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C J Widule

Publications and source records attributed to C J Widule.

5 recordsLinked to original sources
PubMed1983

Kinematic analysis and efficiency estimate of intercollegiate female rowers.

Eighteen female rowers were filmed performing sweep rowing on a Stanford Rowing Ergometer. The rowers were grouped according to ergometer scores (rpm) and the films were analyzed frame-by-frame for the drive phase of the stroke. Parameters characterizing rowing in general were determined as well as those separating the novice from the skilled. Prior to when the oar was perpendicular to the shell, the importance of the trunk was to transfer the power generated by the extension of the knee to the horizontal linear velocity of the oar. When the oar was perpendicular to the rowing shell, the skilled rowers were characterized by a higher horizontal linear oar velocity (2.58 +/- 0.21 m . s-1 vs 2.17 +/- 0.19 m . s-1). This appeared to be due principally to the more rapid extension action of the knee (4.18 +/- 0.48 rad . s-1 vs 3.01 +/- 0.96 rad . s-1). The sequence of first extending the knee then the trunk, combined with a higher sum of trunk and knee angular velocity when the oar was perpendicular to the shell (7.31 +/- 0.76 rad . s-1 vs 5.86 +/- 0.61 rad . s-1) also appears to be related to the higher horizontal linear oar velocity of the skilled rowers. The difference in time between when the maximum angular velocities of the knee and trunk occur is less for the skilled than the novice (0.150 +/- 0.061 s vs 0.235 +/- 0.049 s, respectively). Based on the ratio of actual to possible sum of knee and trunk angular velocity, the efficiency of the skilled was determined to be greater than that of the novice (87.2 +/- 6.9% vs 75.8 +/- 10.1%).

Biomechanical Phenomena↗
PubMedDate not supplied

Selected kinematic characteristics of intercollegiate women triple jumpers.

Eight women triple jump finalists at the 1986 Big Ten Track and Field Championships and 10 women triple jump finalists at the 1986 National Track and Field Competition were filmed during competition. Among selected kinematic characteristics, the following high correlations (r greater than 0.70) were found: the distance of the hop phase correlated highly with the total jump distance; the horizontal position of the center of gravity of the body in relation to the support foot at takeoff correlated highly with the distance of the hop and the jump phases; the horizontal velocity into the step phase correlated highly with the total distance of the jump; the vertical velocity into the hop and step phases correlated highly with the respective phase distance; and there was an inverse correlation between the maximum height of the center of gravity during the flight phase of the step and the total distance. A significant difference was found between men and women triple jumpers in relation to the contribution of the step phase to the total distance of the jump (men, means = 29.5, SD = 1.46; women, means = 26.7, SD = 2.94; P less than 0.05). All remaining relationships among the kinematic variables studied were found to be not significant at P less than 0.05 or were less than r = 0.70. The phase ratios of current women triple jumpers were similar to ratios that have been reported for the novice athlete.

Biomechanical Phenomena↗