A study of muscle pump. Relationship between contraction force and blood volume and pumping action.
- VernacularTitle:筋ポンプに関する研究 筋収縮強度及び血液貯留量と筋ポンプ作用との関係
- Author:
TAKESHI NISHIYASU
;
SHINJI GOTO
;
YOSHIHARU NABEKURA
;
HARUO IKEGAMI
- Publication Type:Journal Article
- Keywords:
muscle pump;
LBNP;
contraction force
- From:Japanese Journal of Physical Fitness and Sports Medicine
1987;36(4):195-201
- CountryJapan
- Language:Japanese
-
Abstract:
The purpose of this study was to investigate the effects of contraction force and the pooled blood volume in the calf on the pumping action of calf muscle contraction. Calf blood volume was controlled by lower body negative pressure (LBNP) and isometric contraction of calf extensor muscle was performed using a handmade dynamometer in recumbent position. The relative volume changes (ΔV/V%) of calf were determined using rubber straingage, when isometric contractions (5, 10, 20, 40 and 60 kg) of the calf muscle were repeated under LBNP of 0, -20, -40, and -60 mmHg.
During resting condition, Δ V/V was increased by 1.04% under -20 mmHg LBNP, 1.88% under -40 mmHg, and 2.54% under -60 mmHg. These increases of ΔV/V were due to the increased blood pooling in the calf. It was shown that the increased blood volume was almost expelled by several bouts of muscle contractions of proper force. The optimum force of contractions for expelling pooled blood was 20 kg under -20mmHg LBNP, and 40 kg under -40 and -60 mmHg LBNP. And it was apparent that the effectiveness of muscle pump was accumulated with repeating contractions, arriving to a plateau after several bouts.
It was shown that the effect of muscle pump in the given contraction force was more effective under the condition with more amount of blood contained in the calf, but the muscle pumping action by light contraction forces couldn't overcome the effect of severe LBNP.
