Muscle actions Flashcards
Pronator teres
pronates forearm
Median nerve
Flexor carpi radialis
Action = flexion and ABduction of wrist Innervation = median nerve
Palmaris longus
Action = flex wrist & tense aponeurosis (the aponeurosis attaches to the skin and thus flexion of the palmaris longus tenses the palm, helps improve grip by resisting shearing forces). Innervation = median nerve
Flexor digitorum superficialis
Action = quick flexion of proximal interphalangeal joints (PIPs) & metacarpophalangeal joints (MPs) of digits 2-5. Innervation = median nerve.
Flexor carpi ulnaris
Action = flex and ADDuct wrist Innervation = ulnar nerve
Flexor digitorum profundus
Action = slow flexion of distal interphalangeal joints (DIPs) and MPs of digits 2-5 Innervation = digits 2-3 are innervated by the median nerve while the digits 4-5 are innervated by the ulnar nerve
Flexor digitorum superficialis
Action = quick flexion of proximal interphalangeal joints (PIPs) & metacarpophalangeal joints (MPs) of digits 2-5. Innervation = median nerve.
Pronator quadratus
pronation, median nerve
Brachioradialis
Action = accessory flexor at elbow Innervation = radial nerve
Anconeus
Action = accessory extensor at elbow joint Innervation = radial nerve
Extensor carpi radialis longus
Action = extends & ABducts wrist Innervation = radial nerve
Extensor carpi radialis brevis
Action = extends & ABducts wrist Innervation = radial nerve
Extensor digitorum
Action = extends digits 2-5 Innervation = radial nerve
Extensor digiti minimi
Action = extend digit 5 Innervation = radial nerve
Extensor carpi ulnaris
Action = extend & ADDuct wrist Innervation = radial nerve
Supinator
Action = supination Innervation = radial nerve
Abductor pollicis longus
Action = ABducts 1st MP joint (of thumb) Innervation = radial nerve
Extensor pollicis brevis
Action = extend MP joint of 1st digit Innervation = radial nerve
Extensor pollicis longus
Action = extend all joints of thumb Innervation = radial nerve
Extensor indicis
Action = extend index finger Innervation = radial nerve
Biceps Brachii M.
A: flexes & supinates forearm (slight arm flexion)
N: musculocutaneous n. & brachial vessels
Coracobrachialis M.
A: flexes arm
N: musculocutaneous n. & brachial vessels
Brachialis M.
A: flexes forearm
N: radial & musculocutaneous nn. & brachial vessels
Triceps Brachii M.
A: extends forearm
N: radial n. & deep brachial vessels
Trapezius
A: elevates, depresses & retracts scapula
N: accessory n. (CN XI) & C3, C4; & transverse cervical vessels
Accessory n. (CNXI):
runs deep to m., posteroinferiorly from jugular foramen
Ventral rami of C3-C4:
runs deep to m., posteriorly from intervertebral foramina
Transverse cervical a. & v.:
runs deep to m., posterolaterally from thyrocervical trunk
Latissimus Dorsi
A: adducts, extends & medially rotates humerus
N: thoracodorsal n. & vessels & intercostal vessels
Levator Scapulae
A: elevates scapula
N: C3, C4, & dorsal scapular n. & vessels
Rhomboids
A: retract (adducts) & elevates scapula
N: dorsal scapular n. & vessels
Splenius capitus & cervicis (spinotransversales mm.)
Cervical
Capitis: Bilaterally - draw head backward and extend neck; individually – rotate head/face ipsilaterally
Cervicis: Bilaterally - extend neck; individually – rotate head/face ipsilaterally
N: Posterior rami of the middle and
Erector Spinae Mm.
A: erect spine (postural mm.) 1° extensors of spine & head
N: dorsal rami of spinal nn. & lumbar & intercostal vessels
Multifidus M.
A: laterally flexes & rotates spine*
N: dorsal rami of spinal nn. & lumbar vessels
Rotatores M.
A: rotate spine*
Bilaterally – extend vertebral column
N: dorsal rami of spinal nn. & intercostal vessels
Serratus Anterior M.
A: protracts scapula & holds it to body wall
N: long thoracic n. & lateral thoracic vessels
Triangle of Auscultation
Superior = Trapezius m.
Inferior = Latissimus dorsi m.
Lateral = Rhomboid major m.
Floor (deep) = 6th intercostal space
Lumbar triangle
Medial = Latissimus dorsi m.
Lateral = External oblique m.
Inferior = Iliac crest
Floor (deep) = Internal oblique m.
Deltoid M.
A: abducts humerus (1°), flexes, extends & rotates humerus (2°)
N: Axillary n. & Post. Circumflex Humeral vessels
Teres Major M.
A: medially rotates & extends humerus
N: Lower (inferior) Subscapular n. & subscapular vessels
Supraspinatus M.
A: abducts humerus
(1st 15°)
N: Suprascapular n. & vessels & dorsal scapular vessels
Infraspinatus M.
A: laterally rotates humerus
N: Suprascapular n. & vessels & subscapular vessels
Teres Minor M.
A: lateral rotation of humerus
N: Axillary n. & suprascapular & subscapular vessels
Subscapularis M.
A: medial rotation of humerus
N: upper & lower subscapular nn. & subscapular vessels
Pectoralis Major M.
A: adducts& medially rotates humerus
N: med. & lat. pectoral nn. & thoracoacrominal vessels
Pectoralis Minor M.
A: protracts scapular
N: Medial Pectoral n. & Thoracoacromial vessels
