Physical Ergonomic Test
Grasp a long object such as a pen or a stick. Hold it out in front of you and notice the angle at which it rests. Slightly release your grip and move your wrist to the left. Now squeeze the object. Do the same moving your wrist to the right. Notice the stress that is not present when grasping in a natural position.
Conventional crutches are not ergonomically designed, and their users—especially their long-term users—run the risk of serious injury.