Muscle Action Review…for Origin, Insertion & Action Test

Flex the knee (tibiofemoral joint)

Medially rotate the flexed knee (t/f joint)

Extend the hip (coxal joint)

Medially rotate the hip (coxal joint)

Tilt the pelvis posteriorly

Semitendinosus, TG pg. 306 (3rd) & 312 (4th)

Depress the scapula (scapulothoracic joint)

Abduct the scapula (s/t joint)

Tilt the scapula anteriorly (s/t joint)

If scapula is fixed:

Assists with forced inhalation

Pectoralis Minor, TG pg. 100 (3rd) & 92 (4th)

Flex the shoulder (glenohumeral joint)

Adduct the shoulder (g/h joint)

Coracobrachialis, TG pg. 107 (3rd & 99 (4th)

Upper fibers:

Bilaterally – Extends the head and neck

Unilaterally – Laterally flex the head and neck to same side

Rotate the head and neck to opposite side

Elevate the scapula (scapulothoracic joint)

Upwardly rotate the scapula (s/t joint)

Middle fibers:

Adduct the scapula (s/t joint)

Stabilize the scapula (s/t joint)

Lower fibers:

Depress the scapula (s/t joint)

Upwardly rotate the scapula (s/t joint)

Trapezius, TG pg. 76 (3rd) & 68 (4th)

Flex the elbow (humeroulnar joint)

Supinates the forearm (radioulnar joint)

Flex the shoulder (glenohumeral joint)

Biceps Brachii, TG pg. 103 (3rd) & 95 (4th)

Gluteus Maximus, TG pg. 309 (3rd) & 315 (4th)

All fibers:

Extend the hip (coxal joint)

Laterally rotate the hip (coxal joint)

Abduct the hip (coxal joint)

Lower fibers:

Adduct the hip (coxal joint)

Extends the shoulder (glenohumeral joint)

Adducts the shoulder (g/h joint)

Medially rotates the shoulder (g/h joint)

Teres Major, TG pg. 79 (3rd) & 71 (4th)

Flex the knee (tibiofemoral joint)

Laterally rotate the flexed knee (t/f joint)

Extend the hip (coxal joint)

Tilt the pelvis posteriorly

Biceps Femoris, TG pg. 306 (3rd) & 312 (4th)

Unilaterally:

Elevate the scapula (scapulothoracic joint)

Downwardly rotates the scapula (s/t joint)

Laterally flexes the neck

Rotates the head and neck to the same side

Bilaterally:

Extends the head and neck

Levator Scapula, TG pg. 91-92 (3rd) & 83 (4th)

Unilaterally:

Laterally flexes the head and neck to the same side

Rotates the head and neck to the opposite side

Bilaterally:

Flexes the neck

Assists in inhalation (elevation of the rib cage)

Sternocleidomastoid, TG pg. 250 (3rd) & 244 (4th)

Unilaterally:

With the ribs fixed, laterally flexes the head and neck to the same side (All)

Rotates the head and neck to the opposite side (All)

Bilaterally:

Elevates the ribs during inhalation (All)

Flex the head and neck (Anterior)

Scalenes, TG pg. 253 (3rd) & 247 (4th)

With the origin fixed:

Abducts the scapula (scapulothoracic joint)

Depress the scapula (s/t joint)

Holds the medial border of the scapula against the rib cage

If the scapula is fixed:

May act in forced inhalation

Serratus Anterior, TG pg. 94 (3rd) & 86 (4th)

Flexes the vertebral column

Rectus Abdominis, TG pg. 216 (3rd) & 210 (4th)

All fibers:

Abduct the shoulder (glenohumeral joint)

Anterior fibers:

Flex the shoulder (g/h joint)

Medially rotate the shoulder (g/h joint)

Horizontally adduct the shoulder (g/h joint)

Posterior fibers:

Extend the shoulder (g/h joint)

Laterally rotate the shoulder joint (g/h joint)

Horizontally abduct the shoulder (g/h joint)

Deltoid, TG pg. 75 (3rd) & 67 (4th)

Latissimus Dorsi, TG pg. 79 (3rd) & 71 (4th)

Extends the shoulder (glenohumeral joint)

Adducts the shoulder (g/h joint)

Medially rotates the shoulder (g/h joint)

Gracilis, TG pg. 314-315 (3rd) & 321 (4th)

Adducts the hip (coxal joint)

Medially rotates the hip (coxal joint)

Flexes the knee (tibiofemoral joint)

Medially rotates the flexed knee (t/f joint)

Tensor Fasciae Latae, TG pg. 318 (3rd) & 324 (4th)

Flexes the hip (coxal joint)

Medially rotates the hip (coxal joint)

Abducts the hip (coxal joint)

Piriformis, TG pg. 322 (3rd) & 328 (4th)

Laterally rotate the hip (coxal joint)

Abduct the hip when the hip is flexed

Peroneus Longus, TG pg. 369 (3rd) & 376 (4th)

