Many aggressive rehabilitation programs have
incorporated body-weight-supported (BWS) treadmill training to enhance
ambulatory ability after spinal cord injury. This training apparently
develops new function-restoring neuronal networks and triggers the
spinal-cord’s “central-pattern generator,” a sort of brain within the
spinal cord that can sustain lower-limb repetitive movement, such as
walking, independent of direct brain control. The article summarizes
various research studies evaluating the impact of treadmill training.
Because specific procedures often vary considerably, it is hard to
over-generalize the results. Some studies suggest considerable benefits,
and others do not.
A key pioneer in developing treadmill training for
SCI is Dr. Anton Wernig (Karlsbad, Germany), a scientist I’ve met
who seems to have almost a Zen-like appreciation of movement in those
with SCI (www.meb.uni-bonn.de/wernig).
In 1992, Wernig and colleagues reported the results of training eight
individuals with incomplete SCI with a variable speed treadmill, on
which the individual was partially supported with a harness (Paraplegia
To enhance correct ambulatory movements, therapists
assisted the subjects. With practice, 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 improved their
ambulation, 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 handrail and one cane.”
In 1995, the investigators reported the results of
a larger study evaluating such training in 44 patients with chronic SCI
(Eur J Neuroscience 1995; 7(4)). The patients had sustained their
injuries ˝ -18 years before initiating 3-20 weeks of training. Most
improved their ambulation. Fourteen of 18 patients learned to walk
without help from others compared to 1 of 14 of those who received
Follow-up assessments indicated that 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
addition, after training, 36 of the 44 patients were capable of stair
walking compared to only six before. Of acutely injured patients, 92%
who used wheelchairs became independent walkers after treadmill training
compared to only 50% after conventional therapy.
Dr. A. L. Hicks et al. (Hamilton, Ontario)
studied the effects of long-term, BWS treadmill training in 14 subjects
(11 men, 3 women) with chronic, incomplete SCI (Spinal Cord 2005;
43(5)). The time since injury ranged from 1.2 to 24 years. Subjects
exclusively trained on the treadmill three times a week for a total of
144 sessions over a 12-15 month period. All subjects who completed the
program improved their treadmill walking ability, including a 54%
reduction in body-weight support, a 180% improvement in walking speed,
and a 335% in the distance covered per session (from 221 to 961 meters).
The improvements were associated with increased
life satisfaction 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. Some improvements diminished over time as
subjects discontinued training. Although such training appeared to
reverse post-injury muscle atrophy, it did not prevent bone loss. The
program did not include over ground walking. (Spinal Cord 2005;
Dr. Bruce Dobkin (Los Angeles, Calif) and
associates compared high-speed BWS treadmill training with a control
program of aggressive over-ground mobility training (Neurology
2006; 66(4)). Injured for fewer than eight weeks, 146 subjects were
recruited from six centers. Subjects were randomized to a 12-week
treadmill or control program (e.g., aided over-ground walking, etc.),
both providing an hour of training per session for at least 45 sessions
over 12 weeks or until reaching a defined level of restored ambulation.
The investigators were unable to detect differences in benefits accruing
between the treadmill and control groups. In a later commentary, Wernig
noted this outcome was to be expected due to equal amounts of upright
Dr. Marcus Wirz (Zurich, Switzerland) and
colleagues (U.S.A. and Germany) treated 20 subjects (18 men, 2 women)
with incomplete, chronic injuries with BWS treadmill training using the
Lokomat, a robotic treadmill device (www.hocoma.ch)
that minimizes the need for assisting therapists (Arch Phys Med
Rehabil 2005; 86).
time elapsing since injury and training ranged between 2-17 years, and
participants’ age ranged from 16 to 64 years. Sixteen had some
ambulatory ability before training.
The program consisted of three to five 45-minute
sessions per week for eight weeks. Ambulatory ability was assessed by a
variety of tests, most of which, - but not all - demonstrated
improvement. Subjects showed better gait speed, endurance, and
performance of functional tasks.
Dr. Patricia Winchester et al. (Dallas)
examined the effects of 12 weeks of BWS treadmill training using the
Lokomat on the brain’s neuronal activity in four men with incomplete
cervical injuries (Neurorehabil Neural Repair 2005; 19(4)).
These subjects sustained their injuries 14 weeks to four years before
starting the program and had sufficient range of motion to stand and
some ankle and toe movement.
The study’s goal was to measure the differences in
brain neuronal activity before and after training - i.e., does treadmill
training promote walking through brain reprogramming? To measure the
intensity of walking-associated brain activity, subjects flexed their
ankles and curled their toes while keeping their heads motionless within
a MRI device. After 12 weeks, three of the four subjects demonstrated
improved walking, and all exhibited increased activity in brain areas
associated with walking.
Drs. Sarah Thomas and Monica Gorassini
(Alberta, Canada) studied the effects of BWS treadmill training on
brain-to-muscle nerve transmission through spinal pathways in
individuals with chronic, incomplete injuries (J
Neurophysiol 2005; 94(4)). Age and
time since injury ranged from 29-78 years and 0.6-28 years,
respectively. On average, the subjects trained for an hour five times
weekly for nearly 17 weeks.
The capacity of these pathways to transmit nerve
signals was measured by stimulating brain areas associated with specific
leg muscles through 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
a device in which electrodes are placed on
the skin over a muscle to detect electrical activity. Results
indicated that the treadmill training improved ambulatory ability, which
was associated with an increase in the transmission capacity between
brain and leg muscles.
Miami Project’s Dr. Edelle Field-Fote et al.
evaluated the effects of BWS, FES-assisted (functional electrical
stimulation) treadmill training on ambulation in 19 subjects with
incomplete, chronic injuries (Arch Phys Med Rehabil 2001; 82(6)).
Training consisted of three-times-a-week, 1˝ -hour sessions for three
months. All subjects improved walking speed and lower extremity
Later, the investigators reported the results of a
study in which 27 individuals with incomplete SCI were randomly assigned
to the following groups: 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 (J
Neurol Phys Ther 2005; 29(3)). Benefits seemed comparable across
Reflecting the ancient adage that a journey of a
thousand miles begins with a single step, no-nonsense, hard-work
treadmill training is increasingly being incorporated into a variety of
rehabilitation programs to maximize restored function after SCI.
Although questions linger concerning the magnitude of its impact,
numerous studies suggest that it promotes some ambulatory recovery.
However, many “the-devil-is-in-the-details”
variables confound the comparison of results between studies.
Adapted from an article appearing in the February
2007 Paraplegia News (For subscriptions, call 602-224-0500 or go