Method of Study for This Section

1. Method of Study for This Section • Read assigned readings of text • Use Thompson Manual and the Dynamic Human CD-ROM to help review structure of bones, joints, and muscles as necessary. This is the purpose of lab. • Complete labs conscientiously and study models of articulated skeleton, shoulder, spine, and knee • Lecture will only provide a selective review of structure, muscles & movements, and movement-related issues • For exams, review lecture notes and understanding questions in both lecture and labs

2. Objectives • Explain how anatomical structure affects movement capabilities on upper extremity articulations. • Identify factors influencing the relative mobility and stability of upper extremity movements • Identify muscles that are active during specific upper extremity movements • Describe the biomechanical contributions to common injuries of the upper extremity.

3. Sh Jt & Girdle Ant Musculature

4. Sh Jt & Girdle Post Musculature

5. Upper Extremity – Chapter 7 Shoulder Girdle Structure:

6. Muscles and Movement of Shoulder Girdle • Illustrations on next three slides • Trapezius (large, superficial medial and sup to scapulae) • Upper portion - elevation, upward rotation • Middle portion - adduction, or retraction • Lower portion - depression, upward rotation • Rhomboids - • elevation, downward rotation, adduction, or retraction • Serratus anterior (underneath scapulae) • abduction, upward rotation • Pectoralis minor (underneath pectoralis major) • downward rotation, abduction, or protraction • Levator Scapulae (underneath upper trapezius) • elevation, downward rotation

7. Elevation and Depression

8. Upward & Downward Rotation

9. Protraction & Retraction

10. Shoulder Joint Structure

11. Shoulder Joint Stabilizers • Stabilizers and rotators - Rotator cuff muscles – • Teres minor - external rotation • Infraspinatus - external rotation • Supraspinatus - abduction • Subscapularis - internal rotation

12. Shoulder Joint Primary Movers • Anterior movers – Anterior deltoid, pectoralis major • Superior movers - middle deltoid • Posterior movers - posterior deltoid • Inferior movers - latissimus dorsi, teres major, lower pectoralis m. • Force vectors of muscles (see next slide)

13. Shoulder Jt Muscles

14. Movements of Shoulder Complex • Every movement of upper extremity involves either stabilizing or accomodating action of the shoulder girdle. • If carrying something in arms, scapular elevators are involved • Arm elevation – scapular protraction and/or upward rotation (first 30°,1/5th is scapular movement; then ½ scapular movement)

15. Shoulder Joint Impingement Syndrome • What is it? Pain from shoulder area resulting from impingement of structures between humeral head, acromion, and coracromial arch. Three stages: • Stage I - edema and hemorrhage of subacromial structures • Stage II - tendon fibrosis and bursal thickening • Stage III - rotator cuff tears, biceps tendon ruptures, and bone spurs II: III: I:

16. Causes of Sh Jt Impingement • Primary impingement: • Repeated movements requiring elevated and/or medially rotated humerus, compounded by weak rotator cuff muscles, causing: impingement of long head of biceps, supraspinatus • Secondary Impingement: • Decreased volume of subacromial space due to glenohumeral joint instability, and perhaps joint capsular tightness • Structural abnormalities: • hooked or curved acromion, calcium deposits, bone spurs, thickened bursa, thickened ligaments

17. Shoulder Jt Impingement (3) • Treatment: • Related to the cause - may involve surgery, rotator cuff strengthening, and flexibility exercises. • Later, avoid humeral elevation and rotation movements. http://www.aafp.org/afp/980215ap/fongemie.html • Website for Shoulder JointImpingement Syndrome

18. Elbow Joint Structure

19. Elbow and Wrist Joint Muscles • True Flexor - Brachialis • Flexor-Supinator - Biceps brachii • Extensor - Triceps brachii • Wrist flexors (medial epicondyle of humerus) • Flexor carpi ulnaris and flexor carpi radialis • Wrist extensors (lateral epicondyle of humerus) • Extensor carpi ulnaris & extensor carpi radialis • Force vectors of muscles on next slide KIN 330 Biomechanics

20. Muscles of elbow joint:

21. Muscles and Movements of Radioulnar Joint • Elbow Flexion - • Forearm Supination - Biceps Brachii • Forearm Pronation - Pronator Teres • Elbow Extension - • Forearm Supination - Supinator • Forearm Pronation -Pronator Quadratus • Muscle force vectors on next slide • Epicondylitis • The most common cumulative trauma disorder (CTD), repetitive stress injury (RSI), repetitive motion disorder (RMD), or overuse syndrome (OS) is epicondylitis • Epicondylitis website

22. Radioulnar Jt Muscles

23. Bones of Wrist and Hand

24. Carpal Tunnel Syndrome • Background Carpal tunnel includes median nerve and 9 flexor tendons ( 4 flex dig sup, 4 flex dig prof, 1 fl pol l)

25. Carpal Tunnel Syndrome (cont’d) • Symptoms • Pain in wrist area, or referred proximally or distally • Tingling of thumb, fingers, or palmar side of hand • Loss of control of muscles affected by median nerve blockage • Causes • Enlargement of tissues within tunnel • Decreased size of tunnel • Extraneous tissue in tunnel • Treatment • Related to cause • Website for prevention of repetitive stress injury at computer workstations: CUergo: Neutral Posture Typing KIN 330 Biomechanics

26. Review & Homework Problems for Chapter 7 • Review problems: • Torque at shoulder with elbow flexed vs extended • Fig 7-15, 7-16 • Compressive force at shoulder jt • Fig 7-17, sample problem 1 p 197 • Elbow flexion force • Figure 7-25, sample problem 2 p 206 • Homework – due Wed October 13 • Introductory problems, p 217: # 8,9,10 • Additional problem, p 218: #10