The influence of construction strategies of sprung surfaces on deformation during vertical jumps.

The purpose of this paper is to assess the influence of variations in the construction of area-elastic surfaces on the local deformation of these surfaces during an actual movement of athletes. Area-elastic surfaces were systematically varied in construction to allow the discussion of the influence of: (a) the number; (b) the spacing of the sleepers; (c) the material of the lowest sleeper; (d) variations of the second layer; (e) variations of the top surface; and (f) addition of a special padding element between the first and second sleepers on maximum deformation. Deformation data were collected using high-speed film from a group of recreational athletes and a group of national team athletes (volleyball) performing a drop jump. The differences in maximum deformation between the various surfaces tested were about 100% from the lowest to the highest value for the recreational athletes and about 1,000% for the national team athletes. The differences in deformation were primarily influenced by the number of sleepers used and/or by construction elements which are close to the top of the surface (top layer, second layer, add rubber padding, number of sleepers). The one sleeper system consistently had the lowest values of maximum deformation.