Validity evaluation of muscle force estimated by simulation using vertical ground reaction force

Abstract

The purpose of this study is to verify the validity of estimating lower limb muscle activity during sagittal plane movement using only vertical ground reaction forces (2DGRF) using a musculoskeletal simulation model, and we conducted two experiments: measurements and simulations. The data from the measurement experiment was used as input data for the simulation, and the lower limb muscle activity by the simulation was calculated. In addition, four types of sagittal plane movements (SJ, CMJ, WALK, and RUN) were performed, and EMG data of BF, RF, LG, and TA were measured and compared with the simulation results. Then, the muscle force estimated using 2DGRF and the muscle force estimated using 3DGRF were compared to verify the validity. The validation results showed that the simulation model underestimated muscle activity, but a change curve similar to the experiment was observed. And there was no significant difference between the muscle force predicted using 3DGRF and 2DGRF. The model is considered to have sufficient validity.