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"B" Level Review of Literature Paper: |
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A Review of Literature of The Importance of Exercise for the Spinal Cord Injured Population
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INTRODUCTION............................................................................................1 LITERATURE
REVIEW..................................................................................2 Investigation of Physiological Responses of SCI
Patients........................3 Designing an Exercise Prescription for the SCI
Patient.............................4 Summary and
Conclusion.........................................................................5 REFERENCES..................................................................................................6
The Benefits of Training for SCI
Patients.................................................2
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Current estimates show the prevalence of spinal cord injury in the United States to be from 250,000 to 300,000 people, with approximately 10,000 new injuries occurring each year (Wells and Hooker, 1990 p. 270). With rates of spinal cord injury being this high, persons with spinal cord injury (SCI) represent a significant portion of the population. Due to the confinement to wheelchairs, SCI often has a devastating effect on the lives of the injured persons. The psychological effects of a spinal cord injury can be a major setback to the rehabilitation process. The victims often have a very bitter attitude towards life, and the desire to regain the healthy body they may have once had is often gone (Rimmer, 1994, p.238). In the past, the life expectancy for SCI patients was significantly lower than the rest of the population due to many diseases which the SCI’s were especially susceptible. Today, due to medical advances, the risk of those infectious diseases are no longer a primary concern, (Cooper, Baldini, Langbein, Robertson, Bennet, and Monical, 1993 p. 560), however the life expectancy is still shortened due primarily to cardiovascular and respiratory disease. Nearly half of the deaths of SCI patients are due to one of these (Wells and Hooker, 1990 p. 273). Jochheim and Stohkendl (1973) gave several reasons for the increased risk of cardiovascular diseases which included 1) Occupations which are not physically challenging, 2) Poor eating habits due partly to overnutrition and partly to weakness of the autonomic nervous system, 3) Luxuries such as tobacco and alcohol to compensate for feelings of loss, 4) Nervous tension or stress, and 5) A sedentary lifestyle often confined to the home or limited radius with little or no exercise involved. The key appears to be exercise. The benefits of exercise for the ambulatory population are well known and documented (Wilmore and Costil, 1994), however until recently, the benefits of exercise for SCI were not studied. Exercise may be even more crucial for a Sd patient because of the psychological benefits as well as the physiological benefits. Jochheim and Strokhendl (1973) point out "The incentive of physical exercises toward activity promises a stabilisation of the personality and social integrative effects by enabling experiences of success and mutual participation." This purpose of this paper is to provide a review of what is known about SCI and exercise benefits. Differences between the fitness levels of trained and untrained SCI patients will be investigated. Also, it will review different physiological responses to exercise including aerobic capacity, physical work, and pulmonary function. Finally the design of an exercise protocol for different types of SCI will be discussed including benefits and trouble spots. |
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The Benefits of Training for SCI Patients The benefits of cardiovascular exercise and training can be easily noted by comparing trained SCI athletes with untrained SCI patients. It must be noted (and will be further discussed later) that training benefits are somewhat contingent upon the level of spinal cord injury. A study by Bhambhani, Holland, Eriksson, and Steadward (1994 p. 260) investigated physiological responses during wheelchair racing comparing quadriplegics to paraplegics. They found the peak values of V02, heart rate, and VE which were obtained during incremental velocity wheelchair exercises to be significantly higher in paraplegics than quadriplegics. No significant differences were found between these groups for 02 pulse (which is the oxygen utilization per heart beat). These findings are consistent with other researchers who investigated the same responses for these two groups (Eriksson, Lofstom, and Ekblom,1988 p. 145). The previously mentioned study by Eriksson et al (1988) also investigated the aerobic power during a maximal exercise by comparing trained versus untrained quad and paraplegics. They found peak V02 differences to be as high as a 38% increase for trained athietes versus nontrained. They noted that a well trained quadriplegic individual is