Force analysis of the belly gutter and Capener splints.

In the management of hand injuries resulting from trauma or diseases like rheumatoid arthritis, hand therapists often design static and dynamic splints to rest and protect joints, provide stability, and enhance joint motion. However, the literature provides little help in analyzing the forces of a splint acting on a digit. This paper studies the forces generated by two different finger splints acting on the proximal interphalangeal joint (PIP) of the finger. The principles of force analysis are based on the Fess and Philips model of mechanics. Factors that affect the resultant forces generated by each splint design are identified, and the properties of each splint are discussed. Although the force generated by the two types of splints may vary only slightly, special features of each splint should be seriously taken into consideration in clinical application.