Unit 3 Muscles OINF

Psoas Major

Psoas Major

Origin: vertebral bodies and intervertebral discs of T12-L5, transverse processes of lumbar vertebrae

Insertion: lesser trochanter of the femur

Innervation: anterior rami L1-L3

Function: Flexes the thigh at the hip joint

Iliacus

Origin: iliac crest, sacrum, superior 2/3 of the iliac fossa

Insertion: lesser trochanter of the femur

Innervation: femoral N

Function: flex the thigh at the hip joint

Gluteus Maximus

Origin: posterior side of the iliac crest, lateral edge of sacrum and coccyx

Insertion: gluteal tuberosity of the femur, iliotibial tract

Innervation: inferior gluteal N

function: laterally rotate and ABDuct the thigh, extend flexed femur at the hip joint, lateral stabilizer of hip and knee

Gluteus medius

Origin: posterior side of the iliac blade

Insertion: greater trochanter of the femur

Innervation: superior gluteal N

Function: medially rotate and ABDuct the thigh at hip joint

Gluteus minimus

Origin: posterior side of the iliac blade

Insertion: greater trochanter of the femur

Innervation: superior gluteal N

Function: medially rotate and ABDuct the thigh at hip joint

Tensor Fascia Latae

Origin: outer lip of iliac crest

Insert: lateral condyle of the tibia via the iliotibial tract

Innervation: superior gluteal N

Function: stabilize the knee in extension

Piriformis

Origin: anterior surface of the sacrum

Insertion: greater trochanter of the femur

Innervation: branches of spinal nerves S1 and S2

Function: laterally rotate extended femur, ABDuct flexed femur at hip joint

Gemellus Superior

Origin: ischial spine

Insertion: greater trochanter of the femur

Innervation: nerve to obturator internus

Function: laterally rotate extended femur, ABDuct flexed femur at hip joint

obturator internus

Origin: deep surface of obturator membrane, anterolateral wall of true pelvis, superior ramus of pubis and bone surrounding obturator foramen

Insertion: greater trochanter of the femur

Innervation: nerve to obturator internus

Function: laterally rotate extended femur, ABDuct flexed femur at hip joint

gemellus inferior

Origin: ischial tuberosity

Insertion: greater trochanter of the femur'

Innervation: nerve to quadratus femoris

Function: laterally rotate extended femur, ABDuct flexed femur at hip joint

quadratus femoris

Origin: lateral aspect of ischium, anterior to the ischial tuberosity

Insertion: intertrochanteric crest of femur

Innervation: Nerve to quadratus femoris

Function: laterally rotate femur at the hip joint

Obturator externus

Origin: external surface of obturator membrane and obturator foramen

Insertion: trochanteric fossa of femur

Innervation: Obturator N

Function: laterally rotate femur at the hip joint

Gracilis

Origin: external surface of body of pubis, ischiopubic ramus

Insertion: medial surface of proximal shaft of tibia

Innervation: obturator N

Function: ADDuct thigh at hip joint, flexes leg at knee joint

Adductor Longus

Origin: external surface of body of pubis

Insertion: linea aspera of femur

Innervation: Obturator N

Function: ADDuct and medially rotate thigh at hip joint

Pectineus

Origin: pectineal line of pubis

Insertion: posterior surface of femur, inferior to the lesser trochanter of the femur

Innervation: femoral N

Function: ADDucts and flex thigh at hip joint

adductor brevis

Origin: external surface of pubis, inferior pubic ramus

Insertion: Linea aspera of femur, posterior surface of femur

Innervation: obturator N

Function: ADDuct and medially rotate thigh at hip joint

adductor magnus (adductor component)

Origin: ischiopubic ramus

Insertion: posterior surface of femur, linea aspera of femur

Innervation: obturator N

Function: ADDuct and medially rotate thigh at hip joint

Adductor Magnus (hamstring component)

Origin: ischial tuberosity of ischium

Insertion: adductor tubercle of femur

Innervation: tibial portion of sciatic N

Function: ADDuct and medially rotate thigh at hip joint

Rectus Femoris

Origin: anterior inferior iliac spine, ilium superior to acetabulum

Insertion: patella via quadriceps femoris tendon

Innervation: femoral N

Function: extends leg at knee joint, flex thigh at hip joint

Vastus Lateralis

Origin: intertrochanteric line of femur, linea aspera of femur, greater trochanter of femur

