Physical therapy of the wrist and hand Functional anatomy wrist and hand

• The wrist includes distal radius, scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate. • The hand includes five metacarpals and 14 phalanges make up the hand and five digits • The wrist is allowed for FL, EXT, radial deviation and ulnar deviation

Functional anatomy: the radiocarpal joint

• The radiocarpal joint: – The concave distal end of the radius and radioulnar disc connects the convex proximal row of the scaphoid, lunate, and triquetrum. – The triquetrum is mainly articulated with the disc

Functional anatomy: the radiocarpal joint

• Physiological motion of • Carpal glide of the wrist proximal row –Flexion – Dorsal – Extension – Volar – Radial deviation – Ulnar – Ulnar deviation – Radial Functional anatomy: the midcarpal joint

• The proximal row of the scaphoid, lunate, and triquetrum articulates with the distal row the trapezium, trapezoid, capitate, and hamate. • The capitate and hamate are convex and glide on the concave surface of the scaphoid, lunate, and triquetrum • The concave trapezium and trapezoid glide on the convex distal surface of the scaphoid Functional anatomy: the carpometacarpal (CMC) joint of digit 2 through 5 • Between each metacarpal and the distal row of carpals and the articulations between the base of each metacarpal • The flexion of the metacarpals and additional adduction of the fifth contribute to the cupping of the hand, improving prehension. Functional anatomy: the carpometacarpal (CMC) joint of the

• Saddle-shaped joint between the trapezium and base of the first metacarpal. • For flexion-extension of the thumb occurring in the frontal plane, the trapezium is convex and the base of the metacarpal is concave. • For abduction-adduction occurring in the sagittal plane, the trapezium is concave and the metacarpal is convex Functional anatomy: the carpometacarpal (CMC) joint of the thumb

• The first metacarpal of • Direction of glide of base the thumb of metacarpal –Flexion – Ulnar – Extension – Radial – Abduction – Dorsal – Adduction – Volar Functional anatomy: the metacarpophalangeal (MCP) joint of the thumb • Convex distal end of each metacarpal and concave proximal phalanx • Supported by a volar and two collateral ligaments Functional anatomy: the interphalangeal (IP) joint

• PIP and DIP for digit 2 to 5; the thumb has only one IP • The articulating surface at the distal end of each phalanx is convex, the articulating surface at the proximal end of each phalanx is concave Hand function: length-tension relationships

• As the fingers or thumb flex, the wrist must be stabilized by the wrist extensors from simultaneously flexing the wrist. • For strong fingers or thumb extension, the wrist flexors stabilize or flex the wrist so the extensors can function more efficiently. Hand function: cupping and flattening

• Cupping of the hand occurs with finger flexion, and flattening of the hand occurs with extension. Hand function: extensor mechanism

• Isolated contraction of the extensor digitorum produces clawing of he fingers (MCP hyperextension with IP flexion from passive pull of the extrinsic flexor tendons) • PIP and DIP extensions occur concurrently and can be caused by the interossei or lumbrical muscles • There must be tension in the extensor digitorum communis tendon for there to the interphalangeal extension Hand function: grips and prehension patterns • Grips invlove clamping an object with partially flexed fingers against the palm of the hand, with counterpressure from the adducted thumb. • Varieties include cylindrical grip, spherical grip, hook grip, and lateral prehension. • Precisions involve manipulating an object that is not in contact with the palm of the hand between the opposing abducted thumb and fingers • varieties include pad-to-pad, tip-to-tip, and pad-to-side prehensions Hand function: grips and prehension patterns

• Combined grips involve digit 1 and 2 performing precision activities, whereas digit 3-5 supplement with power subject to pressure and trauma around the wrist and hand • Median nerve passes through the carpal tunnel at the wrist with the flexor tendons. Nerve entrapment in the tunnel may occur. • Sensory changes: over the radial 2/3 of the palm, the aplmar surfaces of the first three and ½ digits, and the dorsum of the distal phalanges. • Weakness distal to the wrist: opponens pollicis, abductor pollicis brevis, superficial head of the flexor pollicis brevis, and lumbricals I and II • Ape-hand deformity

Ulnar nerve subject to pressure and trauma around the wrist and hand • enters the hand through a tunnel formed by the pisiform and hook of hamate and is covered by the volar carpal ligament and palmaris brevis muscle • Sensroy chnge: ulnar 1/3 of the hand, 5th digit and ulnar side of the 4th digit • Weakness to muscle distal to the site: palmaris brevis, muscles of the hypothenar eminence, lumbricals III and IV, interossei, adductor pollicis, and deep head of the flexor pollicis brevis • Claw-hand deformity subject to pressure and trauma around the wrist and hand

• Radial nerve enters the hand on the dorsal surface as the superficial radial nerve, only sensory. • Sensory change: over the radial 2/3 of the dorsum of the hand and thumb and the proximal phalanx of the 2nd, 3th, the half of the 4th digit • Muscles innervated by radial nerve are proximal to the wrist

