801 Muscles and Actions: Exam 1

Abductor digiti minimi (hand)

Muscle that performs flexion and abduction at the MCP joint of the little finger and extension at the PIP and DIP joints of the little finger.

Abductor digiti minimi (foot)

Muscle responsible for flexing the MTP joint of the 5th toe, abducting the 5th toe, and supporting the longitudinal arch.

Abductor hallicus

Muscle that facilitates flexion and abduction of the 1st toe at the 1st MTP joint and supports the longitudinal arch.

Abductor pollicis brevis

Muscle that performs abduction at the CMC joint of the thumb.

Abductor pollicis longus

Muscle responsible for abduction at the radiocarpal joint and carpometacarpal joint of the thumb.

Adductor brevis

Muscle that adducts and flexes the thigh, assisting in lateral rotation.

Adductor hallicus

Muscle that contributes to flexion and adduction of the 1st toe at the 1st MTP joint and supports the longitudinal arch.

Adductor longus

Muscle involved in adduction, flexion, extension, and stabilization of the pelvis.

Adductor magnus

Muscle responsible for adduction, extension, slight flexion, and stabilization of the pelvis.

Adductor pollicis

Muscle that adducts at the CMC joint and flexes at the MCP joint of the thumb.

Anconeus

Muscle that extends the forearm at the elbow.

Anterior deltoid

Muscle involved in flexion, internal rotation, and adduction.

Anterior scalene

Muscle that elevates upper ribs with mobile ribs and flexes the cervical spine with fixed ribs.

Biceps femoris

Muscle responsible for hip extension, pelvic stabilization, knee flexion, and external rotation.

Brachialis

Muscle involved in flexion at the elbow joint.

Brachioradialis

Muscle that performs flexion at the elbow and semipronation of the forearm.

Coracobrachialis

Muscle responsible for flexion and adduction of the arm.

Coccygeus

Muscle that supports pelvic viscera and facilitates coccyx flexion.

Cricothyroid

Muscle that tightens the vocal folds.

Diaphragm

Principal muscle of respiration aiding in diaphragmatic and thoracic breathing, and compressing abdominal viscera.

Dorsal interossei

Muscles responsible for flexion at metacarpal joints and extension/abduction at interphalangeal joints.

Extensor carpi radialis brevis

Muscle that weakly flexes at the elbow and extends/abducts at the wrist.

Extensor carpi radialis longus

Muscle involved in weak elbow flexion and wrist extension/abduction.

Extensor digiti minimi

Muscle responsible for wrist extension, ulnar abduction, and extension/abduction of the 5th digit.

Extensor digitorum

Muscle that extends the wrist and fingers at MCP, PIP, and DIP joints.

Extensor digitorum brevis

Muscle that extends the MTP and PIP joints of the 2nd and 4th toes.

Extensor digitorum longus

Muscle involved in dorsiflexion at the talocrural joint, eversion at the subtalar joint, and extension at toe joints.

Extensor hallucis longus

Muscle responsible for big toe extension and foot dorsiflexion.

Extensor indices

Muscle that extends the wrist and 2nd digit joints.

Extensor pollicis brevis

Muscle that abducts at the radiocarpal joint and extends at the thumb joints.

Extensor pollicis longus

Muscle involved in wrist extension/abduction, thumb adduction, and thumb joint extension.

External obliques

Muscles that flex, rotate, and stabilize the trunk unilaterally and bilaterally.

External intercostals

Muscles that elevate ribs during inspiration and support intercostal spaces.

Fibularis brevis

Muscle responsible for plantar flexion at the talocrural joint and eversion at the subtalar joint.

Fibularis longus

Muscle that contributes to dorsiflexion at the talocrural joint and eversion at the subtalar joint.

Fibularis tertius

Muscle involved in dorsiflexion at the talocrural joint and eversion at the subtalar joint.

Flexor carpi radialis

Muscle that performs flexion and abduction at the wrist.

Flexor carpi ulnaris

Muscle involved in flexion at the elbow and wrist, and flexion at finger joints.

Flexor digiti minimi (brevis)

Muscle responsible for flexion at the MCP joint of the little finger.

Flexor digitorum accessorius (quadratus plantae)

Muscle that redirects and enhances the pull of the flexor digitorum longus.

Flexor digitorum brevis

Muscle that flexes the MTP and PIP joints of the 2nd to 5th toes, supporting the longitudinal arch.

Flexor digitorum longus

Muscle involved in plantar flexion, inversion, and flexion at toe joints.

Flexor digitorum profundus

Muscle that flexes the wrist and finger joints of the 2nd to 5th digits.

Flexor digitorum superficialis

Muscle responsible for weak elbow flexion and finger flexion at multiple joints.

Flexor hallucis brevis

Muscle that flexes the 1st MTP joint and supports the longitudinal arch.

Flexor hallucis longus

Muscle involved in plantar flexion, inversion, and flexion at toe joints, supporting the arch.

Flexor pollicis brevis

Muscle that performs flexion at the CMC joint of the thumb.

Flexor pollicis longus

Muscle responsible for flexion/abduction at the wrist, thumb flexion at joints, and thumb joint extension.

Frontalis

Muscle that raises the eyebrows and wrinkles the forehead.

Gastrocnemius

Muscle involved in plantar and knee flexion.

Genioglossus

Muscle that protrudes and deviates the tongue anteriorly.

Gluteus maximus

Muscle responsible for thigh extension, external rotation, and abduction/adduction.

Gluteus medius

Muscle that abducts the hip, stabilizes the pelvis, and facilitates internal/external rotation.

Gluteus minimus

Muscle that abducts the hip, stabilizes the pelvis, and facilitates internal/external rotation.

Iliocostalis

Muscle that extends the spine bilaterally and flexes it laterally unilaterally.

Iliopsoas

Muscle involved in hip flexion/external rotation and lumbar spine flexion.

Inferior gemellus

Muscle responsible for external rotation and extension of the hip joint.

Inferior oblique

Muscle that elevates, abducts, and laterally rotates the eye.

Inferior rectus

Muscle that depresses, adducts, and laterally rotates the eye.

Infraspinatus

Muscle involved in external rotation of the shoulder.

Internal intercostals

Muscles that depress ribs during expiration and stabilize the chest wall.

Internal obliques

Muscles that compress the abdomen and rotate the torso unilaterally.

Lateral pterygoid

Muscle that protrudes the mandible bilaterally and facilitates lateral mandibular movements unilaterally.

Lateral rectus

Muscle responsible for eye abduction.

Latissimus dorsi

Muscle that extends, adducts, and medially rotates the shoulder.

Levator ani

Muscle that assists in urinary and defecation control, ejaculation, fetal head positioning, and maintaining abdominal pressures.

Levator palpebrae superioris

Muscle that elevates the upper eyelid.

Levator scapulae

Muscle that elevates and medially rotates the scapula, inclining the neck to the same side.