UltraTrack is a software program for tracking muscle fascicle length and orientation changes through sequences of B-mode ultrasound images. It implements an affine extension to an optic flow algorithm to track movement of the muscle fascicle end-points throughout the sequence of images. 

The underlying algorithm has been previously described and its validity and reliability tested by Cronin et al. (2011) and Gillett et al. (2013). This website accompanies the software implementation of the algorithm published by Farris & Lichtwark (2016) that incorporates features for: tracking multiple fascicles in multiple muscles simultaneously; correcting temporal drift in measurements; manually adjusting tracking results; saving and re-loading of tracking results and loading a range of file formats. The source code was written in Matlab (The MathWorks Inc.) and is available as well as standalone executable versions for MacOS and Windows platforms that do not require a Matlab license to be installed and run. Please cite the above linked papers if using UltraTrack for scientific publications.