It is weil documented that people who stand für lang periods (particularly on hard surfaces)
are prone to increased fluid accumulations in the lower legs as the valves in the venous and
Iymphatic systems fight to maintain their patency. SinGe both systems are very much
capacitance vessels, they are reliant on the calf muscle pump to provide variations in tissue
pressure to help maintain their function and to ensure that over-distension does not occur,
thus leading to their failure to return any accumulated extracellular fluid either direct to the
venous system or indirectly to it via the Iymphatic system. In addition to the impact of the calf
muscle pump another major factor known to control the amount of extra-cellular fluids and
their contents is the extent of graduated external pressure on the tissues. This works by
reducing the outflow of materials from the vascular system (thus reducing the load on the
Iymphatic system) and also acts to provide supporting pressure to ensure that the calf
muscle pump works at optimal effectiveness, thus maintaining optimal tissue and cellular
There was a deliberate intent in this study to recruit normal healthy workers, that is, those
with no varicose or other lower limb disorders, although it is acknowledged that same may
have had latent problems. As far as we are able to ascertain from the literature, no study to
date has investigated the impact of support sacks on other than groups with known venous
The background data on the various groups provided an interesting insight into their
constituents however it was clear that the majority (83%) of the combined groups stood for
more than 7 hours in the day. 22.7% of the overall sam pie smoked, with the highest levels
being in the cleaning/catering group and the lowest in the nursing group.
All members of all groups had (as far as we could ascertain and they were aware) normally
functioning Iymphatic and vascular systems. While same had very paar skin integrity or very
dry skin, none of the other detected conditions in the members of the groups entered into the
study had any significant problem that would impact on the Iymphatic or vascular system
The major parameter of cancern is that of the extracellular fluid volumes. While these consist
of the true extracellular fluid, which is between the cells, the other components of it such as
the intravascular and intra-lymphatic space must be considered. It is likely the use of
external compression has an impact on all three components of the extracellular fluid volume
in the limb, but with the current equipment it is difficult to separate out the impact of this
compression on these three separate compartments. It is moderately weil evidenced
however that external compression will reduce intravascular volume (especially of the veins
as these are capacitance vessels), and that it does reduce the exudation from the blood
vessels into the tissues. Due to the delicate nature of the Iymphatic collectors it's also likely
that this space will also be reduced. The changes in fluids we are measuring thus are likely
to be related to changes in all three compartments.
Due to the lack of significant difference between the groups on the major parameter (je:
duration of standing) the groups were combined für the first pass analysis.
In the right limbs of the untreated groups over the 3 week period of measurement the normal
limbs increased by 207 mls, between the pre shift and post shift measurement. However,
with the use of the below the knee support sacks the volume increase was 140 mls -the
difference of 67 mls of which represented a borderline statistically significant reduction of p =
0.05. This represented a 32% reduction in accumulated fluids over the control group. In
terms of the left limb, there was a slightly greater increase of 211 mls in the control (non
compression) group and a slightly better control of the increase in the treatment
(compression) group of 109 mls, with the difference of 102 mls being statistically different (p
= .001). This represented a 48% reduction in the accumulated fluids over the control group.
Why this difference existed between the limbs is uncertain, but is possibly related to a
differing effect of the external stocking pressure on the Iymph system on the lett limb -in that
the pathway of Iymph from this limb is shorter than from the right and less likely to be
constrained by abdominal influences (such as high levels of abdominal fat) as it crosses this
In terms of how the three groups responded individually, the right leg of the nursing group
showed a non statistically significant reduction of 115mls (45%) while the lett leg showed a
statistically significant (p = 0.010) reduction of 120 mls (60%). The right leg ofthe
catering/cleaning group showed a non significant reduction of 38 mls (23%) and the lett leg a
borderline non significant reduction of 112 mls (52%). In the production workers group the
right leg showed a non significant reduction of 31 mls (18%) while the lett leg showed a
significant reduction of 85 mls (38%)
Again as per the combined group, the impact of the below the knee support stocking is
greater statistically, biologically and certainly practically für the lett leg.
Perometry measurements were only made up as far as the distal patella. For this reason
changes are of a lesser magnitude of difference than für the whole li mb as determined by
bio-impedance. It should also be noted that while bio-impedance measures total fluids,
perometry measures volumes as calculated by circumferences measured at 4 mm intervals.
