Appendicular Lean Mass Index (ALMI)
Appendicular Lean Mass Index (ALMI) is the lean soft tissue mass of the arms and legs combined, divided by height squared (kg/m²), measured by DXA. It excludes bone mineral. The European sarcopenia consensus, EWGSOP2, defines its muscle-quantity cut-offs on this measure.
These percentiles are a FitnessNorms derivation from NHANES 1999-2004 DXA scans for 12,957 US adults aged 20 and over, all race and Hispanic-origin groups, using the measured DXA values and the values NCHS imputed for participants who could not be scanned; see the methodology. The NHANES scans used Hologic scanners with the Schoeller calibration; results from another DXA brand or calibration are not directly comparable.
Under EWGSOP2 (2019), low muscle strength indicates probable sarcopenia; low muscle quantity or quality confirms the diagnosis, and poor physical performance indicates severe sarcopenia. EWGSOP2 uses ALMI cut-offs below 7.0 kg/m² for men and 5.5 kg/m² for women as indicators of low muscle quantity. Where a cut-off sits against this population shifts with age and sex, because the cut-off is fixed while the population median declines. For men it sits near the 11th percentile at 20-24, between the 5th and 8th from 25 to 54, between the 11th and 13th from 55 to 69, and near the 21st at 70-74, the 24th at 75-79, the 37th at 80-84 and the 49th at 85+. For women it sits between the 11th and 14th percentile from 20 to 49, the 15th and 19th from 50 to 69, near the 24th from 70 to 79 and near the 33rd to 34th at 80 and over. A percentile or ALMI value alone does not diagnose sarcopenia.
Data source: FitnessNorms derivation from NHANES 1999-2004 DXA About this study
Reference population: US adults aged 20 and over in NHANES 1999-2004 with measured or NCHS-imputed DXA data, all race and Hispanic-origin groups
Appendicular Lean Mass Index (ALMI) Norms Chart by Age and Sex (kg/m²)
| Age | Sex | Percentile | ||||
|---|---|---|---|---|---|---|
| 5th | 25th | 50th | 75th | 95th | ||
| 20-24 | Male | 6.65 | 7.63 | 8.44 | 9.34 | 11.23 |
| Female | 5.14 | 5.87 | 6.52 | 7.32 | 9.13 | |
| 25-29 | Male | 6.74 | 7.75 | 8.55 | 9.40 | 11.10 |
| Female | 5.13 | 5.93 | 6.70 | 7.67 | 9.42 | |
| 30-34 | Male | 6.89 | 7.85 | 8.61 | 9.51 | 11.21 |
| Female | 5.06 | 5.89 | 6.69 | 7.52 | 9.29 | |
| 35-39 | Male | 6.93 | 7.88 | 8.70 | 9.59 | 11.21 |
| Female | 5.18 | 5.93 | 6.62 | 7.67 | 10.00 | |
| 40-44 | Male | 6.97 | 8.01 | 8.72 | 9.61 | 11.07 |
| Female | 5.14 | 5.92 | 6.70 | 7.67 | 9.69 | |
| 45-49 | Male | 6.91 | 7.90 | 8.67 | 9.31 | 10.91 |
| Female | 5.08 | 5.83 | 6.68 | 7.72 | 9.70 | |
| 50-54 | Male | 6.84 | 7.80 | 8.64 | 9.35 | 10.72 |
| Female | 4.79 | 5.84 | 6.48 | 7.32 | 9.20 | |
| 55-59 | Male | 6.34 | 7.60 | 8.33 | 9.07 | 10.41 |
| Female | 4.97 | 5.74 | 6.52 | 7.51 | 9.44 | |
| 60-64 | Male | 6.50 | 7.68 | 8.42 | 9.13 | 10.36 |
| Female | 5.07 | 5.72 | 6.47 | 7.39 | 9.03 | |
| 65-69 | Male | 6.27 | 7.47 | 8.11 | 8.84 | 10.43 |
| Female | 4.89 | 5.72 | 6.43 | 7.23 | 8.89 | |
| 70-74 | Male | 6.25 | 7.13 | 7.82 | 8.47 | 9.52 |
| Female | 4.74 | 5.54 | 6.22 | 6.91 | 8.36 | |
| 75-79 | Male | 6.10 | 7.05 | 7.66 | 8.29 | 9.55 |
| Female | 4.93 | 5.52 | 5.99 | 6.92 | 8.16 | |
| 80-84 | Male | 6.10 | 6.74 | 7.34 | 7.91 | 8.75 |
| Female | 4.73 | 5.29 | 6.00 | 6.52 | 7.89 | |
| 85+ | Male | 5.59 | 6.36 | 7.02 | 7.62 | 8.72 |
| Female | 4.58 | 5.27 | 5.89 | 6.51 | 7.90 | |
What to expect by age group
Among US adults aged 30 to 34, the middle 50% measure 7.85 to 9.51 kg/m² for men and 5.89 to 7.52 kg/m² for women. Men's median is highest at 40-44 (8.72 kg/m²) and falls to 7.02 kg/m² at 85+. Women's median stays between 6.43 and 6.70 kg/m² from 20 to 69 and is 5.89 kg/m² at 85+. Men's median is 1.13 to 2.16 kg/m² higher than women's in every age bracket.
