Direct Quantification of Balance Amongst Limited Community Ambulators Using Microprocessor Prosthetic Knees
Abstract
The ability to balance one’s body is a fundamental requirement to many activities of daily living. Poor balance leads to falling. The consequences of falling can be very serious, including reduced future mobility, injury, and even death. Balance requires many complex neural processes. Prosthesis users have a more difficult time maintaining balance because part of their natural balance control system includes an artificial mechanical or electrical-mechanical prosthetic device. The prosthetic device is never a perfect replacement and requires time for the user to learn how best to leverage its capacity for mobility and stability. Thus, prosthesis users fall more often than others. Additionally, combat wounded Veterans present with complex presentations due to the traumatic nature of the injuries. Traumatic brain injuries, limb salvage procedures, and psychiatric are some of the additional confounding factors to support. In recently years, technology underlying prosthetic components has greatly advanced. Some (but not all) prosthesis users have access to devices with sophisticated control algorithms. Clinical practice guidelines aim to match the available technology with a patient’s potential for use and improvement. These guidelines undergo continual revision as new research and development takes place. Currently, patients who are categorized as “limited mobility” trans-femoral (above knee) are not categorically prescribed micro-processor knees (MPKs). However, MPKs are designed to improve gait patterns and balance. Is it possible that limited mobility prosthesis users can learn to use MPKs in a positive way? In this project, we test the hypothesis that limited mobility patients are able to improve balance with an MPK. More importantly, we use detailed experiment methods that also allow us to characterize how and why limitations may exist in the ability of prosthesis users to leverage the MPK technology. By understanding the benefits and limitations, we propose that our investigation could lead to (1) improvements in the design of MPKs for K2 (limited mobility) users, (2) specific rehabilitation to help K2 ambulators better use existing MPKs, or (3) a realization of some fundamental limitations in the suitability of MPKs for K2 ambulators. Previous research in this area is minimal. There have been positive reports that describe improvement in self-reported patient falls with an MPK. We build upon these self-reported findings to directly probe balance using a clinical biomechanics and engineering approach. In brief, 13 patients will undergo laboratory balance tests with their prescribed knee and foot. Then, they will be given an Ottobock C-leg MPK for 1 month and retested two times with the same balance tests. Then, for an additional control measure, we will retest again 1 month later with their prescribed knee. In balance tests, controlled external perturbations are delivered to patients to force a reactive balance response. This will be done is a series of tests in both standing and walking. Perturbations will appear random to patients so that we simulate a real-world reaction. Safety harnesses are always included for safety. In all tests, sensors will be placed on various body segments so that we can analyze the detailed responses. We also use data to develop a feedback model simulation of neural processes with and without the MPK. For comparison, 13 age-, gender-, and size-matched control subjects will also be tested. The study will be completed in 2 years. Experiments will take place within the first 3 months of the grant and end at 15 months to provide ample time for data analysis, interpretation, and dissemination. If our hypothesis is supported, safety should increase for limited mobility ambulators. An important knowledge gap would be filled that could ultimately impact future clinical practice guidelines and motivate a larger clinical trial, inclusion of a wider variety of MP
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 19, 2019
- Source ID
- W81XWH1910870
Entities
People
- Adam D. Goodworth
Organizations
- United States Army
- Westmont College