I saw a tape of an interview with my dojo cho, Bud Malstrom, on a news program years ago. Bud was encouraging those with disabilities to become involved in the martial arts. He then took a non-martial artist in a wheelchair, and in less than ten minutes, showed them a technique that allowed them to pin an assailant against a wall. (I believe the "attacker" worked at the tv station, and was not just cooperating.)
As to what o1paw was saying, good call. The Bujinkan focuses mostly on getting offline of the attack. Typically, that is the "block". Striking the limb is usually just to damage the weapon.