Comparison of Electromyography of Calf Muscles and Maximum Vertical Ground Reaction Forces in Single-Leg Landing Movement of Men with and without Genu Varum مقاله

چکیده:

The purpose of this study is to compare the electromyography of calf muscles and maximum vertical ground reaction forces in the single-leg landing movement of men with and without genu varum. Twenty-six male students majoring in physical education and sports science, including 13 with genu varum and 13 with normal knees, participated in this study. Electromyographic activity of some calf muscles was measured simultaneously with ground reaction force data. Genu varum abnormality was measured and recorded using calipers. The subjects performed a single-leg landing movement from a height of 30 cm on a force plate. The landing movement was divided into two phases: 100 milliseconds before the initial contact of the foot with the ground and 100 milliseconds after the foot contact with the ground (force absorption phase). Data analysis was performed using SPSS 16 software and an independent t-test (P≤0.05). The results of the research showed that in the pre-landing phase, there was no significant difference in the activity of the tibialis posterior, medial gastrocnemius, and anterior tibialis muscles between the two groups (respectively (P≤0.76), (P≤0.09) and (P≤0.77)). In the force absorption phase, no significant difference was observed in the activity of the tibialis posterior and anterior tibialis muscles (respectively (P≤0.68) and (P≤0.92)), but the difference in the activity of the medial gastrocnemius muscle between the two groups was significant (P≤0.04). No significant difference was shown in the maximum vertical ground reaction force at the time of toe impact (P≤0.22), but the difference in the maximum vertical ground reaction force at the time of heel impact (P≤0.003) between the two groups was significant. The results of this study showed that individuals with genu varum showed less activity in the medial gastrocnemius muscle during the force absorption phase compared to normal individuals, which may be due to greater forces being applied to the joints of their lower limbs. This may lead to injury and the development of degenerative joint diseases in the long run.