physiologically comparable to an untrained paraplegic with a low level injury, therefore, physical training can largely reduce the differences between quadriplegics and paraplegics. Also by comparing the trained paraplegic athletes to non trained able bodied persons, the able bodied persons achieved only a slightly higher V02 peak, again pointing out the benefits of training. Eriksson et al (1988) as well as Coutts, Rhodes, and McKenzie (1983 p. 479) attempt to provide reasons for the differences between quad and paraplegic performances. One difference they point out is that quadriplegics were traditionally not allowed to do any hard physical training. It was not until 1982 that quadriplegics were able to compete in distance events over 200 meters. The most probable explanation for the differences is likely due to the smaller amount of functional muscle and loss of sympathetic activity for high level quadriplegic injuries. Paraplegics have more working muscle mass as well as trunk stability which is important. The loss of sympathetic nervous innervation affects cardiac performance. Quadriplegics will have a significantly lower peak heart rate (123 average) compared to paraplegics (184 average). The low peak heart rate results in a lower maximal cardiac output. Each year research is performed in conjunction with the Oita International wheelchair marathon in Japan. Studies related to the differences between highly trained and untrained athletes have been a primary focus of Okuma, Ogata, and Hatada (1989), and Ide, Ogata, Kobayaski, Tajima, and Hatada (1994). The 1994 study by Ide et al focused on comparing the anthropometric features of competitors who were deemed fine or poor racers based on the ability to finish the race. The study was a culmination of nine consecutive years of research. Large significant differences were found nearly each year for lung vital capacity and the muscle power of the upper arm of the fine racers compared to poor. For example and average lung capacity for the fine racers was 4325 ml and the average for the poor racers was 3346 ml. An average muscle power was 42 kg for the fine racers and 20.8 kg for the poor. The researchers expected to see significant differences due to age, weight, and body fat percentage, but few were seen. This shows that strength and aerobic training are much more important than age and weight for performance. The study by Okuma et al (1989 p. 237) focused mainly on oxygen consumption for well trained versus non athletic racers. The well trained group had a 38% higher value of oxygen consumption than the non athletic racers. This study also tested racers over successive years and found that each athlete who was tested repeatedly increased their personal oxygen consumption from year to year. Finally this study tested during the off season as well and found the physical fitness to have decreased for both groups however the fitness of the well trained group was still significantly higher in the off season than the non athletes. A spinal cord injury often severely impairs the immune system, and studies have shown that rehabilitation and exercise can have a significant impact in the return of near normal immune function. Kliesch, Cruse, Lewis, Bishop, Brackin, and Lampton, (1996, p.82) studied immune function in 49 spinal cord injury patients. Compared to normal age-matched subjects, the natural killer (NK) cell function was reduced to only 21% of that in healthy individuals at two weeks post injury. T cell function decreased to 40.2% of normal, and T cell activation was also highly diminished. With rehabilitation therapy and exercise these values increased dramatically by 7 months post injury. By seven months post injury, the NK cell function was increased to 42% of the normal, and T cell function increased to 92% of the normal, (Kliesch, et al, 1996, p87). Since it was mentioned earlier that spinal cord injury patients previously were very susceptible to infectious disease which often led to premature death, (Rimmer, 1994, p206), rehabilitation and exercise are one of the keys to returning the body’s immune system function to normal, therefore making SCI patients less susceptible to deadly diseases. Another devastating metabolic consequence of spinal cord injury is the acute disruption of normal calcium balance. This contributes to a rapidly evolving osteopenia, or loss of bone mass, which can be a permanent consequence. The volume of cancellous bone in the body of a SCI patient can be reduced by as much as 33% within only 6 months of injury (Bloomfield, Mysiw, and Jackson, 1996, p. 61). This reduction in bone mass makes SCI patients at extreme risk for fractures, especially later in life. A special type of therapy known as functional electrical stimulation (PBS) cycle ergometry (Rimmer, 1994, p. 231) has been developed in the past ten years as a practical means of inducing function muscle contractions in the paralyzed lower extremities. Bloomfield, et al, 1996, p.62) used FES training over a period of 9 months to investigate whether exercise training could increase the bone mass after SCI. With FES therapy a 78% increase in serum oseocalcin was observed, indicating an increase in bone turnover. The data in this study suggest that FES may be used to increase bone mass in specific areas of the body which have been severely reduced after injury. |
