BACKGROUND: Studies have shown that sensory transduction is a way to introduce needle sensation. OBJECTIVE: To observe the influence of electro-acupuncture at the Zusanli (ST 36) point on lower extremity motor function in various sensory disturbance patients with cerebral stroke.DESIGN, TIME AND SETTING: A randomized, controlled, clinical study was performed at the Department of Neurological Rehabilitation, China Rehabilitation Research Centre from September 2006 to June 2008.PARTICIPANTS: Patients with first-time cerebral infarction or hemorrhage, or with a stroke history, but no neurodysfunction (single damage), were selected for this study. The subjects were right-handed and disease state was stable. A total of 240 inpatients were randomly assigned to the following groups: electro-acupuncture (n = 124) and control (n = 116). The two groups were further assigned into sub-groups: no sensory disturbance, superficial sensory disturbance, deep sensory disturbance, and deep and superficial sensory disturbance. METHODS: On the basis of routine limb function training, the acupoint Zusanli was utilized in all patients from the electro-acupuncture group. Perpendicular acupuncture was 3.0-4.0 cm deep. An electric acupuncture instrument was connected when patients developed the needle sensation, deqi. A stimulation patt consisting of distant and dense waves of 50 Hz was used to elicit slight dorsal foot extension. Acupuncture was administered 5 times per week, 30 minutes per session, for 6 weeks in total.MAIN OUTCOME MEASURES: Fugl-Meyer assessment (FMA) was used to evaluate lower extremity motor function; Ver.1.0 gait analysis to estimate gait (step frequency, step speed, and step scope); lower extremity Composite Spasticity Scale (CSS) to estimate muscle spastic degree.RESULTS: Following treatment, motor function improved in both groups. Compared with the control group, FMA score, step speed, step frequency, and step scope were increased in the electro-acupuncture group, but there was no difference in lower extremity CSS scores between the electro-acupuncture and the control groups (P > 0.05). Compared with the control group, Zusanli (ST 36) electro-acupuncture improved motor function indices as follows: FMA score, step frequency, step speed, and step scope of patients with no sensory disturbance (P < 0.05-0.01), step frequency of patients with superficial sensory disturbance (P < 0.05), and step frequency and step speed of patients with deep sensory disturbance (P < 0.05). CONCLUSION: Zusanli (ST 36) electro-acupuncture effects on lower extremity motor function in stroke patients were improved with no muscle tone rise. Therefore, this form of treatment can be used in convalescent treatment. Moreover, effects were different according to various sensory disturbance types, which suggested that sensory input influenced acupuncture effects.