Future devices will be more reliable, although more versatile and complex. They will require less attention and maintenance, but more skill when maintenance or repair is necessary. They will require less training of the patient before he can use them successfully and will be more immediately responsive to his wishes, giving smooth, integrated movements, varying with the intensity and direction of his effort.

1. The various methods of powering orthoses are described.

2. The details of control systems are given.

3. The applications of these systems are described.