A method and apparatus for determining an adjusted traction force for the patient. The first body supporting portion is positioned in a non-horizontal configuration. A compensating force related to a weight of the first body supporting portion, a weight of an applicable portion of a patient's body, and an angle between the first body supporting portion and a horizontal plane is determined. The compensating force is applied to a desired traction force to determine the adjusted traction force. The adjusted traction force is applied to the patient by moving the first body supporting portion relative to the second body supporting portion along the longitudinal axis to affect the distance between the first body supporting portion and the second body supporting portion.