Impingement syndrome

Any prolong overhead activities (such as swimmer, pitcher, thrower etc) can compromise the space between Humeral head and Coraco-acromial arch, leading to impinging soft tissue. Impingement itself can lead to ore soft tissue micro trauma and swelling. The rotator cuff, bicep tendon and subacromial bursa can be affected.

Impingement syndrome may also result from direct trauma (such as fall onto shoulder or elbow), muscular imbalances, posterior capsule tightness, or the growth of bone spur underneath the acromion. 

Common over 40yr of age. Gradual onset of pain, may last weeks or months. Pain on affected shoulder with active movement or over head activity. Painful when lying on affected side especially at nights.

Examination findings
Painful arch (painful with shoulder abduction from 90' - 120')
Impingement test +ve
Hawkins and Neers tests positive

Xray may show subacromial bone spur
USS can show calcific tendinitis or rotator cuff inflammation and sprain
MRI can detect partial or complete of rotator cuff

Rest, Ice, anti-inflammatories
Strengthening exercise of scapular and thorax and Range of movement exercises
Steroid injection to subacromial space
If evidence of Rotator cuff, can consider repair surgery
To prevent impingement syndrome, overall conditioning, regular strengthening and stretching exercise, and practising proper technique should be encouraged in overhead activities and sports