Several studies using HD animal models have shown that HD mice housed in enriched environments or in cages with running wheels that stimulated physical activity demonstrated a delayed onset and/or slowed decline in motor function compared to mice in non-enriched environments (van Dellen et al. 2000, 2008; Spires et al., 2004). Evidence suggests that aerobic exercise may have neuroprotective effects and helps the elderly and individuals with neurodegenerative diseases to maintain better cognitive and motor function than those who are inactive. More specifically, there is strong evidence from animal and human trials in neurological populations (i.e., Parkinson's Disease, spinal cord injury, and stroke) that treadmill training can improve walking and motor function. Immediate effects of a single-session of treadmill walking in the Parkinson's Disease population were improved over-ground gait measures (i.e., gait speed, stride length, double support percent, stride variability) and longer term treadmill training studies demonstrated additional improvements in Unified Parkinson Disease Rating Scale scores, fall risk, and health-related quality of life (Herman et al., 2008). This study builds upon foundational knowledge gained in animals and other neurologic populations to determine the feasibility, safety and possible immediate benefit of treadmill walking in individuals with HD.
The primary purpose of this pilot study is to investigate the the safety, feasibility and utility of a single 20-minute session of treadmill walking to improve gait parameters in ambulatory individuals with DLB and HD. Secondarily we will explore the effects of treadmill walking on mobility, fall risk, and motor coordination. Based on previous studies utilizing a single-session of treadmill training in the PD population, we hypothesize that treadmill walking will improve overground spatiotemporal gait parameters (gait speed, stride length, double support percent, and stride-to-stride variations in gait) in individuals with DLB and HD (Pohl et al., 2003; Frenkel-Toledo et al., 2005; Bello et al., 2008).
