In clinical practice, acute post-stroke paresis of the extremities fundamentally complicates timely rehabilitation of motor functions; however, recently, residual and distorted musculoskeletal signals have been used to initiate feedback-driven solutions for establishing motor rehabilitation. Here, we investigate the possibilities of basic hand gesture recognition in acute stroke patients with hand paresis using a novel, acute stroke, four-component multidomain feature set (ASF-4) with feature vector weight additions (ASF-14NP, ASF-24P) and supervised learning algorithms trained only by surface electromyography (sEMG). A total of 19 (65.9 ± 12.4 years old; 12 men, seven women) acute stroke survivors (12.4 ± 6.3 days since onset) with hand paresis (Brunnstrom stage 4 ± 1/4 ± 1, SIAS 3 ± 1/3 ± 2, FMA-UE 40 ± 20) performed 10 repetitive hand movements reflecting basic activities of daily living (ADLs): rest, fist, pinch, wrist flexion, wrist extension, finger spread, and thumb up. Signals were recorded using an eight-channel, portable sEMG device with electrode placement on the forearms and thenar areas of both limbs (four sensors on each extremity). Using data preprocessing, semi-automatic segmentation, and a set of extracted feature vectors, support vector machine (SVM), linear discriminant analysis (LDA), and k-nearest neighbors (k-NN) classifiers for statistical comparison and validity (paired t-tests, p-value < 0.05), we were able to discriminate myoelectrical patterns for each gesture on both paretic and non-paretic sides. Despite any post-stroke conditions, the evaluated total accuracy rate by the 10-fold cross-validation using SVM among four-, five-, six-, and seven-gesture models were 96.62%, 94.20%, 94.45%, and 95.57% for non-paretic and 90.37%, 88.48%, 88.60%, and 89.75% for paretic limbs, respectively. LDA had competitive results using PCA whereas k-NN was a less efficient classifier in gesture prediction. Thus, we demonstrate partial efficacy of the combination of sEMG and supervised learning for upper-limb rehabilitation procedures for early acute stroke motor recovery and various treatment applications.

Context/Objective: The hybrid assistive limb (HAL) is a wearable exoskeleton robot that assists walking and lower limb movements via real-time actuator control. Our aim was to clarify the safety and feasibility of using the HAL robotic suit for rehabilitation in patients with severe thoracic myelopathy due to ossification of the posterior longitudinal ligament (T-OPLL). Design: Uncontrolled case series; pre- and post-intervention measurement. Setting: In-patient rehabilitation unit. Intervention: HAL training was provided in 60-minuts session, 2–3 sessions per week, for a total of 10 sessions. HAL training was initiated on average 27.5 days post-surgery. Patients: Eight patients (four males and four females; mean age, 60.9 ± 10.2 years) with severe myelopathy, who had undergone posterior decompression with instrumented fusion, were enrolled. Outcome Measures: Gait speed, step length and cadence were measured along a 10-m walkway every session. The American Spinal Injury Association (ASIA) motor score (lower extremities) and Walking Index for Spinal Cord Injury (WISCI) II were also evaluated at baseline and after 10 sessions. The Japanese Orthopaedic Association (JOA) score was calculated over time after surgery. Results: All participants completed the 10 training sessions, with no serious adverse effect noted. Gait speed, step length and cadence improved over time. Both the WISCI-II and ASIA motor (lower extremities) scores improved from baseline after 10 sessions. The JOA score improved over time post-surgery. Conclusion: HAL training can be feasibly initiated in the early postoperative period, without severe adverse events in patients, with T-OPLL-related severe gait disturbance.

