Transcript Biomech MS System (cont`d), Upper Extremity

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 movementrelated 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 TOC
Carpal 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