Establishing normative reference values for handgrip strength in children and the relationship with nutritional status

Hand grip strength is a simple and objective parameter that can be used to evaluate muscle strength. This study was planned and carried out in order to establish normative reference data for hand grip strength and to associate it with nutritional status in children aged 6-10 who continue their education at the primary school level in public and private schools affiliated to the Ministry of National Education in Ankara. A total of 1533 children (736 boys and 797 girls) and 212 parents participated in the study. Demographic characteristics (age, gender, mother/father occupation) and simple eating habits (such as skipping meals, milk, fish, meat/chicken, egg consumption frequency, and dinner with the family) were asked to the children through questionnaires. Parents were reached through teachers. This questionnaire consisted of questions about the birth/nutrition of children (birth weight, birth height, breast milk intake, etc.), questions about the daily life of children (sleeping time, screen exposure time, and physical activity course), and a 24-hr recall food consumption record of children. The body weight, height, and hand grip strength measurements of the children who volunteered to participate in the study were taken by the researcher in a suitable classroom or room provided by the administration in the school environment. JAMAR hand dynamometer was used for hand grip strength measurements and Southampton Protocol was followed. LMS method (Lambda-Mü-Sigma) was used to create the hand grip strength curves for boys and girls. The mean age of the children is 8.2±1.32 years. According to BMI for age, 27.6% (n=203) of boys and 20.7% (n=165) of girls were obese. In normal weight, 45.1% of boys and 53.3% of girls were found (p<0.001). The mean energy intake was 1439.7±343.8 kcal/day in boys and 1381.5±369.36 kcal/day in girls. The 50th percentile values for dominant hand grip strength in boys were found to be 6,745, 8,103, 9,878, 11,495, 12,166 kgF at 6, 7, 8, 9, and 10 years of age, respectively, and 5,447, 6,811, 8,713, 10,670, and 10,949 kgF for girls. While a statistically significant relationship was found between dominant hand grip strength and BMI for age, weight for age, and height for age in boys, this relationship was shown only with weight for age in girls. Body weight and height were found to be positively and significantly correlated with both dominant and non-dominant hand grip strength (p<0.001). With the increase in birth weight, hand grip strength increases for both hands (p<0.05). In the regression analysis performed with age, gender, height, BMI, birth height, and birth weight group, it was shown that these variables could explain 28% of hand grip strength. Among these variables, height and birth weight group have a statistically significant relationship with dominant hand grip strength (p<0,05). In conclusion, hand grip strength is a measurement method that is closely related to the variables of age, gender, body weight, height, and BMI, and its use can be practical in determining nutritional status. The use of muscle strength measurements in the evaluation of nutritional status in children and adolescents should be expanded. It is thought that this area should be supported by more studies.