Research Paper Advance Articles

Figure 1. Comparison of root mean square errors, mean absolute errors, and adjusted R² between group-specific and total group regression models for ASM estimation. Bar graphs display model performance metrics—root mean square error (RMSE), mean absolute error (MAE), and adjusted R²—across three age groups (Group A: young adults, Group B: middle-aged adults, Group C: older adults). For each group, values from the group-specific regression model (blue) and the total group model (orange) are compared. Across all three metrics, group-specific models demonstrated consistently better performance than the total group model, with lower RMSE and MAE values and higher adjusted R² across all groups. These findings suggest that group-specific models improve the accuracy of ASM estimation by accounting for age-related muscle changes. Abbreviations: RMSE: root mean square error; MAE: mean absolute error; R²: coefficient of determination; ASM: appendicular skeletal muscle mass.