Effects of dynamic and static handgrip exercises on hand and wrist volume

It is not known how the mode of exercise, dynamic and static exercises, affects the limb volume. Therefore, the purpose of this study was to investigate hand and wrist volume (HWV) after dynamic and static handgrip exercise. Nine healthy subjects (age 31.8 ± 7.3 years; height 172.0 ± 5.7 cm; body mass 66.9 ± 8.1 kg, mean ± SD) volunteered for this study. HWV was measured with a hand and wrist volumeter before and immediately after dynamic and static exercises. Initially during rest, HWV was measured after the hand was passively hung for 5 min. Handgrip exercises with an ergonomic hand exerciser were performed at 20% of maximum voluntary contraction in right and left hands by static and dynamic exercises, respectively. Both dynamic and static handgrip exercises consisted of six sets of 30-s contractions with 10-s rest intervals between exercise bouts. The dynamic handgrip exercise was performed by repetitive contraction and relaxation of the hand at a maximum frequency. In order to determine intensity of handgrip exercises, maximum isometric handgrip strength of the right and left hand was measured with a handgrip dynamometer. Data are presented as mean ± SD. After dynamic and static handgrip exercises, HWV increased significantly, and these increases represent 2.2 ± 0.7% (P < 0.001) and 1.4 ± 0.8% (P < 0.001) of resting HWV, respectively. The elevation of HWV after dynamic exercise was significantly higher than that after static exercise (P < 0.05). These results suggest that the higher HWV after dynamic exercise may be caused by higher increased interstitial fluid volume, capillary volume and venous volume in hand and wrist tissues.