Insertion: patella via quadriceps femoris tendon

Innervation: femoral N

Function: extends leg at the knee joint

Vastus Medialis

Origin: intertrochanteric line of femur, linea aspera of femur, pectineal line of femur

Insertion: patella via quadriceps femoris tendon

Innervation: femoral N

Function: extends leg at knee joint

Vastus intermedius

Origin: upper 2/3 of femoral shaft

Insertion: patella via quadriceps femoris

Innervation: Femoral N

Function: extends leg at the knee joint

sartorius

Origin: anterior superior iliac spine

Insertion: medial surface of the tibia inferior and medial to the tibial tuberosity

Innervation: femoral N

Function: flexes thigh at the hip joint, flexes leg at the knee joint

biceps femoris (long head)

Origin: ischial tuberosity

Insertion: head of fibula

Innervation: tibial portion of sciatic N

Function: Flex leg at knee joint, laterally rotate leg at knee joint, extend and laterally rotate thigh at hip joint

Biceps femoris (short head)

Origin: linea aspera of femur, lateral supracondylar ridge of femur

Insertion: head of fibula

Innervation: common fibular portion of sciatic N

Function: flex leg at the knee joint

Semimembranosus

Origin: ischial tuberosity

Insertion: medial and posterior surface of medial tibial condyle

Innervation: tibial portion of sciatic N

Function: flex leg at the knee joint, extend thigh at hip joint, medially rotate thigh at the hip, medially rotate leg at the knee

semitendinosus

Origin: ischial tuberosity

Insertion: medial surface of proximal tibia

Innervation: tibial portion of sciatic N

Function: flex leg at the knee joint, extend thigh at hip joint, medially rotate thigh at the hip, medially rotate leg at the knee

gastrocnemius medial head

Origin: posterior surface of femur superior to the medial condyle

Insertion: calcaneus via the Achilles tendon

Innervation: tibial N

Function: plantarflex foot, flex the knee

gastrocnemius lateral head

Origin: posterolateral surface of the lateral condyle of the femur

Insertion: calcaneus via the Achilles tendon

Innervation: tibial N

Function: plantarflex foot, flex the knee

soleus

Origin: soleal line and medial border of tibia, head of fibula

Insertion: calcaneus via the Achilles tendon

Innervation: tibial N

Function: plantarflex foor

plantaris

Origin: supracondylar line of femur, popliteal ligament of knee

Insertion: calcaneus via Achilles tendon

Innervation: tibial N

Function: plantarflex foot, flex the knee

popliteus

Origin: lateral condyle of femur

Insertion: posterior surface of tibia

Innervation: tibial N

Function: stabilize the knee joint by resisting lateral rotation of tibia on femur, unlocks knee joint by laterally rotating femur on fixed tibia

flexor digitorum longus

Origin: medial side of posterior surface of tibia

Insertion: plantar surfaces of distal phalanges 2-5

Innervation: tibial N

Function: flexes digits 2-5

tibialis posterior

Origin: interosseus membrane, tibia and fibula near the interosseus membrane

Insertion: plantar surface of navicular, plantar surface of medial cuneiform

Innervation: tibial N

Function: inverting foot, plantarflexion of foot, supports medial arch of foot during walking

Flexor hallucis longus

Origin: posterior surface of fibula, interosseus membrane

Insertion: plantar surface of distal phalanx of hallux

Innervation: tibial N

Function: flexes hallux

Fibularis (peroneus) longus

Origin: lateral surface of fibula, head of fibula

Insertion: plantar surface of medial cuneiform, plantar surface of base of metatarsal 1

Innervation: superficial fibular N

Function: everts foot, plantarflexes foot, supports arches of foor

Fibularis (peroneus) brevis

Origin: lower 2/3 of shaft of fibula

Insertion: base of metatarsal 5

Innervation: superficial fibular N

Function: everts foot

Tibialis anterior

Origin: lateral surface of the tibia, interosseus membrane

Insertion: dorsal surface medial cuneiform, dorsal surface base of metatarsal 1

Innervation: deep fibular N

Function: dorsiflex foot at ankle joint, inverts foot, supports medial arch of foot

