J Manipulative Physiol Ther. 1990 Sep; 13(7): 378-83.

The physics of spinal manipulation. Part IV. A theoretical consideration of the physician impact force and energy requirements needed to produce synovial joint cavitation.

Haas M.

Research Department, Western States Chiropractic College, Portland, Oregon 97230.

The critical force and energy required to facilitate synovial joint cavitation are presented as functions of seven parameters: joint and patient stiffnesses, joint and patient elasticities, the proportion of impacting energy entering the joint and patient, and the critical joint distraction at which cavitation occurs. These parameters are governed by numerous properties of the patient, doctor, joint, and the adjustive process. Equations for the critical force and energy are derived and the seven parameters and their governing factors are discussed.