Hollow of the knee

Definition The popliteal fossa is an anatomical structure on the back of the knee. It is diamond-shaped and is bordered on the outside by the biceps femoris muscle – the two-headed thigh muscle. The semimembranosus and semitendinosus muscles are joined inwards, i.e. towards the middle of the knee. Both ensure flexion and internal rotation of … Hollow of the knee