Which tendon is commonly involved in supraspinatus impingement/tendinitis as described in the material?

• A. Supraspinatus
• B. Infraspinatus
• C. Subscapularis
• D. Teres minor

Answer: (A)

The tendon most commonly involved in supraspinatus impingement/tendinitis is the supraspinatus itself. When you lift the arm, this tendon passes beneath the acromion in the subacromial space. Repetitive overhead movements or narrowing of that space compress the tendon against the acromial arch, leading to irritation, inflammation, and progressive tendinopathy or partial tears. The supraspinatus is also the rotator cuff tendon that initiates arm abduction, so it endures the early pinch during elevation, making it the classic structure affected in this syndrome. The other rotator cuff tendons exist and can be involved in various shoulder problems, but they are not the typical primary offenders in impingement/tendinitis.