Difference in fascicle behaviors between superficial and deep quadriceps muscles during isometric contractions

Ryosuke Ando, Kazunori Nosaka, Takayuki Inami, Aya Tomita, Kohei Watanabe, Anthony J. Blazevich, Hiroshi Akima

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


Introduction: In this study we examined changes in fascicle length and pennation of vastus intermedius (VI) and vastus lateralis (VL) from rest to isometric contraction. Methods: Fourteen healthy men performed submaximal (30% and 50% of maximal voluntary contraction; MVC) isometric knee extensions at 60° and 110° knee flexion (0°=full extension). Panoramic images of VL and VI were obtained at rest and during contractions to measure fascicle length and pennation using extended field-of-view ultrasonography, after confirmation that the technique could be used reliably during sustained submaximal isometric contractions. Results: The relative change in fascicle length from rest to 50% MVC was greater in VI than VL at 110° (P<0.05). Pennation increased during contraction at 60° for VL (P<0.05), but not for VI. Conclusion: Muscle-dependent fascicle behaviors were observed during contraction. These findings may provide a mechanistic underpinning for differences in sarcomere length changes, relative force contribution, and blood flow during contraction.

Original languageEnglish
Pages (from-to)797-802
Number of pages6
JournalMuscle and Nerve
Issue number5
Publication statusPublished - 2016 May 1
Externally publishedYes


  • Fascicle length
  • Knee joint angle
  • Pennation
  • Ultrasonography
  • Vastus intermedius
  • Vastus lateralis

ASJC Scopus subject areas

  • Physiology
  • Clinical Neurology
  • Cellular and Molecular Neuroscience
  • Physiology (medical)


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