Calf Muscle Pump Research Articles

Abstract 337: Measurements of Calf Muscle Oxygenation During Standing and Exercise in Patients with Chronic Venous Insufficiency

BACKGROUND Despite the established role of the calf muscle pump for preventing chronic venous insufficiency (CVI), hemoglobin flow in the calf muscle is poorly understood. Near-infrared spectroscopy (NIRS) provides continuous noninvasive monitoring of changes in tissue oxyhemoglobin (O2Hb) and deoxyhemoglobin (HHb) levels. The purpose of this study was to investigate the changes in calf muscle HbO2 and HHb levels during standing and exercise in patients with CVI. METHODS Seventy-four limbs in 73 patients with various clinical stages of CVI were enrolled. Patients were divided into early (C0-C3) and advanced (C4a-C6) according to the CEAP classification. NIRS was used to measure changes in the calf muscle HbO2 and HHb levels, and oxygenation index (HbD; HbD=O2Hb-HHb) while lying spine, standing, and then subsequently performing 10 tiptoe movements. RESULTS Among the 74 limbs evaluated, 47 had early and 27 had advanced CVI. Standing caused increases in both O2Hb and HHb levels. However, there were no significant differences in these increases, or HbD, between early and advanced CVI. In contrast, the time elapsed until the maximum increase in O2Hb concentration was significantly reduced in patients with advanced CVI in comparison with patients showing early CVI (55.5 ± 44.2, 32.6 ± 12.6 s, P=.025). During 10 tiptoe movements, a decrease in O2Hb concentration was observed, and there was no significant difference in the reduction of O2Hb values between early and advanced CVI. In contrast, 10 tiptoe movements produced venous emptying (HHbE) and subsequent retention (HHbR), and the HHbR was significantly increased in patients with advanced CVI compared with those with early CVI (6.0 ± 7.0, 9.0 ± 6.2 μmol/L, P=0.021). Furthermore, HbD falls were more pronounced in patients with advanced CVI (7.4 ± 11.5, -5.9 ± 15.7 μmol/L, P=0.002). CONCLUSIONS Changes in O2Hb and HHb concentrations differ between early and advanced CVI during standing and exercise. Detailed investigation of the interrelationship between O2Hb and HHb during calf muscle pump function would lead to a better understanding of the various clinical stages of CVI.

On the existence of helical flow in veins of the lower extremities.

Helical flow has been shown to be present in the heart and arteries, but its existence in veins has not been demonstrated before. This study aimed to investigate ifhelical flow ispresent in the venous system and if the venous valves contribute to development of this flow pattern. Color and spectral Doppler were used to calculate the true velocity vectors at five cross-sectional planes of the femoral and common femoral veins in 10 healthy individuals and eight patients with chronic venous disease. This study demonstrated that helical flow is a normal finding in the segments of veins that are in close proximity and downstream from a venous valve and a venous junction. This flow pattern is more prevalent when the calf muscle pump is active. Incompetenceof theproximal great saphenous vein affects the outflow pattern, so that the helical flowis nolonger present and is replaced by disorganized turbulentflow. These findings suggest that helical flow is detectable, may have a physiological role in venous circulation, and the absence of it may be a feature of venous disease.

Calf pump activity influencing venous hemodynamics in the lower extremity.

Calf muscle pump is the motive force enhancing return of venous blood from the lower extremity to the heart. It causes displacement of venous blood in both vertical and horizontal directions, generates ambulatory pressure gradient between thigh and lower leg veins, and bidirectional streaming within calf perforators. Ambulatory pressure gradient triggers venous reflux in incompetent veins, which induces ambulatory venous hypertension in the lower leg and foot. Bidirectional flow in calf perforators enables quick pressure equalization between deep and superficial veins of the lower leg; the outward (into the superficial veins) oriented component of the bidirectional flow taking place during calf muscle contraction is no pathological reflux but a physiological centripetal flow streaming via great saphenous vein into the femoral vein. Calf perforators are communicating channels between both systems making them conjoined vessels; they are not involved in the generation of pathological hemodynamic situations, nor do they cause ambulatory venous hypertension. The real cause why recurrences develop has not as yet been cleared. Pressure gradient arising during calf pump activity between the femoral vein and the saphenous remnant after abolition of saphenous reflux triggers biophysical and biochemical events, which might induce recurrence. Thus, abolition of saphenous reflux removes the hemodynamic disturbance, but at the same time it generates precondition for reflux recurrence and for the comeback of the previous pathological situation; this chain of events has been called hemodynamic paradox.

