Abstract
The patterns of activity in various movements and resting discharge in supine and standing positions, in 51 pregnant women, in gravida in the 2nd-10th month of pregnancy, aged 20-37 were electromyographically investigated, with 11 non-pregnant women in parity 0-1, aged 21-46 for comparison. The results obtained from this experiment were as follows.
1. A tendency towards the involvement of all abdominal muscles in various movements was noticed with the progress of pregnancy, which tendency was not observed in the non-pregnant.
2. An increase in the muscle-activity was observed in the first half of pregnancy in various movements, while a decrease in the muscle-activity, especially in the obliques, was found in the latter half of pregnancy in various movements.
3. Takano has reported that muscle-action potentials for various movements are not found in the latter half of pregnancy using a needle electrode, although the present author could observe those in the latter half of pregnancy by using a surface electrode.
