Power Training Post-stroke

This study is currently recruiting participants. (see Contacts and Locations)
Verified April 2014 by Department of Veterans Affairs
Sponsor:
Information provided by (Responsible Party):
Department of Veterans Affairs
ClinicalTrials.gov Identifier:
NCT01970592
First received: October 22, 2013
Last updated: April 30, 2014
Last verified: April 2014
  Purpose

Hemiparesis, strictly defined as (muscular) weakness affecting one side of the body, is seen in three-quarters of individuals following stroke. Weakness in this population results from both neural and muscular factors which include, respectively, the ability to activate skeletal muscle as well as the force generating capacity of the muscle. Our overall goal is to improve walking in persons post-stroke by training subjects with an intervention that specifically targets existing neural and muscular impairments, thereby facilitating locomotor recovery.


Condition Intervention Phase
Stroke
Behavioral: POWER training
Phase 1
Phase 2

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Skeletal Muscle Plasticity As An Indicator of Functional Performance Post-Stroke

Further study details as provided by Department of Veterans Affairs:

Primary Outcome Measures:
  • gait speed, [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • muscle strength [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    The strength of your upper and lower leg muscles will be measured by asking you to contract your muscles as forcefully as possible. Testing will be conducted at a range of different movement speeds (0-240 �/s) on a specialized machine called an isokinetic dynamometer. Both legs may be tested. This testing is designed to assess your ability to generate muscle power. Before testing you will be asked to perform 5 minutes of low intensity cycling. Strength testing will include movements at the hip, knee and ankle in both legs.


Estimated Enrollment: 56
Study Start Date: October 2013
Estimated Study Completion Date: September 2017
Estimated Primary Completion Date: September 2017 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: POWER
Individuals with chronic post-stroke hemiparesis will undergo training to improve muscle power generation for 24 sessions (3 times/week) that includes both resistive and task-specific elements. Session duration will be ~90 minutes/day (inclusive of rest intervals). Training will include five distinct resistance activities aimed at improving muscle power-- each previously reported to contribute to improved walking.
Behavioral: POWER training
Individuals with chronic post-stroke hemiparesis will undergo training to improve muscle power generation for 24 sessions (3 times/week) that includes both resistive and task-specific elements. Session duration will be ~90 minutes/day (inclusive of rest intervals). Training will include five distinct resistance activities aimed at improving muscle power-- each previously reported to contribute to improved walking
Other Name: strength training

Detailed Description:

A primary impairment associated with post-stroke hemiparesis is the failure to make rapid graded adjustment of muscle force (i.e. muscle power) within the context of purposeful complex synergies (e.g., coordination during walking). Not surprisingly, the impact of stroke on walking is significant, with less than 50% of survivors progressing to independent community ambulation. Even among those who achieve independent ambulation, significant residual deficits persist in balance and gait speed, with ~75% of persons post-stroke reporting limitations in mobility related to walking. Muscle weakness is the most prominent motor consequence among the nearly 6 million survivors of stroke living in the United States and the strongest predictor of functional disability in this large clinical cohort. To date, the physiological mechanisms that contribute to muscle dysfunction in hemiparetic subjects are largely unstudied. Moreover, evidence regarding the efficacy of interventions aimed at attenuating impaired muscle function and the ensuing functional consequences in the post-stroke population is equivocal and viable therapeutic options to remediate hemiparetic muscle weakness remain among the most pressing challenges for biomedical research. We propose that impaired muscle power (the product of muscle strength and velocity) generation is causal of functional (walking) disability post-stroke. In addition, coordination deficits are also critical determinants of functional performance. We have developed a comprehensive theoretical framework that defines and measures the factors underlying disordered muscle function and coordination and will apply this framework to Post-stroke Optimization of Walking using Explosive Resistance (POWER) training. Our goals over the four year funding period are to 1) quantify neural and muscular adaptations that contribute to impaired muscle power generation post-stroke; 2) assess effects of POWER training on neural and muscular adaptations in paretic and non-paretic muscle; and 3) determine the relationship between changes in neural and muscular adaptations following POWER training and locomotor improvements. Innovative aspects of the proposed work include the novel training intervention; the advanced magnetic resonance assessments; as well as the unique measure of the coordination that we propose. It is our belief that: a) neural and muscular adaptations following stroke are associated with impaired muscle power generation as well as locomotor ability, b) POWER training attenuates functional deficits by addressing the underlying neural and muscular elements and c) functional improvements following training are predicated on improving the most prominent neural and muscular contributors to muscle power generation. If correct, the data generated will provide an entirely new level of evidence regarding the effectiveness of this novel intervention strategy on improving functional performance as well as the importance of peripheral muscle properties as predictors of locomotor ability post-stroke.

  Eligibility

Ages Eligible for Study:   50 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • age 50-70,
  • stroke within the past 6 to 24 months,
  • residual paresis in the lower extremity (Fugl-Meyer LE motor score <34),
  • ability to walk without assistance and without an AFO on the treadmill 30 seconds at speeds ranging from 0.3 - 0.8 m/s, and
  • provision of informed consent.
  • In addition, all subjects who meet criteria for the training portion must complete an exercise tolerance test and be cleared for participation by the study cardiologist.

Exclusion Criteria:

  • Unable to ambulate at least 150 feet prior to stroke, or experienced intermittent claudication while walking;
  • rating on Modified Ashworth Scale 3 at the knee or ankle;
  • limited lower extremity range of motion of the knee (passive flexion ROM < 90); hip (inability to achieve neutral 0 hip extension); or ankle (inability to achieve 0 of active dorsiflexion);
  • history of congestive heart failure, unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during ADL's;
  • History of COPD or oxygen dependence;
  • Preexisting neurological disorders, dementia or previous stroke;
  • History of major head trauma;
  • Legal blindness or severe visual impairment;
  • history of significant psychiatric illness
  • Life expectancy <1 yr.,
  • Severe arthritis or other problems that limit passive ROM;
  • post-stroke depression (PHQ-9 10),
  • History of DVT or pulmonary embolism within 6 months;
  • Uncontrolled diabetes with recent diabetic coma, or frequent insulin reactions;
  • Severe hypertension with systolic >200 mmHg and diastolic >110 mmHg at rest;
  • Previous or current enrollment in a trial to enhance motor recovery;
  • Presence of non-MR compatible implants, pregnancy or severe claustrophobia.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01970592

Contacts
Contact: Chris M Gregory, PhD (843) 792-1078 Christopher.Gregory@va.gov

Locations
United States, South Carolina
Ralph H. Johnson VA Medical Center, Charleston, SC Recruiting
Charleston, South Carolina, United States, 29401-5799
Contact: Sarah A Jackson, BA MA    843-789-7587    sarah.jackson@va.gov   
Principal Investigator: Chris M. Gregory, PhD         
Sponsors and Collaborators
Investigators
Principal Investigator: Chris M. Gregory, PhD Ralph H. Johnson VA Medical Center, Charleston, SC
  More Information

No publications provided

Responsible Party: Department of Veterans Affairs
ClinicalTrials.gov Identifier: NCT01970592     History of Changes
Other Study ID Numbers: O0844-R
Study First Received: October 22, 2013
Last Updated: April 30, 2014
Health Authority: United States: Federal Government

Keywords provided by Department of Veterans Affairs:
exercise
rehabilitation
walking

Additional relevant MeSH terms:
Stroke
Cerebral Infarction
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases
Brain Infarction
Brain Ischemia

ClinicalTrials.gov processed this record on October 19, 2014