Credits and licences

Not medical or training advice

MyoHeat is an educational visualisation of a simplified biomechanics model. It estimates how load may be shared between muscles; it does not measure your body and is not medical, physiotherapy or training advice. Talk to a qualified professional before starting or changing exercise, especially if you have an injury or health condition.

Legs, pelvis, trunk and all bones: Rajagopal full-body model

Leg and trunk muscles: the 2023 revision with modifications by Lai et al. and Uhlrich et al., from opensim-models. Every bone mesh, arms included: the 2015 release from simtk.org/projects/full_body. Changes: mapped into MyoHeat's coordinates, right side mirrored to the left, and the arm and shoulder-girdle bones fitted onto the shoulder model below.

• Rajagopal A, Dembia CL, DeMers MS, Delp DD, Hicks JL, Delp SL. Full-body musculoskeletal model for muscle-driven simulation of human gait. IEEE Trans Biomed Eng. 2016;63(10):2068–79. doi
• Lai AKM, Arnold AS, Wakeling JM. Why are antagonist muscles co-activated in my simulation? Ann Biomed Eng. 2017;45:2762–74. doi
• Uhlrich SD, Jackson RW, Seth A, Kolesar JA, Delp SL. Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force. Sci Rep. 2022;12:9842. doi

Copyright (c) 2015, Stanford University

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
SOFTWARE.

Shoulder and arm: Thoracoscapular Shoulder Model

From simtk.org/projects/thoracoscapular, with parameters from van der Helm (1994) and Klein Breteler et al. (1999). MyoHeat uses its shoulder and elbow joints and the muscles crossing the shoulder (deltoid, rotator cuff, pectoralis major, latissimus dorsi, teres major, coracobrachialis, biceps and the long head of triceps), licensed under CC BY 4.0.

• Seth A, Dong M, Matias R, Delp SL. Muscle contributions to upper-extremity movement and work from a musculoskeletal model of the human shoulder. Front Neurorobot. 2019;13:90. doi

Changes: evaluated in one rest posture and mapped into MyoHeat's coordinates; the model's own bone meshes are not used; the humeral insertions of pectoralis major and teres major moved down the shaft to their anatomical positions, with fibre and tendon lengths rescaled; forces rescaled to the cross-sectional areas below; a wrap over the olecranon added to the long head of triceps; the scapulothoracic muscles used only as attachment points for MyoHeat's own shoulder-blade muscles.

Elbow and forearm muscles, arm strength

The elbow and forearm muscles are placed by MyoHeat on landmarks of the Rajagopal bones. Arm muscle strengths are MRI cross-sectional areas at a specific tension calibrated to measured maximal joint moments.

• Holzbaur KRS, Murray WM, Gold GE, Delp SL. Upper limb muscle volumes in adult subjects. J Biomech. 2007;40(4):742–9. doi
• Holzbaur KRS, Delp SL, Gold GE, Murray WM. Moment-generating capacity of upper limb muscles in healthy adults. J Biomech. 2007;40(11):2442–9. doi
• Murray WM, Buchanan TS, Delp SL. The isometric functional capacity of muscles that cross the elbow. J Biomech. 2000;33(8):943–52.

Head of Michelangelo's David

The marble head in place of the skull is a 3D scan of the 1899 plaster cast of David's head (Beckett no. 756), digitised by SMK – Statens Museum for Kunst and released under the CC0 dedication. MyoHeat uses the optimised version, with generated normal and occlusion maps, reposted by nebulousflynn at zenodo.org/records/21529251 under CC BY 4.0.

Changes: turned to face forward, cut below the chin, scaled to the skeleton, and given a plain marble colour in place of the scan's texture.

MediaPipe Pose Landmarker

Camera mode tracks your body with MediaPipe Pose Landmarker (the "full" BlazePose GHUM model and the @mediapipe/tasks-vision runtime), served from this site and run in your browser.

• Bazarevsky V, Grishchenko I, Raveendran K, Zhu T, Zhang F, Grundmann M. BlazePose: On-device real-time body pose tracking. CVPR Workshop on Computer Vision for Augmented and Virtual Reality, 2020. arXiv

Licensed under the Apache License, Version 2.0.

Exercise demonstration videos by FitnessScape

Camera mode's demo videos are FitnessScape's exercise demonstration series, published on Wikimedia Commons under the Creative Commons Attribution 3.0 licence. They are also used to calibrate camera mode.

• Deadlift - exercise demonstration video
• Squat - exercise demonstration video
• Bent-over row - exercise demonstration video
• Shoulder press - exercise demonstration video
• Bench press - exercise demonstration video
• Incline press - exercise demonstration video
• Pull-ups - exercise demonstration video
• Hanging crunches - exercise demonstration video
• Leg raises - exercise demonstration video

Changes: re-encoded from WebM to H.264 MP4 for playback on every device, with a still frame taken for each thumbnail. The footage is otherwise unchanged.