Wetenschap en waterpolo


Sports injuries in a high school.
Pediatrics. 1989 Sep;84(3):446-50.
McLain LG, Reynolds S.
Department of Pediatrics, Loyola University, Stritch School of Medicine, Maywood, IL 60153.

A 1-year study was undertaken investigating all sports injuries at a large high school. A total of 1283 student athletes participated in sports and suffered 280 injuries for an overall injury rate of 22%. The largest injury rate was in football (61%) followed by girls and boys gymnastics, wrestling, and boys basketball. Five sports had no injuries--boys' tennis, golf, boys' and girls' swimming, and girls' water polo. Severity of injury was measured by number of days lost per injury. Girls' track had the greatest number of days lost per injury (320) followed by girls' basketball, girls' cross country, boys' track, and boys' wrestling. Sprains and strains accounted for 57% of all injuries. Of the injured athletes, 87 were seen by a physician and only 5 athletes required surgery. The small number of serious injuries requiring surgery suggests that a motivated and competent pediatrician can play an integral role as a team physician.

Determinants of bone density among athletes engaged in weight-bearing and non-weight-bearing activity.
J Appl Physiol. 1989 Sep;67(3):1100-5
Block JE, Friedlander AL, Brooks GA, Steiger P, Stubbs HA, Genant HK.
Department of Radiology, University of California, San Francisco 94143.

To identify the factors associated with greater bone density among athletic individuals, we recruited three distinct groups of young male subjects. Twenty were nationally ranked water polo players, 19 were engaged in weight-training programs, and 20 subjects comprised a nonexercising comparison group. All participants had measurements of spinal trabecular and integral bone density by quantitative computed tomography as well as a determination of hip bone density by dual photon absorptiometry. A series of potential predictor variables included maximal O2 uptake, back strength, leg strength, total kilocalories expended per day, body mass index, paraspinous muscle cross-sectional area, percent body fat, daily calcium intake, and age. We found no significant differences for any of the bone density measures between the two groups of athletic subjects, whereas bone density was generally significantly lower among the nonexercisers compared with either exercise group. Correlation analysis found only weak and somewhat inconsistent relationships when each of the subgroups was examined separately; however, when all subjects were assessed collectively, many more correlations reached significance. Paraspinous muscular area was found to be most robust in this regard, being significantly correlated with all three bone density measures (r = 0.33-0.55). By using step-wise regression analysis in each subgroup, we observed a consistent significant contribution (R2 = 0.18-0.44) of paraspinous muscle area to the variability in bone density at the spine and the hip. When the data of all three subgroups were pooled, regression analysis reconfirmed the importance of the muscle parameter (R2 = 0.06-0.27) to bone density variation, but more importantly it showed that differentiation based on exercise status was most significant (R2 = 0.18-0.22).