Investigation of Physiological Responses of SCI
Patients Spinal Cord Injury patients represent a very specific
population, whose physiological responses differ
significantly from those of normal, able bodied persons
(Pare, Noreau, and Simard, 1993, p.584). For example, many
tests of cardiac and king function have focused on running
or biking, thus the utilization of the lower limbs was
necessary. Since SCI patients do not have the use of lower
limbs, tests were developed to predict their cardiac and
pulmonary fitness based on upper body exertion tests. These
tests produce differing results compared to lower extremity
based tests (Pare, et al, l9913,p. 584), therefore a body
research exists to test these subjects for physiological
responses and establish peak values and norms for this
population. The following section will highlight some areas
of this work. Cooper, Baldini, Langbein, Robertson, Bennett, and
Monical (1993, p. 560) tested the pulmonary function of
wheelchair users to establish a set of equations to predict
the pulmonary function for SCI patients. Since SCI often
impairs many of the pulmonary muscles such as the diaphragm
and intercostals, respiratory function is often
significantly decreased in SCI patients. Baldini, et al,
(1993, p.569) found that for male subjects the time since
the injury and the level of the injury strongly affect the
pulmonary function. Other factors such as age, height, and
weight were not as important for prediction. The study also
found gender differences in pulmonary function. A survey of
subjects was used to assess the exercise habits of the
subjects, and the subjects who indicated regular
cardiovascular exercise produced higher values of pulmonary
function. Coutts, (1988, p43) investigated the heart rate responses
of SCI patients during several different wheelchair sport
activities to investigate which produced the highest heart
rates over sustained periods. Coutts found that the average
heart rate elicited during a wheelchair basketball game was
148 bpm. This was the highest average heart rate. Other
sports elicited lower rates, including volleyball (115),
tennis (128), and racquetball (134). Although these heart
rate values are slightly lower overall than the average able
bodied population during these sports, the data is
consistent with their findings. Since basketball requires a
constant state of physical exertion compared to volleyball
which involves more short anaerobic bursts, the average
heart rates during basketball should likely be higher
(Coutts, et al, p. 49). Rotstein, Sagiv, Ben-Sira, Werber, Hutzler, and Annenburg
(1994, p.196) studied the aerobic capacity and anaerobic
threshold of wheelchair basketball players. These tests were
performed on a wheelchair treadmill in a graded exercise
test, and also using an arm cycle ergometer. During each
test, respiratory and oxygen uptake were measured to
determine maximal aerobic capacity and anaerobic threshold.
The tests performed by Rotstein, et al, (1994, p.
200) were on a rather homogeneous group of athletes (male,
same age range, basketball players). They found their
subjects to have a lower aerobic capacity compared to
previous studies such as Veeger, Hadj Yabmed, Van der Woude,
and Charpentier (1991, p. 1207), in which a more heterogenic
group was used as subjects. Also the method of testing is
important to accurately evaluate aerobic capacity and
anaerobic threshold. The researchers point out that the
wheelchair ergometer (treadmill) be more difficult because
of trying to keep the wheelchair on a straight course, and
therefore may yield values of aerobic capacity which are
higher than an arm cycle ergometer (Rotstein, et al,
1994, p. 201). Pare, Noreau, and Simard, (1993, p. 584) used a
submaximal exercise test to predict the maximal aerobic
power generated by paraplegics on a wheelchair ergometer.
They point out that a submaximal test is more appropriate
than a maximal effort test to predict aerobic power for
several reasons. Newly spinal cord injured patients usually
have a very low fitness level following hospitalization
which put them at risk for adverse reactions to maximal
training including the risk of vertebral fractures. They
stressed again the need for a standardized piece of
equipment such as the wheelchair ergometer to most
accurately predict that aerobic power and establish norms.
Some of their significant findings included that maximal
heart rate for paraplegic patients was only approximately 5
bpm lower than the predicted maximum (220
- Age). Also, they
pointed out that lean body mass contributed to an increased
accuracy of the prediction of aerobic power. A larger upper
body muscle mass allows a higher efficiency of physiological
adaptation to wheelchair exercise, while a smaller muscle
mass may induce inappropriate adaptations to exercise such
as poor muscle blood flow, higher muscle tension, and rapid
contribution of anaerobic metabolism (Pare, 1993, p.
