TIBIAL ROTATIONS DURING STEP UP EXERCISE DO NOT CHANGE KNEE EXTENSOR ACTIVITY IN THE PATELLOFEMORAL PAIN SYNDROME

Abstract

The purpose of this study was to compare the electromyographic activity of vastus medialis (VM) and vastus lateralis (VL) muscles during step up exercises at different tibial rotations, between individuals with and without patellofemoral pain syndrome. The electromyographic activity of the VM and VL muscles during step up exercises was evaluated in three tibial rotations: without rotation, medial and lateral rotation. Thirteen patients with patellofemoral pain syndrome and 16 control subjects performed this exercise three times. The results showed a significant lower electromyographic activity of VM muscle in both groups, compared to the electromyographic activity of VL muscle (p<0.05). Moreover, a significant difference in electromyographic activity between muscles for all rotations and groups (p<0.001) was also found. The results of the present study suggest that tibial rotations performed during step up exercise did not change the electromyographic activity of VM and VL muscles.