Development of a method to determine optimum sitting height for female white water kayakers using makers of stroke efficiency

Abstract

White water kayaking has been underrepresented in the scientific literature, largely due to its recreational nature. White water kayaks are manufactured on male body specifications, due to the male dominated history of the sport. Female kayakers have to therefore adapt the kayaks to meet the demands of the environment and task, and their own anthropometry, commonly achieving this through changes to sitting height. The aim of this thesis was to quantify the differences in anthropometry between male and female white water kayakers and, using anthropometry and an observational model of boat kinematics, to develop a method to identify the optimum sitting height for female white water kayakers. An anthropometry study measured 53 kayakers (31 male; 22 female) and identified that the difference in sitting height between males and females was that females were on average 6.93cm shorter than males. This difference is bigger than seen in either slalom paddlers or the normal population. Overall 72.7% of the measures taken were significantly different between male and female white water kayakers. An observational model of boat kinematics was developed, extending our existing understanding into technique analysis of flat water racing kayakers. This doctoral thesis furthered knowledge around what the body does during the stroke cycle in flat water racing, building upon this to identify the patterns of movement caused by the paddle stroke that the white water kayak undergoes. Normalised measurements of patterns of boat movement and paddle forces were established from up to 1154 individual paddle strokes using three-dimensional kinematics and kinetics. This newly created methodology was then employed to develop a technique efficiency method to predict the optimum seat raise for female white water kayakers using a sample of experienced female white water kayakers (n=7). The optimum seat raises identified for the participants were considerably lower (mean 1.86cm (SD 1.46), range 0-4cm, mode 1) than the 6.93cm mean sitting height difference found between male and female white water kayakers in the anthropometric study. The method, based on percentiles, identified seven measures that can be used together to identify optimum sitting height for female white water kayakers. These include 2D kinematic measurement of pitch, velocity change, left arm reach, and stroke length left to right, alongside a timed slalom course and kinetic measurement of both left and right paddle strokes