Again from the whole group perspective für both the left and right limbs there was a
statistically significant volume reducing effect of the below the knee compression socks. For
the right leg below the knee this represented a statistically significant reduction (p= 0.017) of
67% of the increased volume without the stocking and für the left below the knee a
statistically significant (p = 0.004) reduction of 62%.
An examination of the changes in the separate groups showed the greatest and most
statistically significant reductions of 90% (p =0.045) für the right leg and 77% (p = 0.018) für
the left leg.
The catering/cleaning group showed reductions of 25% (ns) for the right limb and 84% (ns)
for the left limb, while the production workers showed reductions of 35% (ns) and 34% (ns)
for the right and left legs respectively. The major reasons for the lack of statistically
significant changes in these latter two groups seemed to be primarily the result of the large
spread of changes within the groups.
While objective findings such as the above are important, it is the influence of these on how
the person feels which is crucial.
When the whole group subjective comments were considered the wearing of support sacks
resulted in a statistically significant reduction in limb aching (43%, p = 0.011), limb heaviness
(56% p = 0.001), limb tightness (66%, p = 0.004) and limb tiredness (39% p = 0.006). While
cramps reduced, it was not statistically significant.
Whole group findings were mirrored by the three sub group findings but statistical
significance was not achievable except in the nursing group where there was a 60% (p =
0.011) reduction in aching, a 63% (p = 0.001) reduction in heaviness and a 53% (p = 0.005)
reduction in tiredness.
Body Part Discomfort
Changes in body part discomfort may occur as the day progresses, usually in the lower back,
and legs. Generally accompanying this are increased levels of fatigue.
In the whole group, the use of below the knee support sacks significantly reduced neck and
shoulder discomfort by 66% (p = 0.041), and lower back discomfort by 85% (p = 0.017). Left
and right arm, upper back discomfort and level of fatigue were also reduced but not
significantly. They are likely to be practically significant, however this remains to be
The individual group changes in body part discomfort were not statistically significant
although larger sampie sizes would see this.
Other Subjective Comments
Forty four of the participants commented on the support socks, with 24 (55%) of them stating
that the socks had an overall beneficial effect and or feit good and 14 (32%) reported them to
be comfortable to wear. Ten (23%) indicated their legs feit less tired at the end of the day.
However, 12 (27%) reported them to be difficult to get on/off and 8 (18%) indicated them to
be too long. Other difficulties reported were problems with their tightness, hotness, itchiness
and the making of ridges on the legs; however it seems clear that their benefits significantly
outweighed the negatives for most people.
In all Gases, it's likely that reductions in extracellular fluids achieved by the below the knee
support sacks over each and every day will have a significant effect on the cellular and tissue
health in the lower limb (Tuchsen et al 2000). While the end point of this remains to be
explored, it is hypothesised that this change alone may result in a reduced risk of varicosities
of the lower limb and of venous oedemas. The major reason for this is likely to be as a
consequence of the additional external pressure on the venous system and its effect on their
distension and on the exudation of materials from them as weil as their clearance from the
area. Another important reason is the impact of a more efficient use of the calf muscle pump
when supported by external pressure over and above that normally provided by the natural
elasticity of the skin. A third reason is the benefits of this compression on tissue pressures
and the impact that has on the ability to load the Iymphatic system and to clear fluids, waste
products and toxins from the tissues.
This study has shown that the wearing of below the knee light compression garments is
beneficial in terms of leg fluid and volume reduction and in improving how the legs and
general body feel. This is the Gase in a working population that stand für lang periods of time
and who have no known venous or Iymphatic pathologies. As the literature has already
established a link between standing für lang periods and venous pathology, the wearing of
support garments by workers may over the lang term prevent or slow the onset of venous
disorders (ie: varicose veins) and hopefully lead to a happier, healthier and more productive
The garments were weil tolerated by most participants and provide an easy to implement
initiative für those who due to the nature of their work, stand für lang periods. These sorts of
findings mayaiso be generalisable to other standing occupations such as the hospitality and
supermarket industries. This sort of study provides evidence für enterprise bargaining für the
work groups involved, especially the nursing group who previously (but not currently) were
supplied with support stocks as apart of a standard uniform.
