Hrev_master


Veins and Lymphatics 2013; volume 2:e1

[Veins and Lymphatics 2013; 2:e1] [page 1]

Stiffness of compression
devices
Giovanni Mosti
Angiology Department, Clinica MD
Barbantini, Lucca, Italy

This issue of Veins and Lymphatics collects
papers coming from the International
Compression Club (ICC) Meeting on Stiffness
of Compression Devices, which took place in
Vienna on May 2012.
Several studies have demonstrated that the

stiffness of compression products plays a
major role for their hemodynamic efficacy.
According to the European Committee for
Standardization (CEN), stiffness is defined as
the pressure increase produced by medical
compression hosiery (MCH) per 1 cm of
increase in leg circumference.1 In other words
stiffness could be defined as the ability of the
bandage/stockings to oppose the muscle
expansion during contraction.
Measurements of stiffness are performed in

textile laboratories using different extensome-
ters. However, up to now pressure ranges are
declared only for compression stockings; no
pressure ranges can be declared for bandages
as the exerted pressure depends on the stretch
applied to the bandages, number of layers and
leg configuration. Information concerning
stiffness is not given either for elastic stock-
ings or for bandages. 

In vivo experiments have offered useful sur-
rogate data. The leg circumference increases
when moving from the supine to the standing
position and during muscle activities.2-4

To assess stiffness according to CEN defini-
tion, it would be necessary to measure the
increase of compression pressure and of leg
circumference simultaneously, requiring a
pressure measurement device and a strain
gauge plethysmograph. In order to simplify the
stiffness calculation it has been proposed to
assume that the increase of leg-circumfer-
ence, moving from lying to standing position,
is always 1 cm. In this case the so-called static
stiffness index (SSI) could simply be calculat-
ed by subtracting the supine from the standing
pressure.5 A comparison between the two
measuring systems of stiffness (the first
including the measurement of the leg circum-
ference increase and the second just calculat-
ing SSI) was performed showing the same
sensitivity and specificity in distinguishing
between elastic and inelastic systems.2 The
conclusion of this comparison clarified that
SSI is an effective method to calculate stiff-
ness and that more complex measurements do
not give more information. 
Nevertheless the assessment of stiffness in

vivo, as recommended in a previous consensus

meeting of the ICC,6 came under some criti-
cism. Despite the fact that SSI is basically able
to differentiate the elastic properties of MCH,
a great variability among different patients
could be a major issue. This variability
depends on the fact that some other variables
play a role in SSI calculation in addition to
elastic properties of material: the leg position
during measurements, the configuration and
consistency at the measuring site of the leg,
the individual muscle strength, the presence of
fat and others.7

A new standardized method to measure the
stiffness on a mannequin leg was reported8

which presents the advantages to be simple,
highly reproducible, easily available and
cheap. If this method will be widely adopted, it
would also be possible to avoid that every com-
pany producing MCH measure stiffness with
different systems thereby increasing the con-
fusion. In order to differentiate between meas-
urement in vivo and in laboratory (lab) the so
called in vitro measurement, it was proposed
to name the in vitro calculation not anymore
stiffness in vitro, but resistance.9 Regarding
the measuring site on the leg, the B1 point
described in the ICC consensus paper6 was
brilliantly confirmed as the most suitable site
for stiffness measurement.10

Stiffness, together with pressure and hys-
teresis,11 is an important parameter for effec-
tiveness combined with comfort of MCH.
Neumann’s paper rises two important points.11

One is the relevance of another indicator of
stiffness the so-called dynamic stiffness index
(DSI) requiring complex measuring systems.
Nevertheless, an excellent correlation between
SSI and DSI could be shown by using this lab
equipment12 but also in vivo during muscle
exercise.2,13 This supports the idea that in vivo
testing is a valuable tool for assessing the elas-
tic properties especially in connection with
clinical effectiveness of compression devices.
The second point is the importance of the hys-
teresis of different compression materials.
Hysteresis can be measured only in the lab and
remains something obscure for the clinicians
whereas they should receive full information
by companies on this parameter.
An ideal compression device should exert a

