Introduction: Venous disease impairs the quality of life, necessitates time off work and causes venous ulcers. The focus of this thesis is to explore strategies to prevent chronic venous insufficiency (CVI) and venous ulceration. Aims 1. To identify a population at risk of developing venous ulcers 2. To study the pressure profile required by elastic stockings to halve transit venous time 3. To explore the role of compression following ankle fracture Methods: Data was collected from 231 patients with venous ulcers and age and sex matched 210 controls to identify risk factors for venous ulceration. Univariate and multivariate analysis of potential risk factors was undertaken to identify those that independently predict this risk. After identifying the population at risk, prophylactic strategies were developed. The effect of Engineered Compression Stockings (ECS) delivering 15mmHg, 25mmHg and 35mmHg pressure at the ankle on the calf venous transit time and volume was measured to determine the ideal pressure profile required to halve transit venous time, which should be appropriate for DVT prophylaxis. A dorsal foot vein was cannulated in 15 healthy volunteers with no venous disease. The transit time (secs) for ultrasound contrast from a foot vein to the popliteal vein was measured using duplex ultrasound. Calf volumes were recorded by water displacement. ECS delivering 25mmHg of pressure around the ankle were compared with no compression in a randomized controlled trial (RCT) in 90 patients within 72 hours of ankle fracture. Patients were randomised to either i) ECS and air-cast boot or ii) a liner and air-cast boot and were followed at 2, 4, 8, 12 weeks and 6 months. The primary outcome was functional recovery measured using the Olerud Molander Ankle Score (OMAS). Secondary outcomes were i) The American Orthopaedic Foot and Ankle Score (AOFAS), ii) SF12v2 Quality of Life score (QoL), iii) pain, and iv) frequency of DVT. Results The risk factors significantly associated with venous ulceration on multivariate analysis included a history of Deep Vein Thrombosis (DVT), phlebitis, hip replacement, poor mobility, weight/kg>100Kg, varicose veins (VV), family history of VV and weight (kg) between 75-100kg. A simple diagnostic scoring system was derived from this regression analysis with scores of . 3 predicting a 6.7% annual risk and of < 1 a 0.6% risk. Mean transit time without compression was 35, 32 and 33 secs while standing, sitting and lying. Transit time was consistently halved by ECS delivering 25mmHg to 14, 13 and 14 secs respectively (p<0.001). Mean leg volume whilst standing was reduced significantly from 3447ml with no ECS to 3259ml, 3161ml and 3067ml with ECS applying 15, 25 and 35mmHg respectively (p<0.001). ECS in ankle fracture patients reduced ankle swelling at all time points and significantly improved mean OMAS score at six months to 98 compared with 67 for the liner (p<0.001). AOFAS and SF12v2 scores were also significantly improved (p<0.001, p= 0.016). Of 86 patients with duplex imaging at four weeks, only five (12%) of the 43 ECS patients had a DVT compared with 10 (23%) of the 43 controls (p= 0.26). Conclusions: The risk score for venous ulcers will allow us to undertake RCTs on the prevention of leg ulceration. The pressure profile required to halve transit venous time is 25mmHg. The frequency of asymptomatic DVT following ankle fracture is sufficient to justify prophylaxis. Compression has a potential role in the management of ankle fractures by improving functional outcome and QoL. These studies facilitate research into the prevention of venous disease.

