Simulation analysis of real-time continuous stiffness in muscle fibers and tendons of the triceps surae during multi-joint movement
- VernacularTitle:多关节运动中小腿三头肌肌纤维和肌腱实时连续刚度仿真分析
- Author:
Chen LI
1
;
Ye LIU
1
;
Xindi NI
1
;
Yuang ZHANG
1
Author Information
- Publication Type:Journal Article
- Keywords: OpenSim; muscle fiber; tendon; stiffness; simulation; engineered tissue construction
- From: Chinese Journal of Tissue Engineering Research 2025;29(35):7529-7536
- CountryChina
- Language:Chinese
- Abstract: BACKGROUND:The stiffness of muscle fibers and tendons within skeletal muscles is regulated by the neuromuscular system and remains variable.However,observing the mechanical properties of muscle fibers and tendons during complex multi-joint movements is challenging,and the real-time variation patterns of their stiffness are not yet clear.OBJECTIVE:Taking the open-access simulation data of triceps surae at different running speeds and gait phases as an example,to explore the real-time stiffness change rules of muscle fiber stiffness and tendon stiffness.METHODS:OpenSim simulation results of muscle fiber activation,length,velocity parameters,and tendon length parameters of the triceps surae in five long-distance runners at different running speeds were collected from the Website of Stanford University.The instantaneous slope of the force-length relationship curve of muscle fibers and tendons in the Hill-Zajac muscle model used in the simulation was extracted as the real-time stiffness of the triceps surae muscle fibers and tendons.The temporal changes of stiffness indicators of muscle fibers and tendons during gait were analyzed.RESULTS AND CONCLUSION:The regulation of muscle fiber activation-length-velocity status and tendon strain resulted in the stiffness of muscle fibers and tendons changing in the same trend as the applied force.Compared with lower running speeds,the stiffness of the gastrocnemius muscle fibers was higher in the early support phase at higher running speeds(P ≤ 0.01),and the tendon stiffness of the medial head of the gastrocnemius was higher in the early support phase(P≤ 0.02).The stiffness of the gastrocnemius muscle fibers and tendons was lower from the mid-support to the mid-swing phase(P≤ 0.03),and the stiffness of the soleus muscle fibers was higher during the support phase(P ≤ 0.02).Under all running speeds,the stiffness of the triceps surae muscle fibers and tendons showed a trend of being higher during the support phase than during the pre-swing phase(P ≤ 0.03),and the stiffness of the gastrocnemius muscle fibers and tendons increased again in the late swing phase(P ≤ 0.05).These findings indicate that increasing running speed can increase the stiffness of triceps surae muscle fibers and tendons during the stance phase;when running speed and gait phase change,gastrocnemius and soleus muscles have different patterns of muscle fiber and tendon stiffness changes,whereas gastrocnemius can increase its muscle fiber stiffness and tendon stiffness in the late swing phase through pre-activation phenomenon.
