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This case study evaluated the effect of implanted multijoint neuromuscular electrical stimulation gait assistance on oxygen consumption relative to walking without neuromuscular electrical stimulation after stroke. The participant walked slowly with an asymmetric gait pattern after stroke. He completed repeated 6-min walk tests at a self-selected walking speed with and without hip, knee, and ankle stimulation assistance. His walking speed with neuromuscular electrical stimulation more than doubled from 0.28 ± 0.01 m/sec to 0.58 ± 0.04 m/sec, whereas average step length and cadence increased by 0.12 m and 24 steps/min, respectively. As a result, energy cost of walking with neuromuscular electrical stimulation decreased by 0.19 ml O2/kg per meter as compared with walking without stimulation while oxygen consumption increased by 1.1 metabolic equivalent of tasks (3.9 ml O2/kg per minute). These metabolic demands are similar to those reported for stroke survivors capable of walking at equivalent speeds without stimulation, suggesting the increase in oxygen consumption and decreased energy cost result from improved efficiency of faster walking facilitated by neuromuscular electrical stimulation. Although the effect of neuromuscular electrical stimulation on gait economy has implications for community walking within the user's metabolic reserves, this case study's results should be interpreted with caution and the hypothesis that multijoint neuromuscular electrical stimulation improves metabolic efficiency should be tested in a wide population of stroke survivors with varied deficits.

Study Design: Single-subject repeated measures study., Objectives: Neuromuscular electrical stimulation (NMES) can enhance walking for people with partial paralysis from incomplete spinal cord injury (iSCI). This single-subject study documents an individual's experience who both received an experimental implanted NMES system and underwent clinical bilateral hinged total knee arthroplasty (TKA). She walked in the community with knee pain prior to either intervention. Walking performance improved with an implanted NMES system. Knee pain and instability continued to worsen over time and eventually required TKA. This study evaluates the effects of these interventions., Setting: Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland OH, USA., Methods: The differential and combined effects of NMES and hinged knee replacement were assessed in terms of walking speed, toe clearance, knee angle, and participant perceptions with and without stimulation assistance both before and after TKA., Results: The combined approach both reduced pain and restored walking ability to levels achieved prior to developing significant knee pain that prevented walking without NMES. There was an interaction effect between NMES and TKA on walking speed. Toe clearance consistently improved with stimulation assistance and TKA prevented significant knee hyperextension. The greatest impact was on endurance. Knee replacement re-enabled long distance walking with the addition of stimulation again more than doubling her maximum walking distance from 214 to 513 m., Conclusions: These data support further research of combined implantable interventions that may benefit people with iSCI. Furthermore, joint laxity and pain may not necessarily be contraindications to NMES if addressed with conventional clinical treatments.

A patient with multiple sclerosis-related gait dysfunction was followed over the course of his disease. Despite aggressive treatment, he developed significant weakness in ankle dorsiflexors and hip and knee flexors and was no longer capable of consistently taking a step on his own. With electrical stimulation of hip and knee flexors and ankle dorsiflexors using implanted electrodes, he was able to consistently walk short distances as far as 30 m, thus significantly improving his Expanded Disability Status Scale score. This case study supports further exploration into the potential benefits of an implanted pulse generator to ameliorate gait dysfunction and improve quality of life for people with multiple sclerosis.

Objective: The objective of this work was to quantify the effects of a fully implanted pulse generator to activate or augment actions of hip, knee, and ankle muscles after stroke., Design: The subject was a 64-year-old man with left hemiparesis resulting from hemorrhagic stroke 21 months before participation. He received an 8-channel implanted pulse generator and intramuscular stimulating electrodes targeting unilateral hip, knee, and ankle muscles on the paretic side. After implantation, a stimulation pattern was customized to assist with hip, knee, and ankle movement during gait.The subject served as his own concurrent and longitudinal control with and without stimulation. Outcome measures included 10-m walk and 6-minute timed walk to assess gait speed, maximum walk time, and distance to measure endurance, and quantitative motion analysis to evaluate spatial-temporal characteristics. Assessments were repeated under 3 conditions: (1) volitional walking at baseline, (2) volitional walking after training, and (3) walking with stimulation after training., Results: Volitional gait speed improved with training from 0.29 m/s to 0.35 m/s and further increased to 0.72 m/s with stimulation. Most spatial-temporal characteristics improved and represented more symmetrical and dynamic gait., Conclusions: These data suggest that a multijoint approach to implanted neuroprostheses can provide clinically relevant improvements in gait after stroke., To Claim Cme Credits: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to do the following: (1) Describe the rationale for evaluating a multijoint implanted neuroprosthesis to improvewalkingafter stroke; (2)Understand the study design and conclusions that can be inferred as a result of the design; and (3) Discuss the statistical significance and clinical relevance of changes between (a) volitional walking at baseline, (b) volitional walking after training, and (c) walking with stimulation after training., Level: Advanced ACCREDITATION:: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.