For many people, wheelchairs and shopping trolleys seem unrelated. Yet, if you look closely, both share a key design feature: freely rotating front wheels. These wheels, designed to increase agility, have a downside—on uneven surfaces, steering becomes a constant struggle. Just as pushing a full shopping trolley along a slanted sidewalk pulls you off course, manual wheelchair users experience similar difficulties. They often need to use one hand to accelerate and the other to steer or brake, causing fatigue and joint strain over time. Researchers Reto Togni and Stefan Villiger from ETH Zurich’…