low, comfortable pressure during rest, with a
strong or very strong pressure14 during stand-
ing and working in order to counteract ambu-
latory venous hypertension (effective). Such a
device would have a very high SSI but, unfortu-
nately, it doesn’t exist yet. Inelastic material
presenting high stiffness comes close to an
ideal compression device;15 especially when
pressure decreases after some hours from
application in the supine position, the differ-
ence between standing and supine pressure is
very high exerting an effective massaging
effect on the leg during walking and improving
significantly the hemodynamic impairment of

chronic venous insufficiency. Elastic material,
exerting a sustained pressure, not very differ-
ent between supine and standing position or
during muscle exercise, shows a small
improvement on the impaired venous hemody-
namics which is always significantly smaller
than that from inelastic material.16,17

Actually stiff materials exerting strong or
very strong pressure showed to be clinically
effective in ulcer treatment16,18,19 when a sig-
nificant impact on venous hemodynamics is
very important and also in lymphoedema.20

Pressure and stiffness can be critically
reduced in some areas of the leg with concave
rather than convex shape as this is the case in
the retro-malleolar space. Unfortunately this is
a critical area where often venous ulcers occur.
It has been shown that in this region the pres-
sure as well as stiffness can be close to zero as
the pressure doesn’t increase in standing posi-
tion or during muscle activity. Pressure and
stiffness in these areas can be significantly
increased by applying local compression
straps21 which greatly improve the clinical out-
come.22 An increase of pressure and stiffness
can be achieved also at thigh level by means of
eccentric devices, which are able to compress
the thigh veins otherwise difficult to com-
press.23 In this region higher pressure and
stiffness leads to better outcome following sur-
gical or endovascular procedures on the great
saphenous vein.24,25

In conclusion it is important to realize that
stiffness can be mainly considered as a surro-
gate indicator of comfort and effectiveness.
The higher the stiffness the greater comfort
and effectiveness in improving the clinical out-
comes. Stiffness is very high only with inelas-

Correspondence: Giovanni Mosti, Angiology
Department, Clinica MD Barbantini, Lucca, Italy.
E-mail: jmosti@tin.it

Key words: International Compression Club, stiff-
ness, compression devices, conference presenta-
tion.

Conference presentation: part of this paper was
presented at the International Compression Club
(ICC) Meeting on Stiffness of Compression
Devices, 2012 May 25, Vienna, Austria
(http://www.icc-compressionclub.com/).

Received for publication: 15 November 2012.
Revision received: 23 January 2013.
Accepted for publication: 28 January 2013

This work is licensed under a Creative Commons
Attribution 3.0 License (by-nc 3.0).

©Copyright G. Mosti, 2013
Licensee PAGEPress, Italy
Veins and Lymphatics 2013; 2:e1
doi:10.4081/vl.2013.e1

No
n-

co
mm

er
cia

l u
se

 on
ly



Editorial

[page 2] [Veins and Lymphatics 2013; 2:e1]

tic material, or multilayer systems and can be
enhanced by straps applied in a fan distribu-
tion or by eccentric compression devices in the
leg segment that need to be treated.

In vivo measurement techniques must be
better defined in order to minimize the vari-
ability; a parallel match with the lab assess-
ments is a mandatory target for future
researches. Only in this way the stiffness
effective value will scientifically demonstrate
to correspond to the great impact that already
empirically presents in our everyday clinical
practice.

References

1. European Committee for Standardization
(CEN). Non active medical devices.
Working Group 2 ENV 12718: European
Pre-standard ‘Medical Compression
Hosiery.’ CEN TC 205. Brussels: CEN;
2001.

2. Mosti G, Mattaliano V. Simultaneous
changes of leg circumference and inter-
face pressure under different compression
bandages. Eur J Vasc Endovasc Surg 2007;
33:476-82.

3. Stolk R, Wengen Van Der-Franken CPM,
Neumann HAM. A method for measuring
the dynamic behaviour of medical com-
pression hosiery during walking. Dermatol
Surg 2004;30:729-36.

4. Wienert V, Hansen R. Anmessen von medi-
zinischen kompressionsstrümpfen am
liegenden oder am stehenden patienten?
Phlebologie 1992;21:236-8.

