A biomechanical analysis of finger joint forces and stresses developed during common daily activities

The problem of modelling stresses incurred at the finger joints is critical to the design of durable joint replacements in the hand. The goal of this study was to characterise the forces and stresses at the finger and thumb joints occurring during activities such as typing at a keyboard, playing piano, gripping a pen, carrying a weight and opening a jar. The metacarpal and proximal phalanx were modelled using a COMSOL-based finite element analysis. Analysis of these activities indicates that joint forces in excess of 100N may be common at the metacarpophalangeal joint (MCP) due to carrying objects such as groceries or while opening jars. The model predicted that stresses in excess of 2 MPa, similar to stresses at the hip, occur at the MCP with the properties of cancellous bone playing a significant role in the magnitude and distribution of stress.