Task-specificity for Locomotor Recovery Following SCI
Condition: Spinal Cord Injuries
MeSH terms: Spinal Cord Injuries
Study type: Interventional

Summary: 
      The primary goal of the proposed study is to identify the contributions of the amount of
      task-specific practice on locomotor (i.e., walking) recovery in patients with chronic (> 1
      yr) motor incomplete spinal cord injury (iSCI). Consistent with principles of motor learning
      and exercise physiology, the investigators contend that certain training (i.e., dosage)
      parameters of physical rehabilitation are critical to mobility outcomes following
      neurological injury. Specifically, the specificity, amount and intensity of physical
      interventions (i.e., practice) may influence specific outcomes in the patient population
      treated. In ambulatory patients with iSCI, there are very few studies that have controlled
      for or targeted these training variables or their influence on locomotor recovery. Previous
      work suggests these training parameters may influence locomotor recovery in patients with
      other neurological disorders (i.e., stroke), although few studies have attempted to delineate
      similar contributions of in iSCI. Indeed, no studies have carefully controlled the amount of
      task-specific practice during physical rehabilitation of patients with iSCI, and such
      interventions are rarely utilized in the clinical setting. The goal of the present study is
      to delineate the relative contributions of amount of task-specific training on locomotor
      outcomes in individuals with iSCI. Using a cross-over, randomized clinical trial design, the
      investigators anticipated non-specific (i.e., non-stepping) training activities would result
      in smaller improvements as compared to task-specific (stepping) training. The investigators
      will investigate the effects of such training on walking performance and kinematics, as well
      as the impairments thought to contribute to walking performance. Successful completion of
      this project could have an immediate impact on rehabilitation research and treatment of
      people following iSCI, and may be utilized to treat more subacute patients with iSCI or other
      acute-onset neurological disorders.
    

Detailed description: 
      The primary goal of the proposed study is to identify the contributions of the amount of
      task-specific practice on locomotor (i.e., walking) recovery in patients with chronic (> 1
      yr) motor incomplete spinal cord injury (iSCI). The investigators will do this by building on
      previous work directed towards identifying the essential exercise training parameters that
      maximize locomotor recovery. Consistent with principles of motor learning and exercise
      physiology, the investigators contend that certain training (i.e., dosage) parameters of
      physical rehabilitation, including the type (specificity) and amount of task practice, are
      critical to mobility outcomes following neurological injury. Previous work suggests these
      training parameters may influence locomotor recovery in patients with other neurological
      disorders (i.e., stroke), although few studies have attempted to delineate similar
      contributions of amount of task-specific practice in iSCI. Indeed, no studies have carefully
      controlled these training parameters during physical rehabilitation of patients with iSCI,
      and such interventions are rarely utilized in the clinical setting.

      Reasons for these knowledge gaps from other rehabilitation studies to patients with iSCI or
      lack of clinical implementation are unclear, but may be due to adherence to traditional
      rehabilitation theories. One concern is that practicing only stepping tasks reduces attention
      towards hallmark physical impairments following iSCI, such as loss of strength or postural
      stability, which are considered primary determinants of decreased mobility. Only a few
      studies have addressed whether providing only structured stepping training can mitigate these
      impairments without their explicit practice, but not in the iSCI population. A related
      concern is that focused stepping training without significant attention towards impairments
      or gait quality may exaggerate altered movement strategies, which could be reinforced with
      repeated practice. However, there is little data to suggest "worsening" of abnormal gait
      patterns following high intensity training. Rather, recent findings suggest patients
      demonstrate more normal kinematics. If focused task specific (i.e., stepping) training is to
      be applied clinically, the investigators must delineate its contributions towards improving
      locomotor function, and their effects on underlying impairments and gait kinematics.

      The central hypotheses are that stepping training in iSCI results in:1) greater locomotor
      gains as compared to non-specific interventions; 2) gains in selected impairments underlying
      gait dysfunction (i.e., strength and metabolic capacity and efficiency); and, 3) improvements
      in gait quality. To test these hypotheses, the proposed crossover, assessor-blinded,
      randomized clinical trial (RCT) is designed to test the effects of specificity of
      rehabilitation training applied early-post-stroke. In this RCT, patients > 1 year post-iSCI
      will be allocated to 4-6 weeks (20 session) of high-intensity stepping training or
      high-intensity non-specific training. Importantly, training intensity will be held constant
      to account for this potential confounding factor. Blinded assessments will be performed prior
      to and following each training paradigm. The investigators will address 3 specific aims:

      Specific Aim 1: Demonstrate that high intensity stepping training in patients with chronic
      iSCI produces greater locomotor gains as compared to high intensity non-specific training
      strategies.

      Hypothesis 1: High intensity stepping training will result in greater increases in gait
      speeds and distances Specific Aim 2: Test the effects of these training strategies on
      impairments and non-locomotor mobility tasks.

      Hypothesis 2: Higher intensity stepping training groups will result in greater gains in
      metabolic capacity and efficiency.

      Specific Aim 3: Analyze the potential effects of high intensity stepping or non-specific
      training on gait quality.

      Hypothesis 3: High intensity training will result in improved sagittal-plane gait kinematics
      consistent with normal locomotor function, due in part to greater locomotor speeds, as
      compared to non-specific training strategies.

      The aims represent an innovative approach to improving long-term mobility outcomes of
      patients with iSCI by applying selected principles of motor learning and exercise physiology
      yet untested in this population. Expected outcomes will be demonstration of the efficacy of a
      high intensity stepping training paradigm, with further understanding of potential underlying
      mechanisms and movement strategies used with improved locomotor performance. Successful
      completion of this project could have an immediate impact on rehabilitation research and
      treatment of people following iSCI, and may be utilized to treat more subacute patients with
      iSCI
    

Intervention name(s): Variable Stepping Training; Variable Non-specific Training
Intervention type(s): Procedure; Procedure
Intervention description(s): Six weeks (20 sessions) of high intensity stepping training in multiple variable environments; Six weeks (20 sessions) of high intensity stepping training in multiple variable environments
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Parallel-group with optional crossover
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment