Comparative Efficacy of High-Intensity Training Versus Conventional Training in Individuals With Chronic Traumatic Brain Injury: A Pilot Randomized Controlled Study

Abstract

Numerous studies have evaluated the efficacy of interventions to improve locomotion after acute-onset brain injury, although most focus on patients with stroke, with less attention toward traumatic brain injury (TBI). For example, a number of studies in patients post-stroke have evaluated the effects of high-intensity training (HIT) attempting to maximize stepping practice, while no studies have attempted this intervention in patients with TBI. The purpose of this blinded-assessor randomized trial was to evaluate the effects of HIT focused on stepping practice versus conventional training on walking and secondary outcomes in individuals with TBI. Using a crossover design, ambulatory participants with TBI >6-months duration performed HIT focused on stepping in variable contexts (overground, treadmill, stairs) or conventional training for up to 15 sessions over five weeks, with interventions alternated >4 weeks later. HIT focused on maximizing stepping practice while trying to achieve higher cardiovascular intensities (>70% heart rate reserve), while conventional training focused on impairment-based and functional exercises with no restrictions on intensities achieved. Greater increases in 6-min walk test and peak treadmill speed during graded exercise testing were observed after HIT versus conventional training, with moderate associations between differences in stepping practice and outcomes. Greater gains were also observed in estimates of aerobic capacity and efficiency after HIT, with additional improvements in selected cognitive assessments. The present study suggests that the amount and intensity of stepping practice may be important determinants of improved locomotor outcomes in patients with chronic TBI, with possible secondary benefits on aerobic capacity/efficiency and cognition. Clinical Trial Registration-URL: https://clinicaltrials.gov/; Unique Identifier: NCT04503473.

Keywords: gait; locomotion; rehabilitation.

FIG. 1.

CONSORT flow diagram of randomized crossover design. All participants enrolled and randomized completed the study.

FIG. 2.

Differences in primary locomotor outcomes of (A) self-selected speed (SSS), (B) fastest possible speed (FS), (C) 6-min walk test (6MWT), and (D) peak treadmill speed (peak TM); baseline (BSL) and post-training (POST) indicated for both first and second training interventions in order received; dark lines indicate high-intensity training (HIT) in variable contexts, dashed lines indicate conventional training, filled squares denote HIT first, conventional second; open triangles denote conventional first, HIT second.

FIG. 3.

Correlations between differences in steps/sessions (A) and heart rate reserve (B) between training conditions (high-intensity training [HIT]—conventional) vs. differences in changes ( ) in selected outcome measures (i.e., D6MWT = changes after HIT minus changes after conventional); both p < 0.05).