Effect of gaiters on muscle pump activity in healthy volunteers

Exercise of the leg with external limb compression has been reported to be useful for preventing and reducing leg oedema. The aim of this study was to investigate the effects of leg gaiters on calf muscle pump activity. Continuous measurements of the interface pressure at the leg during exercise and determination of the femoral venous velocity at the groin during exercise were carried out in healthy volunteers with elastic stockings alone, leg gaiters alone and gaiters over the elastic stockings. The greatest pressure difference between muscle contraction and relaxation during exercise was observed when gaiters were applied over the elastic stockings at the calf. Gaiters alone without elastic stockings led to a significantly greater pressure difference between muscle contraction and relaxation during exercise than elastic stockings alone (P < 0.01). A significantly higher value of the peak flow velocity of the femoral vein was observed with the combined use of gaiters and elastic stockings than the single use of elastic stockings. Leg gaiters have a beneficial effect of augmenting venous femoral blood flow during calf muscle pump activity in volunteers with a normal valve function of leg veins.

Analysis of sub-bandage pressure of compression bandages during exercise

The sub-bandage pressure produced by any compression bandaging system is likely to vary during the physical activities taken by the patient. It is of significant importance to understand the variation of sub-bandage pressure during the exercise of calf muscle pump. The present paper aims to analyse the dominating factors and their interactions on the sub-bandage pressure during exercise. In this work the circumferential change of the leg because of the exercise of the calf muscle pump (expansion or contraction) is simulated using expansion or contraction actions of an air bladder placed on a mannequin. The study has been carried out using an indigenously developed prototype by pumping or squeezing of air in air bladder using cylinder–piston arrangement. A series of commercially available bandages were studied and the impact of the major factors, namely bandage extensibility (E), bandage tension (T) and the amount of bladder expansion or contraction (A) on the sub-bandage pressure during one cycle of expansion or contraction of air bladder have been analysed. Different levels of the factors have been chosen and a complete factorial design was prepared to obtain the sub-bandage pressure at all combination of the levels of the factors. The results showed that the sub-bandage pressure variations were higher for short-stretch bandage under dynamic mode (p value < 0.05). The variation in sub-bandage pressure were increased by increasing the amount of expansion or contraction of the air bladder and also increased when the bandage was wrapped at higher tension level (p-value < 0.05). N-way ANOVA results showed that some of the interactions effects of these above factors (EA and AT) also significantly affecting the sub-bandage pressure variations (p-value < 0.05). The prototype provides a simpler method to assess the bandage behaviour under different conditions without doing in vivo sub-bandage pressure measurement, and hence could be used to evaluate and compare the effectiveness of different compression bandage under different conditions, prior to their application on the wounded leg.

A home‐based progressive resistance exercise programme for patients with venous leg ulcers: a feasibility study

This study aimed to assess the feasibility of a home-based exercise programme and examine the effects on the healing rates of venous leg ulcers. A 12-week randomised controlled trial was conducted investigating the effects of an exercise intervention compared to a usual care group. Participants in both groups (n = 13) had active venous ulceration and were treated in a metropolitan hospital outpatients clinic in Australia. Data were collected on recruitment from medical records, clinical assessment and questionnaires. Follow-up data on progress in healing and treatments were collected fortnightly for 12 weeks. Calf muscle pump function data were collected at baseline and 12 weeks from recruitment. Range of ankle motion data were collected at baseline, 6 and 12 weeks from recruitment. This pilot study indicated that the intervention was feasible. Clinical significance was observed in the intervention group with a 32% greater decrease in ulcer size (P = 0·34) than the usual care group, and a 10% (P = 0·74) improvement in the number of participants healed in the intervention group compared to the usual care group. Significant differences between groups over time were observed in calf muscle pump function parameters [ejection fraction (P = 0·05), residual volume fraction (P = 0·04)] and range of ankle motion (P = 0·01). This pilot study is one of the first to examine and measure clinical healing rates for participants involved in a home-based progressive resistance exercise programme. Further research is warranted with a larger multi-site study.

What's New in Veins?

Reflux cannot be interpreted without knowledge of the function of the calf muscle pump. The presence or absence of reflux alone has an insufficient predictive value for excellent functional treatment results. Valves are not simple moving slips but have an autonomous 4-step cycle movement that helps the calf muscle pump to be very effective. New calculations of the Starling equilibrium have shown that capillary filtration fraction returns mainly by the lymphatics. All these new findings help the phlebologist design a more precise and thus better treatment plan in phlebology practice.

