Removable shoulder stop assembly with locking mechanism

A removable locking shoulder stop assembly for use on a reformer exercise apparatus is disclosed that includes a flat rectangular lock plate fastenable to the platform adjacent the head rest on the carriage platform. The lock plate has a first locating member and a keyway spaced from the first locating member. An L-shaped shoulder stop bracket has a second locating member configured to mate with the first locating member of the lock plate. An elongated locking handle assembly is connected to the mounting portion of the bracket and spaced apart from the second locating member. The handle assembly aligns with the keyway when the first locating member is mated with the second locating member and is operable to clamp the shoulder stop bracket to the lock plate when the locating members are mated. The locking handle assembly is hand tightened against the mounting portion of the shoulder stop bracket.