Extensor hallucis longus

Origin: medial surface of fibula, interosseus membrane

Insertion: Dorsal surface of distal phalanx of hallux

Innervation: deep fibular N

Function: extends hallux, dorsiflex foot at the ankle joint

Extensor digitorum longus

Origin: proximal half of fibula, lateral condyle of tibia

Insertion: dorsal surfaces of bases of distal and middle phalanges of digits 2-5

Innervation: deep fibular N

Function: extends digits 2-5, dorsiflex at ankle joint

Fibularis tertius

Origin: medial surface of fibula

Insertion: dorsal surface of base of metatarsal 5

Innervation: deep fibular N

Function: dorsiflex foot at ankle joint, everts foot

extensor digitorum brevis

Origin: calcaneus

Insertion: tendons of extensor digitorum longus

Innervation: deep fibular N

Function: extends toes 2-4

Extensor Hallucis brevis

Origin: calcaneus

Insertion: base of proximal phalanx of hallux

Innervation: deep fibular N

Function: extend hallux at metatarsophalangeal joint

abductor hallucis

Origin: calcaneal tuberosity

Insertion: medial side of base of proximal phalanx of hallux

Innervation: medial plantar N

Function: ABDuct and flex hallux at metatarsophalangeal joint

flexor digitorum brevis

Origin: calcaneal tuberosity, plantar aponeurosis

Insertion: plantar surfaces of middle phalanges of toes 2-5

Innervation: medial plantar N

Function: flexes toes 2-5 at proximal interphalangeal joint

Abductor digiti minimi

Origin: calcaneal tuberosity, connective tissue between calcaneus and metatarsal 5

Insertion: lateral side of base of proximal phalanx of digit 5

Innervation: lateral plantar N

Function: ABDuct little toe at metatarsophalangeal joint

Quadratus plantae

Origin: medial surface of calcaneus, calcaneal tuberosity

Insertion: tendon of flexor digitorum longus in sole of foot

Innervation: lateral plantar N

Function: assists flexor digitorum longus tendon in flexing toes 2-5

Lumbricals

Origin: 1st = medial side of tendon of flexor digitorum longus associated with toe 2

2nd to 4th = adjacent surfaces of adjacent tendons of flexor digitorum longus

Insertion: medial margins of extensor hoods of toes 2-5

Innervation: 1st = medial plantar N

2nd to 4th = lateral plantar N

Function: flexion of metatarsophalangeal joint and extension of interphalangeal joints

Flexor hallucis brevis

Origin: plantar surface of cuboid and lateral cuneiform, tendon of tibialis posterior

Insertion: lateral and medial sides of the base of proximal phalanx of hallux

Innervation: medial plantar N

Function: flexes hallux at metatarsophalangeal joint

adductor hallucis

Origin: ligaments of metatarsophalangeal joints of toes, bases of metatarsals 2-4, sheath covering fibularis longus

Insertion: lateral side of base of proximal phalanx of hallux

Innervation: lateral plantar N

Function: ADDcuts hallux at metatarsophalangeal joint

flexor digiti minimi brevis

Origin: base of metatarsal 5, tendon sheath of fibularis longus

Insertion: lateral side of base of proximal phalanx of little toe

Innervation: lateral plantar N

Function: flexes little toe at metatarsophalangeal joint

Plantar interossei

Origin: medial sides of metatarsals 3-5

Insertion: extensor hoods and bases of proximal phalanges of toes 3-5

Innervation: lateral plantar N

Function: ADDuction of toes 3-5 at MTP, resist extension of metatarsophalangeal joint and flexion of interphalangeal joints

Dorsal interossei

Origin: sides of adjacent metatarsals

Insertion: extensor hoods of toes 2-4, bases of proximal phalanges of toes 2-4

Innervation: 1&2 = deep fibular N and lateral plantar N

3&4 = lateral plantar N

Function: ABDucts toes 2-4 at MTP, resists extension of metatarsophalangeal joint and flexion of interphalangeal joints