Fig. 1. Representation of the experimental set-up. (A) Medial view of the GM and PL in the experimental set-up after biceps femoris muscle, semitendinosus and gracilis posticus muscles were removed. The GM and GL were separated by cutting fibres in such a way that the GM was not damaged. The GM is made transparant in the image to show the position of the PL. The soleus, deep flexors, peroneal muscles and muscles in the anterior crural compartment were left intact, but for clarity are not shown. Only extramuscular tissues around the GM were left intact (see B-D). Image A also shows the sciatic nerve (SN) and the femoral artery (FA) approaching GM laterally and medially respectively and entering GM proximally as a neuro-vascular tract (i.e. nerve, bloodvessel and surrounding connective tissue). Proximally, the dissected origin of the GM was attached to a force transducer using a metal rod (represented by an arrow). In the initial condition, the distal tendons of the GM and PL, the epitendinous tissues and a piece of the calcaneal bone were connected to a force transducer with a metal rod (represented by an arrow). The femur was clamped in such a way that the knee could be fixed at an angle of approximately 120°, with the lower leg horizontally. (B) Extramuscular tissues around the distal GM and PL tendons, i.e. remnants of the general fascia, epimysium, neuro-vascular tract and compartmental fascia (referred to as epitendinous tissues and indicated by an arrow). Medial view. Note that these tissues are exposed only for clarity by lifting the piece of the calcaneal bone. (C) Extramuscular tissues around the GM and PL muscle bellies, i.e. remnants of the general fascia and epimysium. Dorsomedial view. This image does not provide a representation of the position of the muscles in the experiment. For clarity, the GM and PL are pulled apart to expose the extramuscular tissues (indicated by an arrow and broken lines). (D) Medial view of the dissected origin of GM. The origin of GM was dissected with a piece of the femur. The image also shows a part of the neuro-vascular tract embedding the femoral artery approaching and entering GM proximally (indicated by an arrow). The sciatic nerve approaches the GM from the lateral side and is therefore not visible.