INTRODUCTION

In diving as well as gymnastics and figure skating, athletes are required to perform both fluid and aesthetically pleasing movements. Kooi and Kuipers reported that in competitive diving, the diver wants to maximize height of the flight phase following takeoff. The more time the diver has before reaching the water, the greater number of twists and somersaults the body can execute (Journal of Applied Biomechanics, 1994, p.335). Athletes dive from a springboard or a concrete platform, and the type of surface a competitor dives from may affect the amount of time a diver has in the air. Because of its structure, the springboard is more compliant than the platform and allows the diver to reach a greater height. Therefore, a diver typically executes two different takeoffs on springboard and platform. Movements during a springboard takeoff are performed at a slower rate than platform because an athlete must synchronize arm swing and knee bend with the oscillation of the board. A diver performing a platform takeoff must execute arm swing and knee bend faster in order to create the height and speed necessary to complete a dive. Our study focused on the back dive. More specifically, we analyzed the back press which consists of the sequence of motions before an athlete's toes leave the diving surface. The mechanics of the back press differ from one surface to the other. We were interested in finding out how the compliance of the springboard and platform affect the movements of the back press during each dive. How does motion at the knee and hip vary between springboard and platform dives? This important question is addressed in the following movement analysis.

The purpose of this movement analysis was to determine if joint angles and velocities differed significantly between the springboard and platform dives. We chose to answer this question by recording our subject during a springboard and platform dive. Then, we analyzed and quantified the movement to determine if joint angles and segment velocities did indeed differ significantly between the two dives.