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

作者：Ando Ryosuke^*; Nosaka Kazunori; Inami Takayuki; Tomita Aya; Watanabe Kohei; Blazevich Anthony J; Akima Hiroshi

来源：Muscle & Nerve, 2016, 53(5): 797-802.

DOI：10.1002/mus.24905

• fascicle length
• knee joint angle
• ultrasonography
• vastus intermedius
• vastus lateralis
• pennation

IntroductionIn this study we examined changes in fascicle length and pennation of vastus intermedius (VI) and vastus lateralis (VL) from rest to isometric contraction.
MethodsFourteen healthy men performed submaximal (30% and 50% of maximal voluntary contraction; MVC) isometric knee extensions at 60 degrees and 110 degrees knee flexion (0 degrees=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.
ResultsThe relative change in fascicle length from rest to 50% MVC was greater in VI than VL at 110 degrees (P<0.05). Pennation increased during contraction at 60 degrees for VL (P<0.05), but not for VI.
ConclusionMuscle-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. Muscle Nerve53: 797-802, 2016

• 出版日期2016-5