Growth diagrams for grip strength in children.

Abstract

Grip strength dynamometers often are used to assess hand function in children. The use of normative grip strength data at followup is difficult because of the influence of growth and neuromuscular maturation. As an alternative, infant welfare centers throughout the world use growth diagrams to observe normative growth. The aim of this study was to develop similar growth diagrams for grip strength in children. We measured the grip strength, hand dominance, gender, height, and weight of 225 children, 4 to 12 years old. We developed separate statistical models for both hands of boys and girls for drawing growth curves. Grip strength increased with age for both hands. For the whole group, the dominant hand produced higher grip strength than the nondominant hand and boys were stronger than girls. The grip strength of boys and girls differed between 2 and 19 N for the different age groups. Because grip strength measurements are accompanied by a rather large variance, the growth diagrams (presenting a continuum in grip strength) make it possible to better observe grip strength development with time corresponding to a more exact age. Depending on the accuracy needed, the use of one combined diagram could be considered. Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.