Continuous Passive Motion Device for Children With Arthrogryposis

The investigators will measure the effect of continuous passive motion (CPM) of the knee joint post-surgery on young children with arthrogryposis. The investigators have developed a motorized brace that will move the joint through a prescribed range of motion and speed while the subject is seated. The objective of this pilot study is to develop the device from subject feedback and determine the right dose and speed of CPM to provide. CPM is routinely used for adults and older children after surgery to maintain range of motion. The machines used are too large for young children therefore the investigators have developed a prototype for small sized kids that will exercise their knee joint post-surgery.