Appendicular Lean Mass Index (ALMI): Females, Age 75-79
Appendicular Lean Mass Index (ALMI) is the lean mass of the arms and legs combined, divided by height squared (kg/m²). It is the standard clinical measure for diagnosing sarcopenia (age-related muscle loss) and is preferred over total lean mass because limb skeletal muscle is more sensitive to aging than trunk muscle. Data are from Kelly et al. 2009, a cross-sectional analysis of DXA body composition scans from 15,258 US adults in NHANES 1999 to 2004. Percentiles were derived using LMS curve fitting applied to the White (non-Hispanic) reference population. Kelly et al. also provide curves for Black and Mexican American adults; values differ, with Black adults showing higher lean mass at equivalent ages. These norms are most applicable to White Western adults and may not represent other ethnic groups. The EWGSOP2 (2019) defines probable sarcopenia as ALMI below 7.0 kg/m² in men or 5.5 kg/m² in women, roughly the P5 to P10 range of this reference population.
Data source: Kelly et al. (NHANES DXA) About this study
Percentile Distribution (kg/m²)
| Percentile | Value (kg/m²) | Rating |
|---|---|---|
| 5th | 5.1 | Poor |
| 25th | 5.83 | Below average |
| 50th | 6.45 | Average |
| 75th | 7.2 | Above average |
| 95th | 8.61 | Excellent |
What these numbers mean for females aged 75-79
A score around 6.45 kg/m² is typical (50th percentile) for females in this age group. Scores above about 7.2 kg/m² fall near the 75th percentile or higher, indicating above-average performance. Scores below about 5.83 kg/m² fall near the 25th percentile, about 75% of the reference population scored higher.
Percentiles show how common a value is, not whether it is healthy.