Common wrist and hand deformities: Colles’ fracture

• Disturbance of the inferior radio-ulnar joint • Residual deformities: radial deviation of the hand and prominence of the ulna • Loss of movement of supination and wrist extension • Two complications after Colles’ fracture: – Delayed rupture of extensor pollicis longus may occur some months after injury and is due to ischaemia or attrition of the tendon Common wrist and hand deformities: Colles’ fracture

– Sudeck’s atrophy: marked swelling of the wrist, hand and fingers, gross stiffness of the fingers, and carpal decalcification Common wrist and hand deformities: ganglions

• In the carpal joint or tendon sheath or in the fingers • Size fluctuated • local swelling and tenderness may only obvious when the wrist is flexed.

Common wrist and hand deformities: De Quervain’s disease

• Tenosynovitis involving abductor pollicis longus and extensor pollicis brevis • P’t may complain of pain on certain movement of the wrist, and weakness of grip • Splitting the lateral wall of the sheath is the choice of treatment

Common wrist and hand deformities: • Compression of the median nerve leads to symptoms related to its distribution • Premenstrual fluid retention, early RA with synovial tendon sheath thickening, and old colles’ or carpal fractures may be responsible by restricting the space • P’t complains paresthesia in the hand except little finger; symptoms may become obvious in midnight; shaking the hand to release the symptoms is usually needed • P’t may have both signs of the cervical spondylosis and carpal tunnel syndrome

Common wrist and hand deformities:

• Ulnar nerve is compressed as passing through the ulnar canal between the pisiform and the hook of the hamate • Symptoms include small muscle wasting and weakness in the hand with sensory disturbance on the volar aspect of the little finger • Causes of nerve involvement are ganglion, occupational trauma, old carpal or metacarpal fractures Common wrist and hand deformities: Dupuytren’s contracture

• Nodular thickening and contracture of the palmar fascia • The palm of the hand is affected first, and later the 4th finger, followed by the little and middle fingers • The progressive flexion of the affected fingers interferes with the function of the hand • affect men more than women over 40 • May be hereditary tendency, or associated with epilepsy, diabetes or alcoholic cirrhosis

Common wrist and hand deformities: tendon and tendon sheath lesions • Mallet finger: – DIP is held in a permanent position of flexion; unable to extend the distal joint – The extensor tendon either ruptures close to insertion in the distal phalanx, or it avulses its bony attachment – Healing may occur over 6 to 12 month period – Use of light splint holding the DIP in hyperextension for 6 weeks is practical

Common wrist and hand deformities: tendon and tendon sheath lesions

• Mallet thumb: – Delayed rupture of the extensor pollicis longus tendon may follow Colles’ fracture or rheumatic arthritis, and repair by tendon transfer is advised Common wrist and hand deformities: tendon and tendon sheath lesions

• Swan-neck deformity: – Flexion of the metacarpophalangeal and distal interphalangeal joints in addition to extension of the proximal interphalangel joint – A result of contracture of the intrinsic muscles and often seen in rheumatoid arthritis

Common wrist and hand deformities: tendon and tendon sheath lesions • Boutonniere deformity: – Flexion of the interphalangeal joint of a finger with extension of the distal interphalangeal joint – Due to rupture of the central slip of the extensor tendon attached to the base of the middle phalanx – Due to incised wounds on the dorsum of the finger and avulsion injuries; – Commonly seen in rheumatoid arthritis – Surgical repair of the extensor band is often undertaken

Common wrist and hand deformities: trigger finger and thumb

• Thickening of a fibrous tendon sheath or nodular thickening in a flexor tendon • When the fingers are extended, the affected finger lag behind and then quite suddenly straightens. • The middle, ring finger or thumb are most frequently involved. • Nodular thickening at the level of the MP joint may also be palpable. Common wrist and hand deformities: “Z” deformity of the thumb

• The thumb is flexed at the metacarpophalangeal joint and hyperextended at the interphalangeal joint • May related to heredity, or rheumatic arthritis.

Common wrist and hand deformities: rheumatic arthritis

• In the early stage the hands are warm and moist • Later the joints become obviously swollen and tender. • Synovial tendon sheath and joint thickening with effusion, muscle wasting, and deformity then become apparent • Tendon rupture and joint subluxation are the main factors leading to the more severe deformities

Common wrist and hand deformities: osteoarthritis of the interphalangeal joint

• Heberden’s nodes: nodular swellings situated dorsally over the bases of the distal phalanges • Bouchard’s nodes: nodular over the bases of the middle phalanges; less common • Occur most in women after the menopause; not related to osteoarthritis elsewhere • Most are symptom-free, may be related to joint damage and consequent pain

Common wrist and hand deformities: osteoarthritis of the carpo-metacarpal joint of the thumb • common between the thumb metacarpal and trapezium and may give rise to disabling pain and dysfunction • May related to Bennett’s fracture or occupational overuse