[Muscles of the leg during immobilisation. An electromyographic study (author's transl)]

By means of electromyographic evaluation we investigated the function of the rectus femoris, the vastus medialis, the tibialis anterior and the triceps muscle. The effects of immobilisation in above or below knee PoP were investigated with view to the muscular activity in walking and the effect of the immobilization in isometric exercises. The results are discussed. The vastus medialis can only be activated very poorly in a PoP and is not inervated at all during gait. The functional activity of the triceps is reduced markedly in either above or below knee PoP. In knee movement this muscle starts to be activated only over 90 degrees of flexion. The results suggest that an above knee PoP is sufficient to immobilise defects of the quadriceps and its tendon. Defects of the triceps and its tendon seem not necessarily to request an above knee PoP for immobilization. This case has however the advantage to decrease the danger of unexpected knee movements followed by a reflectoric muscle contraction. Its force could be greater than the stability of the repaired tendon.