title: The relationship between changes in joint kinematics parameters and mechanomyographic signals during non-isometric contraction in human skeletal muscle.
abstract: The present study determines the effects of summation of contraction on joint kinematics in human ankle and mechanomyography (MMG) signals during non-isometric contraction. The excursion and angular velocity of dorsiflexion and eversion were measured during several summation profiles during non-isometric contractions. The joint kinematics parameters and MMG responses to 1-8 pulses at a constant interval of 10 ms were recorded to investigate the effects of different numbers of stimuli. In an examination of two-pulse trains with different inter-pulse intervals, the joint kinematics parameters and MMG responses to inter-pulse intervals of 10-100 ms were recorded from the tibialis anterior muscle. The main finding was that facilitating effects of subsequent stimulation were limited to angular velocity of eversion during the contribution of a second stimulus, suggesting that facilitating effects of second stimulus reflect angular velocity but not joint angle excursion. A comparison with MMG signals clarified that MMG signals poorly correlate with changes in the joint kinematics parameters (excursion and angular velocity) when the inter-pulse intervals or numbers of stimuli are increased. These findings will provide useful information for assessing the muscle contractile properties with evoked MMG signals during non-isometric contraction.
authors: Faculty of Health and Medical Sciences, Department of Sports and Health Sciences, Aichi Shukutoku University, Japan. yohta@asu.aasa.ac.jp
authors: Yoichi
authors: Y
authors: Ohta
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004558:Electric Stimulation; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007596:Joints / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009213:Myography / Q000379:methods*; D012815:Signal Processing, Computer-Assisted