The muscles in the posterior compartment of the thigh are most commonly known as the hamstrings and allow the leg to carry out a range of functions. They extend the leg at the hip, flex the knee and pull the pelvis down into a posterior tilt. Weak hamstrings can cause a lot of pain in the body, so working them out can prevent the risk of this and improve muscle performance. It’s important for doctors and physiotherapists to know about the structure and function of these muscles as back pain comes occasionally from tight hamstrings.
The group consists of the following muscles:
Biceps Femoris:
Are you starting to see a trend with the word femoris? Muscles with this title have a lot to do with flexing! Just like the biceps brachii in the arm, the biceps femoris has both a long and short head. If you feel the lateral side behind your semi-extended knee, you will be able to feel (palpate) the prominent tendon from both heads joining together and attaching to the fibula (the tibia bone is on the big toe side of the leg; the fibula is on the little toe side of the leg). The main function of this muscle is to flex the leg at the knee. It also extends the thigh at the hip and moves both the hip and knee laterally.
Semitendinosus:
This tendon is called such because it has a mostly tendinous structure. It lies medially to the biceps femoris and sits on top of the semimembranosus. The semitendinosus has the same functions as the biceps femoris, except that it moves the hip and knee medially instead of laterally.
Semimembranosus:
As mentioned, the semimembranosus lies below the semitendinosus. It originates from the pelvis and attaches to the tibia. It has the same function as the semitendinosus, so both muscles reinforce each other.
A hamstring strain refers to excessive stretch or tearing of the muscle fibres. They are often seen athletes involved in running or kicking sports. Damage to the muscle fibres is likely to rupture the surrounding blood vessels – producing a haematoma (a collection of blood). The haematoma is contained by the overlying fascia lata.
Treatment of any muscle strain should utilise the RICE protocol – rest, ice, compression and elevation.
teachmeanatomy.com
Some of my top hamstring muscle exercises
Reverse Lunges
Deep Squats
Single Leg Deadlift
Caroline Jordan gives a very helpful demonstration to help you do all of these at home.
The Food Anatomist 