Everts the foot

Assists to plantar flex the ankle (talocrural joint)

Vastus Lateralis, TG pg. 300 (3rd) & 306 (4th)

Extends the knee (tibiofemoral joint)

Sartorius, TG pg. 320 (3rd) & 326 (4th)

Flex the hip (coxal joint)

Laterally rotates the hip (coxal joint)

Abducts the hip (coxal joint)

Flexes the knee (tibiofemoral joint)

Medially rotates the flexed knee (t/f joint)

Tibialis Anterior, TG pg. 372 (3rd) & 379 (4th)

Inverts the foot

Dorsiflexes the ankle (talocrural joint)

Pectoralis Major, TG pg. 97 (3rd) & 89 (4th)

All fibers:

Adduct the shoulder (glenohumeral joint)

Medially rotate the shoulder (g/h joint)

Assist in elevating the thorax in forced inhalation

(if arm is fixed)

Upper fibers:

Flex the shoulder (g/h joint)

Horizontally adduct the shoulder (g/h joint)

Lower fibers:

Extend the shoulder (g/h joint)

Extensor Hallucis Longus, TG pg. 372 (3rd) & 379 (4th)

Extends the first toe (metatarsophalangeal and interphalangeal joints)

Dorsiflex the ankle (talocrural joint)

Inverts the foot

Flexor Carpi Ulnaris, TG pg. 150 (3rd) & 142 (4th)

Flex the wrist (radiocarpal joint)

Adduct the wrist (radiocarpal joint)

Assist to flex the elbow (humeroulnar joint)

External Oblique, TG pg. 216 (3rd) & 210 (4th)

Unilaterally:

Laterally flex vertebral column to the same side

Rotates vertebral column to the opposite side

Bilaterally:

Flexes the vertebral column

Compresses the abdominal contents

Triceps Brachii, TG pg. 105 (3rd) & 97 (4th)

All fibers:

Extend the elbow (humeroulnar joint)

Long head:

Extend the shoulder (glenohumeral joint)

Adduct the shoulder (g/h joint)

Gastrocnemius, TG pg. 364 (3rd) & 371 (4th)

Flex the knee (tibiofemoral joint)

Plantar flex the ankle (talocrural joint)

Abductor Hallucis, TG pg. 378 (3rd) & 388 (4th)

Abducts the first toe (metatarsophalangeal joint)

Assists to flex the first toe (metatarsophalangeal joint)

Extensor Digitorum Longus, TG pg. 372 (3rd) & 379 (4th)

Extend the second through the fifth toes (metatarsophalangeal and interphalangeal joints)

Dorsiflex the ankle (talocrural joint)

Evert the foot

Brachioradialis, TG pg. 141 (3rd) & 133 (4th)

Flex the elbow (humeroulnar joint)

Assist to pronate and supinate the forearm when these movements are resisted

Supraspinatus, TG pg. 83 (3rd) & 74 (4th)

Abduct the shoulder (glenohumeral joint)

Stabilize the head of the humerus in the glenoid cavity

Adductor Hallucis, TG pg. 380 (3rd) & 390 (4th)

Adducts the first toe

Assists to maintain the transverse arch of the foot

Biceps Femoris, Tg pg. 306 (3rd) & 312 (4th)

Flex the knee (tibiofemoral joint)

Laterally rotate the flexed knee (t/f joint)

Extend the hip (coxal joint)

Laterally rotate the hip (coxal joint)

Tilt the pelvis posteriorly

Semimembranosus, TG pg. 306 (3rd) & 312 (4th)

Flex the knee (tibiofemoral joint)

Medially rotate the flexed knee (t/f joint)

Extend the hip (coxal joint)

Medially rotate the hip (coxal joint)

Tilt the pelvis posteriorly

Iliopsoas, TG pg. 326 (3rd) & 332 (4th)

Flex the hip (coxal joint)

Laterally rotates the hip (coxal joint)

Adducts the hip (coxal joint)

Rectus Femoris, TG pg. 300 (3rd) & 306 (4th)

Extends the knee (tibiofemoral joint)

Flexes the hip (coxal joint)

Infraspinatus, TG pg. 83 (3rd) & 74 (4th)

Laterally rotates the shoulder (glenohumeral joint)

Adducts the shoulder (g/h joint)

Extends the shoulder (g/h joint)

Horizontally abducts the shoulder (g/h joint)

Stabilizes the head of the humerus in the glenoid cavity

Adductor Magnus, TG pg. 314 (3rd) & 320 (4th)

Adduct the hip (coxal joint)

Medially rotates the hip (coxal joint)

Assists in flexion of hip (coxal joint)

Extends the hip (coxal joint)

Brachialis, TG pg. 140 (3rd) & 132 (4th)

Flexes the elbow (humeroulnar joint)

Rhomboid Major, TG pg. 90 (3rd) & 82 (4th)

Adduct the scapula (scapulothoracic joint)

Elevate the scapula (s/t joint)

Downwardly rotate the scapula (s/t joint)