Sushruta Samhita, Sharira 5.3
Mamsam sira snayu asthi sandhi sannipatah — Marma are the locations where Mamsa (muscle), Sira (vessels), Snayu (tendons), Asthi (bone), and Sandhi (joints) meet together. At these junctions, Prana (vital force) is concentrated. Injury to these points produces specific, predictable consequences ranging from pain and disability to death.

Three categories by consequence of injury