Impingement syndrome

the subacromial bursa and supraspinatus tendon become compressed between the humeral head, the acromion and the coraco-acromial ligament.

• This results in pain with forward elevation of the arm and narrowing of the subacromial space 
• Functional impingement:
  • occurs when there is poor control of the shoulder stabilisers and this allows cephalad slippage of the humoral head compressing the subacromial space. 
  • It may also result from overuse of the shoulder or an injury to the shoulder resulting in altered biomechanics and poor stabiliser control.
• Anatomical impingement :
  • secondary to arthritis or hypertrophic changes of the acromion, resulting in a narrowed subacromial space. 
  • result in subacromial bursitis and/or rotator cuff lesions,  although these terms are often used interchangeably to mean the same thing. 

• Symptoms
  • Pain with overhead movements of the arm
• Examination: Hawkins test
  • This test has a sensitivity of 91–92% and specificity of 25–43%
  • therefore a negative test suggests that impingement is unlikely (although still possible) and a positive test is meaningless
  •  
  • Pain constitutes a positive test
• management
  • address the underlying cause. 
  • Physiotherapy assessment and intervention is indicated in most cases. 
  • Surgical management is controversial and is unlikely to be of benefit,