Handgrip strength is a widely used clinical and epidemiological biomarker of musculoskeletal health and is associated with outcomes across the life course. While most prior work has focused on adults, including older adults, handgrip strength is relevant in younger populations where it relates to cardiovascular risk markers, bone health, nutritional status, general muscle strength, and psychosocial outcomes. Existing normative datasets are often derived from Western populations and may not apply to Asian settings. The Korea National Health and Nutrition Examination Survey (KNHANES) offers repeated, nationally representative measurements that enable assessment of temporal patterns and derivation of reference values for Korean adolescents.
This analysis pooled KNHANES waves in which handgrip strength was measured: 2014–2019 and 2022. The total analytic sample comprised 4,867 adolescents aged 10–19 years. Participants were allocated to two‑year age groups: 10–11, 12–13, 14–15, 16–17, and 18–19 years, with sex‑stratified analyses. Participants with missing handgrip data were excluded. KNHANES uses a stratified, multi‑stage, cluster sampling design; analyses accounted for sample weights, strata, and primary sampling units.
Handgrip strength was assessed using a Takei digital hand dynamometer, recorded in 0.1 kg increments. Participants stood with elbows extended and performed maximal squeezes. Testing was performed three times per hand. In waves 2014–2019 six allowed attempts were recorded (three per hand repeated), while in 2022 the protocol used four allowed attempts (two per hand). To harmonize methods for the primary analysis, only the first four attempts (two per hand) from 2014–2019 were considered; a secondary analysis included all six attempts to test consistency. The maximum value across trials was used as the handgrip outcome, consistent with recommendations.
Absolute handgrip strength (kg) and body size–normalized handgrip strength were analyzed. Normalization followed the approach by Nevill et al.: handgrip (kg) divided by (height in meters2 × body mass in kg0.333), reported here as units.
Analyses were conducted separately for males and females within each two‑year age group. A Complex Samples General Linear Model (CSGLM) tested differences in absolute and normalized handgrip across survey years, with survey year as a categorical independent variable and handgrip as the dependent variable. Residual distributions were examined and CSGLM was used given robustness to mild non‑normality. When omnibus tests were significant, pairwise comparisons of estimated marginal means were made against the most recent wave (2022). Weighted percentiles (5th to 95th) were computed to generate reference values. Statistical significance was set at p < 0.05. Analyses were performed with SPSS v.30.
Omnibus tests across survey years were significant for males in all age groups except 18–19 years. Compared with 2022, some earlier survey years showed lower absolute handgrip: for 10–11‑ and 12–13‑year‑olds in 2019 (−2.2 and −2.9 kg; p = 0.005 and 0.001), for 10–11, 12–13, and 16–17‑year‑olds in 2018 (−1.7 to −4.1 kg; p = 0.019 to 0.004), and for 16–17‑year‑olds in 2016 (−4.1 kg; p = 0.013). Conversely, some earlier waves (2014–2015) had higher values in several male age groups (increases of approximately 2.6 to 3.5 kg; standardized differences 0.175 to 0.309 units) when compared to 2022. These year‑to‑year differences were generally small and not uniformly present across every age group.
For females, some age groups showed lower absolute handgrip in 2016–2019 compared with 2022 (reductions of about −1.6 to −2.6 kg; standardized differences −0.123 to −0.302 units). In some groups, 2014–2015 exhibited higher values relative to 2022 (around +1.4 kg; standardized differences 0.178 to 0.316 units). As with males, the pattern was inconsistent across years and age groups, and differences were generally modest.
Weighted percentiles (5th through 95th) were calculated to produce reference values. Reference values pooled across available waves revealed the lowest absolute and normalized handgrip strengths among 10–11‑year‑olds, with progressive increases across older age categories. Values differed by sex, with male percentiles generally higher than female percentiles at corresponding ages. A secondary set of reference percentiles restricted to the 2022 wave was also produced to reflect the most recent single‑wave distribution; details and tabulated percentiles appear in the source tables. The normalization results followed a broadly similar pattern to absolute strength but were not entirely consistent in every comparison.
Using nationally representative, standardized KNHANES data, this analysis examined temporal patterns and produced age‑ and sex‑specific reference percentiles for adolescent handgrip strength in the Republic of Korea. Over the 9‑year observation window, overall handgrip strength was fairly stable. Where differences were observed between survey years and 2022, they were typically small in magnitude, inconsistent across age and sex groups, and absent for some subgroups. The availability of percentiles for both absolute and body size–normalized handgrip supports clinical and research interpretation of individual measurements in Korean adolescents. The authors note that methodological differences in number of allowed attempts across waves were addressed in primary and secondary analyses.
The study provides nationally representative reference values for adolescent handgrip strength in Korea and documents that, across KNHANES waves from 2014–2019 and 2022, handgrip strength remained broadly stable with some small, year‑specific deviations. These percentiles enable clinicians and researchers to contextualize absolute and normalized handgrip measures in Korean adolescents.