A strength measurement device called Accurate Test of Limb Isometric Strength (ATLIS) was developed to precisely and conveniently measure static limb strength in patients with ALS. The investigator will compare ATLIS data with data from the commonly used ALS outcomes measure, the ALS Functional Rating Scale-Revised (ALSFRS-R), in a prospective, longitudinal study. Both outcomes measures will be performed on 100 subjects collected preferably at bi-monthly clinic visits during the study period.
Cedars-Sinai Medical Center will enroll and collect data on 100 subjects. Subjects will be tested every 1 to 6 months for up to two years and no more than 6 times per year. Subjects will be tested at each visit using ATLIS and the ALSFRS-R questionnaire.
18 years or older, all genders, no healthy volunteers. Possible, probable, or definite ALS diagnosis. Active movement in at least two limbs.