Biomechanical Motion Analysis of Elite Flat Water Kayakers with Special Focus on Footrest

The purpose of this study was to gain a better understanding of the importance of footrest use and the symmetry of kayaking motions. Method: Measurements were performed on 11 professional male Hungarian kayakers (n = 11), with a mean age of 24 years (range: 18–30 years), a mean height of 184, 5 cm (range: 172–197 cm), and a mean weight of 84 kg (72–96 kg). Weba sport kayak ergometer, Vicon MXT 3D camera system and surface electromyography were used for the measurements. The unique part of the study was the dynamometer, built into the footrest of the ergometer. The right and left sides differed significantly in terms of range of motion in the joints and activity of the muscles involved. Statistically significant differences were observed in the force applied to the footrest between the right and left sides. There were significant differences between the right and left stroke lengths in most athletes. There was a positive correlation between force applied to the footrest, the stroke length and the kayakers’ power output. Our study identified differences and correlations between the parameters of kayaking motion, highlighting the importance of the footrest. Better and more precise footrest use allows correct technique to be applied with high performance

The effect of manually controlled dynamization on the lengthened callus – preliminary results

The present study evaluated the radiological changes in normal and dynamized callus after limb lengthening in New Zealand White rabbits. The aims of the study were to create a lengthening device that allows axial controlled manual dynamization and to examine the effect of the maximal amount of dynamization on the healing, lengthened callus.10 male domestic white rabbits were divided into two groups (normal distraction group (NDG) and dynamized distraction group (DDG)). Osteotomy was followed by distraction at the same rate and total length in both groups, but in the dynamized distraction group 1 mm manual dynamization was performed for ten minutes three times a day prior to lengthening. Callus formation and lengthening were analysed on the X-ray pictures and on the three-dimensional  CT image respectively. Neither malposition of the pins nor maluninon were found during or after the distraction period. No signifi cant difference was found in the amount of the callus between the NDG and DDG. A lengthening device was created that allows axial  ontrolled manual dynamization and prevents instability in the other two axes and our results showed that this large amount of dynamization did not decrease the formation and quality of the callus. DOI: 10.17489/biohun/2010/2/0