Eligibility Criteria:
Inclusion Criteria:
Community-dwelling men and women who are 54-89 years of age and able to give fully informed consent; able to read, write, and speak English to ensure safe participation in the project; and able to arrange own transportation to Boulder campus.
Exclusion Criteria:
Cognitive impairment, major psychiatric condition, or unstable depressive disorder that would influence the ability to understand the study and cooperate fully in the proposed protocols; any progressive neurological, muscular, cardiovascular, or skeletal disorder that limits participation, such as (but not limited to) (1) amyotrophic lateral sclerosis, multiple sclerosis, multiple system atrophy, muscular dystrophy, myasthenia gravis, Parkinson's disease, spinal muscular atrophy, spinocerebellar ataxia, or spasticity; (2) congenital, mitochondrial, or thyrotoxic myopathies, fibromyalgia, or myositis; (3) peripheral neuropathy, diabetes, or hypertension; or (4) cancer, gout, osteoarthritis with severe pain, or rheumatoid arthritis; chronic pain condition that would impair the ability to participate in the study; currently taking prescribed medication known to influence neuromuscular function, such as carisoprodol, cyclobenzaprine, metaxalone, and methocarbamol; function-limiting injury to the hands, arms, shoulders, neck, or legs; recent hospitalization (within the last 3 months) or enforced bedrest/sedentary state; inability to attend the evaluation and practice sessions in 2 weeks.