Method of Study for This Section

• Read assigned readings of text• Use text readings and the Dynamic Human CD-ROM to help review

structure of bones, joints, and muscles as necessary. This is the purpose of labs

• Complete labs conscientiously and study models of articulated skeleton, shoulder, spine, and knee

• Lecture will only provide a selective review of structure, muscles & movements. Focus will be on muscular analysis of movements and exercises and movement-related issues, such as common injuries.

• For exams, review lecture notes and understanding questions in both lecture and labs

Sh Jt & Girdle Ant Musculature

Sh Jt & Girdle Post Musculature

Upper Extremity – Chapter 7

Shoulder Girdle Structure:

Elevation and Depression

Upward & Downward Rotation

Protraction & Retraction

Shoulder Joint Structure

Shoulder Joint Stabilizers

• Stabilizers and rotators - Rotator cuff muscles – (Fig 7-5)– Teres minor - external rotation

– Infraspinatus - external rotation

– Supraspinatus - abduction

– Subscapularis - internal rotation

Shoulder Joint Primary Movers

• Vector representation of muscle forces• Anterior movers – (Fig 7-13) Anterior deltoid,

pectoralis major• Superior movers - middle deltoid (Fig 7-11)

• Posterior movers - posterior deltoid (Fig 7-14)

• Inferior movers - latissimus dorsi, teres major, lower pectoralis m. (Fig 7-10, 7-12)

Shoulder Jt Muscles

Synergism of prime movers and rotator cuff muscles during arm abduction

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

I: II: III:

Sh Jt Impingement (2)• Good website:

MMG - Patient Education Impingement Syndrome

• Causes– 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

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.

Elbow Joint Structure

• Muscles of elbow joint:

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

KIN 330 Biomechanics

• Muscles of elbow joint:

Radioulnar Jt Muscles

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

• Epicondylitis– The most common cumulative trauma disorder (CTD), repetitive

stress injury (RSI), repetitive motion disorder (RMD), or overuse syndrome (OS) is epicondylitis

– Epicondylitis website:– MMG - Patient Education Cumulative Trauma Disorders TOC

Radioulnar Jt Muscles

Bones of Wrist and Hand

Carpal Tunnel Syndrome• Background

MMG - Patient Education Cumulative Trauma Disorders TOCCarpal tunnel includes median nerve and 9 flexor tendons ( 4 flex dig sup, 4 flex dig prof, 1 fl pol l)

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

Review Problems for Chapter 7

• Torque at shoulder with elbow flexed vs extended– Fig 7-15, 7-16

• Compressive force at shoulder jt– Fig 7-17, sample problem 1

• Elbow flexion force– Figure 7-26, sample problem 2

• Introductory problems, p 217: 5,6,8,9• Additional problems, p 217-218: 5,10

Compressive force at shoulder joint

Elbow flexor tension and Joint compressive force