Many issues arise when human skeletal remains are discovered, and police detectives, prosecutors, and the courts turn to forensic anthropologists and/or pathologists for answers. “How tall was this individual in life?” is one of the questions to be answered.
Sue appears to have been the first to address estimating stature from skeletal remains in the literature, and we now have reliable methods for estimating living stature. The mathematical method is the most common, in which the lengths of an individual’s long limb bones are mathematically regressed against recorded antemortem height or, in rare situations, cadaver lengths. Equations for determining stature from long bones can be calculated using a sample of such people.
When dismembered body pieces are discovered, estimating stature is part of the identification procedure in forensic anthropology. It’s also feasible to estimate stature by looking at the bones. Even small measurements of the body, such as a finger, can be used to estimate stature.
The concept underlying this forensic anthropology technique is that different body component measurements have a link to stature for a given combination of age, ethnicity, and gender. Sculptors and artists were aware of the link between body part measurements. To estimate stature from bones, fragments of bones, or measurements of body components in recent times, regression formulae are applied.
Biological Characterization Based on Stature
Almost every bone contributes to an individual’s overall stature, but the relative contribution varies widely. The femur and tibia are the most significant components of height, both individually and together. A foot bone, on the other hand, obtains very little input. As a result, regression equations constructed from femoral and tibial lengths provide the most accurate measurement of height. These equations have been derived for all of the long bones; while an arm bone will not be as precise as a leg bone, it may be the only part found.
It has been attempted to improve accuracy by combining the contributions of multiple bones. Because skeletal biologists and forensic anthropologists frequently deal with broken bones, methods for estimating stature from fragmentary remains have been developed. The complete length of the bone is first extrapolated from the fragment, then employed in the final regression. This extra step increases the standard error of estimates, but it’s better than doing nothing. The dimensions of the body differ depending on ethnicity and gender. Black people, for example, have longer limb bones in proportion to their height than white people.
To utilize the correct regression formulae for the estimation of stature, it is important to establish sex and race. Trotter’s (1970) guidelines for whites and blacks are the most often utilized. Because bones serve as muscle attachment points, they can reveal some information about body composition. The presence of prominent crests and ridges, as well as the roughness of the bones, indicate that a person was muscular at some point in their life. A gracile or sedentary individual will have smooth bone surfaces and small muscle origins.
It’s vital to remember that, while males have more muscle mass fundamentally than females, “wimpy”-looking males will not have as well-developed attachment sites as female bodybuilders. The diameters or thickness of the bones and their substructures relative to the entire length of the bone can be used to estimate robustness. All short individuals are not necessarily slim, and enormous height is not usually associated with massiveness. Although the typical weight for a specific height can be estimated, there is no way to determine obesity from the bones.
The skeleton is typically used to determine stature in one of two ways:
1) measuring all bones that constitute up the components of stature, summing those measurements, and correcting for missing soft tissue, or
2) using a regression formula with a complete bone measurement.
Incomplete limb bones, non-limb bones, and different statistical approaches are among the other possibilities. Consideration of the individual’s population, sex, and temporal cohort should all be taken into account while choosing a strategy. The approach used is also determined by the presence and condition of the skeletal remains. Alternative statistical approaches to estimating stature exist (e.g., maximum likelihood estimation). Understanding the statistical basis of these approaches allows for a better understanding of the benefits and drawbacks of the various methods. Living stature (i.e., a missing person’s documented height) can be derived from a variety of sources, including self-reported stature, family remembrance, or direct measurement, according to forensic anthropologists.
Dwight was the first to invent the term “anatomical technique.” His anatomical method required building out the skeleton in anatomical position and articulating the bones using day or similar material to replace cartilage at the joints. After that, the length of the articulated skeleton was measured, producing a living stature estimate. Fully implemented a variation of Dwight’s s technique in 1956. Fully’s method was also known as the anatomical method, however instead of laying out the skeleton in anatomical position, Fully recommended measuring the skeletal components and then adjusting for tissues.
ANATOMICAL Vs MATHEMATICAL METHOD
When there is enough skeleton material, both Stewart and Lundy prefer the anatomical method over the mathematical method. In a small sample of American servicemen, Lundy has proven that the anatomical method is as accurate as Trotter and Gleser’s s formulas. The mathematical method has the advantage of being simple to implement and does not require the construction of a complete skeleton. It does not, however, reflect the variability in skeletal proportion in all cases. It utilizes two standard errors for Tratter and Gleser’s formulae makes stature less useful for sorting, and Tratter and Gleser’s equations are inaccurate in many populations.
