MUSCLES-HAMSTRINGS

SUMMARY

'SM' - 2 'semi' muscles inserted medially
1. SEMIMEMBRANOSUS - arises from the ischeal tuberosity. Has a characteristic cross-sectional shape. The sciatic nerve lies a finger's breath from its lateral margin (on the adductor magnus). The flat tendon passes deep to the SEMITENDINOSUS + LONG HEAD OF THE BICEPS. It inserts into the back of medial condyle of the tibia. From this insertion, 3 expansions diverge.
 
2. SEMITENDINOSUS - arises from the medial facet of the ischeal tuberosity. The tendon inserts behind the gracilis (as part of the Pes Anserinus) into the subcutaneous surface of the proximal tibia. 

'BL' - 2 biceps muscles inserted laterally
3. BICEPS FEMORIS - so-called because it possesses 2 heads. Long head - arises from the medial facet of the ischeal tuberosity. Short head - linea aspera + upper part of the lateral supracondylar line. Both fuse to be inserted into the head of the fibula + across the tib/fib joint.

4. Blood supply to the hamsrings - inferior gluteal a. + profunda femoris a. + popliteal a.

5. Nerve supply - sciatic n.

Reference(s)

R.M.H McMinn (1998). Last’s anatomy: regional and applied. Edinburgh: Churchill Livingstone.
Gray, H., Carter, H.V. and Davidson, G. (2017). Gray’s anatomy. London: Arcturus.