Body segment contributions to height achieved during the flight a springboard dive.

The way in which athletes achieve the necessary height to accomplish the rotational requirements of springboard dives was investigated by focusing upon the take-offs of dives from the forward and reverse groups. Films of eight women in the 3-m final of the 1982 Canadian championship and of five men practicing for the 1979 Fort Lauderdale Invitational Meet provided data for the analysis. The vertical acceleration of the diver's center of gravity was expressed relative to that of the metatarsals, which represented the point on the board directly beneath the feet. The divers were only able to accelerate upward relative to the metatarsals for approximately the first half of springboard depression. This period of positive relative acceleration was considered to be a key factor in effective deflection of the springboard. The lower extremities were responsible for about three-quarters of the diver's vertical acceleration during this period. Two-thirds of their contribution was attributed to their role in accelerating the large mass of the trunk upward. The upper extremities accounted for about 10% of the diver's vertical acceleration during the initial half of springboard depression. Their acceleration-time patterns clearly fell into three classifications depending upon whether their upward acceleration relative to the shoulders preceded, coincided with, or followed initial contact with the board for the take-off.