gastrocnemius

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gas·troc·ne·mi·us (mus·cle)

[TA]
superficial muscle of posterior (plantar flexor) compartment of leg; origin, by two heads (lateral and medial) from the lateral and medial condyles of the femur; insertion, with soleus by tendo calcaneus into lower half of posterior surface of calcaneus; action, plantar flexion of foot; nerve supply, tibial.

gastrocnemius

/gas·troc·ne·mi·us/ (gas″tro-ne´me-әs) (gas″trok-ne´me-us) see under muscle.

gastrocnemius

(găs′trŏk-nē′mē-əs, găs′trə-)
n. pl. gastrocne·mii (-mē-ī′)
The largest, most prominent muscle of the calf of the leg, the action of which extends the foot and bends the knee.

gastrocnemius

[gas′trōnē′me·us]
Etymology: Gk, gastroknemia, calf of the leg
the most superficial calf muscle in the posterior part of the leg. It joins the tendon of the soleus as part of the tendo calcaneus. It flexes the leg and plantarflexes the foot. Compare plantaris, soleus.
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Gastrocnemius

gas·troc·ne·mi·us mus·cle

(gas'trok-nē'mē-ŭs mŭs'ĕl)
Origin, by two heads (lateral and medial) from the lateral and medial condyles of the femur; insertion, with soleus by tendo calcaneus into lower half of posterior surface of calcaneus; action, plantar flexion of foot; nerve supply, tibial.
Synonym(s): musculus gastrocnemius [TA] , gastrocnemius.

gastrocnemius

The main muscle forming the bulge of the calf. The gastrocnemius arises by two heads from the back of the lower end of the thigh bone (femur) and is inserted, with the SOLEUS muscle, by way of the ACHILLES TENDON into the back of the heel bone (CALCANEUS). Its action is to extend the ankle joint in walking and standing on tiptoe.

gastrocnemius

the largest muscle of the calf in the human leg.
Figure 1: The autonomic nervous system. Actions on the heart and on smooth muscle. Sympathetic actions on the left and parasympathetic actions on the right. Solid arrows: stimulation (contraction or secretion); broken arrows: inhibition.

gastrocnemius

the most superficial of the muscles of the back of the lower leg. It arises from the medial and lateral femoral condyles by two heads which join to form the inferior border of the popliteal fossa behind the knee. Together with its smaller accessory, the plantaris, and the soleus muscle (arising from the shaft of the tibia), it converges onto the Achilles tendon, to be inserted into the middle of the back of the calcaneum. It acts to plantarflex the foot and raise the heel when walking. Gastrocnemius and plantaris also act as weak flexors at the knee. See Figure 1.

gastrocnemius

large, two-headed muscle within the superficial part of posterior compartment of the lower leg (see Table 1, Table 2and Table 3)
  • origin medial head, from popliteal area of medial femoral condyle; lateral head, from lateral surface of lateral femoral condyle; medial belly is larger than lateral

  • insertion a common tendon (which includes the soleus tendon), i.e. tendo Achilles into middle facet of posterior aspect of calcaneum (see Achilles tendon)

  • nerve supply tibial nerve

  • action (1) knee joint flexion (in conjunction with ham strings); (2) ankle joint plantarflexion (in conjunction with soleus) when knee is extended, raising heel to allow body weight to move forward on to dorsiflexed metatarsophalangeal joints during walking, running, jumping, stair climbing; (3) stabilization of ankle joint in sagittal plane (in conjunction with soleus and extrinsic flexors of foot); (4) venous muscle pump, facilitating venous return

