ACL

Background : Excessive repetitions of the landing and jumping task are a key risk factor for lower extremity injury (specially ACL) in female volleyball players. Aim: this study investigates the effect of Sports-Metrics Volleyball Training (SMVT) on landing technique in female volleyball players. Materials and Methods : The participants of this study were 25 female young volleyball players and randomly divided into training (TG, n=13) and control groups (CG, n=12). The TG performed SMVT for 18 sessions, and the CG performed their regular training. Landing error scoring system (LESS) test were used for assessing landing errors. SPSS (version 25) was used to analyze the statistical data ( P <0.05). Results : The results of the data analysis showed a significant improvement ( P =0.01) in LESS in TG (from 8.62 to 5.54), but no significant changes in CG the LESS ( P =0.62, from 8.00 to 8.23). Eighteen sessions SMVT reduced the landing error by 35.73% in the TG. Conclusion : Base on previous research the SMVT reduces lower extremity injuries and the results of this study showed that SMVT significant improvement the landing technique. Therefore, performing SMVT is recommended for female volleyball players because it is effective in both preventing injuries and improving landing technique.

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.