MSK Muscle actions Flashcards
What is the action of Levator scapulae?
Elevates scapula
What is the action of trapezius?
Upper Fibres: Elevates and rotates scapula
Middle Fibres: retract Scapula
Lower Fibres: Pull scapula inferiorly
What is the action of latissimus dorsi?
Extends, adducts and medially rotates
upper limb
What is the action of the rhomboids?
Retract and medial rotation scapula
What is the action of Serratus posterior superior?
Elevates ribs 2-5
What is the action of serrates posterior inferior?
Depresses ribs 9-12
What is the action of erector spinae?
Acts unilaterally to laterally flex the
vertebral column. Acts bilaterally to
extend the vertebral column and head.
What is the action of Pectoralis major?
Adducts and medially rotates upper limb. Draws scapula
anteroinferior
Clavicular head only acts to flex upper limb
What is the action of Pectoralis minor?
Stabilises scapula by drawing it anteroinferior against
thoracic wall
What is the action of serratus anterior?
abducts and protracts scapula
What is the action of Supraspinatus?
Abducts the arm 0-15 degrees and assists deltoid for 15-90
degrees
What is the action of infraspinatus?
Lateral rotation
What is the action of subscapularis?
medial rotation and adduction
What is the action of teres minor?
lateral rotation and adduction
What is the action of teres major?
Adduction, extension & medial rotation
What is the action of deltoid?
Anterior fibres – flexion and medial rotation.
Posterior fibres – extension and lateral rotation.
Middle fibres – the major abductor of the arm (takes over from the supraspinatus, which abducts the first 15 degrees).
What is the action of biceps brachii
Flexes shoulder & elbow. Supinates forearm
What is the action of brachialis?
Flexes the elbow
What is the action of coracobrachialis?
Flexion and adduction of the shoulder joint
What is the action of triceps brachii and anconeus?
Extension of the elbow
What is the function of flexor carpi ulnaris?
Flexion and adduction of the wrist
What is the action of palmaris longus?
Flexion of the wrist
What is the action of pronator teres?
Pronates and weakly flexes the elbow
What is the action of brachioradialis?
flexes the elbow
What is the action of flexor digitorum superficialis?
flexes the wrist, MCP and PIP joints
What is the action of flexor digitorum profundus?
Flexes wrist, MCP, PIP and DIP joints
What is the action of flexor pollicis longus
Flexion of the thumb at the interphalangeal joint
What is the action of pronator quadratus?
Pronation
What is the action of extensor carpi radials longus?
Extends and abducts wrist
What is the action of extensor carpi radials brevis?
Extends and abducts wrist
What is the action of extensor digitorum?
Extends the wrist & digits at MCP, DIP and PIP joints
What is the action of extensor digiti minimi?
Extends wrist & little finger and MCP, DIP and PIP joints
What is the action of extensor carpi ulnaris?
Extension and abduction of wrist
What is the action of supinator?
Supination
What is the action of abductor pollicis longus?
Abduction of thumb
What is the action of extensor pollicis longus?
Extension of thumb at MCP and IP joint
What is the action of extensor pollicis brevis?
Extension of thumb at MCP joint
What is the action of extensor indicus?
Extends index finger at all joints
What is the function of opponens pollicis?
opposes thumb
What is the action of abductor pollicis brevis?
Abduction of the thumb
What is the action of flexor pollicis brevis?
Flexion of the thumb at MCP joint
What is the action of opponens minimi?
Opposes little finger
What is the action of abductor digiti minimi?
Abducts little finger at MCP joint
What is the action of flexor digiti minimi brevis?
Flexes MCP joint of little finger
What is the function of the lumbricals?
FLEX THE FINGERS AT THE METACARPOPHALANGEAL (MCP) JOINTS, AND EXTEND THEM AT THE INTERPHALANGEAL (IP) JOINTS.
What is the action of the dorsal interossei?
DAB- Abduction of the digits at the MCP joint
What is the action of the Palmar interossei?
PAD- Adduction of the digits at the MCP joint
What is the action of adductor pollicis?
