Ultrasonographic quantification of architectural response in tibialis anterior to neuromuscular electrical stimulation.
While muscle contraction in voluntary efforts has been widely investigated, little is known about contraction during neuromuscular electrical stimulation (NMES). The aim of this study was to quantify in vivo muscle architecture of agonist and antagonist muscles at the ankle joint during NMES. Muscle fascicle lengths and pennation angles of the tibialis anterior (TA) and lateral gastrocnemius muscles were assessed via ultrasonography in 8 healthy young males. Measures were obtained during maximal NMES and torque-matched voluntary dorsiflexion contractions. In the TA, NMES induced a shorter fascicle length (67.2±8.1mmvs 74.6±11.4mm; p=0.04) and a greater pennation angle (11.0±2.4° vs 9.3±2.5°; p=0.03) compared with voluntary torque-matched dorsiflexion contractions. Architectural responses in the antagonist lateral gastrocnemius muscle did not significantly differ from rest or between voluntary and electrically induced contractions (p>0.05). Contraction of the antagonist muscle was not a contributing factor to a greater fascicle shortening and increased pennation angle in the TA during NMES. TA architectural response during NMES likely arose from the contribution of muscle synergists during voluntary contractions coupled with a potentially localized contractile activity under the stimulation electrodes during NMES induced contractions.
['Simoneau-Buessinger|Emilie|E|', 'Leteneur|Sébastien|S|', 'Bisman|Alix|A|', 'Gabrielli|François|F|', 'Jakobi|Jennifer|J|']
D000328:Adult D000843:Ankle Joint D004558:Electric Stimulation D006801:Humans D007537:Isometric Contraction D008297:Male D009119:Muscle Contraction D018482:Muscle, Skeletal D019415:Torque D014463:Ultrasonography D055815:Young Adult
Fascicle length Pennation angle Ultrasonography Dorsiflexion Plantarflexion