[Electromyocartography of the thigh. Attempt at a functional analysis of the locking of the knee against resistance].

Electromyocartographic analysis of the extension of the leg in different positions has shown that: - on the whole energy developped by all superficial muscles of the thigh is more important in the position of dorsal decubitus than in a seated position; - functionnal activity of the rectus femoris muscle varies according to different subjects. Its activity is lower in the seated position, compared to dorsal decubitus, a classic notion; - in contradiction to classic notions, the most active muscle electrically is the vastus lateralis muscle. The vastus medialis muscle is however also very active; - from these results, it is possible to obtain a smaller variability owing to their relative quantification. One observes a hierarchy of electric activity levels of different surfaces, that constitutes the basis of functionnal and clinical study.