Abstract
BACKGROUND: Upper Cross Syndrome (UCS) is associated with postural and muscular imbalances in the upper body. This study investigated the effects of combining respiratory and scapular stabilization exercises on scapular movement patterns, postural alignment, and muscle activation in adolescent girls with UCS. METHODS: In this randomized controlled trial, 50 girls aged 12–15 with UCS were randomly assigned to two groups: one receiving scapular stabilization exercises (SSE) and the other receiving combined dynamic neuromuscular stabilization-based respiratory and scapular stabilization exercises (SRE). Both groups trained three times per week for eight weeks. The primary outcome measures were postural alignment variables, such as forward head posture (FHP), rounded shoulder angle (RSA), thoracic kyphosis angle, and scapular movement patterns. Secondary outcomes included the electromyographic activity of the upper/middle/lower trapezius and serratus anterior during shoulder abduction. Assessments of the variables were conducted at baseline and after the intervention. A mixed repeated measures ANOVA was used to assess group × time interactions (p ≤ 0.05). RESULTS: Mixed repeated measures ANOVA showed significant group*time interactions in scapular movement patterns, postural alignment, and muscle activity across key muscles (P < 0.05). Minimum clinically important difference analysis further indicated that participants in the SRE group demonstrated more clinically meaningful improvements across all outcome measures compared to the SSE group. CONCLUSION: The addition of respiratory training to scapular stabilization may result in more significant improvements in posture and muscle function in adolescents with UCS. These results support its potential efficacy, although further studies are needed to evaluate long-term clinical effectiveness. TRIAL REGISTRATION: The researchers registered this trial on 27/12/2022, with the identifier IRCT20221215056827N1 in the Iranian Registry of Clinical Trials (IRCT) at the following address: https://irct.behdasht.gov.ir. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13102-025-01390-1.