Novel Intervention to Influence Muscle Plasticity in Veterans

Summary

The loss of muscle contraction (paralysis) removes an important stimulus for maintenance of overall health for individuals with complete spinal cord injury (SCI). Increased protein catabolism (atrophy) limits important stresses to the skeletal system. Bone loss doubles the risk of fracture and contributes to increased mortality in Veterans with SCI. Metabolic syndrome and diabetes lead to heart disease in Veterans with SCI at higher rates than the general population. Exercise methods to sustain muscle tissue, bone density, and metabolic stability after SCI are lacking scientific justification. If left unchecked, the secondary complications of SCI can be health limiting or even life threatening to Veterans with paralysis. The importance of maintaining the health of the musculoskeletal system after SCI has never been greater as a cure for paralysis may become a reality. Contemporary rehabilitation interventions lack the ability to functionally load muscle tissue, quantify the dose of load, stress the cardiovascular system, monitor the overall stresses during daily exercise training, or offer portability to improve compliance with the exercise. The long-term goal of this project is to establish the optimal dose of muscle and bone stress during functional exercise in order to improve the health of Veterans with complete paralysis. The practical outcome of this research is to offer a form of activity that is feasible, portable, and grounded in sound scientific principles. The scientific goal is to understand whether the dose of force generated in paralyzed muscle via evoked contractions is critical to muscle atrophy/hypertrophy molecular pathways, physiologic performance, and insulin sensitivity. The investigators will administer various doses of muscle force by manipulating the frequency of electrical stimulation while keeping stimulation current (i.e. muscle fiber recruitment) constant. Interestingly, no previous study has examined the dose of muscle force necessary to trigger adaptations in protein synthesis/degradation pathways. The investigators wish to discover the most effective method to maintain the molecular and physiologic properties of paralyzed muscle. The investigators believe such a method will be in urgent demand as a co-intervention with pharmaceutical strategies in post-SCI rehabilitation.

Conditions

• Spinal Cord Injuries

Interventions

BEHAVIORAL

Low-force muscle stimulation

Electrical stimulation of paralyzed muscle in seated or standing to evoke non-summated, low-force contractions, using either a lab-based system or a portable system for up to 1 year.

BEHAVIORAL

High-force muscle stimulation

Electrical stimulation of paralyzed muscle in seated or standing to evoke summated, high-force contractions, using either a lab-based system or a portable system for up to 1 year.

BEHAVIORAL

Sequential low-force and high-force muscle stimulation

Electrical stimulation of paralyzed muscle in seated or standing to evoke non-summated, low-force contractions, followed by: 1) a 1-month washout period, then; 2) electrical stimulation to evoke summated, high-force contractions.

Sponsors & Collaborators

• University of Iowa

  collaborator OTHER

• VA Office of Research and Development

  lead FED

Principal Investigators

• Richard K Shields, PhD PT · Iowa City VA Health Care System, Iowa City, IA

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-04-30

Primary Completion

2014-12-31

Completion

2014-12-31

Countries

• United States

Study Locations