Predictors of the post-thrombotic syndrome with non-invasive venous examinations in patients 6 weeks after a first episode of deep vein thrombosis.

Post-thrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) affecting a large number of patients. Because of its potential debilitating effects, identification of patients at high risk for the development of this syndrome is relevant, and only a few predictors are known. To assess the incidence and potential predictors of PTS. We prospectively followed 111 consecutive patients for 2 years after a first episode of objectively documented DVT of the leg. With non-invasive venous examinations, residual thrombosis, valvular reflux, calf muscle pump function and venous outflow resistance were assessed at 6 weeks, 3 months, 6 months, 1 year, and 2 years. The Clinical, Etiologic, Anatomic, and Pathophysiologi classification was used to record the occurrence and severity of PTS. Regression analysis with area under the receiver operating characteristic (ROC) curve was performed to identify potential predictors. The cumulative incidence of PTS was 46% after 3 months, and the incidence and severity did not increase further. Men appeared to be at increased risk as compared with women (risk ratio [RR] 1.4, 95% confidence interval [CI] 0.9-2.2), as were patients over 50 years as compared with younger patients (RR 1.4%, 95% CI 0.9-2.1). Patients with thrombosis localized in the proximal veins at diagnosis had an increased risk of PTS as compared with patients with distal thrombosis (RR 2.3%, 95% CI 1.0-5.6). PTS developed in 32 of 52 patients (62%) with residual thrombosis in the proximal veins 6 weeks after diagnosis, as compared with 17 of 45 patients (38%) without residual proximal thrombosis, leading to a 1.6-fold increased risk (95% CI 1.0-2.5). The presence of valvular reflux in the superficial veins was also a predictor at 6 weeks, with a 1.6-fold increased risk as compared with patients without superficial reflux (95% CI 1.1-2.3). A multivariate analysis of these predictors yielded an area under the ROC curve of 0.72 (95% CI 0.62-0.82). PTS develops in half of all patients within 3 months, with no further increase being seen up to 2 years of follow-up. Male sex, age over 50 years, proximal localization of the thrombus at entry, residual proximal thrombosis and superficial valvular reflux at 6 weeks seem to be the most important predictors of PTS in patients with a first episode of DVT. Duplex scanning 6 weeks after diagnosis appears to be clinically useful for the identification of patients at risk of PTS.

Embedding gesture recognition into airplane seats for in-flight entertainment

In order to reduce both psychological and physical stress in air travel, sensors are integrated into airplane seats to detect gestures as input for in-flight entertainment systems. The content provided by the entertainment systems helps to reduce psychological stress, and gesture recognition is used as input for the content. The use of this system thus also stimulates passengers in limited seating space to make movements that would result in the reduction of physical stress. Preliminary user evaluation shows that users of the concept have significantly more active calf muscle pump activity in comparison with current situations and that users feel more active and less fatigued after a long period of sitting in the same position.

Epidemiology and aetiology of C4–6 disease

Although our understanding of chronic venous insufficiency (CVI) has improved, many important questions remain unanswered. Ensuring that patients are appropriately referred for specialist assessment and then receive evidence-based, cost-effective treatment continues to be challenging. The lifetime of risk of chronic venous ulceration (CVU) is around 1% with approximately 10% ulcers being open at any one time. The incidence skin changes disease is about 10 times greater (10%). However, many of the studies upon which these estimates are based are old and/or methodologically flawed. There is reason to believe that the incidence, prevalence and characteristics of CVI/CVU may have changed considerably over the last 10-20 years and that future change is likely. Further cross-sectional and longitudinal epidemiological studies are required to establish the size and nature of the health-care need going forward in developed and increasingly developing countries. CVI culminating CVU is primarily the result of sustained ambulatory venous hypertension, which in turn arises from superficial and/or deep venous reflux with or without deep vein obstruction. However, there are many other elements to this complex condition, for example, microvascular dysfunction; calf muscle pump efficiency; dermal inflammation; disordered fibroblast function and matrix production; failure of epithelialization; congenital and acquired thrombophilia; malnutrition, obesity and diet; and bacterial colonization. None of the currently available treatment modalities is entirely satisfactory and novel therapies based upon a clearer understanding of the disease at the psychological, genetic, mechanical, microvascular and microscopic level are required.

