Establishment of behavioral parameters for the evaluation of osteopathic treatment principles in a rat model of arthritis.

Unilateral arthritis was produced in rats by use of methylated bovine serum albumin in a model of antigen-induced arthritis. The progression of arthritis was measured by computerized motion analysis, bilateral joint circumference, voluntary extension force of the hindlegs, and length of ankle extension. Animals with induced arthritis were assigned to treated and untreated groups on the basis of approximately equal deficits by the parameters measured. A third group of rats, which did not have arthritis induced and received no treatment, served to establish mean normal parameters. Modified techniques of muscle energy, passive movement of the ankle and knee, and passive myofascial stretch were applied to the animals, and the animals were exercised in a mechanized exercise wheel. Parameters associated with gait were examined by computerized motion analysis of walking. Animals treated with manipulation and exercise improved significantly relative to untreated animals with antigen-induced arthritis in vertical ankle lift, ankle-based and foot-based stride lengths, knee circumference, and normalized extension of the ankle. The results demonstrate that the parameters identified can be used to detect functional deficits and significant improvement from those deficits can be derived from a nonpharmacologic treatment paradigm that includes osteopathic manipulation and exercise in an animal model of arthritis. These parameters may be useful in the identification of the relative benefits of independent treatment variables including frequency of osteopathic manipulation and exercise and the relative benefits of each in this model. Also, they may elucidate how these treatments produce their beneficial effects clinically.