Reliability of one repetition maximum measurement for leg extension using an improved leg extension machine

• Main Authors: Yoshikiyo Kanada, Hiroaki Sakurai, Yoshito Sugiura, Tomoaki Arai, Soichiro Koyama, Shigeo Tanabe
• Format: Article
• Language: English
• Published: Fujita Medical Society 2018-11-01
• Series: Fujita Medical Journal
• Subjects: reliability; one repetition maximum measurement; leg extension machine; muscle force
• Online Access: https://www.jstage.jst.go.jp/article/fmj/4/4/4_2018002/_pdf/-char/en
• ISSN: 2189-7247; 2189-7255

Objectives: This study examined the reliability of one repetition maximum measurement (1RM) for leg extension using an improved leg extension machine through a comparison between before and after machine improvement. Methods: Twenty-one healthy adult males were recruited. A ratchet was welded to the knee rotation axis of the leg extension machine to prevent counter rotation due to the free fall of weights. The 1RM measurement for knee extension was performed before and after machine improvement to observe changes in their reliability using the intra-class correlation coefficient (ICC). Results: After machine improvement, an intra-rater reliability of ICC(1,1)=0.99 and inter-rater reliability of ICC(2,1)=0.99 were achieved. Reliability before and after machine improvement was also high, with ICC(2,1)=0.99. Conclusions: The reliability of 1RM measurement for leg extension using an improved leg extension machine was high.