Objective
This study aimed to assess optimal stimulation intensity and to investigate other variables on functional electrical stimulation (FES) for hemiplegic upper limb.

Method
We divided hemiplegic subjects into two groups, acute (n=28) and chronic (n=18), and control subjects into old (n=26) and young (n=27). Electrical stimulation was performed on the forearm of both sides in hemiplegic patients and of the nondominant side in normal controls. The stimulation site that aimed at open hand motion was targeted to the extensor digitorum and extensor pollicis brevis muscles. We measured the peak to peak amount of current and skin impedance while making hand extension.

Results
The acute and chronic hemiplegic groups required a greater current than the control groups (p＜0.01). The hemiplegic side required a greater current than the non- hemiplegic side (p＜0.001). There was no significant difference of current amount between the acute and chronic hemiplegic groups. The current amount was significantly correlated with subject's age (p=0.001). No difference of skin impedance was found among any of the groups.

Conclusion
Irrespective of disease duration on hemiplegia, a greater current is required in the hemiplegic upper limb than in the normal upper limb. Age was an important factor in determining stimulation intensity. (J Korean Acad Rehab Med 2002; 26: 379-384)