Assessment of maximal isometric hand grip strength in school-aged children

Background: Hand grip strength (HGS) test is commonly used as an indicator of overall muscle strength in medical and sport practices. Recently, several studies have proposed that the measurement of the maximal HGS depends on dynamometer's handle position. The aim of the present study was to identify the optimal handle position to obtain maximal HGS using the hand grip dynamometer (HGD) for school-aged children. Methods: HGS was assessed with the Jamar digital HGD. Each participant performed three maximum contractions of each hand on three handle positions progressing from first to third position. Results: A total of 135 healthy children aged 5-9 years participated in the study. Participants obtained significantly higher results using position 2 than using positions 1 or 3. The maximal mean (+/- SD) HGS achieved was 9.9 (+/- 3.1) kg with position 1, 10.4 (+/- 3.1) kg with position 2, and 9.0 (+/- 3.2) kg with position 3. Handle position 2 was the most comfortable position for 73% of participants. Conclusions: Our results provide useful methodological information indicating that the second handle position of the Jamar digital HGD is optimal to measure maximal HGS in non-athletic healthy pediatric participants aged 5-9 years.