Chapter 5
Functional Anatomy of the Upper
Extremity
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Review of Anatomical Structures
• Shoulder girdle
–
An incomplete bony ring in the upper extremity formed by the two
scapulae and clavicles
• Scapula
–
Flat, triangular bone on the upper posterior thorax
• Clavicle
–
“S”-shaped bone articulating with scapula and sternum
–
“Collar bone”
• Glenoid fossa
–
Depression in lateral superior scapula
–
Socket for shoulder joint
• Glenoid labrum
–
Ring of fibrocartilage around rim of glenoid fossa
–
Deepens socket for shoulder joint
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Review of Anatomical Structures (cont.)
• Bursa
– Fibrous, fluid-filled sac that reduces friction
– Located between bones, tendons, and other structures
• Subacromial bursa
– Bursa between acromion process and insertion of
supraspinatus muscle
• Coracoid process
– Curved process arising from upper neck of scapula
– Overhangs shoulder joint
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The Shoulder Complex
• Sternoclavicular joint
– Articulation between sternum and clavicle
• Acromioclavicular joint
– Articulation between acromion process of scapula and
lateral end of clavicle
• Scapulothoracic joint
– Physiological joint between the scapula and thorax
• Glenohumeral joint
– Articulation between the head of the humerus and the
glenoid fossa of the scapula
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Movements of the Shoulder Complex
• Dislocation
• Rotation
• Elevation and Depression
• Protraction and Retraction
• Horizontal Flexion and Extension
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Scapular Movements
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Shoulder Joint Range of Motion
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Shoulder Joint Movement Characteristics
• Large range of motion (ROM) at shoulder
• Extreme ROM required by many activities
– Swimming, throwing, gymnastics
• Ligaments and muscles provide stability
• Scapular and clavicular movements accompany any arm
movement
• Scapulohumeral rhythm
– Movement relationship between humerus and scapula
during arm raising movements
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Muscular Actions
• Review Figure 5-9 on page 148
– 17 muscles that contribute to scapula and shoulder joint
movements are listed
• Major muscles
– Deltoid, trapezius, rhomboids, pectoralis major, latissimus
dorsi, serratus anterior
– Rotator cuff (4 muscles surrounding shoulder joint)
• Infraspinatus, supraspinatus, teres minor, subscapularis
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Arm Abduction and Flexion
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Muscle Action on the Shoulder Girdle
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Shoulder Muscle Strength
• Generate greatest strength in adduction
• Abduction used frequently in daily living
• Weakest movements are internal and external rotation
• Muscles generate high forces within joint
– Almost 90% of body weight at 90° abduction
– Implications?
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Shoulder Strength & Conditioning
• Shoulder muscles easy to stretch and strengthen
• Stretching
– Active and passive
• Strength training
– Weight training, limb/body weight exercises
• Rotator cuff strength and flexibility important
– Stabilization of joint
– Widely used in daily living
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Stretching & Strengthening Exercises
• Review Figure 5-14 on pages 152 and 153.
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Injury
• Sprain
– Rupture of fibers of ligament
• Subluxation
– Partial dislocation
• Fracture
– Break in bone, often clavicle
• Ectopic calcification
– Hardening of organic tissue through deposit of calcium
salts in areas away from the normal sites
• Degeneration
– Deterioration of tissue
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Injury (cont.)
• Bursitis
– Inflammation of bursa
• Impingement syndrome
– Irritation of structures above shoulder joint
– Due to repeated compression between greater tuberosity
and acromion process
• Subacromial bursitis
– Common from impingement syndrome
• Bicipital tendinitis
– Inflammation of the tendon of the biceps brachii
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Elbow and Radioulnar Joints
• Radiohumeral joint
–
Articulation between radius and humerus
–
Capitulum
• Eminence on distal end of lateral epicondyle
• Articulates with head of radius at elbow
• Ulnar-humeral joint
–
“Elbow”
–
Articulation between ulna and humerus
• Medial and lateral epicondyles
• Carrying angle
–
Angle between ulna and humerus with elbow extended
–
10–20°
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Carrying Angle
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Elbow and Radioulnar Joints (cont.)
