Muscle oxygenation during hybrid arm and functional electrical stimulation-evoked leg cycling after spinal cord injury

This study compared muscle oxygenation (StO(2)) during arm cranking (ACE), functional electrical stimulation-evoked leg cycling (FESLCE), and hybrid (ACE+FES-LCE) exercise in spinal cord injury individuals. Eight subjects with C7-T12 lesions performed exercises at 3 submaximal intensities. StO(2) was measured during rest and exercise at 40%, 60%, and 80% of subjects' oxygen uptake (VO2) peak using near-infrared spectroscopy. StO(2) of ACE showed a decrease whereas in ACE+FES-LCE, the arm muscles demonstrated increasing StO(2) from rest in all of VO2) peak respectively. StO(2) of FES-LCE displayed a decrease at 40% VO2 peak and steady increase for 60% and 80%, whereas ACE+FES-LCE revealed a steady increase from rest at all VO2 peak. ACE+FES-LCE elicited greater StO(2) in both limbs which suggested that during this exercise, upper-and lower-limb muscles have higher blood flow and improved oxygenation compared to ACE or FES-LCE performed alone.