The Efficacy of a New Stimulation Technology to Increase Venous Flow and Prevent Venous Stasis

Objectives Electrical stimulation of calf muscles has been shown to be effective in prevention of DVT. The aim was to determine: (a) dependence of venous blood velocity and ejected volume on the rates of stimulated calf contractions: (b) clinical factors affecting efficacy in healthy individuals. Methods The maximum intensity stimulus tolerated was applied to calfs of 24 volunteers. In popliteal veins, Peak Systolic Velocities (PSV), ejected volume per individual stimulus (Stroke Volume SV) and ejected Total Volume Flow per minute (TVF) of expelled blood were determined using ultrasound. Stimulation rates from 2 to 120 Beats Per Minute (bpm) were applied. Results Mean baseline popliteal PSV was 10 cm/s. For stimulation rates between 2 and 8 bpm, the PSV was 10 times higher and reached 96–105 cm/s. Stroke volume (SV) per individual stimulus decreased in a similar fashion. With increasing rates of stimulation the TVF increased by a factor of 12 times (from 20 ml/min to 240 ml/min). Conclusion Electrical stimulation is an effective method of activating the calf muscle pump. Enhancements of popliteal blood velocity and volume flow are key factors in the prevention of venous stasis and DVT. Further studies are justified to determine the stimulation rates in those with a compromised venous system.

Bioimpedance spectroscopy in haemodynamic analysis

Venous insufficiency is estimated to affect between 10% and 35% of the population in the US with symptoms ranging from mild discomfort to chronic ulceration which may reduce quality of life. Early diagnosis is the key to pre-emptive treatment. We have previously reported [5] an impedance technique for measurement of calf muscle pump function although it was noted that the results could be confounded by change in limb geometry during the exercise protocol. We report here a modified protocol to account for change in limb geometry. Impedance of a 20 cm segment of the calf was continuously recorded using an SFB7 bioimpedance spectrometer whilst subjects performed a sequence of manoeuvres: a) supine with leg raised (for 10 min); b) standing (4 s); c) plantar flexion (tiptoe, 4 s); d) standing elevated on one leg removing tension on the measured leg with the foot horizontal (4 s); e) with the leg relaxed (4 s) and then the sequence repeated. The impedance ratio, k = (e-d)/(c-b), was the proportion of the impedance change, occurring during calf muscle pumping, due primarily to change in limb shape only, i.e. independent of the impedance change due to ejection of blood as a function of calf muscle pump action. Thus (1-k) can be used to correct the ejection fraction (%) calculated as (c-b)/(a-b)*100 for the confounding effect of change in limb geometry. Ejection fractions calculated by this method in 10 control subjects were 51.5 ± 30.1% with no values greater than 100% as found previously.

A pilot evaluation of a neuromuscular electrical stimulation (NMES) based methodology for the prevention of venous stasis during bed rest

Bed rest poses an increased risk factor for a potentially fatal venous thromboembolism (VTE). Lack of activation of the calf muscle pump during this resting period gives rise to venous stasis which may lead to deep vein thrombosis (DVT) development. Our aim was to investigate the effects that 4 h of bed rest have on the lower limb hemodynamics of healthy subjects and to what extent electrically elicited contractions of the calf muscles can alleviate these effects. Outcome variables included popliteal vein blood flow and heart rate. Primary results indicated that the resting group experienced a significant decline in popliteal venous blood flow of ∼47% with ∼13% decrease in heart rate. The stimulated groups maintained a significantly higher venous blood flow and heart rate. Volume flow in the contralateral limb remained constant throughout the study and was comparable to that of the stimulated limb's recovery flow. The results suggest that even short periods of bed rest can significantly reduce lower limb blood flow which could have implications for DVT development. Electrically elicited calf muscle contractions significantly improve lower limb blood flow and can alleviate some debilitating effects of bed rest.

Prevention of Venous Stasis in the Lower Limb by Transcutaneous Electrical Nerve Stimulation

Objectives This study aims to investigate the effects of thromboprophylactic transcutaneous electrical nerve stimulation (TpTENS) of the peroneal nerve on venous blood flow in the limbs of volunteers. TpTENS might be considered for use in preventing venous stasis during surgical treatment. Methods In 10 volunteers, peak venous velocity (PV) and flow volume (FV) in the popliteal vein were measured using duplex ultrasonography during calf-muscle stimulation. The effects of TpTENS of the peroneal nerve were compared with those of other mechanical methods, including electrical muscle stimulation, intermittent pneumatic compression, active ankle motion and calf squeeze, used to prevent venous stasis and achieve thromboprophylaxis. Results TpTENS had similar effects on popliteal vein blood flow in comparison with other established methods of thromboprophylaxis. The PV increased its basal flow by 3.9 times ( p < 0.01) and FV by 2.7 times ( p < 0.01), respectively, compared with baseline values. Conclusions TpTENS is as effective as other electrical and mechanical methods of calf-muscle pump activation in achieving acceleration of venous flow in the lower limb.

