We present a novel system for camera-based measurement and visualization of muscle work based on the Hill-Type-Muscle-Model: the exercise exertion muscle-work monitor (\textit{XEM}$^{2}$). Our aim is to complement and, thus, address issues of established measurement techniques that offer imprecise data for non-uniform movements (burned calories) or provide limited information on strain across different body parts (self-perception scales). We validate the reliability of XEM's measurements through a technical evaluation of ten participants and five exercises. Further, we assess the acceptance, usefulness, benefits, and opportunities of \textit{XEM}$^{2}$ in an empirical user study. Our results show that \textit{XEM}$^{2}$ provides reliable values of muscle work and supports participants in understanding their workout while also providing reliable information about perceived exertion per muscle group. With this paper, we introduce a novel system capable of measuring and visualizing exertion for single muscle groups, which has the potential to improve exercise monitoring to prevent unbalanced workouts.

翻译：我们提出了一种基于希尔型肌肉模型的、用于基于摄像头的肌肉功测量与可视化的新型系统：运动负荷肌肉功监测器（\textit{XEM}$^{2}$）。我们的目标是对现有测量技术进行补充，从而解决其存在的问题：这些技术要么为非均匀运动提供不精确的数据（如消耗卡路里），要么对不同身体部位的负荷信息提供有限（如自感用力度量表）。我们通过对十名参与者和五项练习的技术评估，验证了XEM测量的可靠性。此外，我们通过一项实证用户研究评估了\textit{XEM}$^{2}$的接受度、有用性、优势及机遇。我们的结果表明，\textit{XEM}$^{2}$能提供可靠的肌肉功数值，帮助参与者理解其锻炼情况，同时为每个肌群提供可靠的自感负荷信息。通过本文，我们介绍了一种能够测量并可视化单个肌群运动负荷的新系统，该系统有望改进运动监测，从而预防训练不均衡的问题。