Provided are certain chemical entities, and methods of use to modulate skeletal myosin, skeletal actin, skeletal tropomyosin, skeletal troponin C, skeletal troponin I, skeletal troponin T, and skeletal muscle, including fragments and isoforms thereof, as well as the skeletal sarcomere, and methods of use in the treatment of neuromuscular disorders, conditions having muscle wasting, claudication, frailty, metabolic syndrome, muscle atrophy associated with disuse, and muscle fatigue, and other indications.