The present study aimed to quantify the mechanical properties of tendon and aponeurosis during passive stretch and active contraction and to investigate the effects of cooling (5ﾟ water), heating (42ﾟ water) and massage on the mechanical properties of muscle and tendon in vivo. Before and after these conditions, the elongation of the muscle fiber, tendon and aponeurosis of medial gastrocnemius muscle was directly measured by ultrasonography, while the ankle joint was passively moved at 5ﾟ/s within the joint range of +15ﾟ to -30ﾟ (0ﾟ = neutral anatomic position; positive values for plantar-flexion) and subjects performed ramp isometric plantar flexion up to the voluntary maximum. The strain was calculated as the length change relative to the reference length of tendon aponeurosis when the ankle joint was 0ﾟ. While the muscle fiber and tendon structures (tendon and aponeurosis) stretched during passive dorsi-flexion, the elongation and strain of tendon (21.8±3.2mm, 11.6±1.2%) was significantly greater than that of aponeurosis (5.2±2.2mm, 5.2±1.8%). During isometric contraction, the maximal elongation and strain of tendon (10.3±2.3mm, 5.6±1.4%) were significantly greater than that of aponeurosis (3.2±1.6mm, 3.2±1.5%). Furthermore, no significant changes in the elongation of muscle fiber and tendon structures were found after cooling, heating and massage, although the maximal isometric strength decreased significantly after cooling and massage. The present result suggested that the general icing, hot pack and massage did not change the mechanical properties of muscle and tendon.

DESCENTE SPORTS SCIENCE Vol.25/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE