LL Muscles: Innervation and Actions

Nerve supply of Gluteus maximus?

Inferior gluteal nerve

Action of Gluteus maximus?

Extends and laterally rotates hip joint, through iliotibial tract extends knee joint

Nerve supply of Gluteus medius?

Superior gluteal nerve

Action of Gluteus medius?

Abducts thigh at hip joint, tilts pelvis when walking to permit opposite leg to clear ground

Nerve supply of Gluteus minimus?

Superior gluteal nerve

Action of Gluteus minimus?

Abducts thigh at hip joint, tilts pelvis when walking to permit opposite leg to clear ground

Nerve supply of Tensor fasciae latae?

Superior gluteal nerve

Action of Tensor fasciae latae?

Assists gluteus maximus in extending the knee joint

Nerve supply of Piriformis?

Branches of anterior rami of S1 and S2

Action of Piriformis?

Lateral rotator of thigh at hip joint

Nerve supply of Obturator internus?

Nerve to Obturator internus

Action of Obturator internus?

Lateral rotator of thigh at hip joint

Nerve supply of Gemellus superior?

Nerve to Obturator internus

Action of Gemellus superior?

Lateral rotator of thigh at hip joint

Nerve supply of Gemellus inferior?

Nerve to quadratus femoris

Action of Gemellus inferior?

Lateral rotator of thigh at hip joint

Nerve supply of Quadratus femoris?

Nerve to Quadratus femoris

Action of Quadratus femoris?

Lateral rotator of thigh at hip joint

Nerve supply of Sartorius?

Femoral nerve

Action of Sartorius?

Flexes, abducts and laterally rotates thigh at hip joint, flexes and medially rotates leg at knee joint

Nerve supply of Iliacus?

Femoral nerve

Action of Iliacus?

Flexes thigh on trunk, if thigh is fixed flexes trunk on thigh as in sitting up from lying down

Nerve supply of Psoas?

Anterior rami of L1 and L2 (L3 too in case of psoas major)

Action of Psoas?

Flexes thigh on trunk, if thigh is fixed flexes trunk on thigh as in sitting up from lying down

Nerve supply of Pectineus?

Femoral nerve

Action of Pectineus?

Flexes and adducts thigh at hip joint

Nerve supply of Rectus femoris?

Femoral nerve

Action of Rectus femoris?

Extends leg at knee joint, flexes thigh at hip joint

Nerve supply of Vastus lateralis?

Femoral nerve

Action of Vastus lateralis?

Extends leg at knee joint

Nerve supply of Vastus medialis?

Femoral nerve

Action of Vastus medialis?

Extends leg at knee joint, stabilizes patella

Nerve supply of Vastus intermedius?

Femoral nerve

Action of Vastus intermedius?

Extends leg at knee joint, articularis genus retracts synovial membrane

Nerve supply of Gracilis?

Obturator nerve

Action of Gracilis?

Adducts thigh at hip joint, flexes leg at knee joint

Nerve supply of Adductor longus?

Obturator nerve

Action of Adductor longus?

Adducts thigh at hip joint and assists in lateral rotation

Nerve supply of Adductor brevis?

Obturator nerve

Action of Adductor brevis?

Adducts thigh at hip joint and assists in lateral rotation

Nerve supply of Adductor magnus?

Adductor portion: Obturator nerve, Hamstring portion: Sciatic nerve

Action of Adductor magnus?

Adducts thigh at hip joint and assists in lateral rotation, hamstring portion extends thigh at hip joint

Nerve supply of Obturator externus?

Obturator nerve

Action of Obturator externus?

Laterally rotates thigh at hip joint

Nerve supply of Biceps femoris?

Long head: Tibial portion of sciatic nerve

Short head: Common peroneal portion of sciatic nerve

Action of Biceps femoris?

Flexes and laterally rotates leg at knee joint, long head also extends thigh at hip joint

Nerve supply of Semitendinosus?

Tibial portion of sciatic nerve

Action of Semitendinosus?

Flexes and medially rotates leg at knee joint, extends thigh at hip joint

Nerve supply of Semimembranosus?

Tibial portion of sciatic nerve

Action of Semimembranosus?

Flexes and medially rotates leg at knee joint, extends thigh at hip joint

Nerve supply of Adductor magnus (hamstring portion)?

Tibial portion of sciatic nerve

Action of Adductor magnus (hamstring portion)?

Extends thigh at hip joint

Nerve supply of Tibialis anterior?

Deep peroneal nerve

Action of Tibialis anterior?

