PT 612 Practical 2

Muscles

Flexor Carpi Radialis

Origin: Medial epicondyle; Insertion: Base of 2nd and 3rd metacarpals; Action: Flexes and abducts wrist; Innervation: Median nerve (C6-C7)

Palmaris Longus

Origin: Medial epicondyle; Insertion: Palmar aponeurosis; Action: Flexes wrist; Innervation: Median nerve (C7-C8)

Flexor Carpi Ulnaris

Origin: Medial epicondyle and olecranon; Insertion: Pisiform, hook of hamate, base of 5th metacarpal; Action: Flexes and adducts wrist; Innervation: Ulnar nerve (C7-T1)

Flexor Digitorum Superficialis

Origin: Medial epicondyle, coronoid process, and anterior radius; Insertion: Middle phalanges of digits 2–5; Action: Flexes PIP and MCP joints; Innervation: Median nerve (C8-T1)

Flexor Digitorum Profundus

Origin: Anterior ulna and interosseous membrane; Insertion: Distal phalanges of digits 2–5; Action: Flexes DIP joints; Innervation: Medial half – ulnar nerve; Lateral half – median nerve (C8-T1)

Flexor Pollicis Longus

Origin: Anterior radius and interosseous membrane; Insertion: Distal phalanx of thumb; Action: Flexes thumb; Innervation: Median nerve (anterior interosseous branch) (C8-T1)

Extensor Carpi Radialis Longus

Origin: Lateral supracondylar ridge; Insertion: Base of 2nd metacarpal; Action: Extends and abducts wrist; Innervation: Radial nerve (C6-C7)

Extensor Carpi Radialis Brevis

Origin: Lateral epicondyle; Insertion: Base of 3rd metacarpal; Action: Extends and abducts wrist; Innervation: Deep branch of radial nerve (C7-C8)

Extensor Digitorum

Origin: Lateral epicondyle; Insertion: Extensor expansions of digits 2–5; Action: Extends MCP, PIP, and DIP joints of digits 2–5; Innervation: Posterior interosseous nerve (C7-C8)

Extensor Carpi Ulnaris

Origin: Lateral epicondyle and ulna; Insertion: Base of 5th metacarpal; Action: Extends and adducts wrist; Innervation: Posterior interosseous nerve (C7-C8)

Lumbricals (1st–4th)

Origin: Tendons of flexor digitorum profundus; Insertion: Extensor expansions of digits 2–5; Action: Flex MCP joints, extend PIP and DIP joints; Innervation: 1st–2nd: Median nerve (C8-T1); 3rd–4th: Ulnar nerve (C8-T1)

Opponens Pollicis

Origin: Flexor retinaculum, trapezium; Insertion: Lateral shaft of 1st metacarpal; Action: Opposition of thumb at CMC joint; Innervation: Median nerve (recurrent branch)

Flexor Digiti Minimi

Origin: Hook of hamate and flexor retinaculum; Insertion: Base of proximal phalanx of fifth finger, palmar surface; Action: Flexion of 5th finger at MCP joint, assists in opposition of 5th finger; Innervation: Ulnar nerve (deep branch)

Abductor Digiti Minimi

Origin: Pisiform; Insertion: Base of proximal phalanx of fifth finger, ulnar side; Action: Abducts the fifth finger (MCP joint), assists in opposition of 5th finger; Innervation: Ulnar nerve (deep branch)

Opponens Digiti Minimi

Origin: Flexor retinaculum, hook of hamate; Insertion: Ulnar border of 5th metacarpal; Action: Opposition of 5th finger at CMC joint; Innervation: Ulnar nerve (deep branch)

Dorsal Interossei

Origin: Adjacent dorsal surfaces of metacarpals; Insertion: Base of proximal phalanges to extensor expansion of 2nd, 3rd, and 4th fingers; Action: Abduction of 2nd–4th fingers at MCP joints; assists in flexion of 2nd–4th fingers at MCP joints and extension at PIP and DIP joints via extensor aponeurosis; Innervation: Ulnar nerve (deep branch)

Palmar Interossei

Origin: Shaft of 2nd, 4th, and 5th metacarpals (palmar surface); Insertion: Base of proximal phalanges to extensor expansion of 2nd, 4th, and 5th fingers; Action: Adduction of thumb, 2nd, 4th, and 5th fingers toward the 3rd finger; assists lumbricals in MCP flexion and PIP/DIP extension via extensor aponeurosis; Innervation: Ulnar nerve (deep branch)

