Preventing Subacromial Impingement & Rotator Cuff Injuries in Swimmers
Subacromial Impingement- Overview
Why is shoulder pain the most common musculoskeletal complaint in swimming? A competitive swimmer endures constant joint rotation and exceeds thousands of stokes in a single swim session. Swimmers shoulder, also known as subacromial impingement, is a condition with a gradual onset that may lead to microtrauma due to repetitive activity. Subacromial impingement commonly presents as anterior lateral shoulder pain but, in most cases, the onset of symptoms are commonly related to other underlying musculoskeletal conditions.
The shoulder complex consist of three main bones. They are the scapula, clavicle, and the humorous. These three boney structures conform to make up two main shoulder joints. They are the glenohumeral joint and the acromioclavicular joint. The glenohumeral joint attaches the head of the humorous to the scapula by a cuplike socket called the glenoid. Surrounding the humeral head, in the glenoid cavity, lies a labrum. The labrum deepens the glenoid socket providing support for the humeral head during joint translation. The Acromioclavicular joint attaches the acromion process, of the scapula, to the clavicle. This joint is held together by ligaments to provide support to the shoulder complex. The subacromial space is created between these two joints allowing for soft tissue like structures to move freely within the space. The three main soft tissue structures consists of the bicep tendon, rotator cuff muscles, and the subacromial bursa.
Causes of Subacromial Impingement
Subacromial impingement is the result of chronic or acute inflammation of the soft tissue structures that pass through the subacromial space. Irritation and inflammation of these underlying musculoskeletal structures may result in pain, weakness, and reduced rage of motion.
Why do these Musculoskeletal Structures get Inflamed?
The onset of symptom may occur for numerous reasons. A clear clinical assessment is the best way to determine what may be the cause of subacromial impingement. During the clinical evaluation it is important to address postural impairments, muscle imbalances, range of motion anomalies, neuromuscular control, and joint mobility.
How do Subacromial Impingement and Swimming Correlate?
In many cases, subacromial impingement is the result of posterior capsule tightness. Posterior capsular tightness is commonly seen in swimmers due to excessive hypermobility while performing external rotation. Disproportionate anterior translation of humeral head will occur due to hypermobility, during external rotation. This hypermobile movement produces extra strain and irritation on other musculoskeletal structures working to stabilize the joint in alignment. The two main stabilizer muscles working in opposition during anterior translation are the biceps tendon and “Subscapularis” one of the rotator cuff muscles. Their job is to stabilize the and reduced humeral head movement during anterior translation.
Prevention and Treatment for Subacromial Impingement
Treatment for subacromial impingement in many cases can be handled noninvasively through Physical therapy. The patient should first be examined to determine what musculoskeletal impairments are associated with the onset of the pain. Common types of impairments consist of poor posture, insufficient joint mobility, range of motion anomalies, neuromuscular deficiency, and muscle imbalances. After proper diagnosis of the onset of injury, Physical therapy should be started to treat the underlying musculoskeletal conditions. Manual therapy in addition to use of modalities can be used to treat the onset of injury and reduce the symptoms associated with the injury.
In selected cases invasive surgical procedures may be necessary to treat subacromial impingement. This procedure is called subacromial decompression and is performed arthroscopically. This procedure is performed by shaving/ removing part of the acromion, in addition to complete removal of the subacromial bursa. As a result of this procedure the subacromial space will expand and produce more room for the rotator cuff muscles and biceps tendon. Following the arthroscopic procedure, Physical therapy will be necessary to regain full strength and function of the shoulder.