Reviewing Clinical Effectiveness of Active Training Strategies of Platform-Based Ankle Rehabilitation Robots

Table 1

Summary of clinical researches of active training applied in platform-based ankle robots.

Study	Subjects (n)	Subject characteristics	Subject age (yr)	Group	Course of training	Robot	Control strategies	Researching achievement
Deutsch et al. [66]	6	Subjects with chronic stroke	Not stated	Single group	4 weeks; 12 sessions	Rutgers Ankle	VR game training; Haptic effects; Telerehabilitation	Therapeutic effects of injured ankles were not significantly different when therapists were in the same room with patients or appeared in front of patients remotely by a webcam.
Mirelman et al. [13]	18	Subjects with chronic hemiparesis	41–75	Robot VR group (9); Robot group (9)	4 weeks; 12 sessions	Rutgers Ankle	VR game training; Easy to difficult; Haptic effects	Training integrated with VR games were a better selection for ankle rehabilitation therapies.
Burdea et al. [10]	3	Subjects with CP	7–12	Single group	12 weeks; 36 sessions	Rutgers Ankle CP	VR game training; Easy to difficult; Haptic effects	Performance of playing game was mapped to the physical improvement evaluated clinically in ankle strength, gait kinematics, and speed.
Forrester et al. [52]	8	Subjects with chronic stroke	43–75	Single group	6 weeks; 18 sessions	Anklebot	VR game training; Easy to difficult; Assist as needed	Robotic feedback training would be a valuable supplement to locomotor therapies.
Roy et al. [54]	14	Healthy subjects; Subjects with chronic stroke	49–64; 53–74	Control group (7); Stroke group (7)	1 session	Anklebot	VR game training; Easy to difficult; Assist as needed	Firstly observed that immediately following and 48 hours after a single session of anklebot training, motor control of paretic ankles were improved but not for nondisabled ankles.
Roy et al. [2]	8	The same subjects as those in [52]	43–75	Single group	6 weeks; 18 sessions	Anklebot	VR game training; Easy to difficult; Assist as needed; Performance-based progression; Application of EMG	Anklebot training with progressive targets significantly decreased PAS of paretic ankles, even to the normal range in dorsiflexion direction. Furthermore, increased compliance of paretic ankles would result in improvement in unassisted overground walking.
Goodman et al. [23]	10	Subjects with chronic hemiparetic stroke	42–82	HR group(5); LR group(5)	3 weeks; 9 sessions	Anklebot	VR game training; Easy to difficult; Assist as needed; Application of EEG; Rewards	Rewards integrated with performance of subjects conducting anklebot training could accelerate activity-dependent brain plasticity to improve motor control.
Forrester et al. [21]	34	Subjects with hemiparetic stroke	57–66	Robot group (18); Stretching group (16)	10 sessions	Anklebot	VR game training; Assist as needed; Manual stretching	Robot group achieved more improvement in walking speed, motor control, and gait patterning than stretching group.
Forrester et al. [55]	26	Subjects with chronic hemiparetic gait	53–63	SRT group (12); TMR group (14)	6 weeks; 18 sessions	Anklebot; Treadmill	VR game training; Easy to difficult; Assist as needed; Performance based progression	Anklebot therapy would be more effective if integrated with locomotor treadmill.
Michmizos et al. [63]	3	Subjects with CP or lesion of the common peroneal nerve	9	Single group in clinic	At least 3 weeks; 9 sessions	PediAnklebot	VR game training; Easy to difficult; Assist as needed	Subjects obtained significant improvement of explicit motor learning assessed with less jerky, better controlled, and increased speed of movements and implicit motor learning evaluated by the reduction of the average RT (reaction time).
Krebs et al. [60]	4	Subjects with CP	7–11	Single group	6 weeks; 12 sessions	PediAnklebot	VR game training; Easy to difficult; Assist as needed	PediAnklebot could provide better therapeutic effect on ankle rehabilitation through harnessing plasticity among children with CP.
Wu et al. [59]	12	Subjects with spastic CP	5–10	Single group	6 weeks; 18 sessions	Portable rehabilitation robot	I-passive stretching; VR game training; A-active movement; R-active movement	Active rehabilitation training combined with passive stretching was beneficial for children with CP.
Waldman et al. [53]	23	Subjects with poststroke	43–60	Robot group (11); Control group (12)	6 weeks; 18 sessions	Portable rehabilitation robot	I-passive stretching; VR game training; A-active movement; R-active movement	Robotic rehabilitation training should be a beneficial supplement to rehabilitation programs.
Sukal-Moulton et al. [58]	28	Subjects with CP	5–12	Single group	6 weeks; 12 sessions	IntelliStretch rehabilitation robot	Passive stretching; VR game training; A-active movement; R-active movement	Rehabilitation training combining active movement and passive stretching together was feasible in clinic application.
Chen et al. [65]	23	Subjects with CP	5–17	Single group	6 weeks; 18 sessions	Portable rehabilitation robot with TELE	I-passive stretching; VR game training; A-active movement; Telerehabilitation	Robotic rehabilitation training with teleassistance was not only convenient and economical but also effective for patients.
Ren et al. [62]	10	Subjects with acute poststroke	38–71	Single group	3 weeks; 12 sessions	An in-bed wearable robotic device	I-passive stretching; VR game training; A-active movement; R-active movement	The in-bed active movement training combined with passive stretching met clinic requirements and could improve motor ability of ankle joints.
Chen et al. [14]	41	Subjects with CP	5–17	Home-based group (23); Lab-based group (18)	6 weeks; 18 sessions	A portable rehabilitation robot	I-passive stretching; VR game training; A-active movement; R-active movement	Ankle rehabilitation training simply with audiovisual communication available from research engineers was feasible to be conducted at home.
Lee et al. [61]	6	Subjects with multiple sclerosis	44–66	Single group	6 weeks; 18 sessions	IntelliStretch rehabilitation robot	Passive stretching; VR game training; A-active movement; R-active movement	Ankle rehabilitation training could provide subjects with MS better therapeutic effect on sensorimotor functions of lower limbs.
Zhou et al. [67]	5	Subjects with chronic stroke	56–77	Single group	6 weeks; 18 sessions	PNF assisted PKU-RARS	PNF stretching; Passive stretching; Application of EMG	Robot-assisted PNF stretching was an effective therapy method to rehabilitate ankles with contracture and spasticity.
Zhou et al. [68]	7	Subjects with poststroke	41–79	Single group	3 months; 36 sessions	PNF assisted PKU-RARS	PNF stretching; Passive stretching; Application of EMG	Robot-assisted PNF stretching was significantly effective in alleviating spasticity of lower limb and improving its motor function.
Chang et al. [56]	29	Subjects with hemiparesis after stroke	18–81	LF group (9); MF group (11); HF group (9)	6 weeks; 18 sessions	Anklebot	VR game training; Assist as needed	Robot-assisted ankle training was more beneficial to moderate and mild gait speed impairments.

A-active moment = assisted active movement; R-active movement = resisted active movement; PNF = proprioceptive neuromuscular facilitation; I-passive stretching = intelligent passive stretching; VR = virtual reality; CP = cerebral palsy; EEG = electroencephalograph; EMG = electromyography; LF group = low-function group; MF group = moderate-function group; HF group = high-function group. They have another group of subjects who applied to verify the function of the technology or system.