Calf Muscle Pump Function Research Articles

Continuous muscle pump activation by neuromuscular electrical stimulation of the common peroneal nerve in the treatment of patients with venous leg ulcers: A position paper.

The standard treatment for patients with confirmed Venous Leg Ulcers (VLUs) is compression therapy to improve the function of the calf muscle pump. There is a significant cohort of patients who are unable to tolerate optimal compression therapy or indeed any level of compression therapy. In addition, there is a cohort of patients who can tolerate compression whose ulcers show little or no evidence of healing. There is a need for ways to further improve calf muscle pump function and to improve venous ulcer healing in these patients. Published data were reviewed on the use of Muscle Pump Activation (MPA) using common peroneal nerve neuromuscular electrical stimulation (NMES) to improve calf muscle pump function. There is physiological evidence that MPA can improve calf muscle pump function and venous return in both control subjects and in patients with venous disease. The use of MPA has also been shown to improve venous flow volume and venous flow velocity on ultrasound scanning in patients with venous disease. MPA has been shown to improve microcirculation in the skin using Laser Doppler and laser Doppler Speckle Contrast Imaging, in both normal subjects as well as in patients with venous disease and VLU. A recent randomized controlled trial of MPA plus compression therapy compared with compression therapy alone, found significantly faster rates of healing with the use of MPA in addition to compression therapy. There are indications for the use of MPA as an adjunctive treatment to enhance calf muscle pump function in patients with VLU: who cannot tolerate compression therapy who can only tolerate suboptimal, low-level compression whose ulcer healing remains slow or stalled with optimal compression.

Reduced calf muscle pump function is not explained by handgrip strength measurements

ObjectiveReduced calf muscle pump function (CPF) is an independent risk factor for venous thromboembolism and mortality. We aimed to evaluate the relationship between handgrip strength (HGS) and CPF. MethodsPatients referred to the Gonda Vascular Laboratory for noninvasive venous studies were identified and consented. Patients underwent standard venous air plethysmography protocol. CPF (ejection fraction) was measured in each lower extremity of ambulatory patients by comparing refill volume after ankle flexes and passive refill volumes. The cutoff for reduced CPF (rCPF) was defined as an ejection fraction of <45%. Maximum HGS bilaterally was obtained (three trials per hand) using a dynamometer. HGS and CPF were compared (right hand to calf, left hand to calf) and the correlation between the measures was evaluated. Results115 patients (mean age, 59.2 ± 17.4 years; 67 females, mean body mass index, 30.83 ± 6.46) were consented and assessed for HGS and CPF. rCPF was observed in 53 right legs (46%) and 67 left legs (58%). CPF was reduced bilaterally in 45 (39%) and unilaterally in 30 (26%) patients. HGS was reduced bilaterally in 74 (64.3%), unilaterally in 23 (20%), and normal in 18 (15.7%) patients. Comparing each hand/calf pair, no significant correlations were seen between HGS and CPF. The Spearman's rank correlation coefficients test yielded values of 0.16 for the right side and 0.10 for the left side. ConclusionsThere is no significant correlation between HGS and CPF, demonstrating that HGS measurements are not an acceptable surrogate for rCPF, indicating different pathophysiological mechanisms for each process.

The athlete's vein: venous adaptations in the lower limbs of endurance athletes.

Endurance exercise induces cardiovascular adaptations; the athletic phenotypes of the heart and arteries are well characterized, but few studies have investigated the effects of chronic exercise on the venous system. The aim of this study was to describe the anatomy and function of lower-limb deep and superficial veins in athletes compared with controls. Endurance-trained athletes and untrained controls (13 males, 7 females per group) were examined using ultrasound to measure vein diameter and flow, and air plethysmography to assess calf venous volume dynamics and muscle pump function at rest, during a single step, ambulation (10 steps) and after acute treadmill exercise (30 min ∼80% age-predicted heart rate maximum). Diameters of three of the seven deep veins assessed were larger in athletes (P ≤ 0.0167) and more medial calf perforators were detectable (5 vs. 3, P = 0.0039). Calf venous volume was 22% larger in athletes (P = 0.0057), and calf muscle pump ejection volume and ambulatory venous volume after 10 steps were both greater in athletes (20 and 46% respectively, P ≤ 0.0482). Following acute exercise, flow recovery profiles in deep and superficial veins draining the leg were not different between groups, despite athletes performing approximately four times more work. After exercise, venous volume and ejection volume were reduced by ∼20% in athletes with no change in controls (interaction, P ≤ 0.0372) and although ambulatory venous volume reduced, this remained greater in athletes. These findings highlight venous adaptations that compensate for the demands of regular endurance exercise, all of which are suited to enhance flow through the lower-limb venous system.NEW & NOTEWORTHY Although much literature exists describing adaptations to the heart and arteries in response to endurance exercise training, less is known about the effects on the venous system. Characteristics of "the athlete's vein" described here include deep and perforator vein remodeling, improved drainage, and greater calf venous volume at rest and on calf muscle pump activation. Following exercise, athletes demonstrated prompt flow recovery and appropriate volume reductions, and veins beneficially adapt to better tolerate the demands of regular physical activity.

