What feature of the liner assists against shear forces?

The locking mechanism in a liner is essential for its stability and function in a prosthetic device. It serves to securely attach the liner to the socket and the limb, thereby preventing any unwanted movement between the liner and the socket. This stability is crucial for minimizing shear forces, which occur when there is relative motion between the liner and the residual limb during activities such as walking or running.

By ensuring that the liner remains firmly in place, the locking mechanism helps to distribute the forces experienced during movement evenly across the surface of the liner. This reduces the likelihood of shear forces acting on the skin, which can result in discomfort, abrasions, or other complications. In contrast, the other features, while important for comfort and fit, do not primarily focus on countering shear forces in the same manner.