عنوان مقاله [English]
Background and Aims: Various jump-landing tasks, as fundamental sport skills, have a significant role in athletic achievements. Injury to the lower limb is prevalent in athletes engaged in jump-landing activities. Therefore, the study of biomechanics of landing is an important aspect to address in the development of preventive and training strategies. The purpose of the present study was to compare neuromuscular activity pattern of lower extremity during various jump-landing tasks in active young females.
Materials and Methods: In the present quasi-experimental study, nine healthy active women volunteered to participate (age: 21.2 ± 2.7 years, height: 1.68 ± 0.5 m, weight: 63.15 ± 7.73 kg, and fat percent: 25.2 ±4.1). The onset time of wave prior to initial contact and maximum RMS over 150 ms pre-landing and 150 ms post-landing for Vastus Lateralis (VL), Lateral Hamstring (LH), Medial Hamstring (MH) and Lateral Gastrocnemious (LG), in Drop-landing, Jump-landing, and countermovement jump tasks were calculated and then normalized to the peak RMS amplitude of MVIC and reported as percentage of it. Repeated measure ANOVA was used to compare amplitude of muscle activity in different tasks, and dependent t-test was used to compare the mean amplitude and onset time of muscle activity between pre and post contact.
Results: The post-impact activation of LH in countermovement jump was significantly different for different jumps and landings. VL activities in all the three tasks and for LH in drop jump and drop landing were significantly different between pre- and post-contact. No significant difference was observed in the onset of muscle activity prior to impact in the three tasks.
Conclusion: Based on the results, neuromuscular activity was different in various jump-landing tasks. The differences in the demands of tasks can change the lower extremity muscle activity patterns, especially after contact. Therefore, using the most common tasks in sport, especially jump-landing and countermovement jump, instead of jump landing tasks, is essential in the study of landing biomechanics.
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