| Age | Males | Females |
|---|---|---|
| 20-24 | 7.63 to 9.34 | 5.87 to 7.32 |
| 25-29 | 7.75 to 9.40 | 5.93 to 7.67 |
| 30-34 | 7.85 to 9.51 | 5.89 to 7.52 |
| 35-39 | 7.88 to 9.59 | 5.93 to 7.67 |
| 40-44 | 8.01 to 9.61 | 5.92 to 7.67 |
| 45-49 | 7.90 to 9.31 | 5.83 to 7.72 |
| 50-54 | 7.80 to 9.35 | 5.84 to 7.32 |
| 55-59 | 7.60 to 9.07 | 5.74 to 7.51 |
| 60-64 | 7.68 to 9.13 | 5.72 to 7.39 |
| 65-69 | 7.47 to 8.84 | 5.72 to 7.23 |
| 70-74 | 7.13 to 8.47 | 5.54 to 6.91 |
| 75-79 | 7.05 to 8.29 | 5.52 to 6.92 |
| 80-84 | 6.74 to 7.91 | 5.29 to 6.52 |
| 85+ | 6.36 to 7.62 | 5.27 to 6.51 |
Detailed Breakdowns
Select an age group and sex below for detailed percentile charts, tables, and ratings.
Frequently Asked Questions
What is Appendicular Lean Mass Index (ALMI)?
ALMI is the lean soft tissue mass of the arms and legs divided by height squared (kg/m²). It is the quantity the EWGSOP2 muscle-quantity cut-offs are defined on.
What are the sarcopenia thresholds for ALMI?
The European Working Group on Sarcopenia in Older People (EWGSOP2, 2019) uses ALMI below 7.0 kg/m² in men and 5.5 kg/m² in women as cut-offs for low muscle quantity. Low muscle strength is used to identify probable sarcopenia, while low muscle quantity helps confirm the diagnosis; assessment also considers physical performance and clinical context. Where the cut-offs sit in this US population depends on age and sex. For men the cut-off sits near the 11th percentile at 20-24, between the 5th and 8th from 25 to 54, between the 11th and 13th from 55 to 69, and near the 21st at 70-74, the 24th at 75-79, the 37th at 80-84 and the 49th at 85+. For women it sits between the 11th and 14th percentile from 20 to 49, the 15th and 19th from 50 to 69, near the 24th from 70 to 79 and the 33rd to 34th at 80 and over. The cut-off is a fixed value, while the population median declines with age.
Can I compare my DEXA report to these values?
Only approximately. DXA results depend on the scanner brand, software and calibration. These values come from Hologic scanners using the Schoeller calibration in NHANES 1999-2004. A GE Lunar scan, or a Hologic scan with a different calibration, can report a different lean mass for the same body, so a small difference from these percentiles may reflect the scanner rather than the body.
How does ALMI differ from total Lean Mass Index (LMI)?
LMI includes all lean soft tissue in the body (limbs, trunk and organs); ALMI includes only the arms and legs. The EWGSOP2 muscle-quantity cut-offs are defined on the appendicular measure.
Are these norms representative of non-US populations?
They describe US adults measured in 1999-2004. The data cannot establish how other populations compare. For clinical sarcopenia screening, local or population-specific thresholds may be preferred.
How do these values relate to Kelly et al. 2009?
Kelly et al. 2009 fitted separate reference curves for non-Hispanic White, non-Hispanic Black and Mexican American adults from the same NHANES scans. This page pools all US adults, as the site's other NHANES measures do, so its values differ from any one of Kelly's curves. The method behind it reproduces the National Center for Health Statistics' own published percentiles for the same survey years; see the methodology.