Your browser doesn't support javascript.
loading
Evaluation of torque-velocity curve and maximal power output of knee extensor under isokinetic contraction / 体力科学
Japanese Journal of Physical Fitness and Sports Medicine ; : 413-418, 1996.
Article in Japanese | WPRIM | ID: wpr-371739
ABSTRACT
In recent years, the knee extensor forces of athletes have usually been evaluated by measuring isokinetic output torque. The purpose of this study was to confirm the usefulness of normalizing the torque (force) -velocity curve and calculating the maximal power of knee extensor under isokinetic contraction.<BR>Seventy two (46 elite, 26 non-elite) Japanese male sprinters were chosen as the subjects in this study. The peak torque of the dominant side of knee extensor was measured by using the isokinetic dynamometer (Cybex II<SUP>+</SUP>) in three different angular velocities of 60, 180, 300 deg/sec. Moreover, the isometric torque (0 deg/sec) was measured in 39 athletes, 120 and 240 deg/sec of contraction were performed in 12 out of 39 athletes.<BR>The exponent equation (<I>F = F<SUB>o</SUB>× e<SUP>av</SUP>- kv</I> Fenn 1935) was applied to normalize the torquevelocity curve without including the coefficient of viscosity (<I>k</I>) . The maximal power and its optimal velocity was presumed from this torque-velocity curve. The average of measured torque at 0 deg/sec contraction (<I>F<SUB>0</SUB></I>) was lower than that of 60 deg/sec, therefore<I>F<SUB>0</SUB></I>was presumed as the same as the maximal power. Those parameters were not significantly different when calculated from 3 velocities (60, 180, 300 deg/sec) and 5 velocities (plus 120, 240 deg/sec) in 12 athletes. For this reason, each parameter was calculated from 3 velocities.<BR>The maximal torque (<I>F<SUB>0</SUB></I>/BW) was the same between elite and non-elite group (4.0 Nm/kg) . Nevertheless, the coefficient of torque loss (<I>a</I>), maximal power and its optimal velocity were significantly different (-0.1586 -0.1908, 9.6 7.8 watt/kg, 373 309 deg/sec, respectively. P<0.01 Student-t) . It was said that to normalize the torque-velocity curve or to presume the maximal knee extension power and its optimal velocity were useful to assess the muscle function or the performance of athletes under isokinetic contraction.

Full text: Available Index: WPRIM (Western Pacific) Language: Japanese Journal: Japanese Journal of Physical Fitness and Sports Medicine Year: 1996 Type: Article

Similar

MEDLINE

...
LILACS

LIS

Full text: Available Index: WPRIM (Western Pacific) Language: Japanese Journal: Japanese Journal of Physical Fitness and Sports Medicine Year: 1996 Type: Article