The effect of the speed and range of motion of movement on the hyperemic response to passive leg movement

Abstract

Passive leg movement ( PLM )‐induced hyperemia is used to assess the function of the vascular endothelium. This study sought to determine the impact of movement speed and range of motion ( ROM ) on the hyperemic response to PLM and determine if the currently recommended protocol of moving the leg through a 90° ROM at 180°/sec provides a peak hyperemic response to PLM . 11 healthy adults underwent multiple bouts of PLM , in which either movement speed (60–240°/sec) or ROM (30–120° knee flexion) were varied. Femoral artery blood flow (Doppler Ultrasound) and mean arterial pressure ( MAP ; photoplethysmography) were measured throughout. Movement speed generally exhibited positive linear relationships with the hyperemic response to PLM , eliciting ~15–20% increase in hyperemia and conductance for each 30°/sec increase in speed ( P < 0.05). However, increasing the movement speed above 180°/sec was physically difficult and seemingly impractical to implement. ROM exhibited curvilinear relationships ( P <0.05) with hyperemia and conductance, which peaked at 90°, such that a 30° increase or decrease in ROM from 90° resulted in a 10–40% attenuation ( P < 0.05) in the hyperemic response. Alterations in the balance of antegrade and retrograde flow appear to play a role in this attenuation. Movement speed and ROM have a profound impact on PLM ‐induced hyperemia. When using PLM to assess vascular endothelial function, it is recommended to perform the test at the traditional 180°/sec with 90° ROM , which offers a near peak hyperemic response, while maintaining test feasibility.

Impact of Interrepetition Rest on Muscle Blood Flow and Exercise Tolerance during Resistance Exercise

“…Both concentric and eccentric actions were performed during the contraction. The leg was rested at 90 • of knee flexion to minimize the impact that differing degrees of knee flexion have on the blood flow response to knee extension exercise [23]. Since the hyperemic response to knee extension is influenced by the amount of external work performed during a contraction [24,25], the displacement distance of the weight was limited to 15 cm for each contraction.…”

Indices of leg resistance artery function are independently related to cycling V̇O 2 max

“…In addition to the factors mentioned above, previous research has revealed other factors that must be considered when performing and interpreting tests of vascular function. For example, the placement of the cuff proximal or distal to the site of measurement may impact the results of an FMD test (Doshi et al, 2001), the frequency of movement and the range of motion of PLM (Gifford et al, 2019), and the amount of work performed during ROV (Tschakovsky et al, 2004) have been shown to strongly impact the results. Therefore, these factors should be considered when exploring the relationship between vascular function and other variables, like VȮ 2 max.…”