Human soleus sarcomere lengths measured using in vivo microendoscopy at two ankle flexion angles

JOURNAL OF BIOMECHANICS

卷:49

Article

Chen, Xuefeng¹  Delp, Scott L.^1,2 

[1] Stanford Univ, Dept Mech Engn, Room S-321,Mail Code 5450,318 Campus Dr, Stanford, CA 94305 USA

[2] Stanford Univ, Dept Bioengn, Room S-321,Mail Code 5450,318 Campus Dr, Stanford, CA 94305 USA

关键词: Muscle;    Sarcomere;    Soleus;    Ankle;    In vivo imaging;   

DOI  :  10.1016/j.jbiomech.2016.11.010

来源: Elsevier

【 摘 要 】

The forces generated by the soleus muscle play an important role in standing and locomotion. The lengths of the sarcomeres of the soleus affect its force-generating capacity, yet it is unknown how sarcomere lengths in the soleus change as a function of ankle flexion angle. In this study, we used microendoscopy to measure resting sarcomere lengths at 10 degrees plantarflexion and 20 degrees dorsiflexion in 7 healthy individuals. Mean sarcomere lengths at 10 degrees plantarflexion were 2.84 +/- 0.09 mu m (mean +/- S.E.M.), near the optimal length for sarcomere force generation. Sarcomere lengths were 3.43 +/- 0.09 mu m at 20 degrees dorsiflexion, indicating that they were longer than optimal length when the ankle was in dorsiflexion and the muscle was inactive. Our results indicate a smaller sarcomere length difference between two ankle flexion angles compared to estimates from musculoskeletal models and suggest why these models frequently underestimate the force-generating capacity of the soleus. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

Free