biostudies-literatureUnknown12Scheidl MA<h4>Objective</h4>Pilot study with ten healthy adults, testing whether a lightweight, low-cost knee orthosis equipped with EMG-driven impedance control reduces quadriceps muscle effort during the sit-to-stand (STS) transition.<h4>Methods</h4>Ten able-bodied adults performed 15 paced STS repetitions under three conditions: without orthosis (No-Ortho), orthosis worn unpowered (Ortho-OFF; friction-compensated), and orthosis actively powered (Ortho-ON). Surface electromyography (EMG) was recorded using 8-channel thigh bracelets on both legs. EMG signals from the braced leg were processed using ridge regression and slew-rate limiting to generate a normalized control signal that dynamically scales knee stiffness while maintaining constant damping. Median values and trial-to-trial variance of theFrontiers in robotics and AI1732294https://www.ebi.ac.uk/biostudies/studies/S-EPMC12823904biostudies-literatureEMG-controlled knee orthosis lowers effort in sit-to-stand.PMC12823904Schuh KScheidl MACastellini CSierotowicz MBetsch MfalseEMG-controlled knee orthosis lowers effort in sit-to-stand.<h4>Objective</h4>Pilot study with ten healthy adults, testing whether a lightweight, low-cost knee orthosis equipped with EMG-driven impedance control reduces quadriceps muscle effort during the sit-to-stand (STS) transition.<h4>Methods</h4>Ten able-bodied adults performed 15 paced STS repetitions under three conditions: without orthosis (No-Ortho), orthosis worn unpowered (Ortho-OFF; friction-compensated), and orthosis actively powered (Ortho-ON). Surface electromyography (EMG) was recorded using 8-channel thigh bracelets on both legs. EMG signals from the braced leg were processed using ridge regression and slew-rate limiting to generate a normalized control signal that dynamically scales knee stiffness while maintaining constant damping. Median values and trial-to-trial variance of the2025-01-01T00:00:00Z20252026-06-06T22:37:14.853Z2026-06-06T03:10:52.191ZS-EPMC128239044158642110.3389/frobt.2025.1732294