Active elbow flexion is possible in C4 quadriplegia using hybrid assistive limb (HAL®) technology: A case study

The Journal of Spinal Cord Medicine, 2017 · DOI: 10.1080/10790268.2017.1305036 · Published: July 4, 2017

Spinal Cord Injury Assistive Technology Rehabilitation

Simple Explanation

This study explores how a robotic device called the Hybrid Assistive Limb for Single Joints (HAL-SJ) can help someone with complete paralysis from a spinal cord injury regain some movement in their elbows. The HAL-SJ is a wearable robot that supports elbow movement based on the user's intention, detected through muscle signals. The device was used on a 19-year-old man with C4 quadriplegia, where typical movement below the C4 level is lost. After several sessions using the HAL-SJ, the patient was able to voluntarily contract his biceps muscles and operate a standard wheelchair for a short distance independently, indicating a functional improvement.

Study Duration

HAL-SJ intervention (right arm) was performed for 5 weeks (10 sessions), left arm for 12 weeks (10 sessions)

Participants

A 19-year-old man with complete C4 quadriplegia

Evidence Level

Level 4: Case Study

Key Findings

1
HAL-SJ intervention is feasible and effective in restoring elbow flexor function in a patient with C4 chronic spinal cord injury and complete quadriplegia.
2
The patient was able to voluntarily contract the bilateral biceps with right-sided dominance four months after completion of HAL intervention.
3
After the intervention, he was able to actively contract bilateral elbow flexors and drive a standard wheelchair for a short distance.

Research Summary

This case study examined the use of a hybrid assistive limb for single joints (HAL-SJ) in a 19-year-old man with complete C4 quadriplegia to restore function of active elbow flexion. The HAL-SJ intervention for each elbow was administered in 10 sessions. After the 6th and 7th session, respectively, biceps EMG showed that voluntary contraction and right elbow flexion could be performed by motion intention from the right biceps. The HAL-SJ enabled a patient with complete quadriplegia after chronic high cervical SCI to voluntarily contract the bilateral biceps. The HAL-SJ is feasible and effective in restoring elbow flexion allowing for functional enhancement in patients with chronic SCI.

Practical Implications

Restoration of Elbow Flexion

HAL-SJ intervention can potentially restore elbow flexor function in patients with C4 chronic spinal cord injury and complete quadriplegia, improving their independence in activities of daily living.

Motor Learning

Voluntary elbow flexion using the HAL-SJ might provide systematic feedback and is considered to have motor learning effects, promoting central nervous system plasticity.

Clinical Application

The HAL-SJ is a portable device, which is convenient for clinical setting use, even for bedridden patients, making it a practical option for rehabilitation.

Study Limitations

1
Muscle activity was only evaluated through surface EMG and did not measure brain activity.
2
The study is limited to a single case, thus generalizability is limited.
3
Driving a standard wheelchair for a short distance was not a practical setting.

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