1)
Dr. Anton Wernig (Germany)
2)
Dr. A. L. Hicks (Canada)
3)
Dr.
Bruce Dobkin (United States)
4)
Dr. Patricia Winchester (United States)
5) Drs. Sarah Thomas and Monica Gorassini
(Canada)
6) Dr. Edelle Field-Fote (United States)
7) Dr. Markus Wirz (Switzerland, Germany, USA)
8) Dr. Susan Harkema (USA)
Over the past decade, a number of programs and
researchers have emphasized treadmill training to increase ambulatory
ability after SCI. Often such therapy uses some degree of body-weight
support through harness devices and, at least in part, is controlled by
the neural circuits within the spinal-cord below the injury site that can
sustain lower-limb repetitive movement, such as walking, independent of
direct brain control. Procedures vary considerably between programs, and
as a result, there is considerable variability in reported benefits. Brief discussions of a few of these treadmill
programs are included below:
1) Dr. Anton
Wernig and his colleague Sabine Műller (Karlsbad, Germany)
carried out key pioneering work documenting the ability of treadmill
training to increase ambulation after SCI. In a 1992 article (Paraplegia,
30), they reported the results of training eight persons with incomplete
SCI with a “Laufband” variable speed treadmill, on which the patient was
partially supported with a harness. Over time, bodyweight support was
reduced from 40 to 0%. Starting 5-20 months after injury, patients trained
for 1.5-7 months for five days a week,
30-60 minutes daily. All patients
improved their ambulatory ability, including the ability “to walk short
distances, to bear their body weight fully without knee stabilizing braces
and to climb stairs while needing only a hand rail and one cane.”
In 1995, Wernig and colleagues reported the results
of a more extensive study evaluating the effectiveness of Laufband
treadmill training in 44 patients with chronic SCI (Eur J Neuroscience,
7 1995). The patients had sustained their injuries on average a year
(range 0.5-18 years) before initiating 3-20 weeks of training. Virtually
all improved their ambulation. In a comparison study, 14 of 18 patients
learned to walk without help from others compared to 1 of 14 of those who
received conventional therapy. Follow-up studies indicated that most
patients who had improved to the point of walking independently continued
to use their new found abilities over time as a part of every-day life. In
another example of program effectiveness, after training, 36 of the 44
patients were capable of staircase walking compared to only six before. Of
acutely injured patients, 92% who were “wheelchair bound” became
independent walkers after Laufband treadmill training compared to only 50%
after conventional therapy.
In 2000 review article, Wernig et al indicated that
the improvements that accrued from his training of individuals with
chronic SCI generally persisted over time (Progress in Brain Research,
128, 2000).
2) Dr. A. L.
Hicks and colleagues (Hamilton, Ontario) studied the effects of
long-term body-weight-supported treadmill training in 14 subjects with
chronic, incomplete SCI (Spinal Cord 43, 2005). Eleven and three
were men and women, respectively; the average time since injury ranged
from 1.2-24 (average 7.4 years); and 12 and two had ASIA-A and -B (see
Appendix 1) incomplete injuries, respectively. Subjects trained three
times a week for a total of 144 sessions over 12-15 month period.
All subjects who completed the program (13) improved
their treadmill walking ability, including a 54% reduction in body-weight
support (from 73 to 19.5%), a 180% improvement in walking speed (from 0.5
to 1.4 kilometers per hour), and a 335% in the distance covered per
session (from 221 to 961 meters). These improvements were associated with
increased satisfaction with life and physical function, and also improved
muscle mass and composition, and blood lipid profiles and glucose
tolerance consistent with a lowered risk of SCI-related diabetes and
cardiovascular disease. In this study, some of the improvements diminished
over time as subjects discontinued training.
This investigative team also studied the effects of
twice-weekly body-weight supported treadmill training on muscle mass and
bone density in five subjects injured 2-6 months before starting the
program (Giangregorio, et al, Spinal Cord 43(11), 2005). Although
the training appeared to reverse the muscle atrophy accruing soon after
SCI, it not seem to prevent bone loss.
3) Dr. Bruce
Dobkin (Los Angeles, California) and
colleagues compared the effectiveness of body-weight supported treadmill
training with a similar intensity control program of over-ground mobility
training (Neurology, 66(4), 2006).