Adduction of the thumb at the MCP joint
What is the action of gluteus Maximus?
extension of hip & lateral rotation of thigh
What is the action of gluteus medius and gluteus minimus?
Medial rotation
Abduction
Also secures the pelvis in locomotion preventing drop of the opposite limb
What is the action of tensor fascia latae?
extension and lateral rotation of leg on the knee joint.
weak abductor and medial rotator of the hip.
What is the action of piriformis?
Lateral rotation and abduction of the thigh
What is the action of obturator internus
Lateral rotation and abduction
What is the action of the gemelli muscles?
Lateral rotation and abduction
What is the action of vastas lateralis?
Extends the leg at the knee
stabilises patella
What is the action of rectus femoris?
extends the leg at the knee
flexes thigh at hip
What is the action of vastas medalis?
Extends the leg at the knee
Stabilises patella
What is the action of vastas intermedius?
extends the leg at the knee
Stabilises the patella
What is the action of iliopsoas?
Flexion of the hip
What is the action of pectineus?
Adduction and flexion at the hip
What is the action of obturator externus?
Abduction and lateral rotation of thigh
What is the action of adductor brevis?
Adduction of thigh
What is the function of adductor longus?
Adduction of thigh
What is the function of adductor Magnus?
Adducts and medially rotates thigh
What is the action of gracilis?
Adduction of hip
Flexion of knee
What is the action of biceps femoris?
Lateral rotation at hip and knee
Extension of hip
Flexion of knee
What is the action of semitendinosis?
medial rotation of the hip and knee
Extension of hip
Flexion of knee
What is the function of semimembranosis?
Medial rotation of hip and knee
Extension of hip
Flexion at the knee
What is the action of tibialis anterior?
Dorsiflexion of foot at ankle
inversion of foot at ankle
What is the function of extensor digitorum longus?
Dorsiflexion of the foot at the ankle
extension of lateral 4 toes
What is the action of extensor hallucis longus?
Dorsiflexion of the foot at the ankle and extension of the great toe
What is the action of fibularis tertius?
Dorsiflexion and eversion of the foot at the ankle
What is the action of fibularis longus?
Plantarflexion and eversion of the foot (also supports lateral and transverse arches)
What is the action of fibularis brevis?
Eversion of the foot at the ankle
What is the action of gastrocnemius?
Knee flexion
Plantarflexion
What is the action of plantaris??
Knee flexion
plantar flexion and inversion of the foot at the ankle
What is the action of soleus?
Plantarflexion and inversion of the foot at the ankle
What is the action of popliteus?
Laterally rotates the femur on the tibia which “unlocks” the knee and permits flexion
What is the action of tibias posterior?
Plantarflexion and inversion of the foot at the ankle
maintains the medial arch of the foot
What is the action of flexor digitorum longus?
Flexes the lateral 4 toes
What is the action of flexor hallicus longus?
Flexes the great toe
What is the action of extensor digitorum brevis?
Extends medial 4 toes at the MTP and IP joints
What is the action of extensor hallicus brevis?
Extends great toes at MTP joint
What is the action of abductor hallicus?
Abducts and flexes great toe
What is the action of flexor digitorum brevis?
Flexes lateral four digits at proximal interphalangeal joints
What is the action of abductor digiti minimi?
Abducts and flexes 5th digit
What is the action of quadratus plantae?
Flexion of lateral 4 digits
What is the action of the lumbricals of the foot?
Flexes at metatarsophalangeal joints, while extending interphalangeal joint
What is the action of flexor hallicus brevis?
Flexes proximal phalanx of the great toe at metatarsophalangeal joint
What is the action of adductor hallicus?
Adducts great toe
Assist in forming transverse arch of the foot
What is the action of flexor digiti minimi brevis?
Flexes the proximal phalanx of the 5th digit
What is the action of the plantar interossei of the foot?
Adducts digits three to five and flex metatarsophalangeal joint
What is the action of the dorsal interossei of the foot?
Abducts digits two to four and flex metatarsophalangeal joints