592).
Designing an Exercise Prescription for the SCI
Patient The benefits and importance of cardiovascular exercise
for SCI patients has been established throughout this paper.
How can this research be used to help design an exercise
prescription for the newly spinal cord injured patient? One of the most important considerations in setting
cardiac and pulmonary rehabilitation and exercise goals for
a person with an SCI is the level of injury. Due to
different nervous intervention at each vertebrae of the
spinal column, rehabilitation expectations will be different
depending upon the where in the spinal column the injury
occurred. Rimmer (1994, p. 219) gives provides a
comprehensive list of which muscles can be expected to
function with each level of SCI. For example, a person with
a C4 (cervical vertebrae #4) injury will retain
only the scapular elevators which are the trapezius and the
diaphragm. Therefore they are unable to use the arms, trunk,
and lower extremities. Persons with injuries at this level
require assistance with nearly all activities of life, and
cardiovascular fitness is difficult. Most of their exercise
program will be to maintain the body muscle’s range of
motion to prevent contractures (in which the muscle loses
its flexibility and assumes a shortened position). A person with a C78 injury is much different.
They have use of all of their upper limb muscles, however
they don’t have use of their intercostal and abdominal
musculature. They can ambulate a wheelchair independently,
therefore will be able to undergo cardiovascular training.
Thoracic vertebrae injuries allow the use of the abdominal
and intercostal muscles to a full extent, therefore they
have the ability to generate greater amounts of power when
performing cardiovascular events such as racing. Also, they
will generate higher peaks in physiological tests such as
VO2max. According to Rimmer (1994, p. 225)$o promote improved
fitness for wheelchair users, arm exercise protocols should
follow those of leg exercises. This means the exercises
should be performed at intensity and duration beyond what is
encountered in everyday life. Intensity and duration should
be steadily increased until performance goals are met. The
best method for quadriplegic patients to improve
cardiovascular fitness is with an arm crank ergometer (ACE).
Even if the patient does not have use of their hands, the
hands can be strapped to the pedals of the ACE and they can
still operate the machine. Paraplegics can function closer
to their maximal heart rate because their sympathetic drive
is intact, and their exercise programs should be geared
toward exercising at 70% of their maximum (Rimmer, 1994, p.
128). Paraplegics can benefit from both ACE and wheelchair
ergometers as well as road and track exercises. Strength training is a very necessary component of the
exercise program for any SCI (Rimmer, 1994, p. 233). The
maintenance of upper body musculature is extremely important
for performing the activities necessary for daily living.
Also, intensive flexibility exercises are necessary for the
entire body to prevent contractures. As with any person who engages in physical activity there
is an inherent risk of injury. SCI patients must be closely
monitored because they are susceptible to different types of
injury. Wilson and Washington, (1993, p. 334), documented
the prevalence of different types of injury in pediatric
wheelchair athletes. The most common injuries were minor
such as blisters, wheel burns, and foot scrapes. These can
be prevented most easily by gloves and special shoes. Of
more concern however are injuries which involve overheating.
Many patients with SCI have defective thermoregulatory
mechanisms (Rimmer, 1994, p.Z3S) and therefore are
susceptible to hyperthermia. Almost 50% of the athletes in
Wilson and Washington’s study (1993, p. 334)
experienced hyperthermia. It is recommended that persons
with SCI only exercise outside when the temperature is below
70 degrees (Rimmer, 1994, p. 236). Other common injuries of
SCI patients include pressure sores. These are sores like
decubitous ulcers which occur due to the body weight being
centered on one body prominence for extended periods of
time. These often occur over the buttocks area in SCI
patients because of the pressure of sitting in a wheelchair
(Rimmer, 1994, p. 236). The best way to prevent pressure
sores is to provide the patient with the best available pad
for their wheelchair seat. To best aid the SCI patient to achieving their fitness
goals, caution is most important. Monitoring both the
patient’s blood pressure and perceived rate of
exhaustion is important. Glaser (1989, p. 265) points out
that blood pressure responses for persons with SCI can be
very different than able bodied persons. Quadriplegics often
produce a dramatic drop in blood pressure as exercise
progresses. Other injured persons may have hyperreflexia. In
both of these cases, the exercise must be stopped.
