Linear coefficients for intervertebral motion

[Jasmin Honegger]

This post is intended to address a discrepancy between values in the downloadable model and the article "A musculoskeletal model of the lumbar spine" (Christophy et al. 2012).

In Table 3 of the article, there are slopes defining the linear relationship between the total lumbar motion and the motion at each intervertebral joint. However, these coefficients defined in the “CoordinateCouplerConstraint” portion of the OpenSim file do not all match these slope values. For example, the slope for L4 flexion/extension in Table 3 is 0.185 and in the model the slope coefficient is 0.144. I have spoken with the authors on this matter and it has been suggested that the linear coefficients defined in the "CoordinateCouplerConstraint" portion of the OpenSim file should be manually changed to reflect the values in the published article.

-Jasmin