A comparison of high-profile and low-profile dynamic mobilization splint designs

Despite claims that the high-profile dynamic mobilization splint design requires less frequent adjustments than the low-profile design, the authors are not aware of biomechanical evidence supporting such claims. The purpose of this study was to reexamine this claim and quantitatively analyze each design as well as the differences between designs with respect to the actual deviation from a 90 degrees angle of applied force for 60 degrees, 30 degrees, 20 degrees, and 10 degrees gains in proximal interphalangeal joint (PIP) extension. Additionally, for 10 degrees, 20 degrees, and 30 degrees gains in PIP extension, the authors determined the corrective and shear forces as a function of the deviation from a 90 degrees angle of applied force for each design, as well as the difference between the designs. Results show that in all instances examined, the actual difference between the designs is quite small. Implications of such findings are discussed along with newly identified relationships of potential utility to the hand therapist.