Device helps retrain the reach in stroke survivors with limb paresis

Last Updated: 2008-07-04 8:10:22 -0400 (Reuters Health)

NEW YORK (Reuters Health) – A novel nonrobotic device called the Sensorimotor Active Rehabilitation Training (SMART) Arm can assist stroke survivors with severe paresis re-learn the task of reaching, a study shows.

"Severe upper limb paresis is a major contributor to disability after stroke," note Dr. Ruth N. Barker and colleagues of University of Queensland, Australia in the June issue of Stroke.

They developed the SMART device, a low-cost arrangement of a pulley, weights and near-frictionless linear track "designed to reduce task difficulty by decreasing degrees of freedom to be controlled and by minimizing resistance to the movement."

The researcher team investigated the efficacy of the device, with or without electromyography-triggered electrical stimulation, to augment elbow extension in 42 stroke survivors with severe and chronic paresis.

Thirty-three participants completed the study, of whom 10 received training using the SMART Arm with electrical stimulation, 13 received training with the SMART Arm alone, and 10 received no intervention (control). Training consisted of 12 hour-long sessions over 4 weeks.

The primary outcome was upper arm function. Secondary outcomes included various impairment measures including triceps muscle strength and reaching force, and various activity measures such as reaching distance. Assessments were made at baseline, after training at 4 weeks and at 2 months follow up.

According to Dr. Barker and colleagues, both SMART Arm groups "demonstrated significant improvements in all impairment and activity measures" after training and at 12 weeks post-training. There was no significant difference between the two SMART Arm groups and there was no change in the control group.

"Our findings indicate that training of reaching using the SMART Arm can reduce impairment and improve activity in stroke survivors with severe and chronic upper limb paresis, highlighting the benefits of intensive task-oriented practice, even in the context of severe paresis."

Stroke 2008;39:1800-1807.