The relationship between handgrip strength and total muscle strength in the Brazilian army military personnel

BACKGROUND: The primary purpose of this study was to investigate the relationship between handgrip strength (HGS) and total muscle strength (TMS) to determine if the HGS can be an indicator of physical valence in Brazilian Army soldiers. The second purpose of the study was to determine whether there are differences in the relationships among TMS and HGS per limb, handgrip strength dominant (HGS Dom) and handgrip strength non-dominant (HGS N Dom). Finally, this study aimed to verify the relationships between the HGS and TMS adjusted by anthropometric indicators. METHODS: The study included 50 Brazilian Army soldiers, aged between 19 and 25 years with a mean body mass of 71.2 +/- 9.1 kg and a mean height of 175.41 +/- 6.7 cm, from the Army Physical Training Center. HGS was measured with a hydraulic handgripdynamometer, one 3-second-long maximum voluntary isometric contraction, for 3 tests, with a 1-minute interval between them. The muscle strength values were measured using a digital isokinetic dynamometer, for 3 tests with 5 repetitions for 60 seconds and an angular velocity of 60 degrees/s, concentric/concentric type. Total muscle strength was calculated by the sum of the peak isokinetic test measures of the following: upper limbs strength (ULS), trunk strength (TS) and lower limbs strength (LLS), performed by strength tests in the movements of flexion and extension of shoulder, trunk and knee, respectively. RESULTS: Positive and significant (P<0.05) correlations were found between the HGS and ULS (r=0.536), TS (r=0.352), LLS (r=0.460) and TMS (r=0.490). The strongest correlation was found between the HGS in the dominant limb and absolute TMS, in other words, not correct by anthropometric indicators (r=0.658). CONCLUSIONS: We conclude that the HGS Dom can be considered an indicator of absolute total muscle strength in the Brazilian Army military.