Rotator cuff

The rotator cuff is a group of four muscles and their tendons that surround the shoulder joint, stabilizing the ball of the humerus within the shallow socket of the shoulder blade and controlling the precise mechanics of arm movement.

What your rotator cuff does and why it's so vulnerable

The four rotator cuff muscles — the supraspinatus, infraspinatus, teres minor, and subscapularis — wrap around the front, back, and top of the shoulder joint, attaching via tendons to the humeral head. Their combined role is to compress and center the ball of the humerus in its socket throughout the full range of arm movement, keeping the joint stable while the larger muscles — the deltoid, pectorals, and latissimus — produce power.

Without the rotator cuff doing its stabilizing work, the humeral head migrates upward or shifts during movement, increasing friction on the tendons and reducing the efficiency of every arm movement. The supraspinatus tendon, which runs through a narrow space beneath the bony arch at the top of the shoulder, is the most commonly injured — from impingement, degeneration, partial tears, or full thickness tears — because of both its position and the loads it absorbs.

Why rotator cuff problems are so often undertreated or overtreated

Rotator cuff tears are common on imaging in people over 50 with no shoulder pain at all, which makes it easy to either overattribute pain to a tear that isn't actually causing symptoms or dismiss significant dysfunction because "everyone has some degeneration." The degree of structural damage on a scan matters less than how the shoulder is functioning — and that's what physical therapy addresses.

Why surgery isn't always the answer — and why timing matters when it is

Many partial and even full-thickness rotator cuff tears respond well to physical therapy without surgical intervention, particularly in people over 60 where degenerative tears are common. When surgery is the right choice, the quality of the rehabilitation before and after the procedure significantly affects the outcome. A physical therapist can help you understand where you are in that decision and guide your care accordingly.

How Sword Health can help

A physical therapist can assess your rotator cuff function, identify what's driving your shoulder symptoms, and build a targeted program that addresses the mechanics rather than just the pain. Sword connects you with that expertise from home, with clinical oversight throughout your recovery.