Arm crank exercise with static leg FNS in persons with spinal cord injury

Persons with spinal cord injury experience considerable difficulty, during aerobic exercise, in achieving even moderate levels of oxygen uptake. Therefore, the effect of static functional neuromuscular stimulation (FNS) on this parameter during arm crank exercise (ACE) was investigated. Eight subjects with spinal cord injury, lesion levels range C6-T12, performed ACE at 60% and 80% of VO2peak, both with and without concurrent FNS of the lower limbs. ACE was performed with no FNS, with FNS at 40 milliamperes (mA), and with FNS at 80 mA. Significant differences in oxygen uptake were found between ACE without FNS and ACE with FNS-80 mA at 60% VO2peak (10% increase, 12.5 ml.kg-1.min-1 to 13.7 ml.kg-1.min-1, P < 0.05), and between ACE without FNS and ACE with FNS-80 mA at 80% VO2peak (16%, increase, 14.8 ml.kg-1.min-1 to 17.2 ml.kg-1.min-1, P < 0.01). A 10% difference between ACE without FNS and ACE with FNS-40 mA, did not reach significance. These data indicate that, in this population of subjects with spinal cord injury, (a) FNS can increase submaximal ACE oxygen uptake, and (b) that such increases are enhanced both at higher levels of FNS and of work load. Implications for wellness are discussed.