compression socks test, sox and travelsox

7/27/2019 Compression Socks test, sox and travelsox

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UNIVERSIT DI BRESCIA FACOLT DI INGEGNERIADIPARTIMENTO DI INGEGNERIA DELLINFORMAZIONE

Via Branze 38, 25123 Brescia, Italy Phone: +39-030.3715.469/470 Fax: +39-030.380.014E-mail:[email protected] Website: http://www.unibs.it/on-line/dii/Home.html

C.F. 98007650173 P.IVA 01773710171

Report: Comparative compression tests andestensibility/comfort tests on various types of progressive

compression tests

Extensor: Prof. Ing. Franco DocchioLaboratory of Optoelectronics Optolab-BS

University of BresciaVia Branze 38

25123 Brescia, Italy

INTRODUCTION

Different socks exhibiting compression decreasing from the ankle up to the thigh are availableon the market, intended to be used to prevent or reduce abnormal venous flux in the lowerpart of the leg, and to maintain regular share of blood flux between the Deep and the externalveins. Due to their ability of conveying most of the blood flux to the deep vein system, thesesocks are an aid against Deep Vein Thrombosis (DVT). Moreover, progressive compressionsocks are considered to be ideal to optimize the distribution of the blood flux in:

Athlets during marathons and long-term races; Travellers forced to long periods of leg immobilization, at reduced external pressures

such as in international/oversees flights; Diabetic patients, easily subject to oedemas, swelling, etc..

The Company Arcos S.p.A., in an effort to optimize their production, have undergone acomprehensive study of the characteristics of compression socks, either produced by thecompany itself, or available on the market. The aim is to define the strategic advantages of thecompany in relation to competitors, and at the same time to define the characteristics of theideal compression socks for constant quality improvement politics.

Arcos S.p.A. has asked the Laboratory of Optoelectronics to assist them in the performance of an extensive set of measurements and of measurement data interpretation, to the above aim.

The extensor of his Report has spent a period of time at the company premises, together with


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Brescia, 27 May 2010 Pagina 2 di 12

his staff, to work in close contact to the Quality personnel of the Company, usinginstrumentation available at Arcos S.p.A. to perform the tests. Great care was taken by theLaboratory in executing, prior to the execution of the tests, all the necessary instrumentationcalibration and experiment setup.

The results are all shown in this report and discussed by the extensor.

METHODS

To test the socks, we used a commercial instrument, SATRA STM 579, equipped with amonolateral compression measurement load cell. Measurements were perofmed at fourpoints along the sock length, starting from the ankle. For each point the nominal sock diameterwas calculated. Compression values were obtained from the load value obtained by theinstrument, by applying the correction factors prescribed by the manual.

Each point was measured on freshly processed socks, five measurements were made on eachpoint and averaged.

EXPERIMENTAL RESULTS: COMPARATIVE COMPRESSION VALUES FOR FORMER3 SETTINGS

The following models have been tested: JOBST 8-15 Women's Casual, TED Antiembolism,Futuro Medium 21 mm Hg, TED Antiembolism 2, Solidea Relax 140, BTG Flight Socks, FuturoMedium 21 mm Hg, Gloria 18, Mod. 01, Mod. 02, Mod. 03, Mod. 04, Mod. 05, Mod. 06, Mod.07, Mod. 08, Mod. 09, Mod. 10, Mod. 11, Mod. 12, Mod. 13, Mod. 14, Mod. 15, Mod. 16, Mod.17, Mod. 18, Mod. 19, Mod. 20, Arcos Mod. A, Arcos Mod. B, Arcos Mod. C.

Figure 1 shows the results obtained by measuring the compression of all models tested at thefour different locations of the socks (1=ankle, 4=thigh). All compression values are mm Hg.From the Figure it is evident that a number of competitor models exhibit a compression thatincreases from point 1 to point 2. Irrespectively from the behavior at different points, this is asign of non compliance of the socks to the requirements of progressively decreasingcompression, that would ensure the proper effect onto the blood circulation in the deep veinsystem. Increasing compression from point 1 to point 2 would in fact result in blood retention

just above the ankle.


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Figure 2 shows the same graphs of Fig. 1, once the models exhibiting the above pattern havebeen removed. The following models have remained:

JOBST 8-15 Women's Casual, TED Antiembolism, Futuro Medium 21 mm Hg, TED Antiembolism2, Solidea Relax 140, BTG Flight Socks, Futuro Medium 21 mm Hg, Gloria 18, Mod. 02, Mod. 05,Mod. 06, Mod. 09, Mod. 10, Mod. 11, Mod. 15, Mod. 20, Arcos Mod. A, Arcos Mod. B, ArcosMod. C.


