Enhancing Seated Stability and Reaching After Spinal Cord Injury
Abstract
Injury to the spinal cord often leads to paralysis of the muscles of the trunk and pelvis. This inability to adjust the torso by moving slightly side-to-side or forward-backward leads to an unhealthy slouching posture that results in many medical complications including pressure sores, difficulty breathing, frequent falls, and the inability to reach and handle objects while seated. All these problems make it difficult for individuals with spinal cord injury (SCI) to lead normal independent lives. Our laboratory has been in the forefront of using devices that apply small electric currents to the paralyzed muscles in order to make them contract and move the limbs. Previous attempts to apply neural stimulation to restore functional movements after paralysis have generally concentrated on the hands, arms, and legs. In these applications, the torso is generally stiffened statically through continuous contractions of the trunk extensor muscles. Stable sitting times with such systems are often limited, and patterns of stimulation are constant and unchanging regardless of both what the user wants to do and what’s happening around them. Users cannot alter their seated posture to perform various tasks and can easily lose balance if bumped or nudged. The ultimate usefulness of existing systems is therefore quite limited. This project will determine the feasibility of a new comprehensive trunk postural control system for implanted neuroprostheses that restores functional seated balance to individuals with various levels of SCI. Advanced biomechanical modeling and computer simulation techniques will be used to develop new control elements that (a) maintain the stability of the trunk at the nominal erect posture; (b) allow users to deploy their trunk away from the nominal upright seated position whenever they wished to do so; (c) maintain the new user-selected posture by automatically adjusting stimulation based on any changes in trunk tilt away from that posture; and (d) allow users to return to the nominal erect posture, all without loss of stability. The control systems will define new interventions that increase the safety of people with SCI to undertake activities of daily living in environments typically found in the office and home that would otherwise be impossible to accomplish while in a seated position without the potential of falling off the wheelchair or seat.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 29, 2018
- Source ID
- W81XWH1710240
Entities
People
- Musa Audu
Organizations
- Louis Stokes Cleveland VA Medical Center
- United States Army