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
Department of Sports Injury and Biomechanics, Faculty of Sport Sciences and Health, University of Tehran, Tehran, Iran
10.22038/abjs.2025.86402.3928
Abstract
Objectives: While strengthening exercises are known to improve Upper Crossed Syndrome (UCS), it remains unclear whether isometric or isotonic exercises offer greater benefits. This study aimed to compare their effects on forward head posture (FHP), rounded shoulders (RSH), and thoracic kyphosis in individuals with UCS.
Methods: In this randomized controlled trial, 43 sedentary computer users with UCS (aged 30–45) were allocated to isometric (n=15), isotonic (n=14), and control (n=14) groups. The eight-week intervention involved three weekly sessions of 40-60 minutes for the exercise groups. Postural variables were assessed using photogrammetry (FHP, RSH) and a flexible ruler (thoracic kyphosis). Statistical analysis included ANCOVA and Bonferroni post hoc tests (α = 0.05).
Results: Both the isometric and isotonic groups showed significant improvements in FHP (P< .001, MD= -6.79° and MD= -7.97°, respectively), RSH (P< .001, MD= -6.44° and MD= -8.09°, respectively), and thoracic kyphosis angles (P< .001, MD= -7.21° and MD= -7.39°, respectively) compared to the control group. No significant differences were observed between the two exercise groups, though the isotonic group demonstrated slightly greater improvements.
Conclusion: Both isometric and isotonic exercises effectively improved posture related to UCS in sedentary adults, with no clear advantage of one method over the other. Longer intervention periods may help clarify any subtle differences in outcomes.
Khaledi, A. and Minoonejad, H. (2025). 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. The Archives of Bone and Joint Surgery, (), -. doi: 10.22038/abjs.2025.86402.3928
MLA
Khaledi, A. , and Minoonejad, H. . "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", The Archives of Bone and Joint Surgery, , , 2025, -. doi: 10.22038/abjs.2025.86402.3928
HARVARD
Khaledi, A., Minoonejad, H. (2025). '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', The Archives of Bone and Joint Surgery, (), pp. -. doi: 10.22038/abjs.2025.86402.3928
CHICAGO
A. Khaledi and H. Minoonejad, "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," The Archives of Bone and Joint Surgery, (2025): -, doi: 10.22038/abjs.2025.86402.3928
VANCOUVER
Khaledi, A., Minoonejad, H. 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. The Archives of Bone and Joint Surgery, 2025; (): -. doi: 10.22038/abjs.2025.86402.3928
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