• Radioulnar joints
– Articulations between ulna and radius
• Proximal and distal
– Pronation, supination
– Interosseous membrane
• Thin layer of tissue running between ulna and
radius
– Medial and lateral epicondyles
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Elbow Movement Characteristics
and Muscular Actions
• All 3 joints never close packed at same time
• Movements limited by several factors
– Soft tissue, ligaments, joint capsule, muscles
• 24 muscles cross elbow
– Most of these muscles capable of multiple
movements
– Muscles better at some movements than others
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Elbow Flexor Moment Arms
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Biceps Brachii Action
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Forearm Strength and Conditioning
• Flexor group nearly twice as strong as extensor
• Effectiveness of strengthening/stretching exercises
– Depends on position of arm
• Length-tension relationship
• Numerous exercises
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Stretching and Strengthening Exercises
• Review Figure 5-21 on page 162.
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Injury to Forearm
• Overuse injuries more common than trauma
– Throwing, tennis serve
• Ectopic bone
– Bone formation away from normal site
• Rupture
– Torn or disrupted tissue
• Muscle
• Olecranon bursitis
– Irritation of the olecranon bursae
• Commonly caused by falling on elbow
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Injury to Forearm (cont.)
• Medial tension syndrome
– “Pitcher’s elbow”
– Medial elbow pain from excessive valgus forces
• May include ligament sprain, medial epicondylitis,
tendinitis, avulsion fracture
• Osteochondritis dissecans
– Inflammation of bone and cartilage resulting in
splitting pieces of cartilage into the joint
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Wrist & Fingers
• Manipulation activities
• Very fine movements
• Many stable, yet mobile, segments
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Joints of the Wrist
• Radiocarpal
– “Wrist”
– Ellipsoid joint
• Flexion/extension, radial/ulnar flexion
• Distal radioulnar
– Ulna makes NO contact with carpals
– Does NOT participate in wrist movements
• Midcarpal
– Articulation between two rows of carpals
• Intercarpal
– Articulation between a pair of carpals
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Joints of the Wrist (cont.)
• Carpometacarpal
– Articulations between carpals and metacarpals
• Metacarpophalangeal
– Articulations between metacarpals and phalanges
• Interphalangeal
– Articulations between phalanges
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Muscular Actions
• Most originate outside hand region
• Thenar eminence
– Mound on radial side of palm formed by intrinsic
muscles acting on thumb
• Hypothenar eminence
– Mound on ulnar side of palm created by intrinsic
muscles acting on little finger
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Muscular Actions (cont.)
• Muscular actions:
– Hand flexion/extension
– Hand radial/ulnar flexion
– Finger flexion/extension
– Finger abduction/adduction
– Thumb flexion/extension
– Thumb abduction/adduction
– Thumb opposition
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Conditioning
• Why condition hand region?
– Improve grip strength
– Enhance wrist action for throwing, striking
– Prevent injury
• Exercises
– Wrist curls
– Gripping exercises
– Stretching
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Contributions of the Wrist & Hand
• Power grip
–
Powerful hand position
–
Maximally flexing fingers around object
• Precision grip
–
Fine-movement hand position
–
Minimally flexing fingers around object
• Examples:
–
Eating with fork
–
Throwing softball
–
Spiking volleyball
–
Dribbling basketball
–
Changing channel with remote control
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Grip
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Injury of the Wrist & Hand
• Bennett’s fracture
– Longitudinal fracture of base of first metacarpal
• Mallet finger
– Avulsion of finger extensor tendons at distal phalanx
• Result of forced flexion
• Boutonniere deformity
– Stiff proximal interphalangeal articulation
• Caused by injury to finger extensor mechanism
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Injury of the Wrist & Hand (cont.)
• Jersey finger
– Avulsion of finger flexor
• Result of forced hyperextension
• Trigger finger
– Snapping during flexion and extension of fingers
• Created by nodules on tendons
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Injury of the Wrist & Hand (cont.)
• Tenosynovitis
– Inflammation of sheath surrounding tendon
• Carpal tunnel syndrome
– Pressure and constriction of median nerve
• Caused by repetitive actions at wrist
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Carpal Tunnel
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Stretching and Strengthening Exercises
• Review Figure 5-27 on page 172.
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Contribution of Upper Extremity
Musculature to Sports Skills or
Movements
• Upper extremity is obviously important in:
– Everyday activities
• Pushing up out of a chair
• Carrying, lifting
– Sporting/leisure activities
• Swimming, throwing, striking (golf, volleyball)
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Overhand Throwing
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The Golf Swing
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Summary Questions
• What do the upper extremities enable us to do?
• What stabilizes the structures of the upper extremities?
• What are potential injuries to the upper extremities?
• What causes these injuries?
• How can injuries be prevented?
• What are some exercises for stretching and
strengthening the upper extremities?
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