Journal of Rehabilitation Medicine 51-4inkOmslag | Page 7

limbs of patients by increasing venous return, reducing
venous stasis, increasing lymph flow, and increasing
hydrostatic pressure, which would reduce capillary
filtration and assist fluid absorption.
A later study by Man and colleagues (15) randomi-
zed 34 patients with an ankle sprain into either: (i) a
group with NMES applied to the lower leg muscles; (ii)
a group with sub-motor electrical stimulation applied to
the lower leg muscles; or (iii) a group with electrodes
set up on the lower legs with no electrical stimula-
tion applied (sham group). There were no statistically
significant differences between groups for ankle-foot
volume and self-assessed ankle function. Ankle girth
was significantly improved from session 1 to 3 with
the application of NMES; however, the authors note
that this result may be confounded due to inter-group
variance. A statistically significant difference in ankle
girth measurements was recorded among the 3 groups
at baseline in addition to an unexpected difference in
subjects’ height.
Upper limb oedema. Similar to the results of studies
assessing NMES for reducing lower limb oedema,
there are 2 studies that support the feasibility and ef-
fectiveness of NMES for reducing upper limb oedema
(16–17). Other benefits found were improvements in
pain, function, range of motion and strength.
Complex regional pain syndrome. A study by Dev-
rimsel et al. (16) compared the effect of whirlpool
baths and NMES on complex regional pain syndrome
(n = 60). The authors found significant improvements
in pain, oedema, range of motion, fingertip-to-distal
palmer crease distance, hand grip strength and pinch
strength in both groups. The efficacy of the whirlpool
bath treatment was considered more effective due
to statistically significantly better improvements in
outcomes; however, both treatments were regarded
as effective in the treatment of complex regional pain
syndrome and the reduction of oedema.
Cerebrovascular accident patients. A small study
(n = 8) by Faghri (17) used a repeated measure design
to compare the use of NMES to limb elevation on hand
oedema patients following a cerebrovascular accident.
Thirty minutes of NMES of the finger and wrist flexors
and extensors was compared with the effects of 30
min of limb elevation alone. The author found both
treatments to be significantly effective in improving
volume and girth of the arm and hand, and NMES was
more effective for the reduction of hand oedema than
limb elevation within their sample, although no actual
significance values are reported.
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DISCUSSION
In medical research, there is an aim to establish the
lowest dose of medication that is effective in producing
a clinical benefit with the fewest side-effects possible.
The discomfort associated with stimulus may reduce
patient acceptance or compliance with NMES as a
therapy (18); therefore, it is important that there is a
balance between effectiveness and comfort, in order to
promote patient compliance. Technical developments
of NMES devices have improved patient tolerance by
allowing effective stimulation with a lower current
density and pulse duration (18). This may be important
when comparing the NMES devices that stimulate the
motor nerve in comparison with those that stimulate
the motor point. Neural stimulation requires lower
current intensity for the same level of contraction, and
thus devices may be better tolerated by patients. The
use of NMES as a rehabilitative device was reported
to be feasible and safe in all studies, with no recorded
harmful side-effects or adverse events.
Within the studies sourced, there is a wide variation
in the parameters utilized, but, in general, NMES was
applied for periods of 20–30 min. Stimulation occurred
once a day in 5 studies (12–15, 17), 5 times per week in
one study (16), and reduced from 3 times, to 2 times, to
once per month, in 1 study (11). The majority of studies
support the use of a higher dose for a short period of
time, as opposed to a low dose for a long period of time.
It is important to establish the maximum effect for the
lowest intensity of stimulation so that the treatment is
comfortable for the patient. The frequency of applica-
tion and number of repetitions varied between authors,
with the range between 1 and 125 Hz. A high pulse fre-
quency setting is more commonly used for the treatment
of pain, and a lower frequency may be advantageous for
swelling reduction. Duty cycle describes the actual on
and off time of an NMES programme, and commonly,
full amplitude “on” period, which is one-third of the
stimulus “off” time will avoid rapid muscle fatigue. By
creating non-fatiguing muscle contractions, NMES can
dilate blood vessels and help to increase blood flow.
Rehabilitation timing was also non-consistent between
studies, with treatment commencing at different times in
each intervention. The percentage change in oedema is
shown in Table IV; however, variance in methodologies
prevents detailed a comparison being made.
Study limitations
Although the variation in patient groups adds genera-
lity to the effectiveness of NMES for reducing oedema,
Effectiveness of NMES for reducing oedema: a systematic review
J Rehabil Med 51, 2019