5. Partsch H. The static stiffness index: a
simple method to assess the elastic prop-
erty of compression material in vivo.
Dermatol Surg 2005;31:625-30.

6. Partsch H, Clark M, Bassez S, et al.
Measurement of lower leg compression in
vivo: reccommendations for the perform-

ance of measurements of interface pres-
sure and stiffness. Dermatol Surg
2006;32:224-33.

7. Schuren J, Bichel J. Sub-bandage dynam-
ics: stiffness unraveled. Veins and
Lymphatics 2013;2:e2.

8. Hirai M, Partsch H. The Mannequin-leg: a
new instrument to assess stiffness of com-
pression materials. Veins and Lymphatics
2013;2:e3.

9. Cornu-Thénard A, Benigni J-P, Uhl J-F.
Terminology: resistance or stiffness for
medical compression stockings? Veins and
Lymphatics 2013;2:e4.

10. Uhl J-F, Benigni J-P, Cornu-Thénard A.
Where should be stiffness measured in
vivo? Veins and Lymphatics 2013;2:e5.

11. Neumann HAM. Elasticity, hysteresis and
stiffness: the magic triangle. Veins and
Lymphatics 2013;2:e6.

12. van der Wegen-Franken K, Tank B,
Neumann M. Correlation between the stat-
ic and dynamic stiffness indices of med-
ical elastic compression stockings.
Dermatol Surg 2008;34:1477-85.

13. Mosti G, Mattaliano V, Partsch H. Inelastic
compression increases venous ejection
fraction more than elastic bandages in
patients with superficial venous reflux.
Phlebology 2008;23:287-94.

14. Partsch H, Clark M, Mosti G, et al.
Classification of compression bandages:
practical aspects. Dermatol Surg
2008;34:600-9. 

15. Andriessen A, Abel M. Experimental study
on efficacy of compression systems with a
high static stiffness index for treatment of
venous ulcer patients. Veins and
Lymphatics 2013;2:e8.

16. Mosti G. Relevance of stiffness of com-
pression material on venous hemodynam-
ics and edema. Veins and Lymphatics
2013;2:e9.

17. Bender DJ, Fronek H, Arkans E. Quantified
hemodynamics of compression garments.

Veins and Lymphatics 2013;2:e10.
18. Wong IK, Andriessen A, Lee DT, et al.

Randomized controlled trial comparing
treatment outcome of two compression
bandaging systems and standard care
without compression in patients with
venous leg ulcers. J Vasc Surg 2012;55:
1376-85.

19. Mosti G, Crespi A, Mattaliano V. Compa -
rison between a new, two-component com-
pression system with zinc paste bandages
for leg ulcer healing: a prospective, multi-
center, randomized, controlled trial moni-
toring sub-bandage pressures. Wounds
2011;23:126-34.

20. Schingale F-J, Partsch H. Alginate hydro-
colloid impregnated zinc paste bandages-
an alternative in the management of lym-
phoedema? Veins and Lymphatics 2013;2:
e11.

21. Hopkins A, Worboys F, Partsch H. The use
of strapping to increase local pressure:
reporting of a sub-bandage pressure study.
Veins and Lymphatics 2013;2:e12.

22. Hopkins A, Worboys F, Bull R, Farrelly I.
Compression strapping: the development
of a novel compression technique to
enhance compression therapy and healing
for ‘hard-to-heal’ leg ulcers. Int Wound J
2011;8:474-83.

23. Partsch H, Mosti G, Mosti F. Narrowing of
leg veins under compression demonstrat-
ed by magnetic resonance imaging (MRI).
Int Angiol 2010;29:408-10.

24. Mosti G, Mattaliano V, Arleo S, Partsch H.
Thigh compression after great saphenous
surgery is more effective with high pres-
sure. Int Angiol 2009;28:274-80.

25. Lugli M, Cogo A, Guerzoni S, et al. Effects
of eccentric compression by a crossed-tape
technique after endovenous laser ablation
of the great saphenous vein: a randomized
study. Phlebology 2009;24:151-6.No

n-
co

mm
er

cia
l u

se
 on

ly