Etiology — what causes it

Load-related changes within the tendon — most commonly supraspinatus or infraspinatus — driven by training error, abrupt increases in volume or intensity, deconditioning, and biomechanical contributors. The Cook & Purdam continuum model (reactive → disrepair → degenerative) frames the pathology.

Epidemiology — who gets it

Common in overhead athletes (swimming, throwing, tennis, volleyball) and in manual occupations. Peak age in athletes 18–35; in general population 40–60.

Clinical signs

Pain with resisted external rotation (infraspinatus) or empty can (supraspinatus) testing, painful arc, positive Hawkins–Kennedy, reduced scapular control, asymmetric strength testing. Range usually preserved.

Symptoms

Anterolateral shoulder pain, worse with overhead and loaded use, often with night pain on the affected side. Often progressive after a training spike, return to activity after a layoff, or a new repetitive demand.

Best evidence for chiropractic treatment

Heavy slow resistance protocols (Beyer et al., AJSM; Kongsgaard et al., Scand J Med Sci Sports) and progressive isometric loading have strong evidence for tendinopathy management. The Cook continuum guides phase-based loading — early isometric in highly reactive presentations, progressing to heavy slow resistance and energy-storage loading. Manual therapy provides short-term symptom relief. Corticosteroid injection is no better than exercise at 6 months and may impair longer-term outcomes (Coombes et al., Lancet).

Subtypes

  • Reactive phase. High irritability, recent load spike. Isometric loading and load deload.
  • Disrepair. Persistent pain over weeks-to-months. Heavy slow resistance protocol.
  • Degenerative. Older population, structural changes. Capacity-building remains the goal.

When to seek emergency care

Some symptoms need urgent medical attention — not a chiropractic visit. Call 911 or go to the nearest emergency department for: progressive limb weakness, loss of bowel or bladder control, saddle anesthesia (numbness in the groin/inner thighs), severe unrelenting pain unrelieved by position, signs of fracture after significant trauma, chest pain, stroke-like symptoms (face drooping, arm weakness, speech changes), or any rapidly worsening or unusual symptom.

Bottom line

Cuff tendinopathy is a load capacity problem. Heavy slow resistance and progressive loading restore tolerance over 8–12 weeks.