Shoulder Subluxation/Dislocation in Baseball

While most shoulder injuries in baseball are associated with throwing, traumatic shoulder subluxations from diving into a base, sliding, or forceful swings are an under-recognized but serious issue—especially in infielders, outfielders, and hitters. These injuries can cause persistent instability, limit performance, and increase the risk of future dislocations if not managed properly.

What Is a Shoulder Subluxation?
A shoulder subluxation is a partial dislocation of the humeral head from the glenoid fossa that spontaneously reduces. It is different from a full dislocation (which often requires reduction by a medical provider).

Mechanisms in baseball include:

• Diving or falling onto an outstretched hand (FOOSH)
• Arm forcibly extended and externally rotated
• Powerful eccentric follow-through during a swing

This trauma can stretch or tear the anterior capsule, labrum, and inferior glenohumeral ligament complex, leading to instability.

Signs and Symptoms
Symptoms of shoulder subluxation can range from mild to severe:

• Sudden, sharp pain during the injury event
• Feeling of the shoulder “slipping out” and back in
• Localized pain in the front or deep inside the shoulder
• Weakness or instability with reaching or swinging
• Decreased power or confidence in shoulder function
• “Dead arm” sensation after incident
• In severe cases, swelling, guarding, or labral clicking may develop within 24 hours.

Frequency and Risk 
Shoulder subluxations are less frequent than throwing-related pathologies but still significant in high-level baseball. They most commonly affect:

• Infielders diving into bases
• Outfielders landing on an outstretched arm
• Hitters with aggressive follow-throughs or torque-driven swings
  

According to Owens et al. (2009), subluxation events account for up to 40% of all traumatic shoulder instability cases in contact and field sports, with baseball players making up a notable portion of non-contact subluxation presentations.

Diagnosis and Imaging
Evaluation includes:

• History of trauma (diving, fall, swing) with instability feeling
• Physical tests:
  • Apprehension and relocation tests (for anterior instability)
  • Sulcus sign (for multidirectional laxity)
  • Load and shift test
• MRI arthrogram is the gold standard to evaluate:
  • Labral tears (e.g., Bankart lesions)
  • Capsule and ligament integrity
  • Hill-Sachs lesions (compression fractures of the humeral head)

Treatment Options

Conservative Treatment (for first-time or low-grade subluxation)

Phase 1: Acute Protection (0–10 Days)

• • Rest from throwing, hitting, and high-stress movements
  • Imbolization: Sling for 1-2 weeks
  • Ice, anti-inflammatories, and sling (if needed) for pain control
  • Avoid Abduction and External rotation (position of dislocation dependent)
  • Begin gentle pendulum and pain-free ROM
  • Initiate isometrics, if pain free
  • Elbow, wrist and hand AROM 
  • 
    

Phase 2: Mobility & Scapular Control (10–21 Days)

• • Begin pain free PROM and AAROM
  • Avoid ABD combined with ER motions
  • Restore full PROM, especially ER and IR in neutral and 90°
  • Progress/Initiate isometrics for rotator cuff and scapular stabilization
  • Begin rhythmic stabilization drills for dynamic control

Phase 3: Strengthening & Stability (3–6 Weeks)

• • Closed-chain and low load/intensity weight-bearing drills
  • Closed-chain exercises (wall walks, quadruped rhythmic stabilization).
  • Initiate proprioceptive work (e.g., body blade, ball on wall).
  • Avoid heavy overhead activities.
  • Progress to eccentric cuff strengthening, core integration, and med
  • ball control drills
  • Emphasize kinetic chain mechanics in hitting and fielding positions

Phase 4: Return to Play Progression (6–10 Weeks)

• • Progress to OKC ER/IR, rows, prone T/Y/I exercises.
  • Initiate open-chain strengthening, double arm plyometrics
  • Begin light overhead work, push-up progressions.
  • Gradual reintroduction of hitting, diving, and throwing under supervision
  • Continue pre-activity scapular and posterior cuff activation
  • Monitor for any signs of instability or hesitation during full effort tasks

Phase 5: Return to Throw/Hitting and Play (10-16+ weeks) 

• • Must demonstrate:
    • Symmetrical ROM and scapular control.
    • No apprehension or instability with ER and abduction.
    • Satisfactory performance on upper limb tests
      • Follow a structured throwing progression:
        • Phase 1: Flat-ground throws (45–90 ft)
        • Phase 2: Increase intensity and distance
        • Phase 3: Bullpens (~14+ weeks post-injury)
        • Phase 4: Live batting practice

Surgical Consideration
Indicated for:

• Recurrent subluxations
• Presence of labral tears or Bankart/Hill-Sachs lesions
• Failure to regain dynamic stability after 2–3 months of rehab
• Procedures may include arthroscopic Bankart repair, capsular shift, or open stabilization depending on tissue damage.

Return to Sport Timeline

Conservative Rehab: 6–16+ weeks
Arthroscopic Repair: 4–6 months
Open Stabilization: 6–9 months

According to Mair et al. (2002), 80–90% of athletes who undergo non-surgical management for a first-time subluxation return to sport successfully if rehab is completed properly. Surgical cases can also have high return rates but require longer recovery timelines and precise RTP criteria.

Risk of Recurrence and Long-Term Outlook
Up to 40% of first-time subluxation cases recur within two years, especially in contact or overhead athletes 
Poor scapular control and insufficient ER strength are common reinjury factors
Labral damage or generalized hypermobility increases recurrence risk
Prevention Strategies
Posterior cuff and scapular endurance training
Eccentric control drills (e.g., manual ER deceleration, plyometric med ball rebounders)
Core and hip control during diving or reaching mechanics
Use protective bracing or shoulder sleeves in high-risk players
Monitor shoulder workload, especially in dual-role athletes (e.g., pitcher-infielder)

Summary

Anterior shoulder subluxations from diving or hitting are traumatic but manageable injuries in baseball athletes. Whether treated conservatively or surgically, success depends on full restoration of dynamic stability, scapular control, and athlete confidence.

With structured rehab and return-to-play planning, athletes can return to competition safely and efficiently—stronger and more resilient than before.

References

• Owens BD, et al. (2009). Incidence of shoulder instability in the United States military: demographic considerations from a high-risk population. Journal of Bone and Joint Surgery, 91(4): 791–796.
• Mair SD, et al. (2002). Nonoperative treatment of shoulder instability in athletes. The American Journal of Sports Medicine, 30(5): 758–765.
• Burkhart SS, De Beer JF. (2000). Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs. Arthroscopy, 16(7): 677–694.
• Wilk KE, et al. (2011). Rehabilitation of the overhead throwing athlete: Current concepts and clinical applications. Journal of Orthopaedic & Sports Physical Therapy, 41(2): 388–400.
• Arciero RA, et al. (2006). Return to sport after first-time shoulder dislocation in collegiate athletes. The American Journal of Sports Medicine, 34(5): 772–776.
• Paterson et al. Shorter immobilization has similar outcomes to longer immobilization but allows earlier rehab (Paterson et al., 2010).
• AAOS Guidelines for Shoulder Instability
• ARC Consensus Statement, 2022 – Youth shoulder instability management