Elbow, Wrist, and Hand

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Elbow, Wrist, and Hand

• Chapter 6

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Elbow

• Bones humerus, radius, ulna
• Joints humeroulnar, humeroradial, radioulnar
• Humeroulnar hinge joint
• Humeroradial gliding joint (restricted ball and
  socket joint)
• Radioulnar
• Movements flexion, extension (humeroulnar,
  -radial joints) pronation, supination (radioulnar
  joint)

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Elbow muscles

• Anterior biceps brachii, brachialis,
  brachioradialis, pronator teres
• Posterior triceps brachii, supinator

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Elbow muscles

• Brachioradialis elbow flexion
• radial nerve (C5, C6)
• Pronator Teres forearm pronation, assists elbow
  flexion
• median nerve (C6, C7)

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Elbow muscles

• Brachialis true elbow flexion
• musculocutaneous nerve
• Supinator supination of forearm
• radial nerve (C6)

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Elbow muscles

• Triceps Brachii elbow extension
• radial nerve
• Biceps Brachii flexion of forearm, flexion of
  shoulder, extension of forearm, supination of
  forearm, stabilization of shoulder
• musculocutaneous nerve (C5, C6)

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Muscular analysis

• Flexion
• Brachialis is a flexor under all conditions
• During Isometric contractions
• Biceps is most active in supination
• Brachioradialis most active in midposition or in
  supination
• Pronator teres, a moderate flexor, most active in
  a position of pronation
• Isometric flexion greatest in midposition or
  supination
• Extension
• Triceps anconeus, when not by 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

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Wrist

• Bones radius, ulna, carpals (scaphoid, lunate,
  triquetrum, pisiform, trapezium, trapezoid,
  capitate, hamate), metacarpals (I through V)
• Joint radiocarpal joint (condyloid)
• Movements flexion (palmar flexion), extension
  (neutral), hyperextension (dorsiflexion),
  abduction (radial deviation) adduction (ulnar
  deviation) circumduction

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Hand

• Hand mobility due to generous supply of joints
• Radiocarpal joint, Articulation between two rows
  of carpal bones, and Carpometacarpal joint
• Proximal and distal rows of carpal bones permit
  only a slight gliding motion (modified hinge)
• Anterior surface of carpal bone are slightly
  concave form side to side, referred to as the
  Carpal Tunnel

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Wrist and hand

• Anterior flexor carpi radialis, flexor carpi
  ulnaris, palmaris longus, flexor digitorum
  superficialis, flexor digitorum profundus, flexor
  pollicis longus
• Posterior extensor carpi radialis brevis,
  extensor carpi radialis longus, extensor carpi
  ulnaris, extensor digitorum, extensor, digiti
  minimi, extensor indicis

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Fingers

• Bones carpals, metacarpals, proximal/middle/dista
  l phalanges
• Joint CMC joints (irregular), MCP joint
  (condyloid), PIP joint (hinge), DIP (hinge)
• Movements CMC none, MCP flexion, extension,
  hyperextension, ab/adduction, PIP/DIP flexion,
  extension
• Joints between adjacent palanges of any of the
  five digits.
• All are hinge joint, permit only flexion
  extension
• Hyperextension is slight, if present at all
• Each enclosed in a capsule
• Strengthen by collateral ligaments and a in front
  by a volar ligament

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Wrist muscles

• Flexor Carpi Radialis flexes hand
• median nerve (C6, C7)
• Flexor Carpi Ulnaris wrist flexion, ulnar
  deviation
• ulnar nerve (C8, T1)
• Palmaris Longus wrist flexion
• median nerve (C6, C7)
• Flexor pollicis longus thumb CMC and IP flexion
• Median nerve (C8, T1)

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Wrist and finger muscles

• Extensor Carpi Radialis Brevis wrist extension
• radial nerve (C6, C7)
• Extensor Carpi Radialis Longus wrist extension,
  radial deviation
• radial nerve (C6, C7)
• Extensor Carpi Ulnaris wrist extension, ulnar
  deviation
• Innervation radial nerve (C6, C7)
• Extensor digiti minimi MCP extension of 5th
  finger
• Radial nerve (C6-C8)
• Extensor digitorum MCP extension of 4 fingers,
  wrist extension
• Radial nerve (C6-C8)

