Locomotor Adaptation Training to Prevent Mobility Disability

Participants will be forty-eight older adults with pre-clinical mobility disability who will
be randomized into one of three intervention groups: dual-belt treadmill exercise,
traditional treadmill exercise, or non-contact control.

Prior to and following 16 weeks of therapy, we will observe the participants' performing
several functional movements (walking, standing from sitting, sitting from standing, walking
up and down stairs) and measure their muscular activity. These performance-based measures
will be obtained to determine whether their movement function improves as a result of
therapeutic intervention. The participants' absolute performance on any of these tasks does
not matter as much as that they make the very best effort on each of the tests. They are
welcome to take a break at any point in the testing or training.

Inclusion Criteria:

- Age 65 and older

- Gait Speed of ≤ 1m/s

- Summary score 7-10 on the Short Physical Performance Battery, indicating mild to
moderate impairment

- Sedentary as defined by reporting <20 min/wk of performing regular physical activity
in the past month and <125 min/wk of moderate physical activity on the CHAMPS-18
questionnaire

- Willingness to be randomized to any of the treatment groups

Exclusion Criteria:

- Failure to provide informed consent

- Planned surgery in next year

- Hospitalization within the past 6 months

- Smoker > 1 pack per day

- Significant cognitive impairment, defined as a known diagnosis of dementia or a
Modified Mini-Mental State score <24

- Significant cognitive executive impairment, defined as a Montreal Cognitive Assessment
(MoCA) score of<25

- Progressive, degenerative neurologic disease, e.g., Parkinson's Disease, multiple
sclerosis, Amyotrophic lateral sclerosis (ALS)

- Severe rheumatologic or orthopedic diseases, e.g., awaiting joint replacement, active
inflammatory disease

- Terminal illness with life expectancy less than 12 mos, as determined by a physician

- Severe pulmonary disease, requiring either steroid pills or injections or the use of
supplemental oxygen

- Severe cardiac disease, including New York Heart Association Class III or IV
congestive heart failure, clinically significant aortic stenosis, history of cardiac
arrest, use of a cardiac defibrillator, or uncontrolled angina;

- Other significant co-morbid disease that would impair ability to participate in the
exercise-based intervention, e.g. renal failure on hemodialysis, severe psychiatric
disorder (e.g. bipolar, schizophrenia), excessive alcohol use (>14 drinks per wk);
persons with depression will not be excluded

- Develops chest pain or severe shortness of breath during exercise test

- Unable to communicate because of severe hearing loss or speech disorder or language
barrier

- Lives outside of the study site or is planning to move out of the area in next year or
leave the area for >1 month during the next year

- Severe diabetes, requiring use of insulin