What is a rotator cuff sprain?

Rotator Cuff Sprain Definition

A "rotator cuff sprain" is not a standard medical term; the correct terminology is rotator cuff injury, which encompasses a spectrum of pathology including tendinopathy, partial-thickness tears, and full-thickness tears of the rotator cuff tendons. 1

What the Term Actually Represents

The rotator cuff consists of four muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) that form a musculotendinous unit providing dynamic stability to the shoulder joint. 2 When clinicians or patients use the term "sprain," they are typically referring to:

• Rotator cuff tendinopathy: Degeneration or inflammation of the rotator cuff tendons without complete disruption 3
• Partial-thickness tears: Incomplete tears affecting either the articular or bursal surface of the tendon 1
• Strain injuries: Overstretching or minor tearing of the muscle-tendon unit from acute overload or repetitive microtrauma 1

Mechanism of Injury

Rotator cuff injuries occur through two primary mechanisms:

• Acute injury: Sudden trauma such as a fall, shoulder dislocation, or lifting a heavy object, more common in younger individuals 1
• Degenerative changes: Progressive wearing down of the tendon over time from repetitive use, the dominant mechanism in adults over 40 years 1

In younger athletes, particularly overhead throwers, injuries result from repetitive eccentric stress on the supraspinatus, external rotators, and scapular stabilizers, leading to undersurface tears from overuse rather than primary impingement. 1, 4 The mechanism involves weakened posterior shoulder musculature combined with overdeveloped anterior musculature during arm deceleration. 1, 5

Clinical Presentation

Patients with rotator cuff injuries typically present with:

• Pain: Located in the anterior or anterolateral shoulder, worsening with overhead activities (88% sensitivity) 5, 4
• Weakness: Focal weakness during abduction with external or internal rotation, present in 75% of cases 5, 4
• Limited range of motion: Particularly during abduction with rotation 1, 5, 4
• Night pain: Pain that radiates down the upper arm and disrupts sleep 2

In throwing athletes specifically, pain occurs during the release, deceleration, and follow-through phases, with decreased velocity and precision. 1, 5, 4

Important Distinction from True "Sprains"

A critical pitfall is confusing rotator cuff injuries with ligamentous sprains. Sprains by definition involve ligaments, not tendons. The rotator cuff is a tendinous structure, so the injury represents tendon pathology (tendinopathy, tendinosis, or tear) rather than a ligamentous sprain. 2 This distinction matters because treatment approaches differ significantly between ligamentous and tendinous injuries.

Pathophysiological Spectrum

The American Academy of Orthopaedic Surgeons recognizes that rotator cuff pathology exists on a continuum:

• Early stage: Tendinopathy with inflammation and degeneration but intact fibers 3
• Intermediate stage: Partial-thickness tears affecting <50% of tendon thickness 1
• Advanced stage: Full-thickness tears with complete disruption of the tendon 1

Not all tears are symptomatic—54% of asymptomatic patients aged 60 years or older have rotator cuff tears on imaging. 1

Secondary Consequences

Beyond the primary tendon injury, rotator cuff tears affect surrounding structures including joint cartilage, bone, ligaments, and remaining intact tendons, which has significant implications for shoulder function and treatment planning. 6 Scapular dyskinesis—poor coordination of scapular movements during arm elevation—commonly contributes to and results from rotator cuff injury. 1, 5, 4