Estimation of the force-velocity properties of individual muscles from measurement of the combined plantarflexor properties

© 2020. Published by The Company of Biologists Ltd..

The force-velocity (F-V) properties of isolated muscles or muscle fibers have been well studied in humans and other animals. However, determining properties of individual muscles in vivo remains a challenge because muscles usually function within a synergistic group. Modeling has been used to estimate the properties of an individual muscle from the experimental measurement of the muscle group properties. While this approach can be valuable, the models and the associated predictions are difficult to validate. In this study, we measured the in situ F-V properties of the maximally activated kangaroo rat plantarflexor group and used two different assumptions and associated models to estimate the properties of the individual plantarflexors. The first model (Mdl1) assumed that the percent contributions of individual muscles to group force and power were based upon the muscles' cross-sectional area and were constant across the different isotonic loads applied to the muscle group. The second model (Mdl2) assumed that the F-V properties of the fibers within each muscle were identical, but because of differences in muscle architecture, the muscles' contributions to the group properties changed with isotonic load. We compared the two model predictions with independent estimates of the muscles' contributions based upon sonomicrometry measurements of muscle length. We found that predictions from Mdl2 were not significantly different from sonomicrometry-based estimates while those from Mdl1 were significantly different. The results of this study show that incorporating appropriate fiber properties and muscle architecture is necessary to parse the individual muscles' contributions to the group F-V properties.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:223

Enthalten in:

The Journal of experimental biology - 223(2020), Pt 18 vom: 18. Sept.

Sprache:

Englisch

Beteiligte Personen:

Javidi, Mehrdad [VerfasserIn]
McGowan, Craig P [VerfasserIn]
Lin, David C [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Muscle architecture
Muscle modeling
Power–velocity
Research Support, U.S. Gov't, Non-P.H.S.

Anmerkungen:

Date Completed 18.06.2021

Date Revised 24.08.2023

published: Electronic

Citation Status MEDLINE

doi:

10.1242/jeb.219980

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM312572271