Who is this?

1. Who is this?

2. How about this one?

3. Throwing Shoulder

4. Phases of Throwing • Motion takes about 2 seconds • 75% due to wind-up and cocking

5. Phases of Throwing • Wind-up • Early Cocking • Late cocking – arm abducted and ER, scapula retracted, maximum anterior shear force due to AB-ER position and the highest shoulder torgue • Acceleration – transition from eccentric to concentric, only 1/3 kinetic energy stays with ball, remainder dissipated via kinetic chain, late cocking and acceleration in peel back phenomenon associated with slap lesions

6. Phases of Throwing • Deceleration (most violent phase) largest joint loads, including compressin equal to body weight, posterior shear 400N inferior shear >30N, compression >1,000 N, traction forces during deceleration implicated as ne cause of slap lesion • Follow- through

9. Functional stability • Static and dynamic stabilizing systems of the GH joint

10. Static Stability • Joint geometry • Capsule • GH ligaments • labrum

11. Static Stability • Compromise on over head activities and need for dynamic stabilizers

12. Dynamic stabilizers • Neuromuscular interaction of force couples of the rotator cuff and the shoulder muscular • Need for excessive motion in the shoulder requires the dynamic stabilizers to work efficiently, especially at the end of the ROM where static stabilizers are compromise

13. Shoulder ROM greater in overhead athletes • At 90 degrees abduction there is greater ER and decrease IR • 41 pitchers ER 141 IR 83 7 degrees more in the dominate side

14. Total Motion • ER 7 degrees greater • IR 7 degrees less • Total motion is the same

15. Why ROM? • Excessive stress at the end of the ROM • Angular velocity at 7265 degrees per second which is the fastest human movement • End range of ER forces generated – 1 ½ times the body weight in late cocking of ER • Up to 1 ½ body weight distractng the joint • Need for dynamic stabilizers

16. ROM characteristics of overhead sports • Acquire laxity of the anterior capsule • Soft tissue adaptation of the posterior cuff • Osseous adaptation of the humerus

17. Delicate balance between acquire laxity and pathological micro-instability

18. Shoulder pathology • Slap superior labrum anteroposterior lesions • Inpingement of the undersurface of the infraspinatus on the posterior superior labrum (internal impingement)

19. Rotator cuff • External impingement rare • Increase joint laxity and increase rom • Laxity plus overhead leads t rotator cuff dysfunction (secondary impingement) • Traction forces during the follow-through can acutely or chronically damage the RTC muscles • These same traction forces may promote cumulative tensile stress to the posterior-inferior shoulder capsule producing a Bennett lesion

20. Treatment • Surgery if failure to progress within 3 to 6 months • Posterior-superior /internal impingement condition thought to be accentuated by increase shoulder anterior instability poor scapular retraction during late cocking /acceleration and posterior capsule tightness (GIRD)

21. SLAP Lesions • Type 2 • Late cocking/acceleration via peel-back phenomenon and during deceleration due to traction

23. Glenohumeral Internal Rotation Deficit (GIRD) • Posterior shoulder tightness (loss of IR) to accelerate the peel back phenomenon and etiology of slap lesions

24. Glenohumeral Internal Rotation Deficit (GIRD) • is an easily resolveable condition that frequently occurs in pitchers. • As a pitcher increases his/her number of throws, the anterior glenohumeral joint capsule becomes lax while the posterior capsule tightens. • This results in limited internal rotation. • When internal rotation deficits exceed 20-25 degrees on the throwing compared to the non-throwing side the athlete becomes at risk for biceps/RTC tendonitis, labral tears and RTC tears. • Studies have shown that 90% of athletes can regain this internal rotation with posterior capsule stretching.

25. Bennett lesion • Calcification of the posterior band of the inferior GH ligament • Tx – symptomatically

26. The Bennett lesion • an extraarticular curvilinear calcification along the posteroinferiorglenoid near the attachment of the posterior band of the inferior glenohumeralligament. • It is associated with posterior labral tear, posterior undersurface rotator cuff tear, and posterior subluxation of the humeral head . • More prevalent in overhead throwing athletes, the Bennett lesion is thought to be due to a traction injury of the posterior band of the inferior glenohumeral ligament during the deceleration phase of throwing.

27. Exams for Micro-instability of Overhead Athletes • Total Motion • Sulcus maneuver • Anterior drawer test • Anterior fulcrum test • Relocation maneuver during the internal inpingement sign

28. Anterior fulcrum test

29. Anterior drawer test

30. Anterior drawer test

31. Posterior Impingement Sign

32. Relocation maneuver during the Internal Inpingement Sign

33. Swimming

34. How many strokes per year?

35. Swimmers Shoulder