A sedentary lifestyle increases the likelihood of cardiovascular disease, muscle wasting, osteoporosis, decubitus ulcers and peripheral vascular problems.

We know that maintaining physical activity following spinal cord injury can be challenging, but also very rewarding by improving health and keeping these challenges at bay.

Although FES Cycling is now a proven method of maintaining health the scientific literature is not yet able to give complete guidance on optimising exercise protocols following spinal injury.  We do know that FES cycling appears to be best utilised for developing endurance as opposed to strength.

This article discusses a rational approach to exercise with FES Cycling - including the required frequency, duration and intensity of effort required for health gains.
 

Spinal cord injuries are classified as complete or incomplete depending on the level of function.  Complete damage results in little or no central nervous system outflow from autonomic or somatic areas.  The higher the level of spinal cord injury, the more paralysis.  For example, damage to the cervical region can result in quadriplegia, whereas damage to the thoracic or lumbar areas can result in paraplegia.

Individuals with lesions in the cervical and thoracic regions above T1 – quadriplegics – will have reduced sympathetic outflow to the heart and lungs.  This results in a reduction in cardiac output.  Exercise induced cardioacceleration and myocardial contractility are therefore limited. 

Furthermore the vasoconstriction reflex in non-active muscles is not apparent. Reductions in cardiac output limit blood flow to active muscles, which results in early onset of peripheral fatigue.  A low anaerobic threshold at less than 40% of V02 max or early anaerobiosis diminishes aerobic capacity.

Exercise or physical activity is difficult for quadriplegics with higher level, complete cervical lesions.  Since these individuals are sympathomectomized with limited chronotropic and inotropic mechanisms, exercise prescriptions that use target heart rates are inaccurate.

Quadriplegics who are unable to perform unassisted exercise can use a modality such as FES Cycling.  Candidates for FES Cycling must have intact and functional motor units (lower motor neurons and the muscle fibres they innervate)

A stretch reflex or muscle spasticity are usually present in these individuals.  Muscle contractions can be elucidated by placing electrodes on the muscles.

FES technology is peripherally induced and bypasses the central nervous system so increases in heart rate, blood pressure, vasoconstriction and diminished sweating mechanisms in non-active muscles does not result.
In some individuals, autonomic dysreflexia can result in elevated blood pressure, ie > 175 mmHg. Individuals at risk should be monitored during the initial FES sessions and users should avoid exercise in hot environments.

Here are some suggestions for wheelchair dependent users who are quadriplegic

Frequency – Exercise 3 times per week.  If you wish to exercise 5 times per week ensure that these sessions are short and allow plenty of recuperation time between workouts.

Modality – FES cycling

Duration – An aerobic protocol should utilise an intensity that allows the individual to achieve 15 to 30 minutes of continuous, active pedalling.  Intervals will most likely be required to achieve this at first.  Begin slowly, with 5 to 10 minutes of active exercise.

Intensity – Initially begin FES cycling with a resistance setting of 0 and gradually increase this over time.  If you try to use too much resistance too soon muscles will fatigue quickly and benefit will be reduced. As your muscles strengthen, resistance can be increased and you will still achieve an active cycling target of 15-30 minutes.

Other instructions
•    Avoid performing FES Cycling in overly warm environments
•    Record your progress to show your doctor at your next follow-up visit.
•    (The latest version of RehaMove allows extensive data recording and analysis)
•    Stop exercising immediately if you experience faintness or dizziness
•    Be aware of autonomic dysreflexia and be guided by your consultant

Finally.
Please regard these comments as for general guidance only. You should always take advice from your spinal injuries consultant before embarking on an FES Cycling programme.


Reference
Leutholtz, BC; Ripoli, I
Exercise and disease management
Published 1999
ISBN 0849387132