scholarly journals The Venoarteriolar Reflex Significantly Reduces Contralateral Perfusion as Part of the Lower Limb Circulatory Homeostasis in vivo

2018 ◽  
Vol 9 ◽  
Author(s):  
Henrique Silva ◽  
Hugo A. Ferreira ◽  
Hugo P. da Silva ◽  
L. Monteiro Rodrigues
Keyword(s):  
Lower Limb

A Robust and Subject-Specific Hemodynamic Model of the Lower Limb Based on Noninvasive Arterial Measurements

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Laurent Dumas ◽  
Tamara El Bouti ◽  
Didier Lucor
Keyword(s):  
Cardiovascular Diseases ◽  
Arterial Stiffness ◽  
Lower Limb ◽  
Developed Countries ◽  
Numerical Approach ◽  
Subject Specific ◽  
Hemodynamic Model ◽  
Quantification Analysis ◽  
Stiffness Distribution

Cardiovascular diseases are currently the leading cause of mortality in the population of developed countries, due to the constant increase in cardiovascular risk factors, such as high blood pressure, cholesterol, overweight, tobacco use, lack of physical activity, etc. Numerous prospective and retrospective studies have shown that arterial stiffening is a relevant predictor of these diseases. Unfortunately, the arterial stiffness distribution across the human body is difficult to measure experimentally. We propose a numerical approach to determine the arterial stiffness distribution of an arterial network using a subject-specific one-dimensional model. The proposed approach calibrates the optimal parameters of the reduced-order model, including the arterial stiffness, by solving an inverse problem associated with the noninvasive in vivo measurements. An uncertainty quantification analysis has also been carried out to measure the contribution of the model input parameters variability, alone or by interaction with other inputs, to the variation of clinically relevant hemodynamic indices, here the arterial pulse pressure. The results obtained for a lower limb model, demonstrate that the numerical approach presented here can provide a robust and subject-specific tool to the practitioner, allowing an early and reliable diagnosis of cardiovascular diseases based on a noninvasive clinical examination.

scholarly journals In vivo femoropopliteal arterial wall compliance in subjects with and without lower limb vascular disease

1999 ◽  
Vol 30 (5) ◽  
pp. 936-945 ◽  
Author(s):  
Nigel R.M. Tai ◽  
Alberto Giudiceandrea ◽  
Henryk J. Salacinski ◽  
Alexander M. Seifalian ◽  
George Hamilton
Keyword(s):  
Vascular Disease ◽  
Lower Limb ◽  
Arterial Wall ◽  
Wall Compliance

scholarly journals In Vivo Assessment of Lower Limb Muscle Stress State Based on Shear Wave Elastography

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 122185-122196
Author(s):  
Jing Liu ◽  
Kunyang Wang ◽  
Jianan Wu ◽  
Huaibin Miao ◽  
Zhihui Qian ◽  
...  
Keyword(s):  
Stress State ◽  
Shear Wave ◽  
Lower Limb ◽  
Shear Wave Elastography ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Muscle Stress ◽  
In Vivo Assessment

Noninvasive and in vivo assessment of upper and lower limb skeletal muscle oxidative metabolism activity and microvascular responses to glucose ingestion in humans

2019 ◽  
Vol 44 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Rogério Nogueira Soares ◽  
Alessandro L. Colosio ◽  
Juan Manuel Murias ◽  
Silvia Pogliaghi
Keyword(s):  
Oxidative Metabolism ◽  
Lower Limb ◽  
Near Infrared ◽  
Vascular Occlusion ◽  
Lower Limbs ◽  
Clinical Approach ◽  
Specific Detection ◽  
Glucose Ingestion ◽  
Glucose Challenge

