چکیده:
Correct kinematics is an effective factor to reduce musculoskeletal problems. The aim of this study was to compare muscle activity during single-leg squat (SLS) in a group with dynamic knee malalignment (DKMG) and normal cases. 23 active females (mean age of 21.86±2) participated in this comparative study. Lower limb Muscle activity (RMS), pelvic drop angle (PDA), trunk side bend (TSB) and knee valgus (KV) was recorded during SLS. Independent t test was used to compare variables and significance level was 0.05. The results showed no significant differences in PD (P=0.86) and TSB (P=0.25), but KV was greater in DKMG than the control group (P=0.00). Although %MVC of all muscles was greater in DKMG than the control group, only rectus femoris (P=0.04) and gluteus maximus (P=0.05) showed significant differences. Also, a weak correlation between KV with TSB (r=0.33) and rectus femoris activity (r= -0.37) was observed. Findings showed that DKMG had more muscle activity especially in rectus femoris and gluteus maximus which showed the important role of these muscles in controlling lower limb alignment during functional movements. Also, dynamic knee malalignment may deviate trunk towards weight bearing leg for substitution during SLS.
خلاصه ماشینی:
Comparing Electromyographic Activity of Some Lower Limb Muscles in Individuals With and Without Dynamic Knee Valgus During Single-Leg Squat Negaar Kooroshfard1 - Mohammad Hossein Alizadeh 2 – Nafiseh Afshari 3 1.
The aim of the present study was to compare muscle activity in the group with dynamic knee valgus and healthy individuals during a single-leg squat.
RMS muscle activity of the lower limb, hip drop angle, lateral trunk displacement, and knee valgus were recorded during a single-leg squat and an independent t-test with a significance level of alpha 0.
The findings showed increased muscle activity in dynamic knee valgus, especially in the rectus femoris and gluteus maximus, which indicates the importance of these muscles in controlling the alignment of the lower limb during functional movements.
Some studies have shown an inverse relationship between hip and trunk muscle activity and knee kinematics, such that decreased activity of these muscles leads to increased knee valgus in movements such as squats or descending stairs in healthy individuals or those with ACL injury and patellofemoral syndrome (2, 8, 14, 17, 18).
Discussion and Conclusion The results of the present study showed that in individuals with dynamic knee malalignment, compared to the control group, almost all muscles, especially the rectus femoris and gluteus maximus muscles, had greater activity.
Conclusion It seems that the greater knee valgus during squats in this study, which is due to a type of neuromuscular weakness of the lower limb in the group with malalignment, is more related to the function of the rectus femoris and gluteus maximus muscles.
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