Introduction:
Stroke survivors develop substantial disability such as weakness, spasticity, increased stiffness, and reduced range of motion in lower limbs, contributing to reduced quality of life. It is important to stretch impaired ankle and knee to increase range of motion and reduce spasticity, and to conduct active movement training to improve balance and locomotion.
Hypothesis:
We addressed the hypotheses that robot-aided ankle and knee training will reduce motor impairments and improve balance and gait functions, and the improvements will maintain to the 6-weeks follow-up.
Methods:
Seven male stroke survivors participated in the robot-guided ankle and knee rehabilitation training using a pair of ankle and knee rehabilitation robots over 18 training sessions (3 sessions/week for 6 weeks). Three evaluations were done before and after training, and 6 weeks follow-up. Each session involved passive stretching under intelligent control and active movement training under real-time, audiovisual and haptic feedback. About equal time was spent on the ankle and knee training.
Results:
We found significant improvement in 6-Minute Walk Test (6MWT: 294.8 m pre-training to 386.4 m post training; p<0.01), Berg Balance Scale (BBS, 45 pre to 52 post; p<0.05), ankle active range of motion (AROM) (-11.7° pre to 1.7° post; p<0.05, a negative value means not being able to reach 0° dorsiflexion), passive ROM in dorsiflexion (12.7° pre to 23.3° post; p<0.01), and dorsiflexion muscle strength (-0.3 Nm pre to 5.7 Nm post; p<0.05, negative means lower than the passive torque at 0° ankle dorsiflexion). The knee had significant improvement in AROM in extension against the load of the robot (34.8° pre to 15.9° knee flexion post; p<0.05) and maximal flexion strength at 90° knee flexion (19.3 Nm pre to 31.7 Nm post; p<0.01). At the follow-up, the outcomes were found as similar results of post evaluation, e.g., 379m (p<0.05) in 6MWT, 51 (p<0.05) in BBS, and 5.2 Nm (p=0.05) in dorsiflexion strength.
Conclusions:
In conclusions, robot-guided stretching and active movement training reduced impairments at the knee and ankle of stroke survivors resulting in improved mobility. Furthermore, the effect of training was maintained at the 6-weeks follow-up after the treatment.
Haptic feedback through lower limbs exoskeleton for rehabilitation robotics with virtual reality
