Muscle Actions Flashcards
Sternocleidomastoid
Uni - ipsilateral lateral flexion, contralateral rotation
Bi - neck flexion, thoracic cage elevation (inspiration)
Scalenes
Anterior - ipsilateral neck flexion, contralateral rotation & bilateral 1st rib elevation, flexion
Middle - ipsilateral neck flexion, contralateral rotation & bilateral 1st rib elevation, flexion
Posterior - ipsilateral neck flexion, contralateral rotation & bilateral 2nd rib elevation**
Descending part of trapezius
Uni - ipsilateral flexion of neck
Bi - extension of head/neck
Internal intercostals
Depress ribs (forced expiration)
External intercostals
Elevate ribs (inspiration)
Diaphragm
Separates thoracic & abdominal cavity, primary muscle of respiration
External obliques
Uni - contralateral trunk rotation, ipsilateral lateral flexion
Bi - trunk flexion, viscera compression, assist in respiration
Transversus abdominus
Compress abdomen, support viscera
Rectus abdominus
Trunk flexion, compression of viscera, forced expiration
Splenius capitis
Uni - ipsilateral lateral flexion & rotation of head
Bi - extension of head/neck
Splenius cervicis
Uni - ipsilateral flexion and rotation of head
Bi - extension of head/neck
Erector spinae: iliocostalis
Trunk extension & lateral flexion
Erector spinae: longissimus
Trunk extension & lateral flexion (capitis rotates)
Erector spinae: spinalis
Trunk extension & lateral flexion
Transversospinales: multifidi
Spinal extension & stabilization
Transversospinales: semispinales
Thoracis: trunk extension, lateral rotation
Colli: extension, cervical spine rotation
Capitis: extension, rotation of head
Transversospinales: rotatores
Trunk extension, rotation & stabilization
Pec major
Adduction, internal rotation
Upper: shoulder flexion, horizontal adduction
Lower: shoulder extension
Pec minor
Scapular protraction, scapular depression, downward rotation of scapula
Subclavius
Stabilizes clavicle
Trapezius
Upper: head extension, ipsa lateral flexion of neck, contra lateral rotation, scapular elevation & upward rotation
Middle: scapular adduction & stabilization
Lower: scapular depression & upward rotation
Latissimus dorsi
Extension, adduction, internal rotation
Levator scapulae
Uni - scapular elevation & downward rotation, ipsilateral neck rotation, lateral neck flexion
Bi - neck extension
Rhomboid major
Scapular retraction, downward rotation & elevation
Rhomboid minor
Scapular retraction, elevation & downward rotation
Deltoid
Anterior: flexion, internal rotation
Middle: abduction
Posterior: extension, external rotation
Supraspinatus
Abduction, stabilization of GH joint
Infraspinatus
External rotation, adduction, stabilization of GH joint
Teres minor
External rotation, adduction, horizontal abduction, stabilization of GH joint
Subscapularis
Internal rotation, stabilization of GH joint
Teres major
Adduction, internal rotation, extension
Coracobrachialis
Flexion, adduction
Biceps brachii
Elbow flexion, supination
Brachialis
Elbow flexion
Brachioradialis
Elbow flexion
Triceps brachii
Elbow extension
Anconeus
Elbow extension