Wrist and Hand Complex

Finger Abduction

1. Dorsal interossei (DAB) 2. Abductor digiti mini-me

wrist extension

1. ECRL 2. ECRB 3. ECU 4. EPL 5. EPB 6. ED 7. EDM 8. EI

wrist radial deviation (thumb)

1. ECRL 2. ECRB 3. FCR Assists: EPL & EPB, Abductor pollicus longus, flexor pollicis longus

MCP extension for fingers 2-5

1. ED 2. EI 3. EDM 4. Interossei

wrist flexion

1. FCR 2. FCU 3. PL 4. FDS 5. FDP

wrist ulnar deviation (pinky)

1. FCU 2. ECU

DIP flexion

1. FDP

PIP flexion

1. FDS 2. FDM 3. FPL

Name the extrinsic muscles of the thumb

1. FPL 2. EPL 3. EPB 4. abductor pollicis longus (APL)

Thumb MCP Flexion

1. Flexor pollicis brevis (FPB) assist: flexor pollicis longus (FPL)

MCP flexion for fingers 2-5

1. Lumbricals 2. Palmar interoosei 3. FDM assistors: FDS & FDP

thumb palmar abduction (thumb CMC abduction)

Abductor pollicis brevis (APB)

thumb radial abduction (thumb CMC extension)

Abductor pollicis longus (APL)

List the arches of the hand and describe their directions. What is the function of the arches of the hand?

Arches = create a concavity of the palm and concavity of the fingers that help the hand FIT more securely around objects. 1. Longitudinal: runs the length of the hand and is formed by the shape of the metacarpals and fingers; mobile AND fixed 2. distal transverse: runs transversly (across the hand) and is located at the MCP joint; distal transverse is quite mobile. when an object is held in the hand, the mobile first, fourth, and fifth metacarpals wrap around the stable 2nd and 3rd metacarpals. 3. proximal transverse: runs transversly (across the hand) and is formed by the two rows (proximal & distal) or carpal bones: - proximal: mobile (PM) - distal: fixed

when palpating the head of the ulna, what are the differences in forearm supination and pronation?

As the forearm rotates from supination to pronation, the ulnar head shifts DISTALLY within the sigmoid notch.

thumb adduction

adductor pollicis

Compare the around of ROM that occurs at the 2nd and 3rd CMC joints to the ROM that occurs at the 4th & 5th CMC jts. What is the significance of this difference?

- 2nd & 3rd: stable, immoble - 4th & 5th: are mobile; provide cupping & allow hand to conform to object

What WRIST position is assumed when one needs to OPTIMIZE finger flexion strength?

- Extension - when the wrist is EXTENDED, full grip strength may be achieved since the long finger extensors now have adequate length to allow full finger flexion.

Which WRIST position is LEAST effective for grasp?

- Flexion - with the fingers and wrist FLEXED, grip strength is reduced b/c of passive insufficiency (length) of the finger extensors.

describe the motion of the joint components of the wrist during flexion and extension

- Flexion: Carpals slide DORSALLY on radius Hard End Feel: Dorsal radiocarpal ligament, dorsal joint capsule - Extension: Carpals slide VOLARLY on radius grip strength is greater in wrist extension Hard End Feel: Ant. Radiocarpal ligament, ant. Joint capsule, contact between radius and carpals

What is the functional ROM of the wrist that is required for most ADLS?

- Flexion: 0-10 degrees - Extension: 0-35 degrees functional ROM of wrist is: 5 degreess flexion 30 degrees extension 15 degrees ulnar deviation 10 degrees radial deviation

How does the ROM in the MCP jts change from the 2nd finger to the 5th finger? What is the significance of this difference?

- ROM progressively increases from index to little finger (90 to 110) - follows natural transverse arch of the hand - allows for tight grip

Name some functions of the Triangular Fibrocartilage Complex at the wrist

- The distal ULNA is attached to an articular disc known as the triangular fibrocartilage. - Stabilizes distal radioulnar joint and ulnocarpal articulation - Prevents dorsal/volar (palmar) dislocation - shock absorber - The TFCC keeps the forearm bones (radius and ulna) stable when the hand grasps or the forearm rotates.

How do the muscles that act on the WRIST promote optimal function of the muscles that act upon the HAND.

