Knee stability as a predictor of knee injuries in high school football.

Abstract

The purpose of the study was to determine if flexibility or anthropometric measures could be used to predict the incidence of knee injuries in high school football players in North Carolina. The study included 101 subjects from three of the four levels of athletic classification in North Carolina. The investigation began in the summer of 1987 and data collection was completed in December, 1987. The preseason assessment involved measuring flexibility via the Nicholas Flexibility Protocol. Girth measures of the thigh and gastrocnemius musculature and body weight were obtained. Following the season, assessments of subjects' shoe types, intended uses, manufacturers, material of the shoe, and whether the subjects used prophylactic knee braces were made. Incidences of injuries were reported regarding the specific structures injured and the severity of injuries. Statistical analyses revealed no predictive value of a preseason assessment on the incidence of injury. A factor analysis of preseason, postseason, and postinjury assessment data did reveal subjects with fewer quarters of participation experienced higher rates of injury to the structures of the knee. An injury rate of 13.8% was reported in subjects with preseason flexibility scores of 2 or less and 10.3% in the group having 3 or more positive scores. Players with a lower body weight and smaller thigh and gastrocnemius girth measures experienced a higher injury rate.