Secondary Logo

Institutional members access full text with Ovid®

Effects of a New Radio Frequency–Controlled Neuroprosthesis on Gait Symmetry and Rhythmicity in Patients with Chronic Hemiparesis

Hausdorff, Jeffrey M. PhD; Ring, Haim MD, MSc

American Journal of Physical Medicine & Rehabilitation: January 2008 - Volume 87 - Issue 1 - p 4-13
doi: 10.1097/PHM.0b013e31815e6680
Original Research Article: Stroke

Hausdorff JM, Ring H: Effects of a new radio frequency–controlled neuroprosthesis on gait symmetry and rhythmicity in patients with chronic hemiparesis. Am J Phys Med Rehabil 2008;87:4–13.

Objective: To assess the effects of a new neuroprosthesis (NESS L300) designed to ameliorate foot drop on gait symmetry and rhythmicity during walking.

Design: Twenty-four patients (mean age: 54.0 ± 13.5 yrs) with chronic hemiparesis (5.8 ± 5.2 yrs) whose walking was impaired by foot drop. Subjects walked for 6 mins while wearing force-sensitive insoles, once with and once without the neuroprosthesis, in randomized order. Additional assessments with the neuroprosthesis were conducted after using the device for 4 and 8 wks. Walking speed, swing, and stride time were determined, along with a gait asymmetry index and stride time variability—both markers of gait stability and fall risk.

Results: While wearing the neuroprosthesis, the gait asymmetry index instantly improved by 28% (from 0.58 ± 0.30 to 0.42 ± 0.22) and by 45% (to 0.32 ± 0.20; P < 0.001) after 8 wks. Stride time variability decreased by 23% immediately (from 5.7 ± 2.9% to 4.4 ± 1.3%) and by 33% (to 3.8 ± 1.4%; P = 0.002) after 8 wks. Walking speed improved initially by 17% (from 0.53 ± 0.24 to 0.62 ± 0.22 m/sec) and after 8 wks by 34% (to 0.71 ± 0.25 m/sec; P < 0.001).

Conclusions: The studied neuroprosthesis enhances gait and improves dynamic stability in chronic hemiparetic patients, supporting the idea that this is a viable treatment option in the rehabilitation of patients with foot drop.

From the Department of Physical Therapy, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel (JMH); Movement Disorders Unit, Neurology Department, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel (JMH); Division on Aging, Harvard Medical School, Boston, Massachusetts (JMH); Loewenstein Rehabilitation Center, Ranana, Israel (HR); and Department of Rehabilitation Medicine, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel (HR).

Correspondence: Haim Ring, MD, Neurological Rehabilitation Department, Loewenstein Rehabilitation Center, PO Box 3, Raanana 43100, Israel, fax: 972-9-7709193; e-mail: address:

Portions of this work were presented at the 15th European Congress of Physical and Rehabilitation Medicine (ESPRM), May 2006, Madrid, Spain, and at the American Physical Therapy Association's Combined Sections Meeting, February 2007, Boston, Massachusetts. This work was supported in part by Ness Ltd.

© 2008 Lippincott Williams & Wilkins, Inc.