RESUMO Castilho Junior, O T. Avaliaço do efeito da meia elástica na hemodinâmica venosa dos membros inferiores de corredores. 2015. 71f. Dissertação (Mestrado) - Faculdade de Medicina Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto - SP. Introdução: A literatura médica a respeito da eficácia e dos benefícios do uso de meias elásticas de compressão graduada (MECG) na corrida é controversa e inconclusiva. Objetivo: O objetivo foi verificar as alterações da hemodinâmica venosa dos MMII pela pletismografia a ar (PGA) , do lactato sanguíneo e da resposta clínica provocadas pela corrida em atletas amadores saudáveis sem e com o uso de MECG. População e Método: Dez atletas (4 homens e 6 mulheres), corredores voluntários, com idade média 40,3 anos, índice de massa corporal (IMC) médio de 21,88, foram submetidos a avaliações de parâmetros hemodinâmicos venosos por meio da PGA (IEV-índice de enchimento venoso; FE-fraço de ejeção e FVR-fração de volume residual), dosagem de lactato capilar e avaliação clínica (frequência cardíaca, dor e conforto nos MMII) em 3 situações: em repouso (antes da corrida); logo depois de uma corrida de 10 km em esteira com inclinação de 1% sem o uso de MECG e uma semana após com o uso de MECG. Todas as variáveis foram analisadas estatisticamente e considerou-se 5% o nível de significância. Resultado: Após a corrida houve elevação significativa dos valores de IEV dos MMII no grupo sem em relação ao grupo com MECG e em repouso. Houve queda significativa da FVR do membro inferior direito no grupo com MECG em relação aos grupos em repouso e sem meia elástica, o que não ocorreu no membro inferior esquerdo. A FE foi semelhante em todas as situações. O lactato elevou-se no final da corrida no grupo sem MECG e notou-se tendência a elevação no grupo com MECG, mas a diferença inicial e final do lactato nas duas situações permaneceu semelhante. As manifestações clínicas (frequência cardíaca , dor, conforto e lesões) foram semelhantes em todas as situações após a corrida sem e com MECG. Conclusão: Apesar de inalteradas as manifestações clínicas ( frequência cardíaca, dor e desconforto) e dos níveis de lactato de corredores amadores, sadios, após a corrida de 10km com inclinação de 1%, o uso de MECG teve efeitos positivos na hemodinâmica venosa dos MMII, aferidos pela PGA e caracterizados pela redução do IEV em ambos os membros e pela queda da FVR, pelo menos no membro inferior direito. / Background: The literature about the efficacy and the benefits of wearing compression stockings (CS) in running is controverse and inconclusive. Objective: The objective was to verify the changes of venous hemodynamic parameters of the lower limbs measured by air pletismography (APG), of the capillary lactate and of some clinical aspects promoted by running in normal healthy runners wearing or not compression stockings. Methods: Ten volunteer runners (4 men, 6 women), mean age 40,3 years, mean corporal mass index of 21,88, were submitted to evaluation the hemodynamic parameters measured by APG (venous filling index VFI; ejection fraction EF and residual venous fraction - RVF), measurement of capillary lactate and clinical aspects (cardiac frequency, pain, comfort and lesions) in 3 situations: at rest (before running); after a 10 Km running on a treadmill with 1% inclination degree without CS and a week later, after the same running wearing compression stockings. All variables were statistically analised and it was considered 5% as the significance level. Results: After running there was significant elevation of the VFI in the group without CS compared to the groups at rest and with CS. There was also a meaning descent of the RVF levels of the right lower limb of the volunteers wearing CS compared to those without CS and at rest, but this was not noticed on the left lower limb. The EF was the same in all situations. The lactate levels increased after running without CS and there was a tendency of elevation with the use of CS, but the initial and final differences in both situations remained the same. The clinical aspects (cardiac frequency, pain, comfort and lesions) were similar after running with or without CS. Conclusion: Although there were no changes of the clinical aspects (cardiac frequency, pain, comfort and lesions) and the lactate levels of healthy amateur runners after a 10 Km running on a treadmill with a 1% elevation degree, APG showed that the use of CS promoted beneficial effects on venous hemodynamics of the lower limbs, featured by the fall of the VFI levels on both lower limbs and the fall of the RVF levels on the right lower limbs.

Obstructive sleep apnea (OSA) severity is strongly associated with the degree of overnight peripharyngeal fluid accumulation. We hypothesized that intravenous fluid loading would cause upper airway (UA) narrowing or increase the frequency of apneas and hypopneas per hour of sleep (apnea-hypopnea index; AHI). We employed a controlled, randomized double-crossover experiment in 9 healthy men aged 23-46 years. In the control, subjects were administered approximately 80 ml of normal saline intravenously during sleep. In the intervention, subjects were administered approximately 1850 ml of saline during sleep while wearing compression stockings to localize fluid rostrally. The intervention induced nuchal fluid accumulation, resulting in an increase in neck circumference (+0.1 cm during control, +0.6 cm during intervention, P< 0.01 ) and a decrease in UA cross-sectional area (-0.08 cm2 during control, -0.43 cm2 during intervention, P = 0.023). Although the intervention did not increase the AHI (control AHI = 19.5, intervention AHI = 30.3, P = 0.249), the AHI during the intervention correlated with age (r = 0.8, P < 0.01). Thus, intravenous saline loading during sleep can narrow the UA, which in older men may induce or worsen OSA. Further studies are needed to test this hypothesis.

