Impacts -- Dive Into Swimming Pool

IJ and KL were good friends. They had known each other since middle school. Both boys were athletic and participated in high school sports. IJ, who was 17, was a year older than KL. However, KL was taller than his friend and tall for a high school freshmen. It was a hot, July afternoon. IJ was going to go swimming in the backyard pool of a close relative’s home and invited KL to come along. KL obtained permission from his parents and then joined IJ.

The pool was equipped with a diving board. IJ and KL each took a couple of dives off the springboard (low board). On KL’s third dive, he took one or two steps on the board, bounced, and when he became airborne, spread his arms and legs apart. Just before entering the water, he tried to bring his hands in front of his face and tuck his knees into his chest so as to make a big slash. He had done this type of dive before, perhaps a year earlier, but at a different, larger pool.

KL’s next recollection was that he was being pulled into the shallow end. He had a cut on top of his head. He could not move his legs or his arms.

In the United States, there are about 800 new cases of traumatic spinal cord injury each year that occur while engaged in sports activities (Scientific American, Sept. 1999). The leading cause within this category is diving, with about 440 cases of traumatic spinal cord injury each year. Some of these accidents occur in natural bodies of water. Those that occur in swimming pools include dives from the side of the pool into the shallow end. Whatever the number of cases of traumatic spinal cord injury resulting from over diving the deep end of the pool while using a springboard, it appears that most victims are adolescent males and young men.

HF Issues: Ideally, the danger should be mitigated by providing sufficient clearances to ensure that head contact with the pool bottom will not likely cause traumatic spinal cord injury. However, if residual risk remains after reasonable attempts have been made to reduce both the likelihood and severity of injury of such accidents through design and guarding (e.g., elimination of diving board where clearances are inadequate), in my opinion, safety information should be provided that alerts recreational divers to the danger and provides direction how to avoid harm.

HF Investigation and Analysis: KL performed a dive with which he was familiar. It was a popular dive. On the day of the accident, he watched IJ perform the same dive. However, KL was probably at greater risk than his friend of striking the sloping portion of the pool bottom. First, he was several inches taller than IJ and likely stronger. Second, he was not familiar with the shape of the pool. Third, KL had learned the dive a year earlier at a pool that was at least two feet deeper than the pool involved in the accident. Lastly, in the year that had elapsed since learning the dive, KL had grown several inches.

It appears to be a resonable hypothesis that adolescent males who are growing rapidly in stature and strength may be most at risk of hitting the bottom of a pool while using a springboard.

 

For such a youngster, a dive that, a year earlier, was safely executed many times, now may prove dangerous.

For a given pool type, it should be possible to determine the entry point associated with overdiving the deep end for the population most at risk. This point could be demarcated by a line on the sides and bottom of the pool.

It may be necessary to skew the line contour below the water surface so as to partially compensate for distortions caused by differences in refraction as well as in surface agitation.
Warning candidates would have to be developed and tested for their ability to effectively convey the purpose of the “overdive” line and other safety information pertinent to diving from the springboard.
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