The anatomical method takes longer and requires a nearly complete skeleton, which is unusual in forensic cases. However, because the skeletal components are directly measured, the skeletal and body proportions are more accurately reflected. Furthermore, because the individual skeleton is physically measured, it applies to all populations.
The measurement of long bones, such as the humerus, femur, and tibia, is used to estimate stature. If these bones are not available, the ulna, radius, and fibula can provide a good range for an individual’s expected height. To estimate stature, a regression equation should include as many elements as possible. By initially estimating the total length of bones from a regression equation before applying the original technique to determine stature, incomplete fragments can be used to estimate height.
Because stature differs by population and sex, different regression models exist for different populations. As a result, choosing which regression formula to apply is a crucial part of estimating stature. It is necessary to know the population from which an individual is from and the individual’s sex when selecting a formula.
Estimation From Femur
The femur can be divided into four sections. If the femur is discovered in its entirety, the length of the femur can be utilized to calculate stature. However, if just fragments of the femur are recovered, the stature can be estimated using a combination of segments.
Segment 1 is defined as the lesser trochanter midpoint to the most proximal extension of the popliteal surface below the linea Aspera.
Segment 2 is defined as the lesser trochanter midpoint to the most proximal extension of the popliteal surface below the linea Aspera.
Segment 3 is defined as the most proximal extension of the popliteal surface below the linea aspera to the proximal point of the intercondylar fossa.
Segment 4 is defined as the most distal point of the medial condyle from the proximal point of the intercondylar fossa.
Here are some examples of determining stature from a European male’s femur:
· Entire femur: (2.38 x the length of the femur) + 61.41 = stature +/- 3.27 cm
· From two shaft segments: (2.71 x segment 2) + (3.06 x segment 3) + 73.0 = stature +/- 4.41 cm
· From shaft and proximal end: (2.89 x segment 1) + (2.31 x segment 2) + (2.62 x segment 3) + 63.88 = stature +/- 3.93 cm.
Regression Formulas in Stature Estimation
Regression formulae are equations that use the first variable to predict the second one. Another way to put it is that one variable is dependent on another [rather than having two independent variables]. The assumption behind estimating stature from individual elements is that an individual’s height is determined by the length of their bones.
Stature regression models do not predict an individual’s exact height, but rather a range within which that individual’s height is predicted to fall. This range is built using two numbers provided by the formula. The first figure is the average height or stature. The second number is the margin of error, which indicates the range’s upper and lower limits. For example, if the regression’s equating mean is 180cm and the margin of error is 5cm, the individual’s expected range is 180cm+/-cm. Or, to put it another way, the person’s height is between 175cm and 185cm.
Estimation from Humerus
The humerus can be divided into four parts. The length of the humerus can be used to assess stature if it is found in its entirety. If just humeral segments are recovered, however, a mixture of segments can be utilized to determine stature.
Segment 1 refers to the entire humeral head
Segment 2 refers to the entire humeral head
Segment 3 includes the entire olecranon fossa, from the most proximal to the most distal edges.
Segment 4 includes between the most distal margin of the olecranon fossa and the most distal point of the trochlea.
For a European Male*, here are several examples of calculating stature from a humerus:
· For entire humerus: (3.08 x length of humerus) + 70.45 = stature +/- 4.05 cm
· From one segment of the shaft: (3.42 x segment 2) + 80394 = stature +/- 5.31 cm
· From two segments of the shaft: (7.17 x segment 1)+(3.04 x segment 2) + 63.94 = stature +/- 5.05 cm
Estimation from Tibia
The tibia can be divided into five sections. The length of the tibia can be used to estimate stature if it is found in its entirety. However, if just portions of the tibia are found, the stature can be estimated using a mixture of segments. Here are some examples of determining stature from a European male’s tibia:
· For entire tibia: (2.52 x the length of the tibia) + 78.62 = stature +/- 3.37 cm
· From three-shaft segments: (segment 2, 3 and 4): (3.52 x segment 2) + (2.89 x segment 3) + (2.23 x segment 4) + 74.55 = stature +/- 4.56 cm
Karl Pearson’s formula
This formula is specific for negroid population.
Stature= 81.306 + 1.880F [length]
Stature= 70.641 + 2.894H [length]
Stature= 78.664 + 2.376T [length]
Stature= 89.925 + 3.271R [length]
Stature= 72.8 + 1.94F
Stature= 71.4 + 2.75H
Stature= 74.7 + 2.33T
Stature= 81.2 + 3.43R