Obstructive sleep apnea (OSA) severity is strongly associated with the degree of overnight peripharyngeal fluid accumulation. We hypothesized that intravenous fluid loading would cause upper airway (UA) narrowing or increase the frequency of apneas and hypopneas per hour of sleep (apnea-hypopnea index; AHI). We employed a controlled, randomized double-crossover experiment in 9 healthy men aged 23-46 years. In the control, subjects were administered approximately 80 ml of normal saline intravenously during sleep. In the intervention, subjects were administered approximately 1850 ml of saline during sleep while wearing compression stockings to localize fluid rostrally. The intervention induced nuchal fluid accumulation, resulting in an increase in neck circumference (+0.1 cm during control, +0.6 cm during intervention, P< 0.01 ) and a decrease in UA cross-sectional area (-0.08 cm2 during control, -0.43 cm2 during intervention, P = 0.023). Although the intervention did not increase the AHI (control AHI = 19.5, intervention AHI = 30.3, P = 0.249), the AHI during the intervention correlated with age (r = 0.8, P < 0.01). Thus, intravenous saline loading during sleep can narrow the UA, which in older men may induce or worsen OSA. Further studies are needed to test this hypothesis.

RESUMO Castilho Junior, O T. Avaliaço do efeito da meia elástica na hemodinâmica venosa dos membros inferiores de corredores. 2015. 71f. Dissertação (Mestrado) - Faculdade de Medicina Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto - SP. Introdução: A literatura médica a respeito da eficácia e dos benefícios do uso de meias elásticas de compressão graduada (MECG) na corrida é controversa e inconclusiva. Objetivo: O objetivo foi verificar as alterações da hemodinâmica venosa dos MMII pela pletismografia a ar (PGA) , do lactato sanguíneo e da resposta clínica provocadas pela corrida em atletas amadores saudáveis sem e com o uso de MECG. População e Método: Dez atletas (4 homens e 6 mulheres), corredores voluntários, com idade média 40,3 anos, índice de massa corporal (IMC) médio de 21,88, foram submetidos a avaliações de parâmetros hemodinâmicos venosos por meio da PGA (IEV-índice de enchimento venoso; FE-fraço de ejeção e FVR-fração de volume residual), dosagem de lactato capilar e avaliação clínica (frequência cardíaca, dor e conforto nos MMII) em 3 situações: em repouso (antes da corrida); logo depois de uma corrida de 10 km em esteira com inclinação de 1% sem o uso de MECG e uma semana após com o uso de MECG. Todas as variáveis foram analisadas estatisticamente e considerou-se 5% o nível de significância. Resultado: Após a corrida houve elevação significativa dos valores de IEV dos MMII no grupo sem em relação ao grupo com MECG e em repouso. Houve queda significativa da FVR do membro inferior direito no grupo com MECG em relação aos grupos em repouso e sem meia elástica, o que não ocorreu no membro inferior esquerdo. A FE foi semelhante em todas as situações. O lactato elevou-se no final da corrida no grupo sem MECG e notou-se tendência a elevação no grupo com MECG, mas a diferença inicial e final do lactato nas duas situações permaneceu semelhante. As manifestações clínicas (frequência cardíaca , dor, conforto e lesões) foram semelhantes em todas as situações após a corrida sem e com MECG. Conclusão: Apesar de inalteradas as manifestações clínicas ( frequência cardíaca, dor e desconforto) e dos níveis de lactato de corredores amadores, sadios, após a corrida de 10km com inclinação de 1%, o uso de MECG teve efeitos positivos na hemodinâmica venosa dos MMII, aferidos pela PGA e caracterizados pela redução do IEV em ambos os membros e pela queda da FVR, pelo menos no membro inferior direito. / Background: The literature about the efficacy and the benefits of wearing compression stockings (CS) in running is controverse and inconclusive. Objective: The objective was to verify the changes of venous hemodynamic parameters of the lower limbs measured by air pletismography (APG), of the capillary lactate and of some clinical aspects promoted by running in normal healthy runners wearing or not compression stockings. Methods: Ten volunteer runners (4 men, 6 women), mean age 40,3 years, mean corporal mass index of 21,88, were submitted to evaluation the hemodynamic parameters measured by APG (venous filling index VFI; ejection fraction EF and residual venous fraction - RVF), measurement of capillary lactate and clinical aspects (cardiac frequency, pain, comfort and lesions) in 3 situations: at rest (before running); after a 10 Km running on a treadmill with 1% inclination degree without CS and a week later, after the same running wearing compression stockings. All variables were statistically analised and it was considered 5% as the significance level. Results: After running there was significant elevation of the VFI in the group without CS compared to the groups at rest and with CS. There was also a meaning descent of the RVF levels of the right lower limb of the volunteers wearing CS compared to those without CS and at rest, but this was not noticed on the left lower limb. The EF was the same in all situations. The lactate levels increased after running without CS and there was a tendency of elevation with the use of CS, but the initial and final differences in both situations remained the same. The clinical aspects (cardiac frequency, pain, comfort and lesions) were similar after running with or without CS. Conclusion: Although there were no changes of the clinical aspects (cardiac frequency, pain, comfort and lesions) and the lactate levels of healthy amateur runners after a 10 Km running on a treadmill with a 1% elevation degree, APG showed that the use of CS promoted beneficial effects on venous hemodynamics of the lower limbs, featured by the fall of the VFI levels on both lower limbs and the fall of the RVF levels on the right lower limbs.

