Scandinavian Journal of Public Health, 2018; 46(Suppl 21): 54–60 https://doi.org/10.1177/1403494818769851 © Author(s) 2018 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1403494818769851 journals.sagepub.com/home/sjp Background Muscle strength is an important factor in children’s development. It is the basis for locomotive move- ment, and thereby play and social interaction with other children. Sufficient muscle strength in child- hood is, at its essence, the basis for social develop- ment. Without adequate strength, a child may, in the worst case, lag behind in play and become isolated and have trouble making friends. Many would argue that today’s children are less dependent on muscle strength due to less physical activity, and that more indoor activity with electronic equipment reduces the demand on muscle mass [1]. This, true as it may be, raises a major concern about children’s physical status and fitness. For several years, studies have doc- umented an increase in obesity in the child popula- tion, as well as reduced physical activity, increased level of cardiometabolic risk factors and a general decay in physical fitness [2–5]. This makes focus on physical activity and muscular strength in today’s children a priority [6]. Physical activity, with a cer- tain longevity, intensity and quality, is essential to build sufficient muscle mass to withstand the burden of bodily chores during a long life [1]. Studies conducted only decades ago may be used as a reference to see if today’s children are less equipped with the necessary muscle mass [7]. Such investigations of children’s muscle status should be done at regular intervals within any society to moni- tor possible decay. If such is found, it should be reported to health authorities for preventive meas- ures to be initiated [8]. One might theorize that chil- dren with low levels of physical activity have less muscle mass and hence have inferior muscular strength. In addition, children with neuromuscular diseases, progressive developmental diseases and children involved in accidents will experience reduced Handgrip strength in 6–12-year-old children: The Health Oriented Pedagogical Project (HOPP) PER MORTEN FREDRIKSEN 1 , ASGEIR MAMEN 1 , OLE PETTER HJELLE 1 & MORTEN LINDBERG 2 1 Department of Health Sciences, Kristiania University College, Norway, and 2 Central Laboratory Vestfold Hospital Trust, Norway Abstract Aims: The aim of the study was to describe the natural course of handgrip strength development in primary school children and to establish a reference material to be used in future screening studies. In addition, the study aims to investigate a possible association between handgrip strength and cardiovascular risk factors. Methods: Anthropometric measures along with results for handgrip strength, endurance tests, blood pressure and cholesterol were measured on 2272 children of both sexes. An ROC analysis was used to estimate the suitability of handgrip strength as a predictor for known cardiometabolic risk factors. Results: A reference material for handgrip strength is presented for boys and girls aged 6–12 years. The results indicate that handgrip strength is unsuitable as a predictor for cardiometabolic risk factors in children. Conclusions: The results may be used as reference values for handgrip strength in 6–12-year-old children of both sexes. Handgrip strength may not be used as a screening tool for cardiometabolic risk factors in pre-pubertal children. Keywords: Handgrip strength, reference material, children Correspondence: P.M. Fredriksen, Department of Health Sciences, Kristiania University College, Prinsens gate 7-9, 0152 Oslo, Norway. E-mail: permorten. fredriksen@kristiania.no Date received 21 January 2018; reviewed 12 March 2018; accepted 12 March 2018 769851SJP 0 0 10.1177/1403494818769851Fredriksen et al.Scandinavian Journal of Public Health research-article 2018 ORIGINAL ARTICLE