The Science of Frozen Shoulder
Frozen shoulder (adhesive capsulitis) involves thickening and tightening of the shoulder capsule. The normally loose capsule becomes inflamed then fibrotic, severely restricting movement. The condition typically progresses through freezing, frozen, and thawing phases. The exact trigger is often unknown but can follow injury, surgery, or periods of immobilization.
Contributing Factors
The development of frozen shoulder often follows a pattern of disuse and protective guarding. When your shoulder hurts, your natural response is to avoid moving it, which seems logical but unfortunately sets up a destructive cycle. The less you move your shoulder, the more the joint capsule tightens and adheres to itself, creating the "frozen" sensation.
Compensation patterns play a huge role in both the development and perpetuation of frozen shoulder. When your shoulder becomes stiff, you'll unconsciously start using your neck, upper back, and other shoulder to perform daily tasks. This creates massive overuse in these areas while your affected shoulder becomes progressively stiffer from disuse. I see this pattern constantly - patients come in with secondary neck pain and upper back tension from months of compensating for their frozen shoulder.
Poor posture compounds the problem significantly. Forward head posture and rounded shoulders, common from desk work or general poor posture habits, place the shoulder capsule in a shortened position. When the capsule becomes inflamed and begins to tighten, it contracts into this already shortened position, making the restriction even more severe. Risk factors like diabetes, thyroid conditions, or previous shoulder injuries seem to predispose the capsule to this inflammatory and fibrotic response, turning what might be minor irritation into a major restriction.