Which muscles are known as 'Triceps surae'?
TRICEPS SURAE:-Two heads of gastrocnemius + soleus ("three-headed of the calf") These muscles both inse into the calcaneus and form the major pa of the muscle of the posterior leg, ie calf muscle. GastrosoleusLarge size of gastrosoleus is a human character and is directly related to the adoption of an erect posture and to the bipedal gait of man. GASTROCNEMIUS:-Superficial to soleus Origin:- medial and lateral head.Medial head- larger. Arises from medial condyle of femur behind the adductor tubercle, capsule of knee joint, and popliteal surface of femur.Lateral head:-lateral condyle, lateral supracondylar line, and capsule of knee joint. SOLEUS:-sole-shaped, multipennate Origin: fibula- head and upper 1/4th of shaft.Tibia-soleal line,medial border of shaft.Tendinous soleal arch. Inseion: fuses with tendon of soleus to form tendocalcaneus or tendoachilles.Inseed into the middle 1/3 rd of posterior surface of calcaneum. Nerve supply: Tibial nerve (S1, S2) Action:-strong plantar flexors of foot. The gastrocnemius is also a powerful flexor of knee.Soleus- more powerful Gastrocnemius- fast acting In walking soleus overcomes the ineia of the body weight, like the button gear of a car.when movement, is underway, the quicker acting gastrocnemius increase the speed. Soleus/ peripheral hea:-Contractions of these muscles help in venous return from the lower limb. There are large, valveless, venous sinuses in its substance. When the muscle contracts the blood in these sinuses pumed out. When it relaxes, it sucks the blood from the superficial veins through the perforators. <img src=" /> {Reference: BDC 6E pg no.106, chapter 9}
Gastro-soleus
Popliteus
Extensor hallucis longus
Extensor digitorum longus
Lower limb