Estimating Highest Capacity Performance During Evaluation of Walking for Individuals With Traumatic Brain Injury

Traumatic brain injury due to trauma and/or neurologic disease is a leading cause of long-term disability in the United States. Balance impairments observed within the post-TBI population can greatly impact walking abilities and pose a variety of challenges. Following hospital discharge, there is a greater fall risk as well as a decrease in physical activity and increase in sedentary behaviors that lead to deconditioning.

It is difficult to determine the extent of what a person is capable of doing using current overground assessment methods, which are the current standard means of physical capability measurements (i.e. 6-minute walk test, 5 times sit-to-stand, 10-meter walk test). Improvement of walking and balance outcomes in this population requires the re-evaluation of current approaches and the testing/implementation of new approaches. This will allow more appropriate assessment of baseline walking abilities in order to apply the appropriate amount of challenge during rehabilitation training. This study will involve the use of a robotic treadmill device in order to determine maximum walking capacities of participants and compare these capacities to standard overground assessments. It has been shown that walking speeds overground are correlated with walking speeds on a robotic device (and even specifically on the KineAssist-MX, which will be used for this project). If it is found that maximum capacities be greater on the robotic device, rehabilitation training goals can be more appropriately tailored to these participants.

The aims and hypotheses of this research project are:

Aim 1) Assess function at preferred performance in an overground environment vs. a safety-enhanced robotic environment to establish concurrent validity.

Hypothesis 1) Participants with the highest overground performances (strength, speed, and endurance) will have the highest performances on the KineAssist-MX and vice versa.

Aim 2) Assess maximum capacities of participants over ground vs. in the safety-enhanced robotic environment to establish content validity.

Hypothesis 2) Maximum capacity will be higher in the safety-enhanced robotic environment than overground and vice versa. Therefore, people will be able to do more in the robotic environment than overground.

Aim 3) Assess the capacities of individuals across different baseline functional strata to establish usability.

Hypothesis 3) Individuals in the lower quadrants of baseline function will have lower maximum capacities in the safety-enhanced robotic environment.

This study will occur over a two-day period of time during which participants will undergo overground assessments during day 1 and robotic safety-environment assessments during day 2. There will be no interventions implemented.

Inclusion criteria

• Adults ages 18 years and older
• All demographic groups will be invited to participate and would have equal access
• Post-TBI individuals currently enrolled at the Moody Neurorehabilitation Institute
• Ambulatory with or without assistive devices
• Subjects with expressive aphasia in the case of a caregiver able to provide assistance when needed
• English-speaking only
• Medically stable (controlled hypertension, no arrhythmia, stable cardiovascular status)
• Able to provide written informed consent

Exclusion criteria

• Subjects with loss of lower limb
• History of serious cardiac disease (e.g., myocardial infarction)
• Uncontrolled blood pressure (systolic pressure >140 mmHg, diastolic blood pressure >90 mmHg)
• Subjects with receptive aphasia
• Presence of cerebellar and brainstem deficits
• Severe cognitive disorder
• Uncontrolled respiratory or metabolic disorders
• Major or acute musculoskeletal problems
• Spasticity management that included phenol block injections within 12 months or botulinum toxin injections within 4 months of the study
• Participants undergoing any rehabilitation therapy during the timeframe of this study.
• Body weight greater than 250 pounds (due to robotic device weight restrictions)
• Non-English speaking individuals