Shoulder pain is one of those expected injuries in swimmers and it become more apparent with poor technique. The subscapularis muscle is the largest of the rotator cuff muscles and most prone to injury in swimmers. Subscapularis is triangular in shape and originates in the scapula. It is located on the underside of the shoulder blade and extends towards the anterior aspect of the humerus (front of the upper arm).
The function of the muscle is to stabilize and rotate the shoulder joint thereby allowing the arm to turn inward. When the arm is extended the subscapularis muscle draws the humerus forward and downward which in turn acts to prevent the dislocation of the head of the humerus.
Repetitive shoulder movements in swimming create inherent biomechanical changes to the shoulder, potentially causing stress within the shoulder capsule and in turn instability. The etiology however is little understood but Jobe et al (1989) stated that repeated and forceful over head movement causes stretching both anteriorly and interiorly of the capsule-ligament structure surrounding the elbow joint. Thomas et al (2009) however discovered that there was decreased scapular upward rotation.
What we do know is that as the arm is extended the shoulder is internally rotated, if as it moves through into the water the shoulder does not fully internally rotate or the shoulder abnormally circumducts thereby the extended arm lays flatter to the water surface there and there is an increased load placed upon subscapularis. Many swimmers who swim like this will find that the elbow increasingly flexes up to 90 degrees throughout the drag or pull phase instead of remaining around 25 degrees of flexion. Repeated motion leads to repetitive strain injury, triggerpoints or inflammation of the shoulder capsule.
What Therapyroom1 does
- Biomechanically examine shoulder movement in swimming
- Mobilisation of subscapularis to reduce pain
- Remove any triggerpoints that might exist
- Strengthen subscapularis
- Reduce stress and pain in the shoulder
Jobe, F.W., Kvitne, R.S., Giangarra, C.E . (1989) Shoulder pain in the overhand or throwing athlete. The relationship of anterior instability and rotator cuff impingement. Orthopaedic Review [18(9):963-975]
Thomas, S.J., Swanik, K.A., Swanik, C., Huxel, K.C. (2009) Glenohumeral Rotation and Scapular Position Adaptations After a Single High School Female Sports Season. J Athl Train. 2009 May-Jun; 44(3): 230–237.