بررسی مقایسه‌ای نسبت فعالیت عضله پهن داخلی به پهن خارجی در بیماران مبتلا به جابجایی خارجی استخوان کشکک و افراد سالم

ABSTRACT The patellar stability is maintained by ligaments. Muscles and joint capsule. Due to vastus medialis atrophy patella is moving outward and finally causes lateral hyperpressure syndrome. Which is painfull. This is a common syndrome that too many patients suffered from it. The perpose of this study is to determine the level of activity of medial and lateral muscles of the patellofemoral joint that are critical for patellar dynamic stability. Twenty persons (10 healthy and 10 patients with patellar lateralization) participated in this study IEMG and IAV parameters were obtained by telemetric EMG instrument from vastus medialis obliques (VMO) and vastus lateralis (VL) during maximal voluntary isometric contraction in three different angels of knee flexion (15,30 and 45 degrees). While subjects sitted on Biodex machine. In conclusion the findings of this study demonstrate that during maximal voluntary isometric contraction in patients with patellar lateralization minimal VMO activity exists as compared with the highly ctive VL in selected degrees of range of motion. In addition in patients group VMO/VL ratio is less than 1. This is due to deficiency of nuero-muscular control system that decrease functional joint stability.