Voluntary Programs: Programs in which participation is not required.Program Evaluation: Studies designed to assess the efficacy of programs. They may include the evaluation of cost-effectiveness, the extent to which objectives are met, or impact.Volition: Voluntary activity without external compulsion.Program Development: The process of formulating, improving, and expanding educational, managerial, or service-oriented work plans (excluding computer program development).Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Government Programs: Programs and activities sponsored or administered by local, state, or national governments.Isometric Contraction: Muscular contractions characterized by increase in tension without change in length.Voluntary Health Agencies: Non-profit organizations concerned with various aspects of health, e.g., education, promotion, treatment, services, etc.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Torque: The rotational force about an axis that is equal to the product of a force times the distance from the axis where the force is applied.United StatesMuscle Fatigue: A state arrived at through prolonged and strong contraction of a muscle. Studies in athletes during prolonged submaximal exercise have shown that muscle fatigue increases in almost direct proportion to the rate of muscle glycogen depletion. Muscle fatigue in short-term maximal exercise is associated with oxygen lack and an increased level of blood and muscle lactic acid, and an accompanying increase in hydrogen-ion concentration in the exercised muscle.National Health Programs: Components of a national health care system which administer specific services, e.g., national health insurance.