The Science of Rotator Cuff Injuries
The rotator cuff consists of four muscles that stabilize and move your shoulder. These tendons can be injured through sudden trauma or gradual wear. The tendon tissue becomes disorganized and may develop tears. Poor blood supply to certain areas of these tendons makes healing slower. Shoulder blade positioning and muscle imbalances often contribute to ongoing irritation. Rotator cuff injuries frequently occur alongside shoulder impingement, as both conditions share similar biomechanical contributors. In some cases, rotator cuff dysfunction can lead to compensatory patterns that contribute to frozen shoulder or shoulder instability.
Contributing Factors
Forward head posture and rounded shoulders create the perfect storm for rotator cuff problems. When your head sits forward of your shoulders, it pulls your shoulder blades into a protracted position, reducing the space under your acromion where the rotator cuff tendons pass through. This sets up impingement with every arm movement, particularly overhead activities.
Repetitive overhead movements in work or sports place massive demands on these small stabilizing muscles. Your rotator cuff has to work overtime when your shoulder blade doesn't move properly - and poor desk posture weakens the muscles that control your shoulder blade position. Over time, this creates a cycle where the stronger, superficial muscles like your deltoid compensate for weak rotator cuff muscles, leading to altered movement patterns.
The most damaging factor I see is the combination of poor posture with repetitive activities. Whether you're reaching overhead to stock shelves, swimming, or even just reaching for items in high cupboards, if your shoulder blade isn't positioned correctly and moving smoothly, your rotator cuff tendons get pinched and compressed with every movement. Age compounds this problem as the tendons naturally lose some of their elasticity and blood supply, making them more vulnerable to these mechanical stresses.