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Technique comparisons between hard and soft landings of young female gymnasts
INFLUENCE MC; ‘:’ C! ; OF THE DURATION OF INTERSTIMULUS INTERVAL ON PREPARATION RECORDED ON THE CORTICAL AND SPINAL LEVEL Yuko Taniguchi and Mitsumasa Miyashita Laboratory for Exercise Physiology and Biomechanics, Faculty of Education, University of Tokyo, Japan To investigate the influence of the tiurat ion 0f interstimulus interval (ISI) on the time course of motor preparation recorded on the cortical and spinal level, during three different constant ISIS (1, 2, and 4s) in a warned simple reaction time task, either slow brain potential (contingent CNV) (Experiment I) or Hoffman (H-) reflex negative variation: (Experiment II) was recorded. In Exp. I (n=5), the amplitude oi CNV over the motor cortex changed with time in the different manners related to the durations of ISI. The longer the ISI, the less the amplitude of CNV at the instant when the reaction stimulus was given. In Exp. II (n=5), the H-reflex amplitude of I: he the involved leg changed just before the RS. The shorter tel-1c ISI, the larger the change. These results suggest that r 1mc different duration of IS1 may change the difficulty 0f estimation then the strategy and manner of motor‘ and preparation.
TECHNIQUE COMPARISONS BETWEEN HARD AND SOFT LANDINGS OF YOUNG FEMALE GYMNASTS Cynthia L. Tant, Jerry D. Wilkerson, Kathy D. Browder. Department of Physical Education Texas Woman's University, Denton, TX 76204, USA. Techniques between hard and soft landings of young female gymnasts were investigated to determine kinetic and kinematic changes in the reduction of peak vertical forces. Film records and force data were collected on 30 subjects during a pre-and posttest at two heights (25 and 30 cm). Subjects decreased their peak vertical forces from preto posttest Pretest force curves displayed when a session of several soft landings were practiced. one or two definite peaks, while posttest force curves revealed an absence of peaks with equal impulse distribution. During kinematic analysis, two distinct patterns were revealed within each subject. Simultaneous use of the segments (foot, shank, thigh, and trunk) in a short period of time were exhibited during the initial impact stage. Sequential use of the segments over a longer period of time were displayed during the force absorption stage. Total time and the time of trunk flexion were significantly different between pre-and posttests of each stage. Increased trunk flexion during the posttest of the initial impact stage and increased total time in the force absorption stage were technique adaptations to reduce peak forces.
MUSCLE TORQUE AND VELOCITY AND ENDURANCE ATHLETES Taylor, N.A.S., Cotter, Faculty of Rinesiology, New Zealand.
RELATIONSHIPS
IN ELITE
J.D., Stanley, S.N. Physical Education,
POWER
and Marshall, University of
R.N. Otago,
Elite power (n=6) and endurance (n=7) athletes (mean age = 23.6 y, SD = 3.0) were studied during five concentric quadriceps contractions at each of 12 angular velocities ranging from 30 to 388 deg/sec inclusive, using a BIODEX Peak torques were averaged at each angular velocity. When data dynamometer. the peak torque reduction with from both groups were pooled for analysis, This increasing angular velocity was 83 Nm (40.7%) from 30-300 deg/sec. When pooled data change was consistent with that reported in the literature. peak torques were achieved at an were analysed across angular velocities, referenced to 0 degrees at full angle of 59.5 degrees (S.E.M. = 0.78), Clear separation occurred between athlete groups for the mean extension. These data suggest that, over the angular torque-angular velocity curves. velocities studied, power athletes generated greater torque than endurance athletes, and that proportional peak torque decrement with each angular velocity increment was approximately equivalent for both athlete groups.
TECHNIQUE COMPARISONS BETWEEN HARD AND SOFT LANDINGS OF YOUNG FEMALE GYMNASTS Cynthia L. Tant, Jerry D. Wilkerson, Kathy D. Browder. Department of Physical Education Texas Woman's University, Denton, TX 76204, USA. Techniques between hard and soft landings of young female gymnasts were investigated to determine kinetic and kinematic changes in the reduction of peak vertical forces. Film records and force data were collected on 30 subjects during a pre-and posttest at two heights (25 and 30 cm). Subjects decreased their peak vertical forces from preto posttest Pretest force curves displayed when a session of several soft landings were practiced. one or two definite peaks, while posttest force curves revealed an absence of peaks with equal impulse distribution. During kinematic analysis, two distinct patterns were revealed within each subject. Simultaneous use of the segments (foot, shank, thigh, and trunk) in a short period of time were exhibited during the initial impact stage. Sequential use of the segments over a longer period of time were displayed during the force absorption stage. Total time and the time of trunk flexion were significantly different between pre-and posttests of each stage. Increased trunk flexion during the posttest of the initial impact stage and increased total time in the force absorption stage were technique adaptations to reduce peak forces.
MUSCLE TORQUE AND VELOCITY AND ENDURANCE ATHLETES Taylor, N.A.S., Cotter, Faculty of Rinesiology, New Zealand.
RELATIONSHIPS
IN ELITE
J.D., Stanley, S.N. Physical Education,
POWER
and Marshall, University of
R.N. Otago,
Elite power (n=6) and endurance (n=7) athletes (mean age = 23.6 y, SD = 3.0) were studied during five concentric quadriceps contractions at each of 12 angular velocities ranging from 30 to 388 deg/sec inclusive, using a BIODEX Peak torques were averaged at each angular velocity. When data dynamometer. the peak torque reduction with from both groups were pooled for analysis, This increasing angular velocity was 83 Nm (40.7%) from 30-300 deg/sec. When pooled data change was consistent with that reported in the literature. peak torques were achieved at an were analysed across angular velocities, referenced to 0 degrees at full angle of 59.5 degrees (S.E.M. = 0.78), Clear separation occurred between athlete groups for the mean extension. These data suggest that, over the angular torque-angular velocity curves. velocities studied, power athletes generated greater torque than endurance athletes, and that proportional peak torque decrement with each angular velocity increment was approximately equivalent for both athlete groups.