Introduction

Spinal cord injury (SCI) or cerebrovascular accident (CVA) may cause hemiplegia, paraplegia, or limb paralysis, as well as abnormal balance and gait. Patients with limb paralysis have muscle weakness, paresthesia, and joint stiffness. These patients have decreased functional ability and increased risk of falls, making it difficult for them to perform activities of daily living (ADLs) or live independently. Therefore, gait recovery is the goal of rehabilitation therapy for patients with paralysis.
 
Robotic-assisted gait training (RAGT), based on intensive repetitions of tasks, is widely used for improving stance and gait in paralyzed patients. RAGT improves gait through biomechanical feedback and high-intensity repetitive walking in a real-like environment.
 
WALKBOT (P&S Mechanics Co., Ltd., Seoul, Korea), an exoskeleton-type robot system used for gait training, reduces the limitations of classical gait rehabilitation in paralyzed patients. WALKBOT uses the exoskeleton and a body weight support harness to induce stepping movements in accordance with a stored normal biomechanical walking pattern. The robot’s joints have axes similar to the axes of human legs; this allows natural walking movements on all leg joints, as well as exercises involving individual joint muscles. The use of WALKBOT improves gait in paralyzed patients and has the advantage of individualizing therapy for patients based on their physical characteristics.
 
In this study, we evaluated the effects of gait rehabilitation using WALKBOT on lower extremity strength, function, balance, and gait in patients with acute neurologic disorder.

Methods

1. Participants
 
We administered RAGT rehabilitation to 26 patients (SCI: 12; CVA: 14) hospitalized for hemiplegia, paraplegia, or quadriplegia at a general hospital in Wonju, Gangwon-do, South Korea(Table 1).
 
 
http://walkbot.co.kr/wp-content/uploads/kboard_attached/3/202205/202205180338541907500.png

 
 
2. Experimental Methods
 
We used three scales for evaluation before and after training in all patients: Motricity Index (MI), Berg Balance Scale (BBS), and FAC.
 
3. Procedures
 
Patients underwent RAGT 10–15 times over 2 weeks, up to 5 times per week, 20 min per day (total 200~300 min). For the RAGT, a WALKBOT (robot-driven aid with posture control), a weight-bearing device, and a treadmill were used. Compared with other products, the independent drive of ankle joint with WALKBOT prevents excessive plantarflexion and foot drag.

Results

1. Comparison of Clinical Outcomes
 
There were significant improvements in MI, FAC, and BBS scores after WALKBOT RAGT in patients with acute incomplete SCI (p < 0.05) (Table 2) and patients with CVA (p < 0.001) (Table 3).

http://walkbot.co.kr/wp-content/uploads/kboard_attached/3/202205/202205180343381129762.png

http://walkbot.co.kr/wp-content/uploads/kboard_attached/3/202205/202205180344341914055.png

2. Comparison of Combined BBS Scores before and after WALKBOT RAGT
 
After WALKBOT RAGT in paralyzed patients, there were significant improvements in the BBS scores for items 1–11th (p < 0.05), but not for items 12–14th (12: placing alternated foot on stool; 13: standing with one foot in front; 14: standing with one foot) (p > 0.05) (Table 4).
 
http://walkbot.co.kr/wp-content/uploads/kboard_attached/3/202205/202205180346501247247.png

Discussion

RAGT uses a task-oriented approach for paralyzed patients based on the motor re-learning theory through repetitive, high-intensity tasks. WALKBOT eliminates the therapist errors and fatigue associated with traditional physical therapy. In addition, RAGT intensity and gait parameters (e.g., stride length, gait velocity, and gait frequency) can be adjusted with WALKBOT in accordance with the patient’s requirements. Partial support for the patient’s weight makes WALKBOT safer than traditional physical therapy. Traditional gait therapy allows 50–100 steps to be practiced each hour for wheelchair-dependent patients, whereas RAGT allows 1000–2000 steps to be practiced in 30 min.
 
Our study demonstrated significant improvement in lower extremity strength with WALKBOT RAGT in patients with CVA or incomplete SCI. Nyberg & Gustafson reported that the lower extremity strength of CVA patients depends on their walking ability. The use of RAGT improves lower extremity strength and functional ability, compared with traditional gait rehabilitation. Husemann et al. reported significantly increased muscle mass and reduced body fat after RAGT in CVA patients, possibly because gait training increases aerobic metabolism. In addition, several studies have demonstrated that RAGT improves gait and reduces knee and ankle joint spasticity in SCI patients. This reduction in spasticity is associated with smooth, coordinated contraction and relaxation of agonist and antagonist muscles.
In addition, WALKBOT can be used for lower extremity resistance training during walking; it is associated with improved cognitive functions through repeated visual and auditory stimulation. Finally, WALKBOT reinforces the motivation of patients with neurologic disorders to comply with rehabilitation.

Conclusions

This study was aimed to investigate the effects of WALKBOT RAGT on lower extremity strength, balance, and gait in paralyzed patients with the acute phase of incomplete SCI and CVA.
WALKBOT RAGT had significant improvements in MI, FAC, and BBS scores in patients with acute neurologic disorders. In addition, the WALKBOT RAGT protocol used this study might be affected on improving the performance of patients on the difficult balancing tasks used in the BBS.

첨부파일 :Impact of WALKBOT on the Gait and Balance Recovery of Patients with Acute Neurologic Disorders.pdf