Shoulder impingement:
is a condition characterized by pain felt during arm movement when it is elevated. Pain is felt at certain angles during motion and it is the result of a compression of any of the structures passing through the subacromial space.
This space might get compromised for many reasons:
1. After a fall. i.e. on outstretched hand.
2. Abnormal shape of the Acromion process (although the relation between the shape of acromion and rotator cuff tear is still not well established but Type II and Type III acromion are seen in cases of rotator cuff tear). As the picture below show there is a marked reduction of the subacromial space with type II and Type III acromion ( see the vertical black line).
3. Osteoarithritis of the Acromioclavicular joint.
4. Acromial spurs. As the picture below shows how spurs can compromise the subacromial space thus squeezing the structures of that space when the arm is elevated.
5. Inflammation of one of the structures passing through this space associated with swelling ( bursitis if the bursa is inflamed or tendinitis if the bicepital tendon or supraspinatus tendon are inflamed).
6. Poor posture that alters the resting position of the scapula on the chest wall.
7. Poor motor control or the lack of coordination between muscles and muscular imbalance around the joint complex.
8. Elevated position of the head of the humerus in relation to the glenoid ( in case of capsular tightness).
Symptoms include:
- Pain that is felt at certain angles during movement (painful arc) with arm elevation.
- In some cases pain travels down the arm and reaches the elbow and sometimes below it.
