پاسخ عضلانی دختران دچار کایفوزیس در بازیابی تعادل متعاقب آشفتگی پاسچرال

Purpose: This study aimed to determine muscular response in balance recovery after postural&nbsp;perturbation among females with increased thoracic kyphosis. Methods: This is a quasi-experimental study. A total of 12 female students with thoracic&nbsp;kyphosis (>40 degrees) and 12 matched controls were selected to participate in the study. Each&nbsp;subject underwent unexpected perturbation from anterior, posterior, right, and left directions with&nbsp;eyes open and eyes closed conditions while standing on a movable plate, triggered by a weight&nbsp;equivalent to 10% of the subjects&rsquo; body weight. Then, the electromyography activity of some&nbsp;selected muscles was measured. SPSS version 19.0 and Analysis of variance (ANOVAs) with&nbsp;repeated measures were used for data analyses (P<0.05). Results: Significant effects after perturbation were observed with regard to the activation of&nbsp;rectus femoris (P<0.001), biceps femoris (P<0.001), tibialis anterior (P<0.005), gastrocnemius&nbsp;medialis (P=0.032), and gluteus maximus (P<0.001). Whereas, no impact was seen in activities&nbsp;of erector spinae (P=0.461) and rectus abdominal muscles (P=0.224). Also the results showed&nbsp;increase in muscles activities when the eyes is closed compared to open eyes condition (P<0.05).&nbsp;Activities of all muscles were significantly higher in kyphotic group in comparison with control&nbsp;group. However, these differences were statistically significant regarding gastrocnemius medialis&nbsp;(P=0.007), gluteus maximus (P=0.033), and rectus abdominus (P=0.010). Conclusion: Proximal muscles activity was higher in kyphotic subjects than normal subjects&nbsp;during balance recovery after postural perturbation.