This study investigated changes in muscle oxidative metabolism and microvascular responsiveness induced by glucose ingestion in the upper and lower limbs using near-infrared spectroscopy (NIRS). Fourteen individuals (aged 27 ± 1.4 years) underwent 5 vascular occlusion tests (VOT) (pre-intervention (Pre), 30 min, 60 min, 90 min, and 120 min after glucose challenge). NIRS-derived oxygen saturation (StO2) was measured on the forearm and leg muscle at each VOT. Muscle oxidative metabolism was determined by the StO2 downslope during cuff inflation (deoxygenation slope); microvascular responsiveness was estimated by the StO2 upslope (reperfusion slope) following cuff deflation. There was a significant increase in arm (p < 0.05; 1-β = 0.860) and leg (p < 0.05; 1-β = 1.000) oxidative metabolism activity as represented by the faster deoxygenation slope at 60, 90, and 120 min (0.08 ± 0.03, 0.08 ± 0.03, 0.08 ± 0.02%·s–1, respectively) (leg) and at 90 min (0.16 ± 0.08%·s−1) (arm) observed after glucose ingestion when compared with their respective Pre values (leg = 0.06 ± 0.02; arm = 0.11 ± 0.04%·s−1). There was a significant increase in arm (p < 0.05; 1-β = 0.880) and leg (p < 0.05; 1-β = 0.983) reperfusion slope at 60 min (arm = 3.63 ± 2.1%·s−1; leg = 1.56 ± 0.6%·s−1), 90 min (arm = 3.91 ± 2.1%·s−1; leg = 1.60 ± 0.6%·s−1), and 120 min (arm = 3.91 ± 1.6%·s−1; leg = 1.54 ± 0.6%·s−1) when compared with their Pre values (arm = 2.79 ± 1.7%·s−1; leg = 1.26 ± 0.5%·s−1). Our findings showed that NIRS–VOT technique is capable of detecting postprandial changes in muscle oxidative metabolism activity and microvascular reactivity in the upper and lower limb. Novelty NIRS-VOT is a promising noninvasive clinical approach that may help in the early, limb-specific detection of impairments in glucose oxidation and microvascular function.

Validation of a lower limb model with in vivo femoral forces telemetered from two subjects

1997 ◽  
Vol 31 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Tung-Wu Lu ◽  
John J. O’Connor ◽  
Stephen J.G. Taylor ◽  
Peter S. Walker
Keyword(s):  
Lower Limb

Subperiosteal expansion and cortical remodeling of the human femur and tibia with aging

Science ◽  
1982 ◽  
Vol 217 (4563) ◽  
pp. 945-948 ◽  
Author(s):  
CB Ruff ◽  
WC Hayes
Keyword(s):  
Cross Sections ◽  
Lower Limb ◽  
Torsional Rigidity ◽  
American Southwest ◽  
Cross Sectional ◽  
Human Femur ◽  
Second Moments

Increases with aging in subperiosteal dimensions and second moments of area (measures of bending and torsional rigidity) in femoral and tibial cross sections are documented in an archeological sample from the American Southwest. Significant differences between cross-sectional sites and between sexes in the pattern of cortical remodeling with age are also present. These differences appear to be related to variations in the stress or strain levels in different regions of the femur and tibia which result from in vivo mechanical loadings of the lower limb.

Adaptations in human neuromuscular function following prolonged unweighting: I. Skeletal muscle contractile properties and applied ischemia efficacy

2006 ◽  
Vol 101 (1) ◽  
pp. 256-263 ◽  
Author(s):  
Brian C. Clark ◽  
Bo Fernhall ◽  
Lori L. Ploutz-Snyder
Keyword(s):  
Lower Limb ◽  
Strength Loss ◽  
Contractile Properties ◽  
Plantar Flexor ◽  
Postactivation Potentiation ◽  
Flexor Muscle ◽  
Muscle Properties ◽  
Cross Sectional ◽  
Lateral Gastrocnemius

Strength loss following disuse may result from alterations in muscle and/or neurological properties. In this paper, we report our findings on human plantar flexor muscle properties following 4 wk of limb suspension (unilateral lower limb suspension), along with the effect of applied ischemia (Isc) on these properties. In the companion paper (Part II), we report our findings on the changes in neurological properties. Measurements of voluntary and evoked forces, the compound muscle fiber action potential (CMAP), and muscle cross-sectional area (CSA) were collected before and after 4 wk of unilateral lower limb suspension in adults ( n = 18; 19–28 yr). A subset of subjects ( n = 6) received applications of Isc 3 days/wk (3 sets; 5-min duration). In the subjects not receiving Isc, the loss in CSA and strength was as expected (∼9 and 14%). We observed a 30% slowing in the duration of the CMAP, a 10% decrease in evoked doublet force, a 12% increase in the twitch-to-doublet force ratio, and an altered postactivation potentiation response (11% increase in the postactivation potentiation-to-doublet ratio). We also detected a 10% slowing in the ability of the plantar flexor to develop force during the initial phase of an evoked contraction, along with a 6% reduction in in vivo specific doublet force. In the Isc subjects, no preservation was observed in strength or the evoked muscle properties. However, the Isc group did maintain CSA of the lateral gastrocnemius, as the control subjects’ lateral gastrocnemius atrophied 10.2%, whereas the subjects receiving Isc atrophied 4.7%. Additionally, Isc abolished the unweighting-induced slowing in the CMAP. These findings suggest that unweighting alters the contractile properties involved in the excitation-contraction coupling processes and that Isc impacts the sarcolemma.

Sign in / Sign up

Export Citation Format

Share Document