title: Same-session and between-day intra-rater reliability of hand-held dynamometer measurements of isometric shoulder extensor strength.
abstract: [Purpose] The purpose of present study was to establish the same-session and between-day intra-rater reliability of measurements of extensor strength in the maximum abducted position (MABP) using hand-held dynamometer (HHD). [Subjects] Thirteen healthy volunteers (10 male, 3 female; mean ± SD: age 19.8 ± 0.8 y) participated in the study. [Methods] Participants in the prone position with maximum abduction of shoulder were instructed to hold the contraction against the ground reaction force, and peak isometric force was recorded using the HHD on the floor. Participants performed maximum isometric contractions lasting 3 s, with 3 trials in one session. Between-day measurements were performed in 2 sessions separated by a 1-week interval. Intra-rater reliability was determined using intraclass correlation coefficients (ICC). Systematic errors were assessed using Bland-Altman analysis for between-day data. [Results] ICC values for same-session data and between-day data were found to be "almost perfect". Systematic errors not existed and only random error existed. [Conclusion] The measurement method used in this study can easily control for experimental conditions and allow precise measurement because the lack of stabilization and the impact of tester strength are removed. Thus, extensor strength in MABP measurement is beneficial for muscle strength assessment.
authors.affiliation: Faculty of Sports Science, Kyushu Kyoritsu University: 1-8 Jiyugaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8585, Japan.
authors.forename: Takenori
authors.initials: T
authors.lastname: Awatani
authors.affiliation: Faculty of Sports Science, Kyushu Kyoritsu University: 1-8 Jiyugaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8585, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Mori
authors.affiliation: Faculty of Sports Science, Kyushu Kyoritsu University: 1-8 Jiyugaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8585, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Shinohara
authors.affiliation: Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Koshiba
authors.affiliation: Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Nariai
authors.affiliation: Faculty of Sports Science, Kyushu Kyoritsu University: 1-8 Jiyugaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8585, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Tatsumi
authors.affiliation: Faculty of Sports Science, Kyushu Kyoritsu University: 1-8 Jiyugaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8585, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Nagata
authors.affiliation: Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, Japan; Faculty of Physical Education, Osaka University of Health and Sport Sciences, Japan.
authors.forename: Ikuhiro
authors.initials: I
authors.lastname: Morikita
keywords: Prone; Random error; Shoulder abduction