Extensor Pollicis Longus

Origin: Posterior surface of ulna and interosseous membrane; Insertion: Base of distal phalanx of thumb; Action: Extension of thumb at IP joint; assists in extension at MCP and CMC joints; Innervation: Posterior interosseous nerve

Extensor Pollicis Brevis

Origin: Posterior surface of radius and interosseous membrane; Insertion: Base of proximal phalanx of thumb; Action: Extension of proximal phalanx of thumb at CMC and MCP joints; Innervation: Posterior interosseous nerve

Abductor Pollicis Longus

Origin: Posterior surface of radius and ulna, and interosseous membrane; Insertion: Base of 1st metacarpal; Action: Abducts and extends thumb at CMC joint; Innervation: Posterior interosseous nerve

Adductor Pollicis

Origin: Capitate, base of 2nd and 3rd metacarpals; Insertion: Base of proximal phalanx of thumb – medial side; Action: Adduction of thumb at CMC and MCP joints; assists in flexion at MCP joint; Innervation: Ulnar nerve (deep branch)

Abductor Pollicis Brevis

Origin: Flexor retinaculum, trapezium, and scaphoid; Insertion: Base of proximal phalanx of thumb – radial side; Action: Abduction of thumb at CMC and MCP joints; assists in opposition; Innervation: Median nerve (recurrent branch)

Flexor Pollicis Brevis

Origin: Flexor retinaculum, trapezium, trapezoid, and capitate bones; Insertion: Base of proximal phalanx of thumb – radial side; Action: Flexion of thumb at CMC and MCP joints; assists in opposition; Innervation: Superficial head – Median nerve (recurrent branch); Deep head – Ulnar nerve (deep branch)

Extensor Indicis

Origin: Posterior ulna and interosseous membrane; Insertion: Extensor expansion of index finger; Action: Extension of proximal phalanx of index (2nd) finger at MCP joint; assists in adduction of 2nd finger; Innervation: Posterior interosseous nerve

Extensor Digiti Minimi

Origin: Lateral epicondyle of humerus (common extensor tendon); Insertion: Extensor expansion of digit 5; Action: Extension of proximal phalanx of little finger at MCP joint; Innervation: Posterior interosseous nerve

Longus capitis

origin: transverse processes of C3-C6; insertion: occipital bone (basilar part); action: unilaterally - laterally flex the head/neck to the same side, bilaterally - flex head and neck; innervation: ventral rami of C1-C3 spinal nerves

Sternocleidomastoid

origin: manubrium of sternum and medial 1/3 of clavicle; insertion: mastoid process of temporal bone and lateral half of superior nuchal line; action: unilaterally - laterally flex head and neck to same side, rotate head and neck to opposite side, bilaterally - flex neck, assist in inhalation (elevation of rib cage); innervation: spinal accessory nerve, C2-C3 (sensory)

Splenius capitis

origin: nuchal ligament, spinous processes C7-T3; insertion: mastoid process, lateral superior nuchal line; action: unilaterally - rotate head and neck to same side, laterally flex head and neck, bilaterally - extend head and neck; innervation: dorsal rami of middle and lower cervical nerves

Splenius cervicis

origin: spinous processes T3-T6; insertion: transverse processes C1-C3; action: unilaterally - rotate the head and neck to the same side, laterally flex the head and neck, bilaterally - extend the head and neck; innervation: dorsal rami of middle and lower cervical nerves

Scalenes

origin: transverse processes of C2-C7; insertion: 1st rib; action: unilaterally - with ribs fixed, laterally flex the head and neck to same side, rotate the head and neck to opposite side, anterior ONLY - flex head and neck; innervation: anterior rami of C3-C8 spinal nerves

Semispinalis capitis/cervicis/thoracis

origin: transverse processes of C4-T12; insertion: spinous processes 4-6 segments above origin, occipital bone; action: extend vertebral column and head; innervation: posterior rami of spinal nerves

Upper Trapezius

origin: external occipital protuberance, superior nuchal ligament, spinous processes C1-C7; insertion: posterior aspect of lateral 1/3 of clavicle and acromion process; action: elevate and upward rotation of scapula, laterally flex head to same side, rotate to opposite side, extend head and neck; innervation: spinal accessory nerve, C3-C4 (sensory)