OBJECTIVE: To determine the prevalence of generalized joint hypermobility (GJH) in Dutch children aged 5.5 years, and to examine the association between GJH and motor performance and development over time.

STUDY DESIGN: A prospective cohort of 249 children was recruited. GJH was assessed with the Beighton test at age 5.5 years. Motor performance was evaluated at age 2.0 years using the Bayley Scales of Infant Development, Second Edition and at age 5.5 years using the Movement Assessment Battery for Children-Second Edition (subscore categories: manual dexterity, aiming and catching, and static and dynamic balance).

RESULTS: In 249 children, the prevalence of GJH, defined by the Beighton test score, was 34.1% for a score ≥ 4, 22.5% for a score ≥ 5, and 16.5% for a score ≥ 6. No significant association was found between GJH and total motor performance. Manual dexterity in girls (Beighton score ≥ 4) was positively associated with higher level of motor performance (β [SE] = 0.38 [0.17]; P = .028), ranging from +0.04 SD to +0.72 SD, even after correction for covariates. A significant interaction between GJH and body mass index (BMI) growth was found, indicating that the effect of GJH on the rate of development of motor performance declines with increasing BMI growth (β = 0.05 [0.02]; P = .031).

CONCLUSION: In this healthy pediatric cohort, GJH was present in one-third of the sample, and no significant association was found between GJH and total motor performance. The effect of GJH on the rate of development of motor performance appears to decline with increasing BMI growth. Longitudinal prospective studies are recommended to detect influences of GJH on motor performance over time, as well as the influence of body composition and Beighton cutoff points.