The majority of the aims of this study were met, the study design demonstrated that
support stocks were superior to wearing normal work wear in terms of reducing fluid
accumulation and increase in below the knee leg volume plus improving subjective
symptoms, body part discomfort and fatigue. The only target not met was the projected
recruitment numbers für each work group, if the withdrawal/drop out numbers are
considered then the required numbers would have been achieved.
The project was managed weil, each investigator completed all measurements required
and the trial was completed in a timely fashion. The results have been disseminated to
the managers of each work group and a pamphlet outlining the trial and its results hag
been prepared für the workers. There was a slight delay in the original time line due to a
delay in availability of measurement equipment from overseas and an unforseen
shutdown/ maintenance period in the middle of the year at Bridgestone T G Australia.
All the milestones of the trial, except for recruitment numbers (see explanation above)
were achieved. All measurements in terms of the trial (ie: general questionnaire, bio-
impedance, perometry, subjective leg symptoms and body discomfort questionnaires)
were achieved. Analysis and final write up of the results was also achieved.
The quality of the outcomes were good, the equipment used was able to demonstrate
that the support sacks were beneficial für workers who stand für lang periods, both
objectively (Iess fluid accumulation and volume increase) and subjectively (Iess
subjective leg symptoms and body discomfort).
The impact of this study is that it is an easy to implement initiative wh ich in the short
term improves worker comfort and in the lang term may prevent or slow venous
pathology onset and improve productivity.
The results af this study (ta date) have been disseminated in the fallawing ways:
The leader(s) of each work group and the steering committee members have been sent
a summary of the results (with alterations recommended by Work Cover -see appendix
I) für their own record, this included:
~ Dr Jack Walsh -Vascular Surgeon/Specialist, Flinders Medical Centre
~ Mr Rob Hull -Nurse Clinical Educator & Australian Nursing Federation
Representative, Flinders Medical Centre
>> Ms Wendy Robertson -Manager of Tempo Catering Services, employed by
Flinders Medical Centre
~ Ms Shelley Short -Occupational Health & Safety Manger, Flinders Medical
>> Mr Jeff Benham -Occupational Health & Safety affiGer, Bridgestone TG
~ General Management -Bridgestone TG Australia
The preliminary results of this trial were presented at the 6th International Congress on
Work Injuries Prevention, Rehabilitation & Compensation (WorkCongress6). Rome,
The results specifically pertaining to the nursing group with a general overview of the
results of the tempo and factory production groups have been posted on the Flinders
Medical Centre website: http://www.flinders.sa.aov.au/news/Daaes/whatsnew/ and
in the FMC newspaper (Feb 05).
A pamphlet which outlines the trial, where to purchase the support socks, in an easy
to read style hag been completed and will be distributed to the individual work sites
involved in the study.
The research team are being interview about the trial and its results by Channel 7 news
and the southern messenger newspaper on Wednesday 9th of February 2005.
Articles are currently being prepared tor submission to the Australian Nursing Journal
(distributed to all Australian Nursing Federation members) and the Ergonomics journal,
EXTENSION OF RESUL TS
Managers of each work group involved in the study will be encouraged to give all
current and new employees the developed pamphlet so each worker is aware of the
benefits of below the knee support socks.
A meeting is being organized with Mr Jeff Benham (OH&S Officer, Bridgestone T G
Australia) and his representatives and a member of WorkCover and Dur key members
with a view to attempting to facilitate further use of these support sacks.
Union members will be encouraged to approach their organisation regarding the
permanent implementation of these support socks.
The primary investigators will endeavour to present these findings at relevant and
The recommendation of this trial is that below the knee support sacks (probably in
combination with isotonic and isometric leg exercises) be implemented für all workers
who stand für lang periods of time and that this information be disseminated in the above
mentioned ways. Ideally the best way to implement this initiative would be to incorporate
the below the knee support sacks as part of the workers standard uniform.
Further studies could be beneficial in the populations of workers in both the hospitality
and supermarket areas -particularly as these are generally younger persons and the
introduction of documented outcomes through the wearing of the support sacks in these
groups might encourage their use and importantly, lead to better health maintenance
awareness in these younger groups
A Ionger term study on a subgroup might be very interesting in terms of the
documentation of the effects of below the knee support sacks on the incidence/
prevalence of other lower limb issues such as varicose veins which affect a significant
proportion of older populations. Evidence suggests these might be in part be
preventable, but there are certainly opportunities to be better able to be manage them in
their early stages through awareness and obviously same gentle external compression.
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