Stretching and strengthening exercises: their effect on three-dimensional scapular kinematics

Area of Science:

• Biomechanics
• Exercise Physiology
• Musculoskeletal Rehabilitation

Background:

• Forward shoulder posture is a common postural deviation.
• This posture can negatively impact shoulder kinematics and function.
• Targeted exercises may offer a solution for improving posture and shoulder mechanics.

Purpose of the Study:

• To quantitatively assess the impact of specific shoulder exercises on shoulder kinematics.
• To evaluate the effects of these exercises on resting shoulder posture.
• To determine changes in muscle strength and scapular positioning.

Main Methods:

• A 6-week exercise program involving pectoral stretching and resisted strengthening of scapular and glenohumeral muscles.
• Measurements of thoracic inclination and scapular orientation using a 3D digitizer.
• Assessment of glenohumeral rotation and abduction strength via dynamometry.
• Repeated-measures design with pre- and post-intervention testing.

Main Results:

• Significant increases in horizontal abduction and external/internal rotation strength.
• Reduced anterior thoracic inclination, indicating a more erect upper trunk.
• Increased glenohumeral contribution to arm elevation and improved scapular stability during abduction.
• No significant change in resting scapular posture was observed.

Conclusions:

• The prescribed exercise regimen effectively improved muscle strength and upper trunk posture.
• The program enhanced scapular stability and modified the scapulohumeral rhythm.
• These findings suggest a beneficial role for targeted exercises in managing forward shoulder posture and improving shoulder function.