Anatomy & Biomechanics Final- Muscles

Pectoralis major

aDuction, flexion, and medial rotation of GHJ; Medial and lateral pectoral nerves

Abductor pollicis longus

ABduct & Extend thumb (CMC joint); Radial nerve; Deep group of posterior forearm

Gluteus medius & minimus

ABduct and medially rotate thigh, stabilize trunk; Superior gluteal nerve; Gluteal region

Dorsal interosseus muscles (foot)

ABduction of digits, Flexion of MT joints, Extension of IP joints; 1 & 2→ deep branch of fibular n., 3 & 4→ deep branch of lateral plantar n.; Interosseus compartment of foot

Adductor pollicis

ADduction of thumb; Ulnar nerve; Adductor compartment of hand

Deltoid

Actions at GHJ: Anterior→ flexion and medial rotation, Middle → aBduction (after initial 15°), Posterior→ extention & lateral rotation; Axillary nerve

Teres major

Adduction and medial rotation of the arm, Extension when flexed; Lower subscapular nerve

Lumbricals (foot)

Assists flexion of MP joints and maintains extension of PIP joints; Digits 2-4→ lateral plantar n., Digit 1→ medial plantar n.; Central compartment of foot

Tibialis anterior

Dorsiflex ankle, Invert foot; Deep fibular nerve; Anterior leg

Fibularis (peroneus) longus & brevis

Evert foot and weakly plantarflex ankle joint; Superficial fibular nerve; Lateral leg

Extensor hallucis brevis

Extend MP joint of hallux; Lateral branch of deep fibular n.; Dorsal foot

Extensor pollicis longus

Extend and ABduct thumb (CMC); Radial nerve; Deep group of posterior forearm

Extensor carpi radialis longus & brevis

Extend and ABduct wrist joint; Radial nerve; Superficial group of posterior forearm

Extensor carpi ulnaris

Extend and ADduct wrist joint; Radial nerve; Superficial group of posterior forearm

Extensor digitorum

Extend digits 2-5 (MCP, PIP, DIP) & Extend wrist; Radial nerve; Superficial group of posterior forearm

Extensor digitorum longus

Extend digits 2-5 at MTP, PIP, & DIP, Dorsiflex ankle; Deep fibular nerve; Anterior leg

Extensor digitorum brevis

Extend distal IP joints of digits 2-4; Lateral branch of deep fibular n.; Dorsal foot

Triceps brachii

Extend elbow joint, Extend GHJ (long head only); Radial nerve; extensor compartment of arm

Extensor hallucis longus

Extend hallux (MTP & IP joints), Weakly dorsiflex ankle; Deep fibular nerve; Anterior leg

Quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermedialis)

Extend knee joint, Rectus femoris flexes hip joint; Femoral nerve; Anterior compartment of thigh

Gluteus maximus

Extend thigh at hip, ABducts hip, stabilizes trunk; Inferior gluteal nerve; Gluteal region

Extensor pollicis brevis

Extend thumb (CMC, MCP, IP); Radial nerve; Deep group of posterior forearm

Adductor magnus

Extends hip joint; aDductor part→ obturator nerve, Hamstring part→ tibial nerve; Medial compartment of thigh

Latissimus dorsi

Extension & aDduction of GHJ, medial rotation; Thoracodorsal nerve

Adductor longus and brevis

aDduct hip joint; Obturator nerve; Medial compartment of thigh

Lumbricals (hand)

Flex MCP joint; Digits 2 & 3 → Median nerve, Digits 4 & 5 → Ulnar nerve; Central compartment of hand

Flexor carpi radialis

Flex and aBduct wrist joint; Median nerve; Superficial group of anterior forearm

Abductor hallicus

Flex and aBducts big toe at MP joint; Medial plantar n.; Medial foot

Flexor carpi ulnaris

Flex and aDduct wrist joint; Ulnar nerve; superficial group of anterior forearm

Flexor digitorum superficialis

Flex digits 2-5 (MCP and PIP joints); Median nerve; Superficial group of anterior forearm

Hypothenar Muscles

aBducts, flexes, and opposes digiti minimi; Ulnar n.; Hypothenar compartment of hand

Thenar Muscles

aBducts, flexes, and opposes thumb; Median n.; Thenar compartment of hand

Flexor digitorum profundus

Flex digits 2-5 (MCP, PIP, DIP joints); Lateral ½ (digits 2,3) → Median nerve, Medial ½ (digits 4, 5) → Ulnar nerve; Deep group of anterior forearm

Flexor digitorum longus

Flex digits 2-5 and plantarflex ankle joint; Tibial nerve; Deep group of posterior leg

Quadratus plantae

Flex distal IP joint of digits 2-5 (assists FDL); Lateral plantar n.; Central foot

Brachialis

Flex elbow joint; Musculocutaneous nerve; Flexor compartment

Brachioradialis

Flex elbow joint; Radial nerve; Superficial group of posterior forearm

Flexor hallicus longus

Flex hallux and weakly plantarflex ankle joint; Tibial nerve; Deep group of posterior leg

Gastrocnemius

Flex knee joint, Plantarflex ankle joint; Tibial nerve; Superficial group of posterior leg

Flexor pollicis longus

Flex thumb (MCP, IP joints); Median nerve; Deep group of anterior forearm

Sartorius

Flex, aBduct, laterally rotate hip joint, Flex knee joint; Femoral nerve; Anterior compartment of thigh

Adductor hallucis

Flexes & aDducts big toe; Lateral plantar nerve (S2, S3); Central foot

Flexor hallucis brevis

Flexes hallux at MP joint (minimally); Medial plantar n.; Medial foot

Biceps femoris

Flexes knee, extends hip, laterally rotates thigh and leg; Long head→ tibial nerve, Short head→ common fibular nerve; Posterior thigh

Semitendinosus and semimembranosus

Flexes knee, medially rotates tibia/femur, extends hip; Tibial nerve; Posterior thigh

Supraspinatus

Initial aBductor of shoulder (synergist to deltoid in GHJ abduction); Suprascapular nerve

Tibialis posterior

Invert foot and plantarflex ankle joint; Tibial nerve; Deep group of posterior leg

Trapezius

Lateral rotation, retraction, elevation of scapula; CN XI / accessory nerve

Piriformis

Laterally rotates hip; L5-S2 spinal nerves; Gluteal region

Soleus

Plantarflex ankle joint; Tibial nerve; Superficial group of posterior leg

Infraspinatus

Principal lateral rotator of GHJ; Suprascapular nerve

Pronator quadratus

Pronate forearm; Median nerve; Deep group of anterior forearm

Serratus anterior

Protracts and laterally rotates scapula, suspends scapula; Long thoracic nerve

Abductor digiti minimi

Weakly flexes & aBducts pinky toe; Lateral plantar n.; lateral foot

Biceps brachii

When forearm supinated→ flex elbow joint, When elbow flexed→ supimate forearm: Musculocutaneous nerve; Flexor compartment

Dorsal interosseus muscles (hand)

aBduction of digits 2 - 4 (DAB); Ulnar nerve; Interosseous compartment of hand

Teres minor

principal lateral rotator at GHJ; axillary n.