Predictors for Latent Musculoskeletal Fitness Profile in the National Youth Fitness Survey Sample

Musculoskeletal fitness (MSF) predicts youth health, but prior research has focused on separate MSF domains, limiting understanding of whole-body MSF.

To use latent profile analysis to identify MSF profiles and evaluate whether weight status and moderate to vigorous physical activity predict profile.

Data came from the 2012 National Health and Nutrition Examination Survey National Youth Fitness Survey for participants ages 12-15 years (N = 442). Latent MSF profiles were generated using modified pull-up, leg extension, grip strength, and plank assessments. Multinomial logistic regression models controlled for age and sex.

Fit statistics were optimal for a 3-profile model: Profile 1: high leg extension and grip strength, Profile 2: high pull up and plank, and Profile 3: low overall MSF. Participants in Profile 1 were 6.25 (95% CI, 1.82-21.52) times as likely to be overweight than Profile 2, and 6.21 (95% CI, 1.61-23.94) times as likely to have obesity than Profile 3. Participants in Profile 2 were 5.85 (95% CI, 1.99-17.18) and 5.34 (95% CI, 2.14-13.36) times as likely to be active than Profile 1 and Profile 3, respectively.

Profile 1 shows higher levels of overweight/obesity in children than Profile 3, suggesting that a healthy body mass index does not necessarily equate to greater MSF. Findings suggest MSF assessments are not consistently linked to weight status or moderate to vigorous physical activity, and future research should use multiple assessments to account for fitness differences.