GROUND REACTION FORCES OCCURING DURING THE DELIVERY STRIDE OF JAVELIN THROWING

Paul Hurrion¹, Rosemary Dyson¹, Tudor Hale¹, Lee Janaway².

¹University College Chichester, Chichester, West Sussex. PO19 6PE. UK. ²Brunel Institute for Bioengineering, Brunel University, Uxbridge, UB8 3PH. UK

Five male javelin throwers (mean ± SD: age 24 ± 3 years; height 1.83 ± 0.06 m; body weight 888 ± 117 N) performed outdoors. Two Kistler force platforms were mounted beneath an outdoor polyflex runway (0.017 m depth) with positioning adjustment for each subject's delivery stride length. For the back foot the mean (+SD) peak vertical ground reaction force was 2.31 * 0.41 BW, and maximum total force was 2.36 ± 0.50 BW. For the front foot the mean peak vertical force was 5.63 * 1.31 BW, the braking force was 4.50 * 0.96 BW and maximum total force was 7.05 ± 1.57 BW. At the beginning of the delivery stride, when the back foot contacted the ground, the mean peak vertical loading rate was 115 ± 35 BWs^-1 which was less than the front foot loading rate of 192 ± 64 BWs^-1.