Acta Neurochir Suppl. 2007;97(Pt 1):395-402.Related Articles, Links
FES cycling.

Newham DJ, Donaldson Nde N.

Division of Applied Biomedical Research, School of Biomedical and Health Sciences, King's College London, London, UK.

Spinal cord injury (SCI) leads to a partial or complete disruption of motor, sensory, and autonomic nerve pathways below the level of the lesion. In paraplegic patients, functional electrical stimulation (FES) was originally widely considered as a means to restore walking function but this was proved technically very difficult because of the numerous degrees of freedom involved in walking. FES cycling was developed for people with SCI and has the advantages that cycling can be maintained for reasonably long periods in trained muscles and the risk of falls is low. In the article, we review research findings relevant to the successful application of FES cycling including the effects on muscle size, strength and function, and the cardiovascular and bone changes. We also describe important practical considerations in FES cycling regarding the application of surface electrodes, training and setting up the stimulator limitations, implanted stimulators and FES cycling including FES cycling in groups and other FES exercises such as FES rowing.

Med Sci Sports Exerc. 2007 May;39(5):764-80.Related Articles, Links
Functional output improvement in FES cycling by means of forced smooth pedaling.

Szecsi J, Krause P, Krafczyk S, Brandt T, Straube A.

Center for Sensorimotor Research, Department of Neurology, Ludwig-Maximillians University, Munich, Germany.

PURPOSE: Investigation of the influence of forced smooth and normal (nonsmooth) pedaling on the functional output of outdoor functional neuromuscular electrical stimulation (FES)-propelled cycling of spinal cord-injured subjects. SUBJECTS: Twelve subjects with complete spinal cord injury (T4-T12) and limited previous FES training. METHOD: Each subject participated in two separate outdoor sessions: once while pedaling a tricycle in a fixed gear, and a second time while free pedaling the same tricycle; both times with FES. Data on distance covered until exhaustion, cadence, and pedal forces were collected. Energy balance calculations led to evaluations of jerk loss and joint-related concentric/eccentric work. RESULTS: First-trial and total session distances were 68 and 103% longer, respectively, in the forced smooth cycling session than in the free cycling session (P < 0.001). Significantly more additional crank work (accompanied by increased concentric work production) was generated in nonsteady cycling phases to overcome increased jerk losses during free than during fixed-gear pedaling. During fixed-gear pedaling, timing and joint location of muscle work generation were more similar to the cycling of able-bodied subjects than during freewheel pedaling, because most work was generated by knee extensors in the power phase during the former pedaling mode. CONCLUSIONS: The superiority of forced smooth cycling to free cycling, as regards functional output distance, is based on less energy expenditure (less jerk loss and muscle tension) and on more efficient production of energy (more efficient timing and joint location of work production). Some energetic mechanisms that are advantageous for fixed-gear cycling act predominantly in unsteady phases; others work continuously during all phases of cycling.

I was impressed with positive vascular change in two weeks.

Arch Phys Med Rehabil. 2006 Apr;87(4):474-81.Related Articles, Links
Rapid vascular adaptations to training and detraining in persons with spinal cord injury.

Thijssen DH, Ellenkamp R, Smits P, Hopman MT.

Department of Physiology, Institute for Fundamental and Clinical Human Movement Sciences, the Netherlands.

OBJECTIVE: To assess the time course of arterial adaptations during 6 weeks of functional electric stimulation (FES) training and 6 weeks of detraining in subjects with spinal cord injury (SCI). DESIGN: Intervention study (before-after trial). SETTING: University medical center. PARTICIPANTS: Volunteer sample of 9 subjects with SCI. INTERVENTIONS: Six weeks of twice weekly FES cycling and 6 weeks of detraining. MAIN OUTCOME MEASURES: Vascular characteristics were measured by plethysmography (baseline and peak blood flow of the thigh) and echo Doppler (diameter of the femoral artery and flow-mediated dilation [FMD]). RESULTS: After 2 weeks of FES training, arterial characteristics changed significantly; there was an increase in baseline and peak blood flow, an increase in femoral artery diameter, and a decrease in FMD of the femoral artery. Detraining reversed baseline and peak thigh blood flow, vascular resistance, and femoral diameter toward pretraining values within 1 week. However, detraining did not restore the FMD of the femoral artery, even after 6 weeks. CONCLUSIONS: Two weeks of hybrid FES training (4 exercise bouts) is sufficient to improve peak leg blood flow and arterial diameter, and to normalize FMD. In addition, detraining results in rapidly reversed vascular characteristics within 1 week.