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Now we remark that a number of models present a compression value that increases frompoint 3 to point 4. This is another sign of non compliance of the socks to the requirements of progressively decreasing compression, that would ensure the proper effect onto the bloodcirculation in the deep vein system. Increasing compression from point 3 to point 4 would infact result in blood retention just below the thighs.The remaining models have been shown in Figure 3 They are: JOBST 8-15 Women's Casual, TEDAntiembolism, Futuro Medium 21 mm Hg, Gloria 18, Mod. 02, Mod. 09, Mod. 10, Mod. 20,Arcos Mod. A, Arcos Mod. B, Arcos Mod. C.


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Finally, a further selection has been made on the basis of the uniformity of compressionreduction. Socks that have a compression reduction too much disuniform are expected toproduce negative effects on circulation, creating zone of unequal pressure on the veins.Therefore socks have been selected on the basis that the compression variation in any of theintervals considered was equal to, or less than, 20%. The following four socks have beenidentified on this basis. The results are shown in Fig. 4.


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All three models of Arcos socks have passed all the tests conducted so far, together with socknamed Mod 10. We note that Mod. 10 sock has an ankle compression much higher than thatof Arcos socks.


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EXTENSIBILITY

One of the key parameters for adaptivity of the socks to different dimensions andconformation of legs is the lateral extensibility of the socks, i.e., the maximum difference intransverse dimensions of the socks relative to the rest dimension. The higher this value is, themore the sock can adapt to different leg configurations. Needless to say, the extensibilityfactor should be as uniform as possible at all locations along the sock length (ankle-to-thigh).

Another series of experiments were taken on the best performing socks of the previous seriesof experiments: they are:

JOBST 8-15 Women's Casual, TED Antiembolism, Futuro Medium 21 mm Hg, Mod. 10, Arcos

Mod. A, Arcos Mod. B, Arcos Mod. C.The transverse dimensions of the sock have been measured at the four compression measuringpoints of Fig. 1-4, in two conditions: at rest, and at maximum stress. The difference has beencalculated and normalised to the rest value.

The results are shown in Fig. 5. From the Figure it is evident that the three Arcos Models, andthe Mod. 10, exhibit the maximum extensibility of the whole set of socks measured, and themaximum uniformity at all points.


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COMFORT/EXTENSION COEFFICIENT

A comfort/extensibility coefficient has been calculated for all the socks in this set. First, thecompression value has been re-measured at Former 7 and 3, at all measurement points alongthe sock. After correction, the difference between the two values at each point has beencalculated, and divided by the maximum extension at that point.

The results are shown in Figure 6.


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It is evident that, for maximum comfort for all types of legs, the so calculated cefficient shouldhave the following characteristics:

1. It should be as low as possible. The compression should be as independent of theextension at each point as possible

2. It should be as uniform as possible throughout the length of the sock.

Again, from the Figure it appears that Arcos Mod. C is the best performer in terms of requirement no. 1, whereas Arcos Mod. B, and to a lesser extent Arcos Mod. A, are the bestperformers in terms of Requirement 2.

FINAL REMARKS AND IDEAL AND SPECIFICATIONS FOR AN IDEAL PROGRESSIVECOMPRESSION SOCKS

At the end of the report, we summarise the features of the compression socks that arerequired for ideal performance of the socks. These requirements are proposed to medical andclinical specialists who should validate them according to their clinical experience.

1. The sock should exhibit a compression value (in mm/Hg) constantly and uniformlydecreasing from ankle to thigh.


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2. The sock should be as extensible as possible, to adapt to different leg diameters andtypes

3. The sock should exhibit compression values rather independent of the extension, andthe dependence of the compression on the lateral dimension should be as uniform aspossible along the sock length.

From the extensive set of measurements, it appears that all the tested Models of Arcos socksmeet these requirements, more so than most of its competitors. Arcos C is considered to beoptimal, from the point of view of the compression/extensibility tests performed.


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CV of Prof. Franco DocchioProf. Franco Docchio holds a Master in Nuclear Engineering.Formerly CNR researcher Milan, where he carried out research inlaser development, laser applications in industry and bio-medicineand laser-tissue interaction, in 1987 he joined the Department of Electronics for the Automation of the University of Brescia, wherehe presently holds the Full Professorship in ElectricalMeasurements.

Prof. Docchio, co-author of about than 250 publications, mostlyinternational, is founder and member of the Laboratory of Optoelectronics, involved in projects of basic and applied research,in collaboration with international institutions and companies. Inrecent years, within the activities of the Laboratory, he has been

active in the creation and incubation of a number of Spin-Off companies, that operate in thedomain of Optoelectronics, laser processing of materials, optical sensors, 3-D vision, andoptical design. Prof. Docchio has deposited 5 international patents on instrumentation andinnovative techniques for electrooptical measurements.

In the past Prof. Docchio held the position of Vice-Dean of the faculty of Engineering, and of Vice Rector on University Information system development. Today, he has been appointedFellow of the European Optical Society, and is a member of the Athenaeum of Sciences of Brescia. He is also Director of the Italian Journal Tutto_Misure.

compression socks test, sox and travelsox

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