Biceps femoris and semitendinosus tendon/aponeurosis strain during passive and active (isometric) conditions

Publication date: Available online 10 December 2015
Source:Journal of Electromyography and Kinesiology
Author(s): Eleftherios Kellis
The purpose of this study was to quantify strain and elongation of the long head of the biceps femoris (BFlh) and the semitendinosus (ST) tendon/aponeurosis. Forty participants performed passive knee extension trials from 90° of knee flexion to full extension (0°) followed by ramp isometric contractions of the knee flexors at 0, 45 and 90° of knee flexion. Two ultrasound probes were used to visualize the displacement of BFlh and ST tendon/aponeurosis. Three-way analysis of variance designs indicated that: (a) Tendon/aponeurosis (passive) elongation and strain were higher for the BFlh than the ST as the knee was passively extended (p<0.05) (b) Contraction at each angular position was accompanied by a smaller BFlh tendon/aponeurosis (active) strain and elongation than the ST at higher levels of effort (p <0.05) and c) Combined (passive and active) strain was significantly higher for the BFlh than ST during ramp contraction at 0° but the opposite was observed for the 45° and 90° flexion angle tests (p < 0.05). Passive elongation of tendon/aponeurosis has an important effect on the tendon/aponeurosis behavior of the hamstrings and may contribute to a different loading of muscle fibers and tendinous tissue between BFlh and ST.



from #Medicine via ola Kala on Inoreader http://ift.tt/1mcFtri
via IFTTT