The PREPARE pilot RCT of home-based progressive resistance exercises for venous leg ulcers

To establish the feasibility of conducting a home-based progressive resistance exercise programme to improve calf muscle pump function in community-based patients with venous leg ulcers. Participants were randomised to receive a 12-week progressive resistance exercise programme using heel raises in addition to compression. The control was usual care in addition to compression. Randomisation was stratified by ulcer duration and ulcer size. Air plethysmography was used to determine changes in calf muscle pump function from baseline. Changes in ulcer parameters were measured using the SilhouetteMobile device. Forty participants were randomised. There were significantly greater improvements in ejection fraction of the calf muscle in the exercise group compared with the control (usual care) group (mean difference 18.5%, 95% CI 0.03 to 36.6%, p<0.05). Other parameters improved in the exercise group but the mean differences were not significant. Adherence with prescribed exercises was 81% and there was no significant difference in the numbers reporting adverse events. There were also no significant differences in ulcer healing parameters (change in area, percentage change in area, number healed at 12 weeks, time to healing). A community-based randomised trial of progressive resistance exercise is feasible. The prescribed exercises appeared to increase ejection fraction, but the effect of exercise on ulcer healing requires further investigation.

Feasibility of treatment of lower limb edema with calf muscle pump stimulation in chronic heart failure

Persons with chronic heart failure may exhibit a decrease in functional ability related to lower extremity edema in spite of optimal diuretic therapy and salt restrictions. The aim of this pilot prospective clinical study was to test the feasibility of using exogenous calf muscle pump stimulation to decrease lower leg edema and thus improve functional status and quality of life. Six subjects entered into this study and agreed to use the intervention 30 min/day for one month. DXA was used to assess lower extremity composition. Device use averaged approximately 1 h/day and resulted in a reduction in the lean mass of the legs of 0.5 kg (range = 0.08-1.0 L; p = 0.03). Linear regression analysis of reduction of lower limb edema against daily usage suggests that increased utilization of calf muscle pump stimulation was associated with increased water losses, although this trend was not significant (R(2 = 0.4, p = 0.18). This pilot indicates that exogenous calf muscle pump stimulation could be a useful and safe addition to the patients' treatment regimes, but further studies testing a more typical population with heart failure is warranted.

Impeded venous drainage: Novel view of chronic venous disease pathophysiology

Venous valve incompetence role as the primary pathology occurring in patients with chronic venous diseases (CVD) has long been exaggerated. Management strategies based on the current pathophysiological concepts are far from perfect. A novel concept is introduced describing the importance of patency of axial venous system with "Pressure gradient model" providing the venous system architecture required for efficient venous drainage. The roles of calf muscle pump, perforators and venous valves according to the novel concept are described. Impeded venous drainage (IVD) plays the key role in the pathophysiology of CVD. Management of CVD should be directed to correction of IVD instead of correction or ablation of valve incompetence.

Risk factors for chronic ulceration in patients with varicose veins: A case control study

