Effects of maturity and training on bimanual ballistic isometric handgrip

We studied maturity and training effects on maximal force and accuracy of force targeting during ballistic handgrips. Male right-handed nontrained adolescents (16-20 yrs.), trained adolescents (oarsmen--16-18 yrs.) and nontrained adults (21-44 yrs.) did right (R) unilateral (UL), left (L) UL handgrip and bilateral (BL) maximal ballistic handgrips. Next, they targeted 30% of maximal respective UL handgrip. We found peak force L:R ratios in adolescents significantly closer to 1 compared to nontrained adults suggesting less hemisphere dominance in adolescents, especially in trained ones. Nontrained adolescents showed smaller bilateral deficit for L hand than the other groups. Adolescents showed a significant underestimation of L hand during BL task (-4.6%), especially oarsmen (-8.7%), while adults showed neither overestimation, nor underestimation during all tasks. The disappearance of the asymmetry of bilateral deficit and L hand errors of force targeting suggest a diminution of neural cross-talk from dominant to non-dominant hand and its better estimate with maturity.