical measurement options to track the progress of therapy or rehabilitation following injuries to the lower limbs objectively and reproducibly yet simply and with minimal effort and time. We aim at filling this gap with the design of an IMU (inertial measurement unit) system with only one sensor placed on the tibia edge. In our study, the IMU system evaluated a set of 10 motion tests by a score value for each test and stored them in a database for a more reliable longitudinal assessment of the progress. The sensor analyzed the different motion patterns and obtained characteristic physiological parameters, such as angle ranges, and spatial and angular displacements, such as knee valgus under load. The scores represent the patient’s coordination, stability, strength and speed. To validate the IMU system, these scores were compared to corresponding values from a simultaneously recorded marker-based 3D video motion analysis of the measurements from five healthy volunteers. Score differences between the two systems were almost always within 1–3 degrees for angle measurements. Timing-related measurements were nearly completely identical. The tests on the valgus stability of the knee showed equally small deviations but should nevertheless be repeated with patients, because the healthy subjects showed no signs of instability.

Introduction: Hip muscle strength has a good component to improve the execution of movement preventing excessive knee movements, such as dynamic valgus, which is a factor related to ACL injuries, however, the relationship between isometric torque and dynamic valgus is not yet well established. Functional tests that resemble sports have been used for movement analysis and possible injury minimizing factor. Objectives: To compare the knee medialization peak in three kinematic tests with different demands, and its correlation with the isometric torque of the abductors and hip extensors. Methods: The isometric torque was collected by the Lafayette hand dynamometer. Two-dimensional kinematics were used to evaluate three functional tests of different requirements, Single Limb Squat, Lateral Step Down Test and Single Leg Drop Landing Tests. For comparison between values we used the Student T test and for correlation the Spearman test, with p < 0.05. Results: No significant differences were found between the three right kinematic tests, different from the left. And no relationship was established between the isometric hip torque and none of the three kinematic tests. Conclusion: There is no correlation between the dynamic knee valgus peak during different tests. It is concluded that the isometric torque test does not seem to be as sensitive when related to functional tests, but it has good applicability for comparing strength between limbs.

Objective: The purpose of this study was investigate the effect of dynamic knee valgus during overhead squat, on hip and ankle joints muscle strength and range of motion in basketball players. Methods: In this study 35 healthy basketball players (with the mean age 20.98± 1.99, height 183.27 ± 6.64 cm and mass 75.31 ± 9.24 kg), in the control group (n = 18) and dynamic knee valgus group (n = 17) with no lower-extremity injury during the last year were the volunteers. The peak force and the passive range of motion were measured rspecively by a hand-held dynamometer and a goniometer. The Independent T-test at the significance level of 0.05 was used to determine the difference of strength and range of motion in the control and dynamic knee valgus groups. Results: Compared by the control group, the dynamic knee valgus group showed to have a greater strength of the hip external rotation and extension (respectively P=0.000, P=0.004), smaller Plantarflextion strength (P=0.001), smaller dorsiflexion range of motion with knee bent (P=0.021), and greater external rotation of the hip (P=0.002). Conclusions: The results showed that the dynamic knee valgus group exhibited tight and weak ankle musculature, and as appeared, training interventions focused on improving strength and range of motion of the ankle can improve lower extremity kinematics of during overhead squat and modify dynamic knee valgus.

Background: Dynamic knee valgus (DKV) is defined as a combination of excessive femoral adduction, internal rotation, tibial internal torsion, and the medial movement of the knee. It appears that the athletes with DKV are at higher risk of developing knee injuries. Objective: The aim of this study was to evaluate whether the reactive neuromuscular training would improve whole-body dynamic balance and knee joint position sense (JPS) in women with the dynamic knee valgus. Methods: A controlled laboratory study was conducted on 28 female athletes with DKV. The single leg squat test was used to assess the DKV. All participants performed the reactive neuromuscular training, stationary cycling and resting sessions on three different days in a random order. The knee JPS and balance in the participants were measured immediately before and after the interventions. Kinematic analysis was used to measure the knee JPS in sagittal and frontal planes. In this regard, captured photos in the sagittal and frontal planes were analyzed using Kinovea software. The Y-balance test was applied to measure the balance. The data were analyzed by the repeated measures analysis of variance with a Bonferroni correction. Results: The results of the repeated measures analysis of variance showed that there was a significant difference between the sessions with respect to knee JPS in sagittal (F(2, 54) = 3.323, p = .047) and frontal (F(2, 54) = 23.83, p = .001) planes, respectively. Also, a significant difference in Y-balance test scores was observed between the sessions (F(2, 54) = 9.12, p = .001). Conclusions: The results of this study showed that reactive neuromuscular training improved joint position sense and balance in individuals with DKV. The findings of this study may provide a basis for developing injury prevention and rehabilitation strategies in athletes with DKV. [ABSTRACT FROM AUTHOR]

The authors convey their thoughts on the framework for optimizing anterior cruciate ligament (ACL) rehabilitation using a global systems approach. Topics mentioned include the annual incidence of ACL injuries in the U.S., greater medial knee displacement during landing, and single leg squat progression using the trunk as the lever for triaxial resistance.

