Effect of FES Interventions on Gait Dynamics in Stroke Population
Condition: Stroke; Foot Drop
MeSH terms: Stroke; Peroneal Neuropathies
Study type: Interventional

Summary: 
      Our proposal quantitatively analyzes gait dynamics of hemiplegic individuals in response to
      the Function Electrical Stimulation (FES) intervention and identifies the responders to the
      intervention. This study will improve our knowledge of FES intervention and help clinicians
      strategize the FES interventions more effectively based on the responders' gait
      characteristics, thus supporting the NINDS' fundamental goal of translating basic and
      clinical discoveries into better ways to prevent and treat neurological disorders.
    

Detailed description: 
      Hemiplegia with associated foot drop occurs in 50% of the stroke survivors and frequently
      impairs an individual's ability to walk. Functional Electrical Stimulation (FES) based
      neuroprosthetic devices have been developed to correct foot drop. The efficacy of these
      devices were initially examined by Liberson el al. who demonstrated that electrical
      stimulations could assist in restoring functional movements in paralyzed limbs. In addition
      to assistance with foot drop, these devices have showed significant improvements in
      biomechanical variables such as walking speed, distance, stride length and physiological cost
      for individuals with stroke. In order to comprehensively understand the effect of electrical
      stimulations on gait recovery, it is critical to analyze the dynamic aspects of gait and
      measure gait variability during the functional electrical stimulation intervention. In the
      proposed investigation, we will determine the 'gait symmetry' of FES assisted walking using
      bilateral cyclograms of the ankle and knee over a period of 6 months. This novel approach
      will account for the dynamics and complexity of balance by measuring the deviations of joints
      from a line of symmetry at every instance of gait cycle and will provide better measure of
      gait symmetry. Utilization of this outcome measure will allow us to understand the role of
      electrical stimulation at ankle and how this effect gets translated to the knee and hip
      joints during walking. The changes in the surface electromyograms (EMGs) of selective muscle
      groups will demonstrate how FES can contribute to muscle re-training after stroke. We will
      use advanced signal processing algorithms to remove FES artifact from the EMG signal in order
      to comprehensively analyze the carry-over effect of the FES intervention. Finally, we will
      employ Principal Component Analysis (PCA) - an advanced data mining technique to track and
      quantify the overall gait recovery process of individuals with stroke using pattern
      classification algorithms. The gait symmetry measure and the EMGs will be statistically
      classified to see their clear separation at baseline and 6 month intervals. This
      classification will allow us to identify the individuals who were most responsive to the
      intervention. This information is critical and will allow researchers and clinicians to
      re-strategize the rehabilitation process. Such scientific evaluation will provide the base
      for further development and implementation of FES devices or technologies, thus supporting
      the NINDS' fundamental goal of translating basic and clinical discoveries into better ways to
      treat neurological disorders.
    

Intervention name(s): FES
Intervention type(s): Device
Intervention description(s): In phase 1, five subjects (randomly chosen) will be provided the FES device and instructed to use it for ambulation for the 6 months. At the baseline visit, gait data will be collected from this group. On the 6 month follow up visit, same data collection procedure will be performed and the devices will be collected back from the subjects. After performing quality check on these devices, phase 2 of the data collection will start by providing the devices to the other five subjects and their baseline data will be collected.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Foot drop; Functional Electrical Stimulation