No / Intermittent pneumatic compression (IPC) is a mechanical method of delivering compression to swollen limbs that can be used to treat venous leg ulcers and limb swelling due to lymphoedema. This review analyses the evidence for the effectiveness of IPC as a treatment for venous leg ulcers. OBJECTIVES: To determine whether IPC increases the healing of venous leg ulcers. To determine the effects of IPC on health related quality of life of venous leg ulcer patients. SEARCH STRATEGY: We searched the Cochrane Wounds Group Specialised Register (December 2007); the Cochrane Central Register of Controlled Trials (CENTRAL) - The Cochrane Library Issue 4, 2007; Ovid MEDLINE - 2006 to November Week 2 2007; Ovid EMBASE - 2006 to 2007 Week 49 and Ovid CINAHL - 2006 to December Week 1 2007. SELECTION CRITERIA: Randomised controlled studies either comparing IPC with control (sham IPC or no IPC) or comparisons between IPC treatment regimens, in venous ulcer management were included. DATA COLLECTION AND ANALYSIS: Data extraction and assessment of study quality were undertaken by one author and checked by a second. MAIN RESULTS: Seven randomised controlled trials (including 367 people in total) were identified. Only one trial reported both allocation concealment and blinded outcome assessment. In one trial (80 people) more ulcers healed with IPC than with dressings (62% vs 28%; p=0.002). Four trials compared IPC with compression against compression alone. The first of these trials (45 people) found increased ulcer healing with IPC plus compression than with compression alone (relative risk for healing 11.4, 95% Confidence Interval 1.6 to 82). The remaining three trials (122 people) found no evidence of a benefit for IPC plus compression compared with compression alone. One small trial (16 people) found no difference between IPC (without additional compression) and compression bandages alone. One trial compared different ways of delivering IPC (104 people) and found that rapid IPC healed more ulcers than slow IPC (86% vs 61%; log rank p=0.003). AUTHORS' CONCLUSIONS: IPC may increase healing compared with no compression, but it is not clear whether it increases healing when added to treatment with bandages, or if it can be used instead of compression bandages. Rapid IPC was better than slow IPC in one trial. Further trials are required to determine whether IPC increases the healing of venous leg ulcers when used in modern practice where compression therapy is widely used.

La microcirculation est constituée d’un réseau vasculaire qui comprend les artérioles, les veinules et les capillaires. La microcirculation cutanée est un paramètre physiologique important pour les applications cliniques avancées comme le syndrome de Raynaud ou la prévention des escarres. De nombreuses méthodes non ambulatoires ont été développées afin de mesurer la microcirculation sanguine. La tendance actuelle dans le domaine des technologies pour la santé est la miniaturisation des capteurs et de leurs instrumentations associées pour les rendre non-invasifs, portables par le patient et ainsi adaptés aux mesures ambulatoires en conditions réelles, ou appelées aussi « écologiques ». Le manuscrit présente la conception et la réalisation d’un système électronique miniaturisé ambulatoire (µHématron), permettant de réaliser un monitoring continu, en temps réel de la conductivité thermique tissulaire qui est l’image de la microcirculation dans les capillaires. La première expérimentation effectuée a pour l’objectif de confronter le système µHématron avec un moniteur de fluxmétrie laser Doppler, au cours d’une étude destinée à évaluer le confort thermique chez l’homme. Ainsi, une étude d’influence de la température de différentes ambiances sur un certain nombre de paramètres de la peau de sujets sains, y compris la microcirculation cutanée, a été réalisée. Les corrélations obtenues entre les variations des deux signaux des deux instrumentations pour les ambiances neutres, chaudes et froides sont présentées. La deuxième expérimentation est consacrée à l’étude préliminaire de l’effet global des bas médicaux de compression sur la microcirculation cutanée des membres inférieurs de sujets sains. Grâce à l’instrumentation ambulatoire, la microcirculation a pu être évaluée de façon continue pour différentes postures des sujets : allongée, assise, débout et en marche, et ce, pour des différentes classes de bas de compression (I, II, et III). Cette étude a permis d’améliorer la compréhension de l’effet de ces bas sur les sujets sains. / The microcirculation consists of a vascular network that includes arterioles, venules and capillaries. Skin microcirculation is an important physiological parameter for advanced clinical applications such as