Identifying which patients with varicose veins are at risk of progressing to more severe forms of chronic venous disease could help in assigning clinical priorities and targeting appropriate treatments. The aim of this study was to determine, in subjects with varicose veins, the characteristics of venous disease and other factors associated with an increased risk of ulceration. One hundred twenty subjects with varicose veins and an open or healed venous leg ulcer were compared with 120 controls with varicose veins and no history of venous ulcer on this case control study. Subjects were recruited from hospital settings and primary care. Each subject completed a questionnaire on lifestyle and medical history and underwent an examination comprising of clinical classification of venous disease (CEAP), duplex scanning, quantitative digital photoplethysmography, and measurement of dorsiflexion. Multiple logistic regression analyses and calculation of receiver operating characteristic (ROC) curves were performed to identify the combination of factors which most accurately predicted which patients with varicose veins will develop leg ulcers. An increased risk of ulceration was associated with the severity of clinical venous disease, especially with the presence of skin changes (P < .0001). Other significant risk factors included history of deep vein thrombosis (DVT) (P = .001), higher body mass index (BMI) (P = .006), smoking (P = .009), and reflux in the deep veins (P = .0001). Ulceration was associated with reduced volume of blood displaced as reflected by photoplethysmography and a limited range of ankle movement (not wholly due to the effects of an active ulcer) (both P < .05). Multivariate analyses showed that skin changes including lipodermatosclerosis (odds ratio [OR] 8.90, 95% confidence interval [CI] 1.44-54.8), corona phlebectatica (OR 4.52, 95% CI 1.81-11.3) and eczema (OR 2.87, 95% CI 1.12-7.07), higher BMI (OR 1.08, 95% CI 1.01-1.15), and popliteal vein reflux (OR 2.82, 95% CI 1.03-7.75) remained independently associated with increased risk of ulceration while good dorsiflexion of the ankle (OR 0.88, 95% CI 0.81-0.97) and an effective calf muscle pump (OR 0.96, 95% CI 0.92-0.99) remained protective factors. ROC curve analyses indicated that a model based on clinical observation of skin changes, duplex scanning for popliteal reflux, and calf muscle pump tests would be the most accurate in determining which patients with varicose veins develop leg ulcers. The results of this study confirm that, in patients with varicose veins, those with skin changes of chronic venous insufficiency and deep vein incompetence are at greatly increased risk of ulceration. However, the risks may also be increased in those who smoke, are obese, and have restricted ankle movement and reduced calf muscle pump power.

Severity of chronic venous disorders and its relationship to the calf muscle pump

To investigate the relationship between the calf muscle pump and the clinical severity of chronic venous disorders (CVD) and of venous function parameters. 84 limbs in 44 patients underwent duplex scan and digital photoplethysmography (DPPG), the range of ankle movement was measured by digital goniometry and strength of calf muscles was determined by dynamometry. Limbs were allocated on the basis of clinical signs of CVD (according to the CEAP classification) into 4 groups: controls (no signs and symptoms of CVD): 34 limbs, C1/2: 24 limbs, C3/4: 16 limbs, C6: 10 limbs. A higher degree in clinical severity of CVD was related to shorter venous refilltime (VRT) and lower venous pump power (VPP) measured by DPPG. The strength of dorsiflexion was significantly reduced in group C6 compared to controls. There was a positive correlation between measurements of DPPG and the strength of dorsiflexion and also with total strength (p < 0.05). In limbs with pathological reflux (> 1 s) the strength of dorsiflexion, range of ankle plantarflexion movement and total range of ankle movement were significantly reduced compared to those without pathological reflux (p < 0,05). Strength of plantarflexion was significantly reduced in group C1/2 compared to control group (p < 0,05). Strength of dorsiflexion seems to be the main driving factor of normal venous flow and range of ankle movement is impaired in patients with pathological venous reflux. Further prospective studies should clarify if additional strengthening of ankle dorsiflexors should be included in well established venous training programs.

The Effect Of Compression Socks On Recovery After A 30-sec Wingate Test

Compression socks appear to work by reducing venous pooling and improving deeper tissue oxygenation, and may also increase the ejection fraction of the calf muscle pump thereby possibly increasing circulation. Increasing the venous circulation may facilitate an increase in metabolic waste clearance. No research has been conducted on the effects of compression socks during recovery after exercise. PURPOSE: To examine heart rate (HR), oxygen consumption (VO2), perceived exertion (RPE) and lactate clearance after a 30-sec Wingate test. METHODS: A Polar HR transmitter interfaced with a True One 2400 (ParvoMedics) metabolic analyzer and a Borg's 6-20 scale was used to collect HR, VO2, RER and RPE of 17 subjects (28.6±9.0 yrs, 175.2±7.3 cm, 73.3±8.0 kg, 18.7±7.4 %BF, 44.7±9.6 ml·kg·min-1 VO2max) immediately after the Wingate test and 3, 6, and 10 min after, while cycling at 35% VO2max. An Accutrend lactate analyzer was used to determine venous blood lactate at these same time points. Participants served as their own controls in this counter balanced design, once with and once without the knee-high graduated compression sock (OxySocks: 18-22 mmHg). RESULTS: RMANOVA revealed no significant differences between the trials in any of the variables, p>.05 (Table 1). A paired t-test did not reveal a significant difference in total work without (16349.7±323 Joules) and with (15969.8±329 Joules) the sock.Table 1: Physiological and perceptual responses with and without compression socks after a 30-sec Wingate testCONCLUSIONS: This study does not provide evidence that compression socks effect physiological or perceptual variables during recovery after a 30-sec Wingate test.