Learning human joint torques from pixels

2026-08-10Computer Vision and Pattern Recognition

Computer Vision and Pattern Recognition
AI summary

The authors created a new dataset called VID that helps computers estimate the force in human joints using just regular video images, without needing special sensors. Their dataset includes thousands of real images paired with detailed joint movement and force information. They also made a model, VID-Network, that predicts joint forces better than past methods by analyzing sequences of images. This work provides a useful tool for studying how people move in everyday settings using only visual data.

inverse dynamicsjoint torquebiomechanicsmonocular imagesOpenSimmotion captureelectromyographypose estimationRGB imagestemporal inference
Authors
Chen Chen, Rui Cheng
Abstract
Estimating human joint torques from visual observations is a key step toward bringing biomechanical analysis from controlled laboratories to real-world movement scenarios. Existing torque estimation methods typically depend on surface electromyography, motion-capture markers, force plates, or simulated imitation data, which limits their applicability to ordinary RGB images. In this work, we introduce VID, a vision-based inverse dynamics dataset and benchmark for predicting human joint torques directly from real monocular images. VID contains 63,369 synchronized frames with real human images, kinematic annotations, anthropometric attributes, and OpenSim-derived dynamic labels, providing paired visual and biomechanical supervision for real-image inverse dynamics. We further define a standardized evaluation protocol covering overall torque estimation, joint-specific analysis, and action-specific prediction. To establish a strong reference model, we propose VID-Network, which combines pose-pretrained spatial probabilistic features, marker regression, and temporal torque inference to recover joint torques from image sequences. Experiments on VID show that VID-Network achieves an overall mPJE of 1.7612 N$\cdot$m/kg, improving over the best compared baseline by 39.81\%, and obtains the lowest error across all evaluated joint types and most action categories. VID establishes a first practical benchmark for vision-driven human inverse dynamics and provides a foundation for studying biomechanical inference in less constrained environments.