- WRIST and HAND function depends on the close interactions of EXTRINSIC and INTRINSIC muscles. - active and passive insufficiency - just as the WRIST extensor influence grasping, the WRIST flexors influence finger extension.

Describe the functional position of the wrist and hand

- Wrist extension and ulnar deviation are the most important positions for movements of ADLs. - Wrist extension for stabilization of hand & flexion of distal joints. - Wrist in slight extension (0 - 20) - Wrist in slight ulnar deviation (0 - 10) - Fingers flexed at MCP (4) - Fingers flexed at PIP (30) with slight flexion at DIP - Thumb beneath index finger in palmar abduction

Name the function of the annular pulley and tendon sheath of FDS and FDP

- annular pulleys: guide, support extrinsic finger flexors - prevent FDS & FDP bowstringing

what is the closed pack position of the MCP jt?

- full flexion

what is the closed pack position of the wrist? closed packed - the maximum area of surface contact occurs

- full wrist extension

what is the norma end feel for ulnar deviation?

- hard end feel UD: radial collateral ligament, radial portion of capsule

what is the normal end feel for radial deviation? why?

- hard end feel + firm RD: ulnar collateral ligament, ulnar portion of capsule, contact b/t radial styloid and scaphoid

Name the stability components of the wrist

1. NO muscle attaches to PROXIMAL row of carpals 2. NO direct articulation of ULNA with CARPALS 3. Carpal Ligaments and Collateral Ligaments: provide stabilization and prevent hyper ROM 4. Bony stability 5. Ligaments: provide PASSIVE stability to radiocarpal and midcarpal jts

5th finger opposition

1. Opponens digiti minime (ODM)

Finger Adduction

1. Palmar interossei

Name the primary stabilizing ligaments at the wrist

1. Ulnar/radial collateral 2. Dorsal/volar radiocarpal 3. TFCC

which muslces of the thumb are affected in de quervain's tenosynovitis? occurs when the 2 tendons around the base of your thumb become swollen.

1. extensor pollicis longus 2. extensor pollicis brevis 3. abductor pollicis longust

Name the 3 functions of the (palmar) volar plate?

1. firmly attached to base of proximal phalanx 2. reinforce the joint capsule 3. prevent/limit hyperextension 4. enhance jt stability

PIP & DIP extension

1. lumbricals 2. EPL

describe the sensory and functional loss and demonstrate the posturing of hand wrist complex if there is a 1. ulnar nerve injury 2. median nerve injury 3. radial nerve injury

1. ulnar nerve injury: Claw Hand - motor: decreased ability to spread fingers or close fingers, decreased grip strength, inability to oppose little finger to thumb, MCPS held in hyperextension, weak thumb adduction (loss of adductor pollicis) - sensory: sensory loss of medial palmar surface leads to minimal functional loss 2. median nerve injury: Ape Hand - motor: functional loss of prcecision grip, power grip weakened, decreased thumb flexion/opposition, and decreased flexion of IF/MCPs (loss of lumbricals), decreased PIP flexion - sensory: funcational loss due to decreased radial palmar sensation 3. radial nerve injury: Wrist drop - motor: extensor digits/wrist, difficuty with appraoch of hand for grasp and decreased release, weak thumb abduction - sensory: loss of dorsal hand sensation leads to minimal functional loss

Name the intrinsic muscles of the thumb (thenar muscles)

FAAO 1. flexor pollics brevis (FPB) 2. abductor pollicis brevis (APB) 3. opponens pollicis (OP) 4. adductor pollicis (AP)

Which carpal bones are in the distal row?

distal: Hamate, capitate, trapezoid, trapezium "Some lovers try positions that they can't handle"

Describe the joint position of the elbow, wrist, and fingers that create PASSIVE insufficiency of FDP & FDS passive = elongation

elbow = extension wrist = extension

Describe the joint position of the elbow, wrist, and fingers that create ACTIVE insufficiency of FDP & FDS active = shorten & FORCE is MINIMAL

elbow = full flexion wrist = full flexion when the elbow is in a position of full flexion and wrist is in a position of full flexion, and the client attempts to grasp a ball, grasp is difficult because the FDS and FDP become actively insufficient.

thumb IP extension

extensor pollicis longus (EPL)

thumb IP flexion

flexor pollicis longus (FPL)

Which carpal bones are in the proximal row?

proximal: Scaphoid, lunate, Triequetrum, Pisiform "Some lovers try positions that they can't handle"