Reliability, minimal detectable change and measurement errors in knee extension muscle strength measurement using a hand-held dynamometer in young children.

[Purpose] Few studies have assessed the reliability of muscle strength measurement using a hand-held dynamometer, specifically in Japanese young children. This study aims to investigate the reliability, minimal detectable change and measurement error in knee extension muscle strength measurements in young children using a hand-held dynamometer. [Participants and Methods] The study participants comprised 36 kindergarten-enrolled children of 3-6 years age. An experienced physiotherapist measured their isometric knee extension strength. Appropriate orientation and practices were performed prior to measurement. The same physiotherapist took the muscle measurements twice; and the maximum value was used as the muscle strength value. The measurements were repeated at intervals of approximately 30 min to verify reproducibility. [Results] The initial isometric knee extension strength was 10.6 ± 3.3 kgf and the Intra-class correlation coefficient (1,1) was 0.765. The standard error of measurement was 1.6 kgf and the minimal detectable change was 4.4 kgf. No significant systematic errors were observed. [Conclusion] Isometric knee extension strength measurement using a hand-held dynamometer in young children has good reliability with a low risk of systematic errors.

Maintenance of the rate of stair use over a long-term period using a stair climbing campaign.

OBJECTIVE: This study was a long-term survey of a stair climbing campaign that made use of point-of-choice prompts aimed at achieving exemplary behavior in citizens. METHODS: The campaign began in September 2007 at the Kochi Prefectural Office. We monitored office workers who climbed the stairs or used the elevator in the prefectural office building, excluding weekends, from August 2007 through February 2009. Prompts were placed on the stair risers. A total of 59 days were monitored during the observation period. A questionnaire was distributed to 250 workers to examine the influence of the prompts following completion of the observation period. RESULTS: A total of 16,583 observations of the choice of workers to use the elevators or stairs were made during the observation period. The mean number of stair users was 281.0 ± 66.0 per day. Stair use increased significantly from 31.5 to 58.1% among women and from 26.3 to 62.4% among men during months 1-3 of the campaign. Stair use was maintained in more than 51% of women and 60% of men during the entire campaign period. The following response (valid records: 81) was given by 10% of the respondents regarding the use of stairs: "my use of stairs increased due to the message banners". CONCLUSIONS: The stair climbing campaign was effective for increasing stair use and was maintained over a long-term period. However, most office workers thought that their increased stair use was not due to prompts placed on risers; therefore, the reason for the increased stair use remains unclear.