Effect of ankle pump exercise on fatigue sensation, comfort, and lower limb hemodynamics among deep vein thrombosis patients

Background: Ankle pumping exercises utilize a calf muscle pump function to pump blood to the heart by muscle contraction. Ankle pumping exercises are often used for the relief of edema and the prevention of deep vein thrombosis. So, the current study aimed to evaluate the effect of ankle pump exercise on fatigue sensation, comfort, and lower limb hemodynamics among deep vein thrombosis patients. Design: This study was carried out using a quasi-experimental research design. Setting: This study was applied in the Orthopedic Department at Ain Shams University Hospital. Subjects: It consisted of a convenient sampling technique enrolled to select a sample of 100 patients with deep vein thrombosis in the previously selected department who agreed to participate in the study and were randomly assigned into two equal groups, with 50 patients in each group (the intervention group who received ankle pump exercise and the control group who received routine hospital care only). Tools: three tools were used (I): A patient interviewing sheet, (II): Rating of Perceived Exertion (RPE), and (III): Comfort evaluation scale.

Exercise Training as an Adjunctive Therapy for Chronic Venous Insufficiency Patients: Evidence from Research to Practice.

Chronic venous insufficiency, which is defined as a condition relevant to persistent ambulatory venous hypertension, is a common cause of venous leg ulcers. Compression therapy is commonly used to relieve ambulatory venous hypertension and heal leg ulcers. Exercise is considered as adjunctive therapy, targeting calf muscle pump function, to additionally favor the compression treatment for facilitating the healing process. Different exercise training regimens for promoting wound healing and its relevant outcomes are reviewed and discussed in this study.

Reduced calf muscle pump function is a risk factor for venous thromboembolism: a population-based cohort study

The calf muscle pump is a major determinate of venous return in the legs but has not been studied as a risk factor for venous thromboembolism (VTE). A population-based cohort study of Olmsted County, Minnesota residents was performed using calf pump function (CPF) measurements from venous plethysmography studies from 1998 to 2015. Patients with a history of VTE were excluded. Nursing validated VTE outcomes from the Rochester Epidemiology Project were identified after the index study date, and patients with reduced CPF (rCPF) were compared with patients with normal CPF. A total of 1532 patients with recorded CPF (28% air and 72% strain gauge plethysmography) were included; 591 (38.5%) had normal CPF, 353 (23.0%) had unilateral rCPF, and 588 (38.3%) had bilateral rCPF. Any VTE occurred in 87 patients (5.7%) after a median follow-up of 11.7 years (range, 0-22.0 years). Comparing patients with bilateral reduced to bilateral normal CPF, the unadjusted hazard ratio (HR) for incident VTE was 2.0 (95% confidence interval [CI], 1.2-3.4) and after adjusting for age, BMI, and Charlson Comorbidity Index, the HR was 1.68 (95% CI, 0.98-2.89). The adjusted HR for ipsilateral deep vein thrombosis was evaluated in 3064 legs comparing legs with reduced to normal CPF and was 1.71 (95% CI, 1.03-2.84). Mortality was significantly higher in both the bilateral (P < .001) and unilateral (P < .001) rCPF groups compared with normal CPF. Our results demonstrate that CPF is a risk factor for VTE in an otherwise low-risk ambulatory population and might be a useful component in risk stratification models.

