The Relationship between Thoracic Kyphosis with Scapular Upward Rotation and Scapulohumeral Rhythm Ratio

Numerous studies have investigated the effect of different factors on scapulohumeral rhythm ratio. The purpose of this study was to investigate the relationship between thoracic kyphosis with scapular upward rotation and scapulohumeral rhythm ratio.

one hundred nine male students (age: 18-25 years) selected as statistical sample randomly. A flexible ruler was used for measuring thoracic kyphosis. Humeral abduction and scapular up or dawn ward rotation were measured by two inclinometers at the scapular resting position, 45°, 90° and 135° shoulder abduction in frontal plane. Subjects performed humeral abduction with the dominant shoulder in the frontal plane. The scapulohumeral rhythm ratio was calculated from division humeral abduction to upward rotation of the scapula from scapular resting position to 45°, 90°, and 135° humeral abduction in the frontal plane. Pearson Correlation Coefficient test was used to determine a significant relationship between thoracic kyphosis and scapular upward rotation and scapulohumeral rhythm ratio. The significance level was set at α< 0.05.

Findings showed there is negative significant relationship between thoracic kyphosis and scapular upward rotation in 90° and 135° shoulder abduction. In addition this study findings a positive significant relationship between thoracic kyphosis with scapulohumeral rhythm ratio in 90° and 135° shoulder abduction in the frontal plane.

Significant correlation between thoracic kyphosis with scapular upward rotation and scapulohumeral rhythm ratio indicates the importance of proper spine alignment to prevent shoulder joint disorders.