Plug In Gait, is based on the following journal papers:

Bell, A.L., Pedersen, D.R. & Brand, R.A. (1990). A comparison of the accuracy of several hip center location prediction methods. Journal of Biomechanics, 23, 617-621

Davis, R., Ounpuu, S., Tyburski, D. & Gage, J. (1991). A gait analysis data collection and reduction technique. Human Movement Sciences, 10, 575-587

Kadaba, M.P., Ramakrishnan, H.K. & Wooten, M.E. (1987). J.L. Stein, ed. Lower extremity joint moments and ground reaction torque in adult gait. Biomechanics of Normal and Prosthetic Gait. BED Vol (4)/DSC Vol 7. American Society of Mechanical Engineers. 87-92.

Kadaba, M.P., Ramakrishnan, H.K., Wootten, M.E, Gainey, J., Gorton, G. & Cochran, G.V.B (1989). Repeatability of kinematic, kinetics and electromyographic data in normal adult gait. Journal of Orthopaedic Research, 7, 849-860

Kadaba, M.P., Ramakrishnan, H.K. & Wooten, M.E. (1990). Lower extremity kinematics during level walking. Journal of Orthopaedic Research, 8, (3) 383-392

Macleod, A. And Morris, J.R.W. (1987). Investigation of inherent experimental noise in kinematic experiments using superficial markers. Biomechanics X-B, Human Kinetics Publishers, Inc., Chicago, 1035-1039.

Ramakrishnan, H.K., Wootten M.E & Kadaba, M.P. (1989). On the estimation of three dimensional joint angular motion in gait analysis. 35th annual Meeting, Orthopaedic Research Society, February 6-9, 1989, Las Vegas, Nevada.

Ramakrishnan, H.K., Masiello G. & Kadaba M.P. (1991). On the estimation of the three dimensional joint moments in gait. 1991 Biomechanics Symposium, ASME 1991, 120, 333-339.

Sutherland, D.H. (1984). Gait Disorders in Childhood and Adolescence. Williams and Wilkins, Baltimore.

Winter, D.A. (1990) Biomechanics and motor control of human movement. John Wiley & Sons, Inc.

These references have information on kinematic and kinetic calculations, as well as anthropometrics and repeatability of the model. The upper body model has not been validated in any peer reviewed journal papers and therefore there are no articles on repeatability of the upper body model.