Reduced Calf Muscle Pump Function Is a Risk Factor for Venous Thromboembolism and Mortality

Background: Venous return from the lower extremities is pumped upwards to the right side of the heart in a process that is facilitated by one-way valves and the venous muscle pump, of which the calf muscle pump is a major contributor1-3. Venous plethysmography can quantitatively assess calf pump function (CPF). The association between the CPF and venous thromboembolism (VTE) has not been investigated. Methods: Venous plethysmography (VP) data (strain gauge or air plethysmography) from the Mayo Clinic Vascular Lab database (1998-2015) of CPF (bilaterally reduced, unilaterally reduced, and bilateral normal) were examined in Olmsted County Residents. The Rochester Epidemiology Project (REP) captures the population of Olmsted County and contains demographic information, medical diagnoses, hospital admissions, and surgical procedures as well as validated VTE events and death. Patients with signs of obstructed outflow in either extremity on the venous plethysmography (a possible sign of acute or chronic deep vein thrombosis) study were excluded. Patients with a history of VTE diagnosed before the physiologic study were also excluded. If more than one measurement of calf muscle pump function was performed, only the first measurement was used. The primary outcome was a composite of any VTE, including proximal and distal deep vein thrombosis (DVT) and pulmonary embolism (PE). Results: 1703 Olmsted County residents had venous plethysmography studies performed. MN research authorization was denied in 64 patients and 107 were excluded for any documented VTE preceding index VP study. 1532 patients with recorded CPF (28% air and 72% strain gauge plethysmography) were studied: 591 (38.5%) had normal CPF, 353 (23.0%) had unilateral reduced CPF (rCPF), and 588 (38.3%) had bilateral rCPF. The mean age was 64.4 (SD 18.4), 68.9% were female, and the mean BMI was 29.5 (SD 6.4). Any VTE occurred in 87 patients (5.7%) after a mean follow up of 10.9 years (range 0-22.0 years). Isolated lower extremity DVT (excluding concurrent PE) occurred in 49 patients and PE+/-DVT occurred in 38 patients. Death occurred in 352 patients (23%). Bilateral rCPF compared to bilateral normal CPF was associated with VTE (p=0.007), DVT only (p=0.02) and death (p&amp;lt;0.001) but not PE+/-DVT (p=0.13). Unilateral rCPF compared to bilateral normal CPF was not associated with VTE, but was associated with death (p&amp;lt;0.001). Kaplan-Meier curves for VTE and death are shown in Figure 1. The hazard ratio for bilateral rCPF compared to bilateral normal CPF for VTE was 2.0 (95% CI 1.2-3.4) and for DVT only was 2.2 (95% CI 1.1-4.2). A sensitivity analysis for the main outcome of VTE did not show significant interaction based on the type of plethysmography (strain vs. air), by age stratified at 65 years, sex, or BMI stratified at 30 (p&amp;gt;0.1 for each comparison). Conclusion: In this population-based study of Olmsted County residents with no prior VTE, rCPF function as measured by venous plethysmography is associated with increased risk for VTE, particularly lower extremity proximal DVT. More research is required to understand what additional measures of venous physiology influence these findings and whether CPF could be used in VTE risk stratification. Disclosures No relevant conflicts of interest to declare.

Calf muscle pump function as a predictor of all-cause mortality.

Calf muscle pump (CMP) promotes venous return from the lower extremity and contributes to preload and cardiac output. Impaired CMP function may reflect a measure of frailty or cumulative disease burden or may impede cardiac function. The study objective was to test the hypothesis that impaired CMP negatively impacts survival. Consecutive adult patients who underwent venous strain gauge plethysmography at the Mayo Clinic Gonda Vascular Laboratory (January 1, 1998 - December 31, 2011) were assessed for overall survival. Patients with venous incompetence, venous obstruction or unilateral calf pump dysfunction were excluded. Risk of mortality was assessed with Cox proportional hazard ratios and after adjusting for Charlson Comorbidity Index variables. Over the study period, 2728 patients were included in the analysis. Compared to patients with normal CMP, those with impaired CMP were older (p < 0.001), predominantly female (p = 0.01) and had higher mean Charlson scores (p < 0.001). Patients with impaired CMP had a higher mortality rate at 5 (8.9% vs 2.4%), 10 (17.5% vs 5.9%), and 15 years (22.8% vs 8.3%) compared to those with normal CMP (p < 0.001 for each comparison). Of patients with heart failure, those with impaired CMP had worse survival at each 5-year increment compared to those with normal CMP (p < 0.05 at each increment). In conclusion, impaired CMP appears to be an independent predictor of poor outcomes after adjusting for variables within the Charlson Comorbidity Index. The association between impaired CMP, heart failure, and mortality may represent a negative impact on circulatory function or a surrogate measure of frailty.

