Pilot study on the improvement effects of scapulothoracic exercises on the respiratory functions in sedentary young female adult with forward shoulder posture: a randomized control trial

Introduction
Upper body muscular imbalance is a potential risk factor in various shoulder problems and respiratory functions. Exercises aimed at the pectoralis minor and scapular stabilizer muscles could alleviate muscular imbalances in forward shoulder posture (FSP). However, the efficacy of these exercises on respiratory function, including chest mobility, lung capacity, and respiratory muscle strength in FSP remains unclear.

Material and methods
Material and methods: In this randomized clinical trial, 28 female participants with FSP, aged 18–23 years, were divided into the control and exercise groups. The exercise programs were conducted five days/week for eight weeks. The distance from the acromion process to the wall was measured to determine FSP. Pectoralis minor length (PL) were measured from coracoid process to the fourth costosternal joint, thoracic kyphosis (TK) was measured along the thoracic spines, chest expansion was measured from the amplitude of thoracic wall circumference during full expiration and inspiration, maximal respiratory muscle strength generated during respiration (MIP), and maximum respiratory muscle strength during expiration (MEP); all were assessed pre- and post-exercise intervention.

Results
After the eight-week training program, an improvement in FSP was observed, manifested as decreased mean difference (p < 0.05) and TK (p < 0.003). The PL (p < 0.05) and lower part of chest expansion (p < 0.010) were restored compared to the control group. The strength generated in respiration (MIP) also improved in the exercise group (p < 0.013).

Conclusions
An eight-week pectoral muscle stretching and scapular stabilizer strengthening programme could reduce FSP, improving chest mobility and respiratory muscle strength.