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Finger muscles

• Flexor digitorum superficialis flexes MCP and
  PIP joints of 4 fingers
• median nerve
• Flexor digitorum profundus flexes all three
  finger joints
• median and ulnar nerves

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Wrist and thumb muscles

• Extensor indices MCP extension of 3rd finger
• Radial nerve (C7)
• Extensor pollicis longus Wrist and thumb
  extension
• Radial nerve (C6-C8)
• Extensor pollicis brevis MCP extension at thumb
• Radial nerve (C6-C8)
• Abductor pollicis longus CMC abduction of
  thumb, wrist abduction
• Radial nerve C6, C7

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Thumb

• Bones proximal distal phalanges, 1st
  metacarpal and trapezium
• Joint carpometacarpal joint (saddle shaped)
• Movements abduction, adduction, flexion,
  extension, circumduction, opposition

Hyperadduction
Abduction
Extension
Opposition
Flexion
Hyperflexion
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Thumb and hand muscles

• Anterior abductor pollicis longus, extensor
  pollicis brevis, extensor pollicis longus, flexor
  pollicis longus
• Posterior abductor pollicis brevis, adductor
  pollicis, flexor pollicis brevis, opponens
  pollicis
• Extrinsic muscles of wrist and hand muscles
  that span wrist as well as hand
• Proximal attachment is above wrist, assist in
  wrist function
• Intrinsic muscles have proximal attachment at or
  distal to carpal bones, fine motor control
• Thenar muscles operate the thumb, hypothenar
  muscles operate little finger, deep palm muscles
  are in between

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Thumb muscles

• Opponens pollicis opposes thumb to fingers
  (intrinsic)
• median nerve (C6, C7)
• Adductor pollicis adducts thumb (intrinsic)
• ulnar nerve (C8, T1)

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Thumb muscles

• Flexor pollicis longus thumb flexion
  (extrinsic)
• median nerve (C8, T1)
• Flexor pollicis brevis thumb flexion
  (intrinsic)
• median nerve (C6, C7)
• Abductor pollicis brevis abducts thumb
  (intrinsic)
• median nerve
• Abductor pollicis longus extends, rotates thumb
  (extrinsic)
• radial nerve

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• Abductor digiti minimi abducts MCP joint of 5th
  digit
• ulnar nerve
• Opponens digiti minimi opposes 5th digit with
  thumb
• ulnar nerve
• Dorsal Interossei abduct fingers at MCP joint
• ulnar nerve
• Palmar Interossei adduct fingers at MCP joint
• ulnar nerve
• Lumbricals flexes MCP while extending IP joints
• 1st /2nd median nerve, 3rd /4th ulnar nerve

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Hand function

• Grasp, prehension
• Hand is adapted to hold and manipulate objects
• How the hand is used depends on size, shape,
  weight of object, how object will be used,
  involvement of proximal segments of upper
  extremity
• Shoulder joint/girdle places hand in space
• Elbow moves hand closer to or further away from
  body
• Wrist provides stability
• Functional Position Optimal position for wrist
  and hand for the hand to be most effective in
  terms of strength and precision
• Wrist slightly extended, MCP and PIP joints are
  flexed and thumb in opposition
• Power Grip object needs to be held forcefully
  while being moved about by more proximal joints
• Cylindrical all fingers flexed around an
  object, thumb wraps around object in other
  direction overlapping fingers
• Spherical all fingers and thumb adducted around
  an object fingers spread apart
• Hook 2nd-5th fingers flexed about an object in
  a hooklike manner, thumb is not involved

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Spherical
Hook
Cylindrical
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• Precision Grip object needs to be manipulated
  in finer movements
• Pinch thumb abducted, index finger MCP joint
  flexed, other joints extended
• Three-Jaw Chuck thumb and first two digits
• Lateral prehension pad of thumb presses against
  radial side of index finger inserting key
• Side-to-side adduction of first two digits,
  thumb not involved
• Lumbrical MCP and PIP joints flexed, DIP
  extended, thumb opposes fingers to hold an object
  horizontal (holding a plate or tray)