Raynaud's syndrome or the prevention of ulcers. Many non-ambulatory methods were developed to measure blood microcirculation. The current trend in the field of health technology is the miniaturization of sensors and their associated instrumentation to make them non-invasive, portable by the patient and adapted to ambulatory measurements in time real, or also known as « ecological ». The manuscript presents the design and the realization of an ambulatory miniaturized electronic system (μHematron), to achieve continuous monitoring of the effective thermal conductivity in real-time that is the image of the microcirculation in the capillaries. The first experimentation was performed to compare the µHematron system with a laser Doppler flowmetry monitor, during a study which aims to evaluate thermal comfort in humans. A study of the effects of different temperature environments on a group of skin parameters of healthy subjects, including the cutaneous microcirculation, was performed. Correlations between changes in the two signals of both instrumentations for neutral, hot and cold temperatures are presented. The second experimentation is aimed to a preliminary study of the global effect of medical compression stockings on the cutaneous microcirculation of the lower extremities of healthy subjects. Thanks to the ambulatory instrumentation, the microcirculation has been measured continuously for different postures of subject: lying, sitting, standing and walking, and this for different classes of compression stockings (I, II, and III). This study has improved the understanding of the effect of these stockings on healthy subjects.

Bakgrund: Djup ventrombos (DVT) är en allvarlig komplikation postoperativt och kan leda till ett livshotande tillstånd för patienten. Graderade kompressionsstrumpor (GCS) används på många postoperativa avdelningar tillsammans med andra profylaktiska åtgärder för att förebygga utvecklingen av DVT. Kompressionsstrumpor används även till att förebygga posttrombotiskt syndrom (PTS) efter en DVT. PTS kan utvecklas på grund av att de venösa klaffarna skadas vid en DVT, till följd stockar sig blodet och ödem bildas vilket leder till försämrad näring- och syretillförsel till vävnaderna. Syfte: Syftet var att genom en litteraturstudie undersöka om kompressionsstrumpor hade någon effekt för att förebygga DVT postoperativt samt om kompressionsstrumpor hade någon effekt att förebygga PTS efter en DVT. Metod: Litteraturstudie som baserads på 11 RCT studier. Resultat: GCS utan andra profylaktiska åtgärder visade sig ha en god effekt för att undvika utvecklingen av DVT på patienter som genomgått en operation. Däremot visade sig användandet av GCS i kombination med andra beprövade profylax inte ha någon större effekt för att reducera uppkomsten av DVT ytterligare. Resultatet angående GCS effekt för att undvika utvecklingen av PTS visade ingen entydighet. Slutsats: GCS har en förebyggande effekt för att undvika uppkomsten av DVT. Användningen av GCS i kombination med andra profylax potentierar däremot inte effekten av preventionen för DVT. GCS verkan för att förebygga uppkomsten av PTS är inte entydigt och flera studier behövs för att se evidens kring detta. / ABSTRACT  Background: Deep vein thrombosis (DVT) is a serious complication postoperatively and can lead to a life threatening condition for the patient. Graded compression stockings (GCS) are used in many post-operative departments along with other prophylactic measures to prevent the development of DVT. Compression stockings are also used to prevent postthrombotic syndrome (PTS) after a DVT. PTS can develop because the venous valves are damaged by a DVT, as a result, the blood is stored and edema is formed, which leads to poor nutritional and oxygen supply to the tissues. Aim: The aim of the literature study was to investigate whether compression stockings had any effect in preventing DVT postoperatively, and also whether the compression stockings had any effect in preventing PTS after a DVT. Method: Literature study based on 11 RCT studies. Results: GCS without other prophylactic measures was found to have a good effect in avoiding the development of DVT in patients who underwent surgery. However, the use of GCS in combination with other proven prophylaxis was found to have no significant effect in further reducing the onset of DVT. The results regarding the GCS effect to avoid the development of PTS showed no unambiguity. Conclusion: GCS has a preventive effect to avoid the onset of DVT. However, the use of GCS in combination with other prophylaxis does not potentiate the effect of prevention for DVT. The effect of GCS in preventing the onset of PTS is not unambiguous and several studies are needed to see evidence of this.

