Abstract: An orthotic such as a knee, ankle, elbow or wrist brace is provided. The orthotic includes one or more compression devices that adjust the amount of compressive force applied to a body part based upon fluctuations in atmospheric pressure. One embodiment of the invention incorporates one or more inflatable air bladders connected to an air pump and an atmospheric pressure sensor. The brace places the inflatable air bladder proximate a joint where it can be inflated to provide compressive support for the joint. The invention also comprises a method for adjusting the compressive force applied to a body part based upon fluctuations in atmospheric pressure.