View Full Version : Replies: Looking for a Force-Length-Velocity relation

06-27-2008, 07:05 AM
Dear all,

Thank you for answer. Here there is a resume of replies to:
I am currently studyng my MSc in Automatic Control at the CITEDI IPN,research center.Biomechanics is not our speciality, but We are trying to aply control system teory to muscle-actuated mechanical systems. We are working with Zajac's musculo-tendon model and now We are looking for an adecuate Hill-type model of the Force-Length-Velocity relation to use with this model for many motor tasks. There are a lot of models and We would like to use the adecuate Force-Length-Velocity relation. I would be grateful if you could send me some information about this.

Adriana Salinas Avila
CITEDI, IPN Av. del Parque No. 131O (entre Blvd. Industrial y Av. Von Humboldt)Mesa de OtayTijuana, Baja California, MéxicoC.P. 22510Tel. local: (664) 623-1344FAX local : (664) 623-1388

Hi Adriana,There are many popularly-used versions of the Hill model. Zajac's model is also a Hill-based model. I use a model similar to the one described by van Soest and Bobbert: van Soest AJ and Bobbert MF (1993). The contribution of muscle properties in the control of explosive movements. Biological Cybernetics, 69(3), 195-204. Another source that gives a lot of detail on their Hill-based muscle model is: Pandy MG, Zajac FE, Sim E, and Levine WS (1990). An optimal control model for maximum-height human jumping. Journal of Biomechanics, 23(12), 1185-1198. Some other sources that might be of interest: Caldwell GE (2004). Muscle modeling. In: DGE Robertson et al. (eds.), Research Methods in Biomechanics. Champaign, IL: Human Kinetics. van den Bogert AJ, Gerritsen KGM, and Cole GK (1998). Human muscle modelling from a user's perspective. Journal of Electromyography and Kinesiology, 8(2), 119-124. Winters JM and Woo SL (1990). Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer. Hope this helps,Ross Miller
Adriana Io he trabajado bastante con estos modelos y tu podráencontrar todas las relaciones deducidas en mi tesisde doctorado, que está nel mio sitehttp://lmeneg.tripod.com/ Para que el modelo trabaje bién, ha sido necessáriohacer algunas modificaciones en el modelo de Zajac. Encotrás también la mia tesis de maestria, onde elmodelo de musculo está mejor explicado, hay algunaspequeños problemas en la dedución, que foramcorrigidas en la de doctorado. Las dos tesis están en Portugués, pero pienso que notendrás mayores dificultades para endenderlas. suerte, Luciano MenegaldoInstituto Militar de EngenhariaRio de JaneiroBrasil---------------------------------------------------------------------------------
nel site http://www.geocities.com/limatmsi/ encontrás como simular estos modelos. saludos Luciano ----------------------------------------------------------------------------
The usual way is to just multiply the active length tension curve by the force velocity curve, and then add passive.Of course a Hill model does not represent transient responses very well.Be sure to include the force-velocity curve for lengthening with the discontinuity of slope about zero velocity.Example functions in Igor are:Function P2V(P,PIso) //Finds sarcomere velocity for active sarcomeres variable P,PIso variable V If (P