Context: Increased frontal-plane knee motion during functional tasks, or medial knee displacement, is a predictor of noncontact anterior cruciate ligament injury and patellofemoral pain. Intervention studies that resulted in a reduced risk of knee injury included some form of feedback to address aberrant lower extremity movement patterns. Research on integrating feedback into single-legged tasks and the ability to train 1 task and test another is limited. Objective: To determine if adding real-time visual biofeedback to common lower extremity exercises would improve single-legged landing mechanics in females with medial knee displacement. Design: Cohort study. Setting: University laboratory. Patients or Other Participants: Twenty-four recreationally active females with medial knee displacement were randomized to a visual-biofeedback group (n = 12; age = 19.75 ± 0.87 years, height = 165.32 ± 8.69 cm, mass = 62.41 ± 8.91 kg) or a control group (n = 12; age = 19.75 ± 0.97 years, height = 166.98 ± 6.89 cm, mass = 59.98 ± 6.24 kg). Intervention(s): Individuals in the feedback group viewed a real-time digital model of their body segments generated by Microsoft Kinect. The skeletal model changed color according to the knee-abduction angle of the test limb during the exercise tasks. Main Outcome Measure(s): Participants completed 3 trials of the single-legged drop vertical jump (SL-DVJ) while triplanar kinematics at the trunk, hip, knee, and ankle were collected via 3-dimensional motion capture. The feedback and control groups completed lower extremity exercises with or without real-time visual biofeedback, respectively. After the intervention, participants completed 3 additional trials of the SL-DVJ. Results: At baseline, the feedback group had 3.83° more ankle eversion than the control group after initial contact. After the intervention, the feedback group exhibited 13.03° more knee flexion during the flight phase of the SL-DVJ and 6.16° less knee abduction after initial contact than the control group. The feedback group also demonstrated a 3.02° decrease in peak knee-abduction excursion compared with the baseline values (P = .008). Conclusions: Real-time visual biofeedback immediately improved faulty lower extremity kinematics related to knee-injury risk. Individuals with medial knee displacement adjusted their movement patterns after a single training session and reduced their medial knee motion during a dynamic task. [ABSTRACT FROM AUTHOR]

(1) Dynamic knee valgus is a predisposing factor for anterior cruciate ligament rupture and osteoarthritis. The single-leg squat (SLS) test is a widely used movement pattern test in clinical practice that helps to assess the risk of lower-limb injury. We aimed to quantify the SLS test using a marker-less optical system. (2) Kinect validity and accuracy during SLS were established by marker-based OptiTrack and MVN Xsens motion capture systems. Then, 22 individuals with moderate knee symptoms during sports activities (Tegner > 4, Lysholm > 60) performed SLS, and this was recorded and analyzed with a Kinect Azure camera and the Dynaknee software. (3) An optical sensor coupled to an artificial-intelligence-based joint recognition algorithm gave a comparable result to traditional marker-based motion capture devices. The dynamic valgus sign quantified by the Q-angle at the lowest point of the squat is highly dependent on squat depth, which severely limits its comparability among subjects. In contrast, the medio-lateral shift of the knee midpoint at a fixed squat depth, expressed in the percentage of lower limb length, is more suitable to quantify dynamic valgus and compare values among individual patients. (4) The current study identified a new and reliable way of evaluating dynamic valgus of the knee joint by measuring the medial shift of the knee-over-foot at a standardized squat depth. Using a marker-less optical system widens the possibilities of evaluating lower limb functional instabilities for medical professionals.

Objectives: Fatigue can decrease knee stability and increase the injury risk. However, fatigue is rarely being applied throughout movement analysis. The aim of this study was to investigate if the knee stability throughout SLDLs differ between cyclic and acyclic sports, before and after fatigue in general, and between the dominant and non-dominant leg of soccer players., Methods: A total of 43 active male ( n  = 34) and female ( n  = 9) athletes (age: 26.5 ± 7.2) participated in this study with a pre-post-design. Subjects performed a single leg drop landing (SLDL) from a plyobox. For each leg, the two-dimensional frontal plane projection angle (FPPA) was analyzed. After pretesting the shuttle run test was performed until exhaustion, before repeating the measurements., Results: ANOVA with repeated measures was applied and identified no significance difference for the FPPA between cyclic and acyclic sports ( F  = 0.98, p  = 0.33), a significant difference before and after fatigue ( F  = 12.49, p  = 0.002) and no significant difference between the dominant and non dominant leg of soccer players ( F  = 4.35, p  = 0.26)., Discussion: Fatigue seems to be able to have a significant influence on knee stability in the frontal axis. Therefore, fatigue should be included in motion analysis for injury prevention and return to play tests because during this physical state most injuries happen., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Becker, Simon, Dindorf, Dully, Bartaguiz, Schmitz, Kothe, Fröhlich and Ludwig.)

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More than 70% of all knee injuries in soccer occur in non-contact situations. It is known that increased lower limb dynamic knee valgus is associated with such situations. Little has been found out about differences in knee kinematics of the dominant (kicking) and non-dominant (supporting) leg during a single leg landing. A total of 114 male adolescent soccer players (age 14.6 ± 1.1 years) from elite (N = 66) and amateur soccer clubs (N = 48) performed a single leg drop landing down from a box. For each leg, the two-dimensional dynamic knee valgus angle (DKVA) was calculated. Paired t-tests were used to statistically determine significant differences between dominant and non-dominant leg DKVA, and t-tests were calculated between the two performance groups. Statistically significant differences (p < 0.05) were identified for the DKVA between the dominant and non-dominant leg for both amateur and elite players, showing a greater DKVA for the dominant leg. Group differences for the DKVA between amateur and elite players were not found, neither for the dominant, nor for the non-dominant leg. It can be concluded that the non-dominant leg showed more stable dynamics than the dominant leg during unilateral landing regardless of the player's performance level. This could be due to adaptions to sport-specific requirements. Therefore, it is recommended that programs to prevent knee injuries among soccer players consider the dynamics of each leg individually. [ABSTRACT FROM AUTHOR]