Estimation of gait parameters by measuring upper limb–walker interaction forces

Walkers are designed to assist pathological gait by providing weight support, assisting balance and enhancing rehabilitation, as they rely on user’s ability to walk. Nevertheless, it is important to continuously obtain certain gait parameters (i) to characterize gait patterns, (ii) to perform follow up and improve rehabilitation strategies and (iii) to efficiently and safely control the device. Due to usability issues and for a broad analysis of gait, it is essential to design sensor architectures that avoid user preparation or environmental instrumentation. In this paper, we present a measurement system for the precise detection of Heel-Strike (HS) and Toe-Off (TO) and for continuous cadence estimation and tracking based on force interaction between user’s upper-body and walker handles. HS and TO estimation methods present mean errors of 1.35 and 0.55% respect to gait cycle. For continuous cadence estimation, the Mean Square Error is below 3.3 steps per minute.