La thérapie par compression médicale est reconnue comme une composante essentielle dans le traitement des pathologies veineuses et demeure incontournable dans la prise en charge des affections veineuses aux différents stades de la pathologie (jambes lourdes, œdèmes, ulcères). Si le bénéfice est reconnu par les patients eux-mêmes ainsi que par les médecins, il n’existe à l’heure actuelle que peu d’éléments permettant de quantifier ce bénéfice. Dans ce contexte, l’objectif de ces travaux de thèse est d’apporter des éléments de compréhension et d’objectiver les effets bénéfiques des bas médicaux de compression (BMC) aux niveaux physiologique, neurophysiologique et comportemental. Trois axes de recherche ont été dégagés. Le premier axe de recherche est l’étude de l’effet de la compression sur l’activité microcirculatoire cutanée dans les membres inférieurs en utilisant le dispositif Hématron, dispositif ambulatoire exclusif d’évaluation de l’activité microcirculatoire cutanée. Les résultats ont montré une amélioration de l’activité microcirculatoire pour différentes classes de BMC et pour différentes positions. Ces résultats tendraient à mettre en cause l’hypothèse, largement admise, que les BMC améliorent le retour veineux principalement en diminuant la section des veines (superficielles voire profondes). La deuxième piste de recherche concerne l’objectivation de l’amélioration de la qualité de vie liée au port des BMC, généralement exprimée subjectivement par les personnes atteintes de pathologie veineuse. Les résultats préliminaires montrent que l’analyse de la variabilité cardiaque permet de mettre en évidence une relation entre le paramètre indicateur de l’activité de la balance sympatho-vagale et le port de la compression médicale au cours d’une journée. Compte tenu de la grande dispersion des résultats, cette étude serait à poursuivre sur une population plus large pour aboutir à des conclusions fiables. Le dernier axe de recherche est lié à l’impact du port des BMC sur le comportement du sujet et plus précisément sur sa déambulation. Les patients déclarent une fatigue physique dans les membres inférieurs moins intense en fin de journée grâce à la compression médicale. Notre hypothèse est que le port des BMC impacterait directement la dynamique de la déambulation. Pour évaluer la cinétique de la marche, nous avons conçu, développé et validé une instrumentation intégrant des capteurs accéléromètres. Des tests préliminaires ont permis de dégager des paramètres pertinents caractéristiques de la déambulation. La prochaine étape sera de conduire une campagne d’expérimentation destinée à objectiver la fatigue comportementale en fin d’après-midi mesurée avec ou sans compression médicale portée au cours de la journée. / Medical compression therapy is recognized as an essential component in the treatment of venous diseases and is indispensable in the treatment of venous diseases at different stages of the disease (heavy legs, edema and ulcers). Although the benefit is recognized by the patients themselves and by physicians, there is at present little evidence to quantify this benefit. Against this background, the aim of this thesis is to provide more understanding and objectify the benefits of compression stockings (MCS) on in terms of physiology, neurophysiology and gait dynamics. Three areas of research were identified and studied. The first line of research is the study of the effect of compression on skin microcirculatory activity in the lower limbs using the Hematron ambulatory device. The results showed an improvement in skin blood flow activity for different classes of MCS and at different positions. These results would tend to challenge the widely accepted assumption that MCS improve venous return primarily by decreasing the cross-sectional area of (superficial or deep) veins. The second line of research involves the objectification of the improvement in the quality of life resulting from the wearing of MCS, usually this is expressed subjectively by people with venous disease. Preliminary results show that the analysis of heart rate variability highlights a relationship between the indicators of sympathovagal balance activity and the use of medical compression during the day. Given the wide dispersion in the results, this study should be carried out on a larger population to draw more reliable conclusions. The last line of research relates to the impact of MCS on the behavior and, in particular, the gait of the subject. Patients report that physical fatigue in the lower limbs is less prevalent at the end of the day with compression therapy. Our hypothesis is that the wearing of MCS has a direct impact on gait. To evaluate the kinetics of walking, we have designed, developed and validated an instrumentation involving accelerometers sensors. Preliminary tests have yielded relevant parameters characteristic of gait dynamics. The next step is to conduct an experimental campaign to objectify behavioral fatigue, with or without the wearing of medical compression, at the end of the afternoon.