Clinical Medicine & Physiology
Lund-Browder Pediatric vs Wallace Rule of Nines TBSA% Formula: Age-Adjusted Head & Legs
Calculate age-adjusted Total Body Surface Area %TBSA in infants, children, and adults using Charles C. Lund and Newton C. Browder’s (1944) developmental anatomy chart (where infant Head = 19% vs adult 7%) alongside Alexander Wallace’s (1951) Adult Rule of Nines.
Why applying adult "Rule of Nines" (9% Head) to an infant underestimates cranial surface area by > 10% TBSA!
Published in The Lancet by Scottish surgeon Alexander B. Wallace (1951) following Pulaski & Tennison, the Adult Rule of Nines assigns rapid 9% multiples to adult body regions: Head & Neck = 9%, Anterior Trunk = 18%, Posterior Trunk = 18%, Each Arm = 9% (18% both), Each Leg = 18% (36% both), and Perineum = 1% (Sum = 100%)! However, human infants are born with disproportionately large heads and short legs!
Measured anatomically by Charles C. Lund and Newton C. Browder (1944, Surgery, Gynecology & Obstetrics) and enshrined in Advanced Trauma Life Support (ATLS) / ABA pediatric resuscitation charts, a newborn/infant (< 1 yr) has Cranial-Neck Area = 19% TBSA (more than DOUBLE an adult’s 7%–9%!) and Combined Thighs + Lower Legs + Feet = 26% TBSA (13% per leg vs 18% adult)! Across childhood growth from Age 0 to Age 15+, the Pediatric Rule of Growth shifts roughly 1% TBSA per year of age (above age 1) from the Head (19% -> 7% adult) symmetrically into Both Lower Extremities (+0.5% per leg per year -> 38% combined Lund-Browder adult legs + buttocks/feet), while Trunk (Anterior 13% + Posterior 13% + Buttocks 5% + Genitalia 1% = 32%) and Arms + Hands (10% each = 20%) remain age-invariant!
| Lund-Browder Developmental Age Bracket | Total Head + Neck Max %TBSA (2% Neck + Cranium) | Both Thighs + Lower Legs + Feet Max %TBSA | Invariant Trunk+Buttocks+Perineum (32%) + Arms (19–20%) |
|---|---|---|---|
| Infant (0 to < 1 Year) | 21% (19% Head + 2% Neck) | 27% (13.5% per Leg incl. 3.5% Foot) | 52% (Grand Sum = 100%) |
| 5-Year-Old Child | 15% (13% Head + 2% Neck) | 33% (16.5% per Leg) | 52% (Grand Sum = 100%) |
| 10-Year-Old Child | 13% (11% Head + 2% Neck) | 35% (17.5% per Leg) | 52% (Grand Sum = 100%) |
| Adult (>= 15 Years, Lund-Browder) | 9% (7% Head + 2% Neck) | 39% (19.5% per Leg) | 52% (Grand Sum = 100%) |
Age-Adjusted Lund-Browder Maximum Cranial Head %TBSA (Excl. 2% Neck)
Implements exact clinical Lund-Browder age-bracket table for Cranial Head (Anterior + Posterior A-region): <1 yr -> 19%, 1–4 yr -> 17%, 5–9 yr -> 13%, 10–14 yr -> 11%, >=15 yr Adult -> 7%.
=IF(B2 < 0, "Age Cannot Be Negative", IF(B2 < 1, 19, IF(B2 < 5, 17, IF(B2 < 10, 13, IF(B2 < 15, 11, 7)))))Patient Partial- + Full-Thickness %TBSA from Fractional Regional Involvement
Multiplies age-adjusted Cranial Head max % (from Age B2) by Fraction_Head_Affected (B3 in 0..1), plus Anterior/Posterior Trunk % affected (B4 out of 26%), plus age-adjusted Single-Leg max % (13.5%, 14.5%, 16.5%, 17.5%, 19.5%) * Fraction_Leg_Affected (B5 in 0..2 legs).
=IF(OR(B2 < 0, B3 < 0, B3 > 1, B4 < 0, B4 > 26, B5 < 0, B5 > 2), "Invalid Age or Regional Fractional Involvement", ROUND(B3 * IF(B2 < 1, 19, IF(B2 < 5, 17, IF(B2 < 10, 13, IF(B2 < 15, 11, 7)))) + B4 + B5 * IF(B2 < 1, 13.5, IF(B2 < 5, 14.5, IF(B2 < 10, 16.5, IF(B2 < 15, 17.5, 19.5)))), 2))Try the example
Use the original values or change them to test your understanding.