Shoulder instability (labral tear, dislocation, subluxation)
The labrum is a rim of cartilage that deepens the shoulder socket. Tears (such as SLAP and Bankart lesions) make the joint looser, so the ball can slip partly (subluxation) or fully (dislocation) out—most often forwards when the arm is out to the side and turned outward, like falling on an outstretched hand or the bottom of an incline press. A previous dislocation or naturally loose joints raise the risk.
Overview
📖 Rehab Science- Medical name
- Glenohumeral instability with labral pathology (e.g. SLAP or Bankart lesion)
- Common name
- Loose or dislocating shoulder
- Structures involved
- Glenoid labrumGlenohumeral jointShoulder capsule and ligamentsGlenohumeral LigamentsRotator cuff
The labrum is a rim of cartilage that deepens the shoulder socket. Tears (such as SLAP and Bankart lesions) make the joint looser, so the ball can slip partly (subluxation) or fully (dislocation) out—most often forwards when the arm is out to the side and turned outward, like falling on an outstretched hand or the bottom of an incline press. A previous dislocation or naturally loose joints raise the risk.
Source: Rehab Science · Ch 16 · PDF pp. 397, 398show sources ▾
Page numbers are those of the uploaded PDF edition. "Find original" opens a PubMed search for the cited study.
Anatomy & biomechanics
ℹ Additional explanationThe socket is shallow—like a golf ball on a tee. The labrum is the tee's lip; ligaments and capsule are the straps.
Signs & symptoms
📖 Rehab Science| Pain location | Deep inside the joint ("can't touch it"), often front of shoulder. |
|---|---|
| Pain characteristics | Sharp, catching pain with certain movements followed by deep aching for hours. |
| With movement | External rotation, reaching overhead, out to the side or across the body. |
| other | Popping, clicking or grinding; feelings of weakness, looseness or that the shoulder could slip out; apprehension in unstable positions. |
Source: Rehab Science · Ch 16 · PDF pp. 398, 399· 2 original research citationsshow sources ▾
- [Ch 16·10] Guerrero P, Busconi B, Deangelis N, Powers G. Congenital instability of the shoulder joint: assessment and treatment options. J Orthop Sports Phys Ther. 2009;39(2):124-134. find original ↗
- [Ch 16·12] Burkhead WZ Jr, Rockwood CA Jr. Treatment of instability of the shoulder with an exercise program. J Bone Joint Surg Am. 1992;74(6):890-896. find original ↗
Page numbers are those of the uploaded PDF edition. "Find original" opens a PubMed search for the cited study.
Why does this happen?
📖 Rehab Science- Trauma — fall on outstretched arm or forced abduction/external rotation
- Previous dislocation damaging passive restraints
- Congenital hypermobility
- Loss of control under load in reaching positions (e.g. incline bench press)
Source: Rehab Science · Ch 16 · PDF p. 398show sources ▾
Page numbers are those of the uploaded PDF edition. "Find original" opens a PubMed search for the cited study.
Aggravating factors
📖 Rehab Science| Movement / activity | Why it may cause symptoms | Temporary modification |
|---|---|---|
| Overhead lifting and throwing | Places the joint near end range where passive restraints are compromised. | Avoid end-range overhead loading until phase 3 control is established. |
| Reaching up | Combines lever length and rotation—typical subluxation positions. | Work in mid-range with the elbow closer to the body. |
| Stretching the shoulder | Stretching a hypermobile joint can increase instability (no stretching in phase 2). | Prioritise strength and motor control instead of stretching. |
Aggravating factors are temporary—tissues are sensitised or not ready yet. The protocol rebuilds capacity so these tasks become comfortable again.
Source: Rehab Science · Ch 16 · PDF p. 399· 2 original research citationsshow sources ▾
- [Ch 16·10] Guerrero P, Busconi B, Deangelis N, Powers G. Congenital instability of the shoulder joint: assessment and treatment options. J Orthop Sports Phys Ther. 2009;39(2):124-134. find original ↗
- [Ch 16·12] Burkhead WZ Jr, Rockwood CA Jr. Treatment of instability of the shoulder with an exercise program. J Bone Joint Surg Am. 1992;74(6):890-896. find original ↗
Page numbers are those of the uploaded PDF edition. "Find original" opens a PubMed search for the cited study.
Assessment & tests
MRI or MR arthrography may be used by a clinician to assess labral injury when surgery is being considered.
No single positive test proves a diagnosis. Clinical tests are interpreted together with history and examination by a trained professional.
Differential considerations
📖 Rehab ScienceConditions with overlapping symptoms may need professional assessment to tell apart.
Treatment & recovery
📖 Rehab Science8–12 weeks of physio focused on stability and strength. People with naturally loose shoulders or no traumatic injury do well with rehab (about 50–85% success); after a traumatic dislocation that keeps recurring, success with rehab alone is only about 15% and surgery should be considered. Phase 1: self-massage, then ACTIVE range of motion (skipping passive, because lifting is usually less painful than with cuff injuries and active work trains control), then isometrics. Phase 2: no stretching—light rows, presses, lateral raise, bench lift-off and cuff rotation. Phase 3: curl, D2 flexion, prone 90/90, then weight-bearing control (shoulder taps → clock → dolphin press) and finally the shoulder press.
Source: Rehab Science · Ch 16 · PDF pp. 399, 400, 401· 3 original research citationsshow sources ▾
- [Ch 16·10] Guerrero P, Busconi B, Deangelis N, Powers G. Congenital instability of the shoulder joint: assessment and treatment options. J Orthop Sports Phys Ther. 2009;39(2):124-134. find original ↗
- [Ch 16·11] Misamore GW, Sallay PI, Didelot W. A longitudinal study of patients with multidirectional instability of the shoulder with seven- to ten-year follow-up. J Shoulder Elbow Surg. 2005;14(5):466-470. find original ↗
- [Ch 16·12] Burkhead WZ Jr, Rockwood CA Jr. Treatment of instability of the shoulder with an exercise program. J Bone Joint Surg Am. 1992;74(6):890-896. find original ↗
Page numbers are those of the uploaded PDF edition. "Find original" opens a PubMed search for the cited study.
Prevention
📖 Rehab ScienceMaintain cuff, biceps and scapular strength and closed-chain control; avoid stretching hypermobile shoulders; build strength in arm-away-from-body positions.