Table 1: Muscles acting on the joints of the lower limb and foot
JointMuscleMuscle originMuscle insertion
Hip onlyAdductor longus
Adductor brevis
Adductor magnus
Psoas major
Iliacus
Pectineus
Gluteus minimus
Gluteus medius
Gluteus maximus (deep quarter)
Piriformis
Obturator externus
Obturator internus
Gemelli
Body of pubis
Body and inferior ramus of pubis
Inferior ramus of pubis
Lumbar vertebrae
Iliac fossa
Body and superior ramus of pubis
Ileum
Ileum
Sacrum
Sacrum
Obturator membrane
Internal surfaces of ileum, pubis
Ischium, sides of sciatic notch
Linea aspera of posterior femur
Linea aspera of posterior femur
Lower medial femur, adductor tubercle
Lesser trochanter
Femur, inferior to lesser trochanter
Posterior area of lesser trochanter
Anterior area greater trochanter
Lateral area greater trochanter
Gluteal tuberosity of femur
Greater trochanter
Trochanteric fossa
Medial area greater trochanter
Medial area greater trochanter
Hip and kneeBiceps femoris (long head)
Semimembranosus
Semitendinosus
Gracilis
Sartorius
Tensor fasciae lata
Rectus femoris
Gluteus maximus (superior three-quarters)
Ischial tuberosity
Ischial tuberosity
Ischial tuberosity
Body and inferior ramus of pubis
Anterior superior iliac spine
Anterior one-quarter of iliac crest
Anterior ileum
Posterior area of ileum and sacrum
Head of fibula
Posterior-area medial tibial condyle
Upper one-quarter medial tibia
Upper one-quarter medial tibia
Upper one-quarter medial tibia
Lateral condyle tibia via iliotibial tract
Patella, via quadriceps tendon
Lateral condyle tibia via iliotibial tract
Knee onlyVastus medialis
Vastus intermedius
Vastus lateralis
Biceps femoris (short head)
Popliteus
Anterior upper femur and tendon of adductor magnus
Anterior and lateral surfaces of body of femur
Greater trochanter and linea aspera of femur
Linea aspera
Lateral condyle of femur
Superior and medial surfaces of patella and capsule of knee joint
Superior surface of patella and suprapatellar bursa
Superior and lateral surfaces of patella and capsule of knee joint
Head of fibula
Posterior surface of upper tibia
Knee and ankleGastrocnemius
Plantaris
Lateral surface of lateral condyle and posterior surface of medial femoral condyle
Posterior surface of lateral femoral condyle
Calcaneum, via Achilles tendon
Calcaneum, via Achilles tendon (acts with gastrocnemius)
Ankle onlySoleusSoleal line and middle one-third of medial border of tibia and posterior surface of upper one-third fibulaCalcaneum, via Achilles tendon
Ankle and tarsusPeroneus longus
Peroneus brevis
Tibialis anterior
Tibialis posterior
Peroneus tertius
Lateral surface of upper two-thirds of lateral fibula
Lateral surface of lower two-thirds of lateral fibula
Lateral surface of upper one-half of tibia and local interosseous membrane
Upper one-half of tibia, fibula and local interosseous membrane
Anterior surface of distal one-quarter of fibula
Base of first metatarsal and lateral side of medial (first) cuneiform
Base of fifth metatarsal
Base of first metatarsal and inferomedial aspect of medial (first) cuneiform
Medial (first) cuneiform, inferior aspects of all tarsal bones (except the talus) and bases of second, third and fourth metatarsals
Dorsal shaft of fifth metatarsal
Tarsus and toesExtensor digitorum brevis
Flexor digitorum brevis
Flexor accessories (quadratus plantae)
Abductor hallucis
Abductor digiti minimi
Superior and anterior surfaces of the calcaneum
Medial process of calcaneal tuberosity
Plantar, medial and lateral aspects of calcaneum
Medial process of calcaneal tuberosity and flexor retinaculum
Calcaneal tuberosity
Dorsum of proximal phalanx of hallux, and extensor expansions of toes 2-4
Plantar, middle phalanges of toes 2-5
Tendon flexor digitorum longus
Medial side of proximal phalanx of hallux
Lateral side of proximal phalanx of fifth toe
Toes onlyDorsal interossei
Plantar interossei
Lumbricals
Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis
Adjacent sides of metatarsals 1-5
Medial sides of metatarsals 3-5
Digital tendon slips of flexor digitorum longus
Medial plantar aspect of the cuboid
Bases of 2-4 metatarsals and transverse plantar ligament of 2-4 metatarsophalangeal joints
Base of fifth metatarsal
Lateral side of toes 2-4 and medial side toe 2
Medial sides of bases of proximal phalanges of toes 3-5
Extensor expansions toes 2-5
Medial and lateral sides of base of proximal phalanx of hallux
Lateral side of base of proximal side of hallux
Lateral side of base of proximal phalanx of toe 5
Table 2: Movements occurring about the joints of the lower limb and foot
Movement about jointMuscle causing the movementNerve supply to muscle
Hip flexionIliacus
Psoas major
Rectus femoris
Sartorius
Tensor fasciae lata
Pectineus
Adductor longus
Adductor brevis
Ventral rami of L1 and L2
Ventral rami of L1 and L2
Femoral
Femoral
Superior gluteal
Femoral
Obturator
Obturator
Hip extensionGluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris, long head
Adductor magnus, ischial part
Inferior gluteal
Tibial part of sciatic nerve
Tibial part of sciatic nerve
Tibial part of sciatic nerve
Tibial part of sciatic nerve
Hip adductionAdductor longus
Adductor brevis
Adductor magnus
Gracilis
Pectineus
Quadratus femoris
Obturator
Obturator
Obturator
Obturator
Femoral
Ventral rami of L4, L5 and S1
Hip abductionGluteus medius
Gluteus minimus
Tensor fasciae lata
Piriformis
Obturator internus, in flexion
Superior gluteal
Superior gluteal
Superior gluteal
Ventral rami of L5 and SI
Ventral rami of L5 and S1
Medial rotation of leg at hipTensor fasciae lata
Gluteus minimus
Anterior fibres of gluteus maximus
Adductors longus, brevis and magnus
Iliopsoas
Superior gluteal
Superior gluteal
Superior gluteal
Superior gluteal
Ventral rami L1 and L2
Lateral rotation of leg at hipSartorius
Gluteus maximus
Obturator internus
Gemelli
Obturator externus
Quadratus femoris
Piriformis, in flexion
Femoral
Inferior gluteal
Ventral rami of L5, S1 and S2
Ventral rami of L5, S1 and S2
Obturator
Ventral rami of L4, L5 and S1 Ventral rami of L5, S1 and S2
Knee flexionSemimembranosus
Semitendinosus
Biceps femoris, long head
Biceps femoris, short head
Gracilis
Sartorius
Popliteus
Gastrocnemius
Sciatic (tibial)
Sciatic (tibial)
Sciatic (tibial)
Common peroneal
Obturator
Femoral
Tibial
Tibial
Knee extensionVastus medialis
Vastus lateralis
Vastus intermedius
Rectus femoris
Gluteus maximus
Tensor fasciae lata
Femoral
Femoral
Femoral
Femoral
Inferior gluteal
Superior gluteal
Lateral rotation of leg = medial rotation of thigh in knee flexionBiceps femoris, long head
Biceps femoris, short head
Gluteus maximus
Tensor fasciae lata
Tibial
Common peroneal
Inferior gluteal
Superior gluteal
Medial rotation of leg with knee flexedPopliteusTibial
Medial rotation of leg with knee extendedSemimembranosus
Semitendinosus
Gracilis
Sartorius
Sciatic (tibial)
Sciatic (tibial)
Obturator
Femoral
Ankle plantarflexionGastrocnemius
Soleus
Plantaris
Tibialis posterior
Flexor hallucis longus
Flexor digitorum longus
Peroneus longus
Peroneus brevis
Tibial
Tibial
Tibial
Tibial
Tibial
Tibial
Superficial peroneal
Superficial peroneal
Ankle dorsiflexionTibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Peroneus tertius
Deep peroneal
Deep peroneal
Deep peroneal
Deep peroneal
Subtalar and midtarsal inversionTibialis anterior
Extensor hallucis longus
Tibialis posterior
Deep peroneal
Deep peroneal
Tibial
Subtalar and midtarsal eversionPeroneus longus
Peroneus brevis
Extensor digitorum longus
Peroneus tertius
Superficial peroneal
Superficial peroneal
Deep peroneal
Deep peroneal
1 Toe plantarflexion (MTPJ; IPJ)Flexor hallucis longus
Flexor hallucis brevis
Tibial
Medial plantar
2-5 Toes plantarflexion (MTPJs; IPJs)Flexor digitorum longus
Flexor accessorius (quadratus plantae)
Flexor digitorum brevis
Lumbricals
Interossei
Tibial
Lateral plantar
Medial plantar
Medial plantar, toe 2; lateral plantar toes 3-5
Lateral plantar
1 Toe dorsiflexionExtensor hallucis longus
Extensor hallucis brevis
Deep peroneal
Deep peroneal
2-5 Toes dorsiflexion
2-4 Toes dorsiflexion
Extensor digitorum longus
Extensor digitorum brevis
Deep peroneal
Deep peroneal
Toe abduction (away from midline of foot = adduction toward midline of body)
Toe 1
Toes 2-4
Toe 5
Abductor hallucis
Dorsal interossei
Abductor digit minimi
Medial plantar
Lateral plantar
Lateral plantar
Toe adduction (toward the midline of foot = abduction away from midline of body)
Toe 1
Toes 2-5
Adductor hallucis*
Plantar interossei
Lateral plantar
Lateral plantar