A Wearable Compression Device to Normalise Calf Muscle Pump Function in Chronic Venous Insufficiency for Each Postural Position

Background For the currently used compression therapy, the applied compression pressure is usually inadequate to exert an effective impact on the veins in different body positions. The aim was to assess the venous ejection fraction achieved by a new compression device which automatically adjusts the interface pressure to body position in an acute experimental setting. Methods A new portable, battery driven compression device providing pressure adjusted to allow for body position, and connected to a less or very stiff calf cuff wrap was tested. In patients with superficial venous incompetence, the ejection fraction (EF) of the calf pump was measured by strain gauge plethysmography. Applied in a random sequence, values achieved without compression, with the two cuffs, and with compression stockings exerting 23–32 mmHg, were compared. The applied compression pressures were simultaneously recorded in the supine and standing positions, and during walking. Comfort was assessed by a visual analogue scale (VAS) with 0 corresponding to very low comfort and 10 to very comfortable. Results In 16 patients with CEAP clinical stage C3–C6, EF without compression was 37%, increasing to 46.9% with stockings, to 64.8% (p Conclusions The tested devices were comfortable at rest and haemodynamically effective during walking by automatically adjusting compression pressures to body position. They are significantly more effective than elastic stockings in improving EF. The system is able to overcome the problems of fast pressure loss by continuously re-adjusting the compression pressure.

Venous Stasis Leg Ulcers: A Review

Chronic venous stasis ulcers (CVSU) of the lower extremity affect up to 5% of the population over 65 years and 1.5% of the general population. CVSU is caused by chronic venous disease produced by venous hypertension. Venous hypertension results from valvular incompetence within the deep venous system, or by the obstruction of venous outflow. Both of these mechanisms produce poor venous return. Additionally, poor mobility and decreased calf muscle pump function are thought to be contributing factors. Life-long use of compressive therapy is indicated in patients with chronic venous disease in lower extremities. It reduces ambulatory venous pressure. These include bandaging systems, garments (stockings), or devices.

Some features of compression therapy for early forms of chronic venous diseases of the lower limbs

The current compression garment selection guide is targeted at the earliest clinical stages of chronic venous disease (CVD) and assumes a priori that application of a higher class of compression improves the calf muscle pump function, which is the major mechanism promoting venous return from the lower limb to the heart.Objective of the study: to evaluate the calf muscle pump function in patients with the early forms of CVD using different classes of compression garments.Material and methods: A total of 30 patients (45 lower limbs) with Class 1 CVD (CEAP classification) were enrolled in the study. The calf muscle pump function was evaluated during wearing compression garments using remote cableless photoplethysmography of Bodytronic measurement system (Bauerfeind, Germany) with automatic data processing. The investigators measured venous refilling time (T0) and pump capacity (V0) in patients without compression garments and also in those wearing classes 0, I and II compression garments (RAL standard, Venotrain micro, Bauerfiend socks). All indicators were measured three times with an interval of 30 minutes. The final values of T0 and V0 were calculated as average.Results and discussion: when the indicators were measured without compression and with zero compression, T0 was 26.7 ± 1.2 sec and 25.4 ± 1.1 sec (p = 0.56); V0 - 8.6 ± 0.7% and 8.0 ± 0.4% (p = 0.47). When the calf muscle pump function indicators were measured using class I compression garments, its performance was improved. Thus, T0 and V0 (p &lt;0.01) increased significantly to 38.9 ± 2.1 sec and 12.9 ± 1.4%, respectively. When the calf muscle pump function indicators were measured using class II compression garments, T0 and V0 were 38.1 ± 1.6 sec and 8.1 ± 0.6%. Thus, the use of class I compression garments significantly improved the calf muscle pump function in patients with early manifestations of CVD. The higher level of compression (class II) did not improve T0 and worsened V0. This fact can be explained by excessive compression of the muscular venous sinuses caused by wearing class 2 compression garments, which, apparently, worsened the propulsive ability of the calf pump.Conclusion: the use of class I compression garments is optimal for the management of hemodynamic disorders in patients with early forms of chronic venous diseases (C1 according to CEAP). The higher class of compression does not improve the hemodynamic parameters of the calf muscle pump.

