Biomedical Engineering Reference
In-Depth Information
induces numerous adaptations towards improved whole body fitness, particularly
within the skeletal muscles. These adaptations have positive sequelae for the pre-
vention and treatment of metabolic disorders (Hawley, 2009), especially amongst
individuals with neurological pathophysiology.
Regular muscle strength and aerobic fitness training are normally prescribed
to people with neurological disabilities to enhance their psychosocial and physical
wellbeing (Skidmore, 2008). Individuals with stroke may perform exercise (Aziz,
2008) or task-oriented training (Rensink, 2009) to preserve and restore their fitness
and functional capacity. People with traumatic brain injury (Bateman, 2001; Ross,
2009) may require regular exercise and physical training to improve their severely
impaired wellbeing (Mayo Clinic, 2009).
7.2.1 Spinal Cord Injury and Exercise
SCI generally results from a traumatic lesion to the neural tracts within the spinal
canal that results in sensory loss, motor deficit and bladder/bowel dysfunction
(Anderson, 2002; Lifshutz, 2004). The most common causes of spinal cord injury
are motor vehicle accidents (55%), followed by violence, falls, and recreational
sports participation (Yeo, 1998).
Since the affected population is primarily young adults, and with improved
medical treatment, the lifespan after SCI has significantly increased. However,
as cervical or thoracic lesion SCI may lead to loss of lower limb movements,
tetraplegia and paraplegia almost always result in significant physical decon-
ditioning. Consequently, individuals with SCI often have significant reduction
of their physical fitness due to limited movement capacity, which can lead to
secondary degenerative disorders such as diabetes, hypertension and the early
onset of cardiovascular disease (Jacobs, 2004). Effective rehabilitation, including
aerobic fitness and muscular strength training can be useful preventive measures
against secondary health problems.
Exercise is one possible strategy to reduce or reverse some of these post-
injury complications (Jacobs, 2004). In individuals with SCI, voluntary exercise
improves cardiovascular health, and increases the strength and endurance of the
limbs that undergo training (Hicks, 2003). In contrast to voluntary exercise, FES-
evoked training, which electrically stimulates the paralysed muscles to produce
coordinated movements offers unique benefits to the paralysed limbs (Creasey,
2004). Theoretically, greater physical fitness can be achieved by including the
lower limbs in the exercise as they make up the greater muscle mass of the body
(Jacobs, 2004). Therefore FES leg exercise systems are now being integrated into
their rehabilitation to optimize training (Sisto, 2009).
7.3 ELECTRICAL STIMULATION OF MUSCLES
Electrical stimulation-induced exercise applies trains of short, intense electrical
pulses to generate muscle contractions and thereby elicit an exercise response
(Dudley, 1999). Such artificially-evoked exercise usually involves the lower limbs,
