Alteration of muscle activity during voluntary rehabilitation training with single-joint Hybrid Assistive Limb (HAL) in patients with shoulder elevation dysfunction from cervical origin

Abstract

Shoulder elevation, defined here as arm raising, being essential for activities of daily living, dysfunctions represent a substantial burden in patients’ lives. Owing to the complexity of the shoulder joint, the tightly coordinated muscular activity is a fundamental component, and neuromuscular impairments have devastating effects. A single-joint shoulder type version of the Hybrid Assistive Limb (HAL) allowing motion assistance based on the intention of the user via myoelectric activation has recently been developed, and its safety was demonstrated for shoulder rehabilitation. Yet, little is known about the physiological effects of the device. This study aims to monitor the changes in muscle activity and motion during shoulder HAL rehabilitation in several patients suffering from shoulder elevation dysfunction from cervical radicular origin. 8 patients (6 males, 2 females, mean age 62.4 ± 9.3 years old) with weakness of the deltoid muscle resulting from a damage to the C5 nerve root underwent HAL-assisted rehabilitation. We combined surface electromyography and three-dimensional motion capture to record muscular activity and kinematics. All participants showed functional recovery, with improvements in their Manual Muscle Testing (MMT) scores and range of motion (ROM). During training, HAL decreased the activity of deltoid and trapezius, significantly more for the latter, as well as the coactivation of both muscles. We also report a reduction of the characteristic shrugging compensatory motion which is an obstacle to functional recovery. This reduction was notably demonstrated by a stronger reliance on the deltoid rather than the trapezius, indicating a muscle coordination tending toward a pattern similar to healthy individuals. Altogether, the results of the evaluation of motion and muscular changes hint toward a functional recovery in acute, and chronic shoulder impairments from cervical radicular origin following shoulder HAL rehabilitation training and provide information on the physiological effect of the device.

Feasibility and Efficacy of the Newly Developed Robotic Hybrid Assistive Limb Shoulder Exercises in Patients with C5 Palsy during the Acute Postoperative Phase

“…One member of our research group, Lafitte MN, used shoulder HAL for elevation training in patients with shoulder elevation dysfunction and assessed the muscle activity during shoulder HAL training [ 23 ]. According to their results, the trapezius activity during shoulder elevation with HAL in patients with difficulty executing this movement was significantly lower than that when this movement was performed without HAL; these findings were consistent among healthy controls as well.…”

“…The Hybrid Assistive Limb (HAL) is a wearable, robotic, movement-assistive device that detects muscle action potentials (bioelectric signals) from the user’s skin surface percutaneously and activates the actuator located lateral to the hip and knee joints to assist the user’s voluntary movements [ 18 ]. We have been performing robotic rehabilitation using the novel robotic technology with a single-joint HAL in patients with postoperative C5 palsy and associated upper arm disability [ 19 , 20 , 21 , 22 , 23 ]. Shoulder HAL is a wearable motor-assistance robot that detects muscle action potentials (bioelectric signals) on the skin of the lateral arm, and controls or activates actuators located lateral to the shoulder joint ( Figure 1 ).…”

Shear stiffening gel-enabled twisted string for bio-inspired robot actuators

“…Wearable robot actuators allow motion assistance based on the intention of the user through myoelectric activation. Indeed, muscle-like actuators with variable stiffnesses are desirable for coactivation with human muscles to produce compensatory motion 15 , 16 . In this paper, inspired by human muscles in terms of stiffness tuning and manner of contracting, a new type of variable stiffness actuator is explored by combining a twisted string actuator (TSA) with shear stiffening gels (STGs), producing biologically inspired motions and matching the broad stiffness performance of skeletal muscles.…”

Ecoflex Flexible Array of Triboelectric Nanogenerators for Gait Monitoring Alarm Warning Applications

“…Nowadays, badminton is gaining popularity, and significantly emphasizes footwork as a critical part of its technique [14][15][16][17][18]. Monitoring the exact pace of a game not only allows for fast and efficient returns but also lowers the risk of injuries [19,20]. As such, badminton gait analysis can be used as a valuable tool for diagnosing motor skills and enhancing training program optimization [21][22][23].…”