Lateral differences of the forearm range of motion

Malunion is a common complication of distal radius fracture and often causes a reduction in the range of motion. The measurement of the range of motion is a part of the process for evaluating the final motion after a malunion of a distal radius fracture is diagnosed. However, the amount of range of motion reduced due to the malunion often is calculated upon the assumption that the motion is equal in both forearms. Although this assumption has been questioned, not much work has been conducted which defines the difference in range of motion between the two forearms. In this work, a methodology has been proposed to measure the forearm range of motion using inertial measurement units. The motion was measured in both forearms of a control group. Afterwards, the motion was compared between both forearm sides; then, differences and relationships were drawn. Our results indicated that the forearm rotational motion is larger in the dominant forearm. Moreover, pronation and supination motions differ among the limbs, supination being always larger than pronation. In the dominant forearm, supination is much larger than pronation, while in the non-dominant their magnitudes are rather close. These results provide important data for a more accurate way to determine how the malunion of a fracture or another pathology affects the forearm motion.