C. Preliminary Studies/Progress Report As this is a pilot study, there is no preliminary data using muscle ultrasound longitudinally in patients with ALS. The study by Arts et al used muscle ultrasound to assist in the ALS diagnosis, but to our knowledge, muscle ultrasound has not been used to detect longitudinal changes in the illness. This study will help in the development of future studies testing pharmacologic agents in ALS, by providing muscle ultrasound as a validated endpoint in the progression of ALS.