Abstract

An alternating cycle of eccentric-concentric contractions in locomotionrepresents a sequence when storage and utilization of elastic energy takesplace. It is possible that this storage capacity and its utilization dependson the imposed stretch loads in activated muscles, and that sex differencesmay be present in these phenomena. To investigate these assumed differences,subjects from both sexes performed vertical jumps on the force-platform fromthe following experimental conditions: squatting (SJ) from a static startingposition; counter-movement jump (CMJ) from a free standing position and witha preparatory counter-movement; drop jumps (DJ) from the various heights(20 to 100 cm) on to the platform followed immediately by a vertical jump. Inall subjects the SJ, in which condition no appreciable storage of elasticenergy takes place, produced the lowest height of rise of the whole body center of gravity (C.G.). The stretch load (drop height) influenced the performance so that height of rise of C. of G. increased when the drop heigth increased from 26 up to 62 cm (males) and from 20 to 50 cm (females). In alljumping conditions the men jumped higher than the women. Verf.-Referat (gekuerzt)