OCC 501 Occupational Therapy Lab Weeks 6-8 Comprehensive Mastery Guide: Advanced Clinical Skills, Intervention Techniques, and Practical Application – 58 Expert-Curated Questions and Answers with Detailed Rationales, Case Studies, and Hands-On Skill Assessments

Characteristics of lumbricals

- split innervation--> ulnar and median nerve

- come off of FDP--> never connect to bone directly

- Come off extensor sheath

Ulnar nerve innervations

- hypothenar muscles

- flexor carpi ulnaris

- 3rd + 4th lumbricals

Extensor Carpi Radialis Longus Action

Wrist extension and wrist abduction (radial deviation of wrist)

Extensor Carpi radialis brevis action

wrist abduction and wrist extension

More medial in forearm

Anconeus action

(DOES NOT CROSS wrist) No wrist extension

Extends elbow by assisting triceps and extends forearm

Extensor Digitorum

Extends digits (2-5) only medial 4 digits and extends wrist

Extensor Carpi Ulnaris

Extends wrist and adducts wrist (ulnar deviation)

Brachioradialis action

flexes forearm at elbow joint (mid pronation)

DOES NOT CROSS ELBOW joint

Extensor Digiti Minimi

Extends 5th digit at MCP and IP joints

Origin of Extensor Digit Minimi

Lateral epicondyle

Insertion of Extensor Digiti Minimi

Inserts onto extensor hood of little finger

Innervation of Extensor Digiti Minimi

Posterior Interosseous nerve

Extensor Carpi Ulnaris Origin

lateral epicondyle

posterior border of ulna

Extensor Carpi ulnaris insertion

Inserts onto base of 5th metacarpal

Extensor Carpi ulnaris innervation

Radial nerve (posterior interosseous)

extensor carpi radialis longus origin

lateral supracondylar ridge of humerus

Extensor carpi radialis longus innervation

Radial nerve

Extensor Carpi radialis longus insertion

Inserts onto base of 2nd metacarpal bone

Extensor Carpi radialis brevis origin

Lateral epicondyle

Extensor carpi radialis brevis innervation

Radial nerve (deep branch)

Extensor carpi radialis brevis insertion

base of 3rd metacarpal

Brachioradialis origin

lateral supracondylar ridge of humerus

Brachioradialis insertion

distal end of radius

Brachioradialis innervation

Radial nerve

Anconeus origin

lateral epicondyle of humerus

Anconeus insertion

Lateral surface of olecranon and superior part of posterior surface of ulna

Anconeus innervation

radial nerve

Supinator action

Supinates forearm by rotating radius

Supinator origin

lateral epicondyle

supinator insertion

lateral surface of proximal 1/3 of radius

Medial epicondylitis (golfer's elbow)

Overuse of flexor muscles or repetitive flexion

Lateral epicondylitis

Overuse of extensor muscles or repetitive extension

epicondylitis

Overuse strain from flexor or extensor muscle

Abductor Pollicis Longus Action

Abducts and extends thumb at CMC joint

Abductor pollicis longus Insertion

Base of 1st metacarpal

Abductor pollicis longus origin

posterior surface of radius and ulna, interosseous membrane

Abductor pollicis longus innervation

Radial nerve (posterior interosseous)

extensor pollicis brevis action

Extends thumb at MCP joint

Extensor pollicis brevis innervation

posterior interosseous nerve

Extensor pollicis brevis insertion

base of proximal phalanx of thumb

Extensor pollicis brevis origin

Posterior surface of radius and interosseous membrane

extensor indicis action

Extends index finger

Extensor indicis origin

posterior surface of distal third of ulna and interosseous membrane

Extensor indicis insertion

extensor digitorum to 2nd digit

Extensor indicis innervation

posterior interosseous nerve

extensor pollicis longus action

Extends distal phalanx of thumb at interphalangeal joint as well as MCP and CMC joint

Extensor pollicis longus insertion

base of distal phalanx of thumb

Extensor pollicis longus origin

Posterior surface of ulna and interosseous membrane

Extensor pollicis longus innervation

posterior interosseous nerve

Brachialis Action

flexes elbow joint

Brachialis innervation, origin, and insertion

Origin: Anterior surface of humerus distal 1/2

insertion: coronoid process and radial tuberosity of ulna

innervation: musculocutaneous

Coracobrachialis

Flexes arm and adducts humerus/ arm

Coracobrachialis origin and insertion

origin: coracoid process

insertion: middle medial shaft of humerus

Biceps brachii long head

Origin: supraglenoid tubercle of scapula

Insertion: radial tuberosity

Biceps brachii short head

origin: coracoid process

insertion: radial tuberosity

Biceps brachii (short head and long head action)

Flexes and abducts shoulder and elbow, and supinates forearm at radioulnar joint

Mallet Finger

flexion of DIP due to rupture of distal extensor tendon appearance is a droopy finger tip

Boutonniere deformity

Finger flexes at PIP joint due to rupture of central extensor tendon proximal to PIP joint

DIP able to extend but PIP unable to extend

SLAP lesion

defect in superior labrum that begins posteriorly and extends anteriorly impacting attachment of long head of biceps on labrum

- Forceful contraction of biceps