Transcranial direct current stimulation combined with isokinetic strength training to improve lower limb motor function in chronic stroke survivors: A randomized controlled study.

Abstract

Background: Lower limb motor dysfunction is a common sequela of stroke. Further research is needed to identify effective rehabilitation methods to improve motor function.

Objective: To investigate the therapeutic effects of transcranial direct current stimulation (tDCS) and isokinetic strength training (IST), both individually and in combination, on two primary outcomes: lower limb motor function and lower limb muscle strength in individuals with chronic stroke. Additionally, it also explored the effects on balance, gait, and muscle tone as secondary outcomes.

Design: Randomized controlled trial.

Setting: Inpatient department of university hospital.

Participants: A total of 56 individuals with chronic stroke (aged 35 to 77 years) were selected and randomly divided into four groups: control group (n = 14), tDCS group (n = 14), IST group (n = 13), and combined group (n = 15).

Intervention: Two intervention techniques were employed: (1) 20 minutes of 2 mA tDCS, and (2) 20 minutes of IST. In addition, all participants received 80 minutes of standard rehabilitation therapy.

Outcome measures: The primary outcomes were peak torque (PT) of knee flexion and extension and the Fugl-Meyer Assessment of Lower Extremity (FMA-LE) score. The secondary outcomes included the Berg Balance Scale, the 10-meter Walk Test, and the Modified Ashworth Scale scores. Data were collected at baseline and 4 weeks after the treatment.

Results: After 4 weeks of treatment, the tDCS group showed a significant increase in knee extension PT and FMA-LE scores compared to baseline data by 3.59 (p = .009) and 2.07 (p = .009) respectively. In the IST group, knee flexion, extension PT, and FMA-LE scores were significantly higher than baseline data by 5.67 (p = .001), 7.18 (p < .001), and 3.00 (p = .007), respectively. The combined group showed significant increases in knee flexion, extension PT, and FMA-LE scores compared to baseline data by 10.13 (p < .001), 13.04 (p < .001), and 5.27 (p < .001). The combined group showed significantly superior treatment effects compared to the control group, tDCS group, and IST group.

Conclusion: Both tDCS and IST were effective in improving lower limb muscle strength and motor function in individuals with chronic stroke, but the combination of these two techniques was more effective.