A Wearable Compression Device to Normalise Calf Muscle Pump Function in Chronic Venous Insufficiency for Each Postural Position

For the currently used compression therapy, the applied compression pressure is usually inadequate to exert an effective impact on the veins in different body positions. The aim was to assess the venous ejection fraction achieved by a new compression device which automatically adjusts the interface pressure to body position in an acute experimental setting. A new portable, battery driven compression device providing pressure adjusted to allow for body position, and connected to a less or very stiff calf cuff wrap was tested. In patients with superficial venous incompetence, the ejection fraction (EF) of the calf pump was measured by strain gauge plethysmography. Applied in a random sequence, values achieved without compression, with the two cuffs, and with compression stockings exerting 23-32mmHg, were compared. The applied compression pressures were simultaneously recorded in the supine and standing positions, and during walking. Comfort was assessed by a visual analogue scale (VAS) with 0 corresponding to very low comfort and 10 to very comfortable. In 16 patients with CEAP clinical stage C3-C6, EF without compression was 37%, increasing to 46.9% with stockings, to 64.8% (p<.001) by less stiff and to 75.5% (p<.001) by stiffer wraps. The median interface pressure (supine/standing) was 31/56mmHg for the less stiff device, 32/68mmHg for the stiffer device, and 23/26mmHg for the stockings. The static stiffness index and the walking pressure amplitudes were significantly higher than those generated by the stocking, and the highest values were found with the stiffer wrap material. The device comfort was high both in the supine and standing positions (VAS 8±2). The tested devices were comfortable at rest and haemodynamically effective during walking by automatically adjusting compression pressures to body position. They are significantly more effective than elastic stockings in improving EF. The system is able to overcome the problems of fast pressure loss by continuously re-adjusting the compression pressure.

Prescribed Exercise With Compression vs Compression Alone in Treating Patients With Venous Leg Ulcers

Exercise is recommended as an adjuvant treatment for venous leg ulceration (VLU) to improve calf muscle pump function. However, the association of exercise with VLU healing has not been properly aggregated, and the effectiveness of different exercise interventions has not been characterized. To summarize the association of different exercise interventions with VLU healing when used as an adjuvant to any form of compression. The Cochrane Controlled Trials Register, MEDLINE, Embase, CINAHL, PsycInfo, and SCOPUS databases were searched through October 9, 2017. Randomized clinical trials (RCTs) of any exercise compared with no exercise in participants with VLU were included, where compression was used as standard therapy and a healing outcome was reported. Independent title screening and full text review by 2 authors (A.J., J.S.) with appeal to a third author (J.P.) if disagreement was unresolved. Of the 519 articles screened, a total of 6 (1.2%) studies met the inclusion criteria for systematic review, including 5 for meta-analysis. Independent quality assessment for Cochrane risk of bias and data extraction by 2 authors with appeal to third author if disagreement unresolved (PRISMA). Data pooled using fixed effects model. The a priori primary outcome was any healing outcome (proportion healed, time to healing, or change in ulcer area). Secondary outcomes (adverse events, costs, and health-related quality of life) were only collected if a primary outcome was reported. Six RCTs were identified and 5 (190 participants) met inclusion criteria for meta-analysis. The exercise interventions were progressive resistance exercise alone (2 RCTs, 53 participants) or combined with prescribed physical activity (2 RCTs, 102 participants), walking only (1 RCT, 35 participants), or ankle exercises (1 RCT, 40 participants). Overall, exercise was associated with increased VLU healing at 12 weeks although the effect was imprecise (additional 14 cases healed per 100 patients; 95% CI, 1-27 cases per 100; P = .04). The combination of progressive resistance exercise plus prescribed physical activity appeared to be most effective, again with imprecision (additional 27 cases healed per 100 patients; 95% CI, 9-45 cases per 100; P = .004). The evidence base may now be sufficiently suggestive for clinicians to consider recommending simple progressive resistance and aerobic activity to suitable patients with VLU while further research is produced.

Optimizing calf muscle pump function.