A total of 146 subjects, who had
sustained incomplete (i.e., ASIA B-D) injuries within the previous eight
weeks, were recruited from six US and Canadian collaborating centers.
Subjects were randomized to either a 12-week treadmill- or
control-training program (e.g., parallel bars, etc.) in which they
received about one hour of training per session.
To be included in the analysis, a subject must have
completed at least 45 sessions over the 12-week period (the maximum
possible being 60) or have reached a defined level of restored ambulation.
Improvements were measured by either 1) the Functional Independence
Measure Locomotor (FIM-L) score, which assesses the degree of assistance
(either from the help of others or assistive devices) the subject needs to
walk a defined distance, or 2) walking speed.
The investigators concluded that there was no
statistical difference in results between treatment groups and that care
must be taken in interpreting putative positive results of past treadmill
studies that lack sufficient consideration of potential confounding
factors, especially in a post-injury period in which considerable
functional improvement already accrues. On the other hand, although this
study did not demonstrate a statistically significant benefit for
treadmill training - or lacked the statistical power to do so - it
conversely does not prove that such benefit does not exist.
4) Dr.
Patricia Winchester and colleagues (Dallas, Texas) examined the
effects of
12
weeks of body weight-supported training on supraspinal activation (i.e.,
neuronal activity in brain) in four men with incomplete cervical injuries
(Neurorehabil Neural Repair, 19(4), 2005). The study specifically
used the Lokomat Driven Gait Orthosis, a robotic treadmill device
developed by the Swiss company Hocoma (www.hocoma.ch).
The device minimizes the need for assisting therapists. The four subjects
had sustained their injuries 14 weeks to four years before starting the
training program, and all had sufficient range of motion to stand and some
ability to move the ankle and toes.
Basically, the study’s goal was to measure through
MRI brain imaging the differences in supraspinal activation before and
after this 12-week training program. Simply stated, does such training
facilitate ambulation-enhancing brain reprogramming (i.e., plasticity). To
measure the intensity of walking-associated brain activity, subjects
flexed their ankles and curled their toes while keeping their heads still
in the MRI device. At the end of the 12-week training period, three of the
four subjects demonstrated improved walking, and all exhibited increased
activity in areas of the brain associated with locomotion. The accrued
benefits seemed less pronounced when more time had elapsed since injury.
Although it is difficult to generalize the results of a small pilot study,
the results suggested that body weight-supported treadmill training exerts
a beneficial neuro-programming effect in the brain, which, in feedback
style, may enhance walking in patients with incomplete SCI.
5)
Drs. Sarah Thomas and Monica
Gorassini (Alberta, Canada) studied the effects of treadmill
training on brain-to-muscle nerve transmission through corticospinal tract
pathways in individuals with chronic, incomplete injuries (J
Neurophysiol 94, 2005). Mostly male, their age ranged from 29-78
years, and the time since injury ranged from 0.6-28 years. The subjects
trained on a body-weight supported treadmill for an hour five times a week
for nearly 17 weeks on average.
The capacity of these corticospinal tracts to
transmit nerve signals was measured by stimulating areas of the brain’s
motor cortex associated with target leg muscles. The stimulation was done
by a transcranial-magnetic-stimulation (TMS) device placed over the scalp
that activates descending neuronal pathways. The amount of signal getting
through to the leg muscles was then measured by surface EMG, a technique
in which electrodes are placed on the skin overlying a muscle to detect
the muscle’s electrical activity. Overall, the results indicated that such
treadmill training program improved ambulatory ability which was
associated with an increase in the transmission capacity between the brain
and the target muscles.
6) Dr.
Edelle Field-Fote et al (Miami, Florida) evaluated the effects
of bodyweight-supported, FES-assisted (functional electrical stimulation)
treadmill training on ambulation in 19 subjects with ASIA-C
incomplete injuries sustained at least one year before entry into the
study (Arch Phys Med Rehabil, 82(6), 2001). Training consisted of
three-times-a-week, 1.5-hour sessions for three months. All subjects
showed improvement in over-ground walking speed and lower extremity
strength.
In a study published the following year (Phys Ther
82(7), 2002), the investigators showed that such training also
improved intra-limb coordination in 9/14 subjects with chronic, incomplete
injuries.
