Name, locate, & describe the structure & ligamentous reinforcements of the elbow, forearm, wrist, and hand joints. 2. Name & demonstrate the movements possible in these joints. 3. Name & locate muscles & muscle groups, and name their primary actions. 4. Analyze the fundamental movements with respect to joint & muscle actions. 5. Describe common athletic injuries.
6-4 Distal humerus -trochlea & capitulum. Ulna - semilunar notch: Coronoid process Olecranon process Radial head Radial notch of ulna Fig 6.1
6-5 All 3 joints enveloped in a capsule, lined by synovial membrane. Strengthened by radial & ulnar collateral ligaments. Annular ligament encircles the radial head & binds it to ulna. Fig 6.2 & 6.3 Fig 6.4a Movements of the elbow joint
6-6 Proximal: previously described. Distal: Pivot joint Radius articulates with head of ulna. Strengthened by: Volar radioulnar ligament Dorsal radioulnar ligament Fig 6.1 The radiolunar joints--movements
6-8 Function: Flexes and supinates the forearm. Function: Flexion at the elbow. Fig 6.7 Fig 6.5
6-9 Brachioradialis Function: Contributes to elbow flexion. Pronator Teres Function: Pronates the forearm, assists in elbow flexion. Pronator Quadratus Function: Pronation of the forearm. Fig 6.8 Fig 6.9
6-10 Triceps Brachii Function: Powerful extensor of elbow. Supinator Function: Supination of the forearm. Fig 6.10
6-11 Function: Working with the triceps, extends the forearm. Fig 6.11
6-12 Flexion Biceps brachii, brachioradialis, brachialis Brachialis active in all conditions. Biceps brachii most active with supination, least with pronation. Fig 6.6 pronation supination
6-13 Extension Triceps & anconeus, against gravity. Pronation Pronator teres & pronator quadratus. Supination Supinator & biceps; Long head more active with greater muscle length, while short head more active with shorter muscle length.
6-14 Great mobility due to generous supply of joints: Radiocarpal (wrist) joint. Articulation between two rows of carpal bones. Carpometacarpal joints. Fig 6.12 Trapezoid Trapezium Hamate Capitate Lunate Triquetral Scaphoid
6-15 Condyloid joint 4 ligaments Volar radiocarpal Dorsal radiocarpal Ulnar collateral Radial collateral Fig 6.14 Circumduction: fingertips describe a circle, hand describes a cone. Fig 6.16 Movements of the hand at the wrist
6-16 Proximal row of 4 carpal bones articulate with four carpal bones of distal row. Permits only a slight gliding motion. However, the gliding adds up to a modified hinge type of movement. Anterior surface of carpal bones are slightly concave, referred to as the carpal tunnel.
6-17 The thumb is a prime example of a saddle joint. Joints between bases of metacarpal bones are irregular. All are enclosed in capsules. Fig 6.13
6-19 Because of short ligaments in this region, motion in these joint is almost nonexistent. Limited to slight gliding. 5 th carpometacarpal joint is slightly more mobile.
6-20 Joints at bases of four fingers, uniting proximal phalanges with metacarpals. Condyloid joints Encased in capsules Protected by collateral ligaments. Also a dorsal ligament. Fig 6.17 Fig 6.20 Movements of Metacarpophalangeal Joint of the Fingers
6-21 Flexion: volar surface of the thumb approaches base of thumb. Extension: return movement from flexion.
6-22 Joints between adjacent phalanges of any of the five digits. All are hinge joints, permit only flexion & extension. Hyperextension is slight, if present at all. Each enclosed in a capsule. Strengthen by collateral ligaments and in front by a volar ligament.
6-29 Abductor digit minimi Function: Abducts little finger. Flexor digiti minimi Function: Flexes little finger. Opponens digiti minimi Function: Opposition of little finger. Abductor pollicis brevis Function: Abducts thumb. Flexor pollicis brevis Function: Flexes thumb. Opponens pollicis Function: Opposition of thumb. Fig 6.26
6-31 Thumb Metacarpal Flexion Extension Abduction Adduction Opposition Thumb Phalanges Flexion Extension
6-32 Long finger muscles do not have sufficient length to permit full ROM in joints of fingers & wrist at the same time. Example: make a tight fist, now flex wrist, fingers loosen their grip. Length of Long Finger Muscles Relative to Range of Motion in Wrist & Fingers
6-33 Power grip involves flexion of all fingers Fig 6.30 CylindricalSphericalHook
6-34 Precision involves thumb & two fingers, depending on shape & size of object Fig 6.30
6-35 Result of direct blow or falling on outstretched hand. Usually both ulna & radius fracture. In the young usually a greenstick type. Immobilization of the elbow is important to reduce movement at fracture site.
6-36 Results from falling on outstretched hand with elbow extended or hyperextended. Most common is backward displacement of ulna & radius in relation to humerus. Dislocation is frequently accompanied by fracture. Most common is to medial epicondyle. Very serious - likely to involve blood vessels & nerves.
6-37 From falling on palm of hand with wrist hyperextended. Usually a sprain of ligaments. May be a strain to tendons. May be pain, weakness, limited ROM.
6-38 This is an overuse, repetitive stress injury. Long hours working with small hand tools and keyboards. Nerve & blood vessel compression as they pass through carpal arch & transverse carpal ligament. Indicators are pain, numbing of fingers.
6-39 External force applied to tendon pulls off a piece of bone. Often from rapid pronation/supination or high energy flexion of fingers. Probability for occurrence greatest during growth and maturation.
6-40 Lateral epicondylitis – “tennis elbow” Medial epicondylitis – ‘Little League elbow” Both are repetitive stress injuries. Micro-traumas or tears in muscle & soft tissue at proximal attachments. Indication is pain on activity. Rest, ice, anti-inflammatory drugs, bracing often used as treatment.