Context: Spinal cord infarction (SCI) causes gait disturbance because of paresis, spasticity, and sensory disturbance of the lower limbs. There is no effective medical treatment for SCI, and conventional rehabilitation alone is the main approach to helping individuals work toward independent walking. The aim of this study was to evaluate the effect of gait treatment using the Hybrid Assistive Limb (HAL) on acute SCI. Findings: A 61-year-old female and a 62-year-old male with incomplete paraplegia participated in this study. Our study participants received gait treatment with HAL 3–4 times per week, with a total of 7–8 sessions (20 min), in addition to conventional physical therapy. The American Spinal Injury Association Impairment Scale, Lower Extremity Motor Score (LEMS), Modified Ashworth Scale (MAS), the Walking Index for Spinal Cord Injury (WISCI II), comfortable gait speed (CGS), stride, cadence, Barthel Index (BI), Functional Independence Measure (FIM), modified Rankin Scale (mRS), joint angles, and adverse effects were assessed prior to HAL treatment and post-HAL treatment. HAL facilitated intensive gait treatment in people during the acute phase after SCI. Improvements in LEMS, WISCI II, CGS, stride, cadence, BI, FIM, mRS, and joint angles were observed in both study participants. Furthermore, decreased spasticity in the gastrocnemius muscle was found in one participant as assessed by MAS. Conclusion: Gait treatment using HAL may be beneficial for paraplegic, non-ambulatory individuals with acute SCI. HAL may be useful for intensive gait treatment without increasing spasticity.

Foot and ankle disabilities (foot drop) due to common peroneal nerve palsy and stroke negatively affect patients’ ambulation and activities of daily living. We developed a novel robotics ankle hybrid assistive limb (HAL) for patients with foot drop due to common peroneal nerve palsy or stroke. The ankle HAL is a wearable exoskeleton-type robot that is used to train plantar and dorsiflexion and for voluntary assistive training of the ankle joint of patients with palsy using an actuator, which is placed on the lateral side of the ankle joint and detects bioelectrical signals from the tibialis anterior (TA) and gastrocnemius muscles. Voluntary ankle dorsiflexion training using the new ankle HAL was implemented in a patient with foot drop due to peroneal nerve palsy after lumbar surgery. The time required for ankle HAL training (from wearing to the end of training) was approximately 30 min per session. The muscle activities of the TA on the right were lower than those on the left before and after ankle HAL training. The electromyographic wave of muscle activities of the TA on the right was slightly clearer than that before ankle HAL training in the resting position immediately after ankle dorsiflexion. Voluntary ankle dorsiflexion training using the novel robotics ankle HAL was safe and had no adverse effect in a patient with foot drop due to peroneal nerve palsy.

Background: Spinal and bulbar muscular atrophy (SBMA) is a progressive neuromuscular degenerative disease characterized by the degeneration of lower motor neurons in the spinal cord and brainstem and neurogenic atrophy of the skeletal muscle. Although the short-term effectiveness of gait treatment using a wearable cyborg hybrid assistive limb (HAL) has been demonstrated for the rehabilitation of patients with SBMA, the long-term effects of this treatment are unclear. Thus, this study aimed to investigate the long-term effects of the continued gait treatment with HAL in a patient with SBMA.Results: A 68-year-old man with SBMA had lower limb muscle weakness and atrophy, gait asymmetry, and decreased walking endurance. The patient performed nine courses of HAL gait treatment (as one course three times per week for 3 weeks, totaling nine times) for ~5 years. The patient performed HAL gait treatment to improve gait symmetry and endurance. A physical therapist adjusted HAL based on the gait analysis and physical function of the patient. Outcome measurements, such as 2-min walking distance (2MWD), 10-meter walking test (maximal walking speed, step length, cadence, and gait symmetry), muscle strength, Revised Amyotrophic Lateral Sclerosis Functional Assessment Scale (ALSFRS-R), and patient-reported outcomes, were evaluated immediately before and after gait treatment with HAL for each course. 2MWD improved from 94 m to 101.8 m, and the ALSFRS-R gait items remained unchanged (score 3) for approximately 5 years. The patient could maintain walking ability in terms of gait symmetry, walking endurance, and independence walking despite disease progression during HAL treatment.Conclusion: The long-term gait treatment with HAL in a patient with SBMA may contribute to the maintenance and improvement of the gait endurance and ability to perform activities of daily living. The cybernics treatment using HAL may enable patients to relearn correct gait movements. The gait analysis and physical function assessment by a physical therapist might be important to maximize the benefits of HAL treatment.