Background The tip toe manoeuvre has been promoted as the gold standard plethysmography test for measuring calf muscle pump function. The aim was to compare the tip toe manoeuvre, dorsiflexion manoeuvre and a body weight transfer manoeuvre using the ejection fraction of air-plethysmography and evaluate which has the best pumping effect. Methods Sixty-six archived tracings on 22 legs were retrieved from an air-plethysmography workshop and analysed. Pumping performance was measured using the calf volume reduction after each manoeuvre. Results Expressed as median [inter-quartile range], body weight transfer manoeuvres resulted in a significantly greater ejection fraction (%) than tip toe manoeuvres at 59.7 [53.5-63.9] versus 42.6 [30.5-52.6], P < 0.0005 (Wilcoxon). There was no significant difference in the ejection fraction between the tip toe manoeuvre versus dorsiflexion manoeuvre, P = 0.615. The repeatability (confidence interval: 95%) of 66 ejection fraction tests was excellent: tip toe manoeuvre (±1.2), dorsiflexion manoeuvre (±1.3) and body weight transfer manoeuvre (±1.6). Conclusion The body weight transfer manoeuvre appears to be a better method of measuring the full potential of the calf muscle pump with a 40.1% relative increase in the ejection fraction compared to a tip toe manoeuvre. Exercises which involve body weight transfers from one leg to the other may be more important in optimizing calf muscle pump function than ankle movement exercises.

IP263 Effect of Total Knee Arthroplasty on Calf Muscle Pump Function

IP263 Effect of Total Knee Arthroplasty on Calf Muscle Pump Function

Evaluating the effectiveness of a self-management exercise intervention on wound healing, functional ability and health-related quality of life outcomes in adults with venous leg ulcers: a randomised controlled trial.

Exercise that targets ankle joint mobility may lead to improvement in calf muscle pump function and subsequent healing. The objectives of this research were to assess the impact of an exercise intervention in addition to routine evidence-based care on the healing rates, functional ability and health-related quality of life for adults with venous leg ulcers (VLUs). This study included 63 patients with VLUs. Patients were randomised to receive either a 12-week exercise intervention with a telephone coaching component or usual care plus telephone calls at the same timepoints. The primary outcome evaluated the effectiveness of the intervention in relation to wound healing. The secondary outcomes evaluated physical activity, functional ability and health-related quality of life measures between groups at the end of the 12 weeks. A per protocol analysis complemented the effectiveness (intention-to-treat) analysis to highlight the importance of adherence to an exercise intervention. Intention-to-treat analyses for the primary outcome showed 77% of those in the intervention group healed by 12 weeks compared to 53% of those in the usual care group. Although this difference was not statistically significant due to a smaller than expected sample size, a 24% difference in healing rates could be considered clinically significant. The per protocol analysis for wound healing, however, showed that those in the intervention group who adhered to the exercise protocol 75% or more of the time were significantly more likely to heal and showed higher rates for wound healing than the control group (P = 0·01), that is, 95% of those who adhered in the intervention group healed in 12 weeks. The secondary outcomes of physical activity, functional ability and health-related quality of life were not significantly altered by the intervention. Among the secondary outcomes (physical activity, functional ability and health-related quality of life), intention-to-treat analyses did not support the effectiveness of the intervention. However, per protocol analyses revealed encouraging results with those participants who adhered more than 75% of the time (n = 19) showing significantly improved Range of Ankle Motion from the self-management exercise programme (P = 0·045). This study has shown that those participants who adhere to the exercise programme as an adjunctive treatment to standard care are more likely to heal and have better functional outcomes than those who do not adhere to the exercises in conjunction with usual care.

The clinical importance of air plethysmography in the assessment of chronic venous disease.

Air plethysmography is a non-invasive test that can quantify venous reflux and obstruction by measuring volume changes in the leg. Its findings correlate with clinical and hemodynamic measures. It can quantitatively assess several components of venous hemodynamics: valvular reflux, calf muscle pump function, and venous obstruction. Although clinical uses of air plethysmography have been validated, it is used almost exclusively for medical research. Air plethysmography can be used to assess chronic venous disease, to evaluate improvement after venous surgery, to diagnose acute and past episodes of deep venous thrombosis, to evaluate compression stocking therapy, to study the physiological implications of high-heeled shoes in healthy women, and even to evaluate the probability of ulcer healing.

Supervised exercise training as an adjunctive therapy for venous leg ulcers: study protocol for a randomised controlled trial.

