Comparative Effectiveness of Isometric and Isotonic Exercises on Hyperkyphosis, Forward Head Posture, and Rounded Shoulders in Computer Users with Upper Crossed Syndrome: A Randomized Controlled Trial.

Abstract

While strengthening exercises have demonstrated efficacy in improving symptoms associated with Upper Crossed Syndrome (UCS), it remains unclear whether isometric or isotonic modalities offer greater benefits. This study compared their effects on forward head posture (FHP), rounded shoulders (RSH), and thoracic kyphosis in individuals with UCS. In this randomized controlled trial, 43 sedentary computer users diagnosed with UCS (aged 30-45 years) were randomly assigned to isometric (n = 15), isotonic (n = 14), or control (n = 14) groups. The eight-week intervention comprised three weekly supervised sessions for both exercise groups, each lasting 40 to 60 minutes. Postural variables were assessed using photogrammetry (FHP, RSH) and a flexible ruler (thoracic kyphosis). Statistical analyses included analysis of covariance (ANCOVA) and Bonferroni-adjusted post hoc tests, with statistical significance set at α = 0.05. Both the isometric and isotonic groups showed statistically significant improvements in FHP (P < .001; mean difference [MD] = -6.79° and -7.97°, respectively), RSH (P < .001; MD = -6.44° and -8.09°, respectively), and thoracic kyphosis (P < .001; MD = -7.21° and -7.39°, respectively), compared to the control group. No statistically significant differences were observed between the two exercises groups, although the isotonic group exhibited marginally greater improvements. Both isometric and isotonic exercises effectively improved posture-related outcomes associated with UCS among sedentary adults. However, no definitive advantage was observed between the two exercise types. Future studies with longer intervention durations and larger sample sizes may elucidate any clinically meaningful differences.