Dorsiflexes foot at ankle joint, inverts foot at subtalar and transverse tarsal joints, holds up medial longitudinal arch of foot

Nerve supply of Extensor digitorum longus?

Deep peroneal nerve

Action of Extensor digitorum longus?

Extends toes, dorsiflexes foot at ankle joint

Nerve supply of Peroneus tertius?

Deep peroneal nerve

Action of Peroneus tertius?

Dorsiflexes foot at ankle joint, everts foot at subtalar and transverse tarsal joints

Nerve supply of Extensor hallucis longus?

Deep peroneal nerve

Action of Extensor hallucis longus?

Extends big toe, dorsiflexes foot at ankle joint, inverts foot at subtalar and transverse tarsal joints

Nerve supply of Extensor digitorum brevis?

Deep peroneal nerve

Action of Extensor digitorum brevis?

Extends toes

Nerve supply of Peroneus longus?

Superficial peroneal nerve

Action of Peroneus longus?

Plantar flexes foot at ankle joint, everts foot at subtalar and transverse tarsal joints, supports lateral longitudinal and transverse arches of foot

Nerve supply of Peroneus brevis?

Superficial peroneal nerve

Action of Peroneus brevis?

Plantar flexes foot at ankle joint, everts foot at subtalar and transverse tarsal joints, supports lateral longitudinal arch of foot

Nerve supply of Gastrocnemius?

Tibial nerve

Action of Gastrocnemius?

Plantar flexes foot at ankle joint, flexes knee joint

Nerve supply of Plantaris?

Tibial nerve

Action of Plantaris?

Plantar flexes foot at ankle joint, flexes knee joint

Nerve supply of Soleus?

Tibial nerve

Action of Soleus?

Powerful plantar flexor of ankle joint, provides main propulsive force in walking and running

Nerve supply of Popliteus?

Tibial nerve

Action of Popliteus?

Flexes leg at knee joint, unlocks knee joint by lateral rotation of femur on tibia and slackens ligaments of joint

Nerve supply of Flexor digitorum longus?

Tibial nerve

Action of Flexor digitorum longus?

Flexes distal phalanges of lateral four toes, plantar flexes foot at ankle joint, supports medial and lateral longitudinal arches of foot

Nerve supply of Flexor hallucis longus?

Tibial nerve

Action of Flexor hallucis longus?

Flexes distal phalanx of big toe, plantar flexes foot at ankle joint, supports medial longitudinal arch of foot

Nerve supply of Tibialis posterior?

Tibial nerve

Action of Tibialis posterior?

Plantar flexes foot at ankle joint, inverts foot at subtalar and transverse tarsal joints, supports medial longitudinal arch of foot

Nerve supply of Abductor hallucis?

Medial plantar nerve

Action of Abductor hallucis?

Flexes and abducts big toe, braces medial longitudinal arch

Nerve supply of Flexor digitorum brevis?

Medial plantar nerve

Action of Flexor digitorum brevis?

Flexes lateral four toes, braces medial and lateral longitudinal arches

Nerve supply of Abductor digiti minimi?

Lateral plantar nerve

Action of Abductor digiti minimi?

Flexes and abducts fifth toe, braces lateral longitudinal arch

Nerve supply of Quadratus plantae?

Lateral plantar nerve

Action of Quadratus plantae?

Assists flexor digitorum longus in flexing lateral four toes

Nerve supply of Lumbricals?

First: Medial plantar nerve, remainder: Lateral plantar nerve

Action of Lumbricals?

Extends toes at interphalangeal joints

Nerve supply of Flexor hallucis brevis?

Medial plantar nerve

Action of Flexor hallucis brevis?

Flexes metatarsophalangeal joint of big toe, supports medial longitudinal arch

Nerve supply of Adductor hallucis?

Deep branch of lateral plantar nerve

Action of Adductor hallucis?

Flexes metatarsophalangeal joint of big toe, holds together metatarsal bones

Nerve supply of Flexor digiti minimi brevis?

Superficial branch of lateral plantar nerve

Action of Flexor digiti minimi brevis?

Flexes metatarsophalangeal joint of little toe

Nerve supply of Dorsal interossei?

Lateral plantar nerve

Action of Dorsal interossei?

Abduct toes, flex metatarsophalangeal joints, extend interphalangeal joints

Nerve supply of Plantar interossei?

Lateral plantar nerve

Action of Plantar interossei?

Adduct toes, flex metatarsophalangeal joints, extend interphalangeal joints