The effect of changing limb position on the validity of venous occlusion plethysmography.
Venous occlusion plethysmography (VOP) is a technique used for the non-invasive measurement of limb blood flow. A fundamental technical consideration of venous occlusion plethysmography is that the limb in question must be placed above heart level. However, in light of advances in technology and methodology, the necessity of this has been questioned. We investigated the validity of the VOP technique with the forearm approximately 10 cm above and below the level of the heart in both resting and dynamic conditions. Nine healthy male participants performed four bouts of handgrip exercise, two at each of 15% and 30% maximum voluntary contraction (MVC) (one above and one below the heart). As hypothesized, resting forearm blood flow (FBF) measured below the level of the heart was significantly lower than for above the heart (p = 0.046). However, the opposite occurred during exercise, where FBF measured after the fifth minute of handgrip contractions was significantly higher below the level of the heart (p = 0.013). Furthermore, the ability to accurately quantify FBF below the level of the heart was severely impeded by artifact, and as such VOP appears to remain constricted to use above the phlebostatic level.
Institute of Health and Biomedical Innovation and School of Human Movement Studies, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Qld 4059, Australia.
Amanda M
AM
Rojek
Rachel E
RE
Wood
Ian B
IB
Stewart
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002138:Calibration; D015444:Exercise / Q000502:physiology; D005121:Extremities / Q000098:blood supply / Q000502:physiology*; D005542:Forearm / Q000098:blood supply / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D010991:Plethysmography / Q000706:statistics & numerical data*; D011187:Posture / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results