In a 2005 article (J Neurol Phys Ther, 29(3)),
they reported the interim results of a study comparing various body-weight
supported training approaches: 1) treadmill training with manual
assistance, 2) treadmill training with FES stimulation, 3) over-ground
training with FES stimulation, and 4) treadmill training using robotic
assistance. Twenty-seven individuals with incomplete SCI were randomly
assigned to these groups. Preliminary data suggest that the accruing
benefits were comparable across training approaches.
In a 2009 article, the investigators reported the
results of treating 51 subjects with SCI with the aforementioned
body-weight-supported training approaches on various parameters of gait
quality. These parameters included cadence, step length, stride length,
symmetry index, intralimb coordination, and timing of knee extension.
The investigators concluded that “all training approaches were
associated with improvements in gait quality.”
Reported in 2011,
Dr. Edelle Field-Fote’s team compared the results of treating 71
patients with SCI randomized to one of the aforementioned training
approaches. In this study, the primary outcomes were walking speed and
the distance covered in two minutes. All subjects had ASIA C or D
incomplete injuries (see appendix) possessing minimal walking ability.
Subjects trained five days per week for 12 weeks with their assigned
approach. With the exception of the robotic-assistance method, all the
training approaches generated some walking improvement, with the most
benefits accruing from overground training. The investigators concluded
“overground locomotor training resulted in greater improvements in
functional walking capacity than did treadmill training.” They
speculated that such training produced the best results because it more
closely incorporated the dynamics of real-world walking.
7) Dr. Marcus
Wirz (Zurich, Switzerland) and colleagues
(USA and Germany) treated 20 subjects with chronic, incomplete injuries
with body-weight-supported treadmill training using the aforementioned
Lokomat robotic device (Arch Phys Med Rehabil 86, April 2005). All
subjects had ASIA C or D (see appendix) incomplete injuries; 11 and 9 had
tetraplegic and paraplegic injuries, respectively; and 18 were men and 2
were women. The time elapsing since injury and training onset ranged
between 2-17 (average 5.9) years, and mean subject age was 40 (range 16-64
years). Sixteen patients had some ambulatory ability before training.
The program consisted of three to five 45-minute
sessions per week for eight weeks. Ambulatory ability was assess by a
variety of tests, including 1) “Walking Index for SCI – II (WISCI-II),”
which assesses the amount of assistance required during ambulation and the
use of assistive devices or lower-extremity bracing, 2) a 10-meter walk
test to measure gait speed, 3) a 6-minute walk test to determine gait
endurance, and 4) a “Timed Up & Go” test to measure performance of
multiple tasks, such as getting up from a chair, walking, and returning to
chair.
After completing the program, only two subjects
improved in walking ability as assessed by the WISCI-II scores. However,
as evaluated by the other measures, most patients improved their gait
speed, endurance, and performance of functional tasks.
8) In 2012,
Dr. Susan J. Harkema and
colleagues (USA) published the results of a large, multicenter study
evaluating the impact of locomotor training-based rehabilitation on 196
individuals with incomplete injuries, all of whom retained some ability
to voluntarily move lower limbs. Of these individuals, 148 were men; 138
and 58 had cervical and thoracic injuries, respectively, and the time
since injury ranged from 32 days to over 25 years (~50% had been injured
a year or less). In terms of walking ability, 36% were nonambulatory,
36% used a walker, 21% used a cane, and 7% used no assistive devices.
On average, patients received 47 (minimum 20;
maximum 251) treatment sessions, consisting of one hour of
body-weight-supported treadmill training followed by an overground
assessment to evaluate progress and focus future training and an
integration component designed to incorporate improvements into daily
routines. To assess progress, patients were periodically tested with
three outcome measures: 1) balancing ability, 2) the distance covered in
six minutes of walking, and 3) the time it takes to walk 10 meters.
Eighty-seven percent of the patients demonstrated
improvement on at least one outcome measure, and 57% on all three
outcome measures. In general, patients whose injuries were more recent
tended to accrue greater benefits. The investigators concluded that
“rehabilitation, which provides intensive activity-based therapy, can
result in functional improvements in individuals with chronic incomplete
SCI.”
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