Pediatric anthropometrics are inconsistent with current guidelines for assessing rider fit on all terrain vehicles

Background/purpose: This study sought to establish objective anthropometric measures of fit or misfit for young riders on adult and youth-sized all-terrain vehicles and use these metrics to test the unproved historical reasoning that age alone is a sufficient measure of rider-ATV fit. Methods: Male children (6–11 years, n = 8; and 12–15 years, n = 11) were selected by convenience sampling. Rider-ATV fit was quantified by five measures adapted from published recommendations: (1) standing-seat clearance, (2) hand size, (3) foot vs. foot–brake position, (4) elbow angle, and (5) handlebarto- knee distance. Results: Youths aged 12–15 years fit the adult-sized ATV better than the ATV Safety Institute recommended age-appropriate youth model (63% of subjects fit all 5 measures on adult-sized ATV vs. 20% on youth-sized ATV). Youths aged 6–11 years fit poorly on ATVs of both sizes (0% fit all 5 parameters on the adult-sized ATV vs 12% on the youth-sized ATV). Conclusions: The ATV Safety Institute recommends rider-ATV fit according to age and engine displacement, but no objective data linking age or anthropometrics with ATV engine or frame size has been previously published. Age alone is a poor predictor of rider-ATV fit; the five metrics used offer an improvement compared to current recommendations