Informing Adaptive Exoskeletons for A-Frame Ladder Climbing: An EMG Study of Phase-Specific Muscle Demand

Abstract

Climbing A-frame ladders places high physical demand on the legs. We measured how lower-limb muscles work through each phase of climbing to identify when and where effort is greatest. Using surface electromyography, we found that the quadriceps are most active while supporting the body, the calf muscles assist during push-off, and the tibialis anterior engages mainly for foot clearance. During descent, the quadriceps appeared to play a substantial role in controlling lowering through eccentric action. These findings provide insight into when leg support may be most needed and suggest potential timing windows for future exoskeleton assistance during ladder climbing.