Summary and Conclusion This paper has reviewed the scientific literature
available as to the importance of exercise for a person with
a spinal cord injury of any type. A spinal cord injury is a
profound life impacting event, which can lead to devastating
consequences. Exercise and fitness, however, can greatly
increase the quality of life of these individuals. Fitness
can lead to greater independence as well as longer life
expectancy and reduced risk of cardiovascular and pulmonary
diseases. All of the literature studied points out the
importance of continued research in this area. Being a
relatively new field of study since wheelchair sports were
not introduced until the 1950’s, there is still much to
be learned about exercise and SCI. All of the benefits are
still unknown, but the benefits which have been documented
cannot be ignored
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REFERENCES Bhambhani, Y., Holland, L., Eriksson, P., &
Steadward, R. (1994). Physiological Bloomfield, S., Mysiw, W., & Jackson, R. (1996). Bone mass and endocrine adaptations to training in spinal cord injured individuals. Bone,19, 61-68. Coutts, K., Rhodes, E., & McKenzie, D. (1983). Maximal exercise responses of tetraplegics and paraplegics. Journal of Applied Physiology, 55, 479-485. Coutts, K. (1988). Heart rate of participants in wheelchair sports. Paraplegia, 26, 43-49. Cooper, A., Baldini, F., Langbein, W., Robertson, R. & Bennet, S. (1993). Prediction of pulmonary function in wheelchair users. Paraplegia, 31, 5 60-570. Eriksson, P., Lofstrom, L., & Ekblom, B. (1988). Aerobic power during maximal exercise in untrained and well trained persons with quadriplegia and paraplegia. Scandinavian Journal of Rehabilitative Medicine, 20, 14 1-147. Glaser, R. (1985). Exercise and the locomotion for the spinal cord injured. Exercise and Sport Sciences Reviews, 13. 263-303. Ide, M., Ogata, H., Kobayashi, M,Tajima, F., & Hatada, K. (1994). Antrhopometric features of wheelchair marathon race competitors with spinal cord injuries. Paraplegia, 32 174-179. Jochheim, K., & Strohkendl, H. (1973) The value of particular sports of the wheelchair-disabled in maintaining health of the paraplegic. Paraplegia, 11, 173-176. Kliesch, W., Cruse, J., Lewis, R., Bishop, G., Brackin, B, & Lampton, J. (1996). Restoration of depressed immune function in spinal cord injury patients receiving rehabilitation therapy. Paraplegia, 34, 82-90. Okuma, H., Ogata, H., & Hatada, K. (1989). Transition of physical fitness in wheelchair marathon competitors over several years. Paraplegia, 27, 237-243. Pare, G., Noreau, L, & Simard, C. (1993). Prediction of maximal aerobic power from a submaximal exercise test performed by paraplegics on a wheelchair ergometer. Paraplegia, 31, 584-592. Rimmer, J., (1994) Fitness and rehabilitation programs for special populations. Brown and Benchmark, Madison, WI. Rotstein, B., Sagiv, M., Werber, G., Hutzler, J., & Annenburg, H. (1994). Aerobic capacity and anaerobic threshold of wheelchair basketball players. Paraplegia, 32, 196-201. Veeger, H., Hadj, J., Yahmed, M., VanderWoude, L., Charpentier, P. (1991). Peak oxygen uptake and maximal power output of olympic wheelchair-dependent athletes. Medical Science Sports Exercise, 23, 120 1-1209. Wells, C., & Hooker, 5. (1990). The spinal injured athlete. Adapted Physical Activity Ouarterly, 7, 265-285. Wilmore, J., & Costill, D. (1994). Physiology of sport and exercise. Champaign: Human Kinetics. Wilson, P., & Washington, R. (1993). Pediatric wheelchair athletics: sports injuries and prevention. Paraplegia, 31, 330-337 |