Background and Purpose: Prior literature suggests a relationship between spatiotemporal gait asymmetry and metabolic cost of walking, balance, endurance, quality of life, and physical activity in people with chronic stroke. Our purpose was to determine whether targeting spatiotemporal gait symmetry would concomitantly improve these measures. Methods: This study represents secondary outcome measures from a trial in which 48 participants with chronic stroke were randomized to groups that all targeted spatiotemporal gait asymmetry. Measures of balance, daily step count, endurance (6-minute walk test [6MWT), metabolic cost of walking, quality of life (Stroke Impact Scale [SIS]), and overground spatiotemporal asymmetries were collected 1 week prior to and following training. Separate analyses were performed for those who trained for spatial versus temporal asymmetry. The effect of time (pre/post) was examined for all measures and correlational analyses evaluated the potential relationships between changes in spatiotemporal asymmetry and all other measures. Results: Individuals who trained to target step length asymmetry improved balance, 6MWT distance, metabolic cost of walking, and SIS-Mobility. Individuals who trained to target stance time asymmetry improved balance, 6MWT distance, SIS-Mobility, and SIS-Global recovery scores. However, step length asymmetry improvements were only related to improved 6MWT distance (P = 0.025; r = −0.49). Stance time asymmetry improvements were only related to improved metabolic cost of walking (P = 0.031; r = 0.558). Discussion and Conclusions: Despite a targeted training approach and noted improvements in most measures, these changes did not appear to arise from improved spatiotemporal gait asymmetry. Furthermore, improvements in gait function observed in the laboratory setting did not appear to translate to increased community mobility. Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A316).

Aerobic exercise and action observation are two clinic-ready modes of neural priming that have the potential to enhance subsequent motor learning. Prior work using transcranial magnetic stimulation to assess priming effects have shown changes in corticospinal excitability involving intra- and interhemispheric circuitry. The objective of this study was to determine outcomes exclusive to priming- how aerobic exercise and action observation priming influence functional connectivity within a sensorimotor neural network using electroencephalography. We hypothesized that both action observation and aerobic exercise priming would alter resting-state coherence measures between dominant primary motor cortex and motor-related areas in alpha (7–12 Hz) and beta (13–30 Hz) frequency bands with effects most apparent in the high beta (20–30 Hz) band. Nine unimpaired individuals (24.8 ± 3 years) completed a repeated-measures cross-over study where they received a single five-minute bout of action observation or moderate-intensity aerobic exercise priming in random order with a one-week washout period. Serial resting-state electroencephalography recordings acquired from 0 to 30 minutes following aerobic and action observation priming revealed increased alpha and beta coherence between leads overlying dominant primary motor cortex and supplementary motor area relative to pre- and immediate post-priming timepoints. Aerobic exercise priming also resulted in enhanced high beta coherence between leads overlying dominant primary motor and parietal cortices. These findings indicate that a brief bout of aerobic- or action observation-based priming modulates functional connectivity with effects most pronounced with aerobic priming. The gradual increases in coherence observed over a 10 to 30-minute post-priming window may guide the pairing of aerobic- or action observation-based priming with subsequent training to optimize learning-related outcomes.