Joint Position. The pattern of linear motion was similar in the two dives. The hip joint lowered and moved backward during the descent phase and rose in the vertical direction during the ascent and flight phases. The maximum displacement for the horizontal component was 0.44 m for the springboard dive and 0.41 m for the platform dive. The maximum displacement for the vertical component was 0.96 m for springboard and 0.39 m for platform. The change for both vertical and horizontal position was greater during the springboard dive, yielding greater resultant motion than the platform dive.
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Figure 8. Position of the hip joint in the springboard dive take-off (left) and platform dive take-off (right). Positive values indicate upward motion in the vertical direction and backward motion in the horizontal direction. Solid lines represent horizontal motion, dashed lines represent vertical motion, and small dashed lines represent combined motion. | |
Joint velocity. During both the springboard and platform dives, the hip joint linear velocity was upward in the ascent phase and then downward during the descent phase of the movement. The vertical velocity was the greatest contributing factor to resultant linear velocity in both dives.
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Figure 9. Velocity of the hip joint in the springboard dive take-off (left) and platform dive take-off (right). Positive values indicate upward velocity in the vertical direction and backward velocity in the horizontal direction. Solid lines represent horizontal velocity, dashed lines represent vertical velocity, and small dashed lines represent combined velocity. | |
Center of mass. We compared the center of mass for the lumbar spine, thigh, and lower leg segments at time of peak knee flexion. The center of mass for the two movements was located anterior to the hip joint and almost directly superior to the ankle joint. The location was similar for both dives.
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Figure 10. Location of the center of mass (CM) in the springboard dive take-off (left) and the platform dive take-off (right). Body segments are lumbar spine, thigh, and lower leg. | |
