Blood pressure response to force–velocity properties of the knee-hip extension movement

Abstract

This study aimed to examine the effects of maximum static and dynamic forces during and after knee-hip extension movement on blood pressure. Blood pressure was measured with a combination of oscillometric and tonometry methods before, during, immediately after and 30 s after knee-hip extension movements performed under maximum isometric and various isotonic force conditions on the servo-controlled dynamometer. The force-velocity relation of knee-hip extension movement was linear (r (2 ) = 0.9989), so that maximum isometric force (F (max)) and unloaded velocity (V (max)) were obtained by extrapolation. F (max) coincided with measured maximum isometric force (F (0)) (F (0)/F (max) = 1.03 +/- 0.25). During isometric contraction, mean arterial pressure (MAP) increased to a larger extent and the increase was significantly higher than those during all controlled-load range of isotonic force measurements. The magnitude of MAP response during maximum isometric exercise was positively correlated with both F (0) (r = 0.687, P < 0.01) and V (max) (r = 0.586, P < 0.05). On the other hand, there was no significant correlation between F (0) and V (max) (r = 0.451, P > 0.05). It is suggested that measurements of muscular function with isotonic trials cause smaller increase in blood pressure than isometric trials do. Also, it was indicated that individuals with greater muscular strength and speed might respond with larger changes in blood pressure to strenuous muscular exercises.