Machine learning outperforms anthropometric scaling in predicting muscle parameters and spinal loading: a subject-specific musculoskeletal modeling study
摘要
Subject-specific musculoskeletal models are valuable for studying postoperative complications. These models require CT/MRI to define muscle geometry and force-generating parameters; consequently, their use in routine clinical settings remains limited. Current practice; i.e. anthropometric scaling, introduces substantial error. This study aimed to determine if machine learning could predict subject-specific muscle parameters from readily available data, thereby improving spinal load prediction.
MethodsUsing 250 CT-derived musculoskeletal models, we trained machine learning algorithms (Random Forests, Autoencoders, and Multilayer Perceptrons) to predict muscle geometry and maximum-isometric-force. Inputs were restricted to demographics and 3D vertebral centroids. We integrated these predicted parameters into OpenSim, simulating 11 static postures. The resulting spinal joint forces were compared against CT-derived subject-specific musculoskeletal models (Ground Truth) and anthropometric scaling.
ResultsA hybrid Random Forest–Autoencoder approach performed best. Relative to anthropometric scaling, it lowered maximum-isometric-force RMSE (27 vs. 34 N) and geometry RMSE (7.6 vs. 8.8 mm). Spinal load predictions were also more accurate: R² between predicted and Ground-Truth spinal forces rose from 0.83 to 0.9 for compressive forces (RMSE 184 to 145 N), and shear-force R² increased from 0.67 to 0.8 (RMSE 238 to 178 N). Overall, global load-estimation error improved by ~ 18% for both modalities.
ConclusionWhile not a perfect substitute for volumetric imaging, the proposed machine learning workflow significantly reduces the estimation errors inherent in standard anthropometric scaling. This approach offers a superior approximation for generating subject-specific musculoskeletal models in clinical settings where CT or MRI data are unavailable.