knee

Introduction: The present study aimed to compare hip muscle resistance training with and without feedback on trunk, pelvis, and lower extremity motions in frontal and sagittal planes among active females with dynamic valgus. Materials and Methods: Twenty-Nine active females (Mean±SD age: 22.8±2.4 years, height: 1.70±0.6 m, weight: 69±7.1 kg) were randomly assigned to a hip muscle resistance training with feedback group (n=15) or a hip muscle resistance training without feedback group (n=14). Both training programs lasted 6 weeks (3 sessions/week). The peak angles of lateral trunk flexion, contralateral pelvic drop, hip flexion, knee flexion, and valgus during single-leg drop landing and single-leg vertical drop jump were assessed in the research participants at baseline and 6 weeks post-training. Unipodal functional screening tests were captured with two standard digital video cameras. Results: After 6 weeks, significant differences were observed in knee valgus and lateral trunk flexion, contralateral pelvic drop, and knee flexion angles, i.e., compared between hip muscle resistance training with feedback and hip muscle resistance training without feedback (P<0.05), except for non-dominant leg hip flexion in single-leg vertical drop jump (P>0.05). Conclusion: In the explored active females with dynamic valgus, hip muscle resistance training with feedback seems to be better at improving trunk, pelvis, and lower extremity motions in frontal and sagittal planes, compared to hip muscle resistance training without feedback; however, no significant difference was observed concerning hip flexion during single-leg vertical drop jump between the study groups.

Background: Drop landing is one of the tasks performed in many sports skills. Lower limb injuries have the highest prevalence in sports where jump landing is repeated frequently. One of the most common landing injuries is an anterior cruciate ligament (ACL) tear, which increases knee valgus and may contribute to an increased risk of ACL injury in athletes. In this situation, fatigue is one of the components that can affect various parameters of the landing task. Aim: The purpose of this study was to investigate and compare the acute and delayed effects of fatigue on the time to stability (TTS) of female gymnasts with and without dynamic knee valgus (DKV) during the landing task. Materials and Methods: In this semi-experimental study with a pretest-posttest design, 42 female gymnasts were selected through purposive and available sampling and divided into two groups of 21: a control group without DKV and an experimental group with DKV. The TTS in these individuals was measured before, after, and 24 hours after the fatigue protocol using the Kistler force plate device. The data was analyzed using SPSS software and statistical methods of analysis of covariance with repeated measures at a significance level of P ≥0.05. Results: According to the findings of this study, it showed that there is a significant difference in the variable of TTS in three time periods (before, after, 24 hours after fatigue) in the control and experimental groups ( P = 0.026). Conclusion: The results of the present study showed that plyometrics on the TTS are significantly different between people with DKV and without DKV, and people with DKV are necessarily at a greater risk of injury during landing tasks.