Electromyographic comparison of exercises for scapulothoracic muscle activation in men with upper crossed syndrome: A cross-sectional study.

Objective: This study aimed to determine the optimal exercise for improving Upper Crossed Syndrome (UCS) using electromyographic (EMG) activity of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) during ten exercises.

Method: A cross-sectional study involved 30 male students (mean age: 25.3 ± 2.5 years; height: 176.8 ± 7.2 cm; weight: 77.7 ± 2.5 kg; BMI: 23.8 ± 0.72 kg/m) with UCS. Participants were selected based on postural assessments (forward head posture ≥44°, rounded shoulder ≥49°, thoracic kyphosis ≥42°). EMG was used to measure activation levels of UT, MT, LT, and SA, and the UT activation ratio relative to MT, LT, and SA during ten exercises. One-way ANOVA was applied for data analysis.

Results: Side-lying external rotation, standing diagonal flexion with Thera-band, and lying prone "V" demonstrated the least UT activity, with the highest MT and LT activation. The standing diagonal flexion with Thera-band elicited the highest SA activity. UT/MT, UT/LT, and UT/SA ratios were less than one in multiple exercises. Significant differences in muscle activation levels and ratios were observed across all exercises (P ≤ 0.05).

Conclusion: The findings suggest significant clinical implications for UCS rehabilitation. The identified exercises effectively engage MT and LT while minimizing UT activation, addressing muscular imbalances. Favorable UT/MT, UT/LT, and UT/SA ratios further support these exercises in correcting UCS. These exercises may help counteract the underlying muscular imbalance in UCS by promoting a more balanced activity ratio among the shoulder girdle muscles, potentially improving posture and reducing UCS symptoms.