{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,4]],"date-time":"2026-11-04T23:54:31Z","timestamp":1793836471814,"version":"4.6.1"},"reference-count":38,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T00:00:00Z","timestamp":1755216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sports"],"abstract":"<jats:p>Background: This study includes an investigation of lower-limb muscle strength and physical activity among children in Japan and China, with the aim of promoting children\u2019s health. Methods: A total of 564 children (300 boys, 264 girls) aged 9\u201312 years from public primary schools in Tokyo, Japan, and Jiangxi Province, China, were included. Height, body weight (BW), hip adductor and abductor strength, and toe grip strength were measured. The side-step test (SST) and timed-up-and-go test (TUGT) were performed. Exercise habits were assessed via a questionnaire. Results: Japanese students produced significantly higher values than Chinese students in SST (23.3\u201337.1%) and TUGT (6.6\u20138.0%), except among 11-year-old girls. Japanese boys aged 10\u201311 and girls aged 10\u201312 had significantly greater hip adductor strength\/BW and toe grip strength\/BW. Japanese students also showed significantly higher hip abductor strength\/BW at all ages. Additionally, the proportion of children engaging in vigorous-intensity physical activity (VPA) was significantly higher in Japanese boys aged 10\u201312 and girls aged 9\u201311 than in their Chinese counterparts. Conclusions: Chinese students showed diminished lower-limb strength and agility compared to Japanese students. These findings highlight the importance of promoting outdoor play, particularly VPA, to improve children\u2019s physical fitness and health, especially in China.<\/jats:p>","DOI":"10.3390\/sports13080271","type":"journal-article","created":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T10:33:42Z","timestamp":1755254022000},"page":"271","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Marked Differences in Lower-Limb Muscle Strength and Motor Performance Between Japanese and Chinese Children Aged 9\u201312: A Cross-National Study"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-0185-814X","authenticated-orcid":false,"given":"Kun","family":"Niu","sequence":"first","affiliation":[{"name":"Graduate School of Health and Sport Science, Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya-ku, Tokyo 158-8508, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaoru","family":"Tsuyama","sequence":"additional","affiliation":[{"name":"Graduate School of Health and Sport Science, Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya-ku, Tokyo 158-8508, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/S2352-4642(19)30323-2","article-title":"Global Trends in Insufficient Physical Activity among Adolescents: A Pooled Analysis of 298 Population-Based Surveys with 1.6 million Participants","volume":"4","author":"Guthold","year":"2020","journal-title":"Lancet Child Adolesc. 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