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Jpn J Biomechanics Sports Exercise 7(3):214-221, 2003

Non-invasive estimation of the joint torque of the vastus lateralis during pedaling based on tendon elongation

MURAOKA Tetsuro1)2), MURAMATSU Tadashi3), TACHI Masanobu1), KAWAKAMI Yasuo4), KANEHISA Hiroaki1), FUKUNAGA Tetsuo4)

1) Laboratory of Sports Sciences, Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo
2) Japan Society for the Promotion of Science
3) Institute of Physical Education, Keio University
4) Department of Sports Sciences, Graduate School of Human Sciences, Waseda University


The purpose of this study was to estimate the knee extension torque generated by vastus lateralis (VL) during pedaling on the basis of VL tendon elongation (d Lt). The fascicle length and pennation angle of VL during isometric knee extensions (0, 20, 60, 100 Nm ; 30, 45, 60, 75, 90, 105deg) were measured using a B-mode ultrasonography (n = 5). d Lt was estimated from these measurements and the relations between d Lt, knee joint angle and the knee extension torque generated by VL (TQ) were obtained. d Lt of the same subjects during pedaling was taken from a previous study. TQ during pedaling was estimated on the basis of d Lt during isometric knee extensions and pedaling (TQd Lt). TQ during pedaling was also estimated on the basis of the inverse dynamics (TQinv). The peak value of TQd Lt (19.8 + 11.2 Nm) during pedaling was significantly greater than that of TQinv (9.3 + 4.0 Nm) (p < 0.05), which might be related to the lower activation level and the different activation pattern of the rectus femoris compared with those of the VL. The pattern of TQinv differed significantly from that of TQd Lt, which might be related to the activation of the biceps femoris that increased in the latter half of the knee extension phase during pedaling. Since the methodology used in this study is non-invasive and measures the parameter that is closely correlated to the joint torque generated by a single muscle, it can be a useful tool for investigating the mechanics of human movements.

Key Words: ultrasonography, muscle fascicle length, knee extension, inverse dynamics

Submittted for Publication : June 3, 2003,

Accepted for Publication : September 12, 2003



JJBSE バイオメカニクス研究