BackgroundVenous leg ulcers are common, chronic wounds that are painful and reduce quality of life. Compression therapy is known to assist in the healing of venous leg ulceration. Supervised exercise training that targets an improvement in calf muscle pump function might be a useful adjunctive therapy for enhancing ulcer healing and other aspects of physical and mental health. However, the evidence of exercise for individuals with venous ulcers is sparse. Here, we describe the protocol for a study that aims to assess the feasibility of undertaking a randomised controlled trial of a supervised exercise programme in people who are receiving compression for venous ulceration.Methods/DesignThis is a randomised, controlled, assessor-blinded, two-centre, feasibility trial with two parallel groups. Eighty adults who are receiving lower-limb compression for a venous leg ulcer will be randomly assigned to receive usual care (compression only) or usual care plus a 12-week supervised exercise programme. Participants in the exercise group will be invited to undertake three, 60-minute sessions of supervised exercise each week, and each session will involve a combination of treadmill walking, upright cycling and strength and flexibility exercises for the lower limbs. Participants will be assessed before randomisation and 3, 6 and 12 months after randomisation. Primary outcomes include rates of recruitment, retention and adherence. Secondary outcomes include time to ulcer healing, proportion of participants healed, percentage and absolute change in ulcer size, health-related quality of life (EQ-5D-5L and VEINES-QOL/Sym), lower-limb cutaneous microvascular function (laser Doppler flowmetry coupled with iontophoresis) and physical fitness (30-second sit-to-stand test, chair sit and reach test, 6-minute walk test and ankle range of motion). The costs associated with the exercise programme and health-care utilisation will be calculated. We will also complete interviews with a sub-sample of participants to explore their experiences of having a venous ulcer and the acceptability of the exercise intervention and study procedures.DiscussionData from this study will be used to refine the supervised exercise programme, investigate the acceptability of the intervention and study design and determine the most appropriate outcome measures, thereby providing estimates of the factors needed to design an adequately powered trial across several centres.Trial registrationCurrent Controlled Trials, ISRCTN10205425 (May 2014) - http://www.controlled-trials.com/ISRCTN10205425 Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-015-0963-z) contains supplementary material, which is available to authorized users.

A 1D pulse wave propagation model of the hemodynamics of calf muscle pump function.

The calf muscle pump is a mechanism which increases venous return and thereby compensates for the fluid shift towards the lower body during standing. During a muscle contraction, the embedded deep veins collapse and venous return increases. In the subsequent relaxation phase, muscle perfusion increases due to increased perfusion pressure, as the proximal venous valves temporarily reduce the distal venous pressure (shielding). The superficial and deep veins are connected via perforators, which contain valves allowing flow in the superficial-to-deep direction. The aim of this study is to investigate and quantify the physiological mechanisms of the calf muscle pump, including the effect of venous valves, hydrostatic pressure, and the superficial venous system. Using a one-dimensional pulse wave propagation model, a muscle contraction is simulated by increasing the extravascular pressure in the deep venous segments. The hemodynamics are studied in three different configurations: a single artery–vein configuration with and without valves and a more detailed configuration including a superficial vein. Proximal venous valves increase effective venous return by 53% by preventing reflux. Furthermore, the proximal valves shielding function increases perfusion following contraction. Finally, the superficial system aids in maintaining the perfusion during the contraction phase and reduces the refilling time by 37%. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.

Effect of physical therapy on wound healing and quality of life in patients with venous leg ulcers: a systematic review.

Patients with venous leg ulcers (VLUs) have calf muscle pump dysfunction, which is associated with reduced ankle range of motion (ROM). Physical therapy or exercise that targets ankle joint mobility may lead to improvement in calf muscle pump function and subsequent healing. However, little is known regarding the effect of physical therapy or exercise on healing and quality of life (QOL), which is impaired in patients with VLUs. To systematically review the current literature on the effect of physical therapy on healing and QOL outcomes in patients with VLUs and to identify research gaps that warrant further investigation. PubMed (MEDLINE), CINAHL, and Cochrane databases were searched in April 2014. We found 10 articles, consisting of randomized clinical trials and single-arm cohort studies with small sample sizes, that used physical therapy or exercise for patients with open or healed VLUs. Although there is evidence that exercise strengthens the calf muscle pump and improves ankle ROM, few studies have investigated the effect of these interventions on QOL and healing, and few involved the supervision of a physical therapist. The lack of evidence and randomized clinical trials suggests the need for further investigation on physical therapy-oriented exercise on wound healing and QOL. In addition, more studies are needed to investigate sustainability of the increased ankle ROM after physical therapy has ended or if VLU reoccurrences are prevented.