The Effect Of The NESS L300 Neuroprosthesis
On Gait Stability And Symmetry
Jeffrey M. Hausdorff, Ph. D
Division on Aging, HarvardMedicalSchool, Boston, MA
Haim Ring , MD
Loewenstein Rehabilitation Center, Ra’anana, Israel
Citation
Hausdorff J.,Ring H,The Effect on the NESS L300
Neuroprosthesis on Gait Stability and Symmetry. Abstract,
CSM 2007: Platform Presentations: Research Platform
Sessions I: Locomotor Control: Journal of Neurologic
Physical Therapy, 2006:30(4) p198
Purpose/Hypothesis
To assess the effect of the NESS L300, an FES neuroprosthesis designed to ameliorate foot drop, on the stability and symmetry of walking in patients with foot drop.
Number of Subjects
24 patients (mean age: 54.0±13.5 yrs) with chronic hemiparesis (5.8±5.2 yrs) whose walking was impaired by foot drop. Patients were post stroke (n=21) or traumatic brain injury (n=3).
Materials/Methods
Subjects walked for 6 minutes wearing force-sensitive insoles in randomized order, once with and once without the neuroprosthesis. Two additional gait assessments with the NESS L300 were conducted after using the device for four and eight weeks. Walking speed, swing and stride time were determined, along with gait symmetry index and stride time variability, both markers of gait stability and fall risk.
In order to simulate daily life situations, gait speed was also measured during 10 meter walk on obstacles course (a portion of the Emory functional ambulation profile). All patients signed informed consent approved by the Loewenstein Rehabilitation Center Institutional Review Board (IRB).
Results
All subjects were able to walk with the NESS L300 immediately after fitting. A repeated measures model was used for each parameter to analyze the neuroprosthesis effect with the 4 test-time points, and the Dunnett’s multiple comparisons test to compare baseline to results using the NESS L300. While wearing the FES neuroprosthesis
walking speed improved immediately by 17% (from 0.53 ± 0.24 m/sec to 0.62 ± 0.22 m/sec), and after eight weeks by 34% (to 0.71±0.25 m/sec; p<0.001). The gait symmetry index was 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 eight weeks. Stride time variability decreased by 23% (from 5.7±2.9% to 4.4±1.3%) and by 33% (to 3.8±1.4%; p=0.002) after eight weeks. The improvement in gait speed was even more dramatic when walking over the obstacle course. The speed was immediately increased by 24% (from 0.34±0.16m/sec to 0.42 ± 0.17 m/sec) and reached to 0.49±0.20 m/sec after 8 weeks (p<0.001),with overall improvement of 44% in gait speed.
Conclusions
These results demonstrate that even the initial application of the NESS L300 enhances gait. An increase in walking speed was observed in conjunction with a dramatic improvement in gait rhythmicity and steadiness. The ability to increase gait velocity while walking over obstacles may reflect better ability to overcome difficulties at walking in a daily life environment. Furthermore, improvement apparently continues with ongoing use.
Clinical Relevance
These findings suggest that stroke and traumatic brain injury survivors can gain meaningful benefits from using a lower limb neuroprosthesis right away and intensify their gait abilities even more with usage.
© 2006 Neurology Section, APTA NESS ® and NESS L300 ™ are trademarks of Bioness Neuromodulation Ltd, Ra’anana, Israel