Note: Primary action of muscles is printed in normal type; muscles that give some contribution to this action are printed in italics .

The nerve supply to the lower limb (lower leg and foot) is derived from the sciatic and femoral nerves. Dysfunction or compromise of either of these nerves causes marked motor, sensory and autonomic effects in the lower leg and foot.

MTPJ, metatarsophalangeal joint; IPJ, interphalangeal joint.

Table 3: Presentations of osteochondritis/osteochondrosis in the leg and foot
OCSite affectedTypeAge of onset (years)
Blount's diseaseProximal tibial epiphysisUnderdevelopment of medial epiphysis1-3; 6-13
Buschke's diseaseCuneiformsOssification anomaly11-15
Freiberg's diseaseSecond/third metatarsal headCrushing OC12-18
Iselin's diseaseBase of fifth metatarsalTraction apophysitis11-15
Kohler's diseaseNavicularCrushing OC3-7
Legg-Calve-Perthe diseaseCapital femoral epiphysisTrue OC2-16
Osgood-Schlatter diseaseTibial tuberosityTrauma-related11-15
Osteochondritis dissecansTalar dome
Lateral femoral condyle of knee
Osteonecrosis12-18
Sever's diseaseCalcaneal apophysisTraction apophysitis10-14
Sinding-Larson-Johansson diseasePatellaTraction apophysitis10-14
Treve's diseaseSesamoids (1 MTPJ)True OC15-20

1 MTPJ, first metatarsophalangeal joint.