title: Physiological Evaluation of Childcare-Associated Muscle Load on the Neck and Shoulder Region in Japanese Women.
abstract: The awkward movements and postures associated with childcare activities can lead to musculoskeletal symptoms in the neck and shoulders. "Dakko" is a method for carrying a child in Japan, and recently it has been reported to cause shoulder stiffness. To our knowledge, the relationship between childcare activities and the physical load on the neck and shoulders is poorly understood. The present study aims to clarify the muscle load on the neck and shoulder region through dakko simulations. First, the association between dakko movements and trapezius muscle activity is clarified by image and electromyogram analyses. Based on this clarification, the distributions and intensity of the muscle load from repetitive dakko movements are clarified using myogenic potential topography. During dakko movements, trapezius muscle activity was observed when lifting up and setting down the child, but not when holding the child. For the repetitive movements, myogenic electrical potentials were observed in the trapezius region after movement load, and individual characteristics of participants were revealed in both the load distributions and the recovery process. Repetitive dakko movements likely induced sustained muscle tonus in the trapezius, which may be a factor related to shoulder stiffness.
authors.affiliation: Department of Fundamental Nursing, Faculty of Medicine, Miyazaki University, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Yoshinaga
authors.affiliation: Graduate School of Nursing Science, Miyazaki University, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Kiyokawa
authors.affiliation: Department of Humanics Nursing, Miyazaki Prefectural Nursing University, Manabino, Miyazaki 880-0929, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Kuramoto
authors.affiliation: Interdisciplinary Graduate School of Medicine and Veterinary Medicine, Miyazaki University, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
authors.forename: Hiroe
authors.initials: H
authors.lastname: Kinoshita
authors.affiliation: Department of Fundamental Nursing, Faculty of Medicine, Miyazaki University, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Nemoto