1. Department of Orthopaedics
Somatotype
Arthur Stewart
Mandy Plumb
Department of Orthopaedics

3. It is independent of size, age and gender.
Somatotype
Definition
Somatotype is a physique classification system which recognises a body shape category, which necessarily falls between pre-determined end limits.
It is defined as a quantified expression and description of the present morphological conformation of a person.
It is independent of size, age and gender.

4. Somatotype
Somatotype is a three figure reference which characterises physique and body shape.
It comprises values, originally proposed on a 7-point scale, which summarise the physique, and can be plotted on the tri-polar somatochart.

5. Somatotype Components
Average value
Endomorphy
Mesomorphy
Ectomorphy 2 3 4 5 6
lean
fat
slender
muscular
heavy
light

6. Somatotype
History
Originally proposed as a genotypic morphology rating on a 7 point scale by Sheldon (1940), drawing from earlier work of Kretschmer (1921) who classified three ‘poles’ to represent extreme physique variation, and Viola (1933) which related dimensions of the thorax, trunk and limbs to a ‘normotype’
Partly influenced by an alternative methodology from Parnell (1954), Heath and Carter (1967) introduced a three numeral rating somatotype which has become the most universally applied, which involved a photoscopic and anthropometric method, later to be revised in 1990.

7. Somatotype Assessment
Methods
*Equipment required
Photoscopic
Anthropometric*
somatotype rating form
computer-calculated
Combined
the criterion measure
Stadiometer
Weighing scale
Bone caliper
Skin caliper
Anthropometric tape

8. Somatotype Rating Form

9. Somatochart
Central
Endomorph
Mesomorph
Ectomorph

11. Anthropometric Somatotype Assessment
(Heath & Carter, 1967)
Endomorphy
Roundness or fatness, based on 3 skinfolds Independent of size
Mesomorphy
Musculo-skeletal robustness, based on elbow & knee breadths, and corrected girths of calf and upper arm
Ectomorphy
Relative fragility, based on height and weight
Derived on 10 measurements
Independent of size
Descriptor of shape
Assumes proportionality of size, development and symmetry
Only relative data on composition

12. Measurements Required
Total mass (kg)
Stature (cm)
Upper arm circumference (cm)
Max. Calf circumference (cm)
Femur breadth (cm)
Humerus breadth (cm)
Triceps skinfold (mm)
Subscapular skinfold (mm)
Supraspinale skinfold (mm)
Medial calf skinfold (mm)
Measurements on the Right; Larger girths in the case of Left handed subjects; mean of 2 or median of 3.

13. Endomorphy calculation
Add the skinfolds at the triceps, subscapular and supraspinale sites
Multiply this sum by / height
This total (in mm) is “X” in the following calculation:
Endomorphy
= X X X3

14. Mesomorphy calculation
Record height (H), humerus breadth (HB) and femur breadth (FB), max calf girth and max upper arm girth, with the arm flexed to 45º and tensed.
Calculate corrected arm (AG) and calf girth (CG) by subtracting triceps and medial calf skinfolds from the respective girths.
Substitute these values in the following equation:
Mesomorphy = 0.858HB FB AG CG H + 4.5

15. Ectomorphy calculation Record height in cm and weight in kg
Divide the height by the cube root of weight to calculate the reciprocal of the ponderal index or RPI. The magnitude of the RPI determines which formula is used to calculate ectomorphy.
If RPI > 40.74, Ectomorphy = 0.732RPI
If < RPI < 40.74, Ectomorphy = 0.463RPI
If RPI < 39.65, Ectomorphy = 0.5

16. Rounding
From equations - round decimal to one decimal place eg
For general description, plotting and category boundaries, round to the nearest half unit
eg. 3-4-1
Rating form are in nearest half units

17. Somatotype Attitudinal Distance
The distance between any two somatopoints (in 3D space)
- calculated in component units
SAD A,B = [(endoA-endoB)2 + (mesoA - mesoB) 2 + (ectoA - ectoB) 2 ]0.5
where A and B are two somatotypes
Somatotype Attitudinal Mean
The average 3D distance between all somatoplots and their mean

18. Physique advantages
Absolute strength, injury resistance, hypothermia resistance, positive self image
Cardiac health
Low energy cost of locomotion
power:weight ratio
Injury protection via diminished forces
Absolute mass for blocking sports; Hypothermia resistance, floatation

19. Physique disadvantages
Power at expense of endurance; poor heat dissipation; exercise can become obsessive in bodybuilders
Low power: weight; high energy cost of locomotion; impaired heat dissipation; cardiac risk factors; low self esteem
Lack of upper body strength; risk of diminished self image

20. Somatotypes of 106 male athletes
Mesomorphy
Endomorphy
Ectomorphy
Data from Stewart & Hannan, (2000)

21. Somatotype Convergence
Athletes’ physiques evolve according to training status and periodisation. Variation in physique (i.e. SAM) reduces as competitive standard increases, as the athletes become increasingly selected
Early training
Performance peak
Discus throwers
High jumpers
400m runners
Sumo wrestlers

22. Somatotype comparison in cyclists
Reference: Anthropometrica
Road racing cyclists’ data from Stewart & Hannan (2000)

23. Summary
The relevance of somatotype in sport
Each component independently affects performance in most sports
Talent identification for sporting potential of individuals
Tool for matching individuals with sports which they may have advantages for
Tool for determining training goals and outcomes
Affects body image and self esteem

24. References
Anthropometrica: Norton, K & Olds, T. (Eds) (1996) University of New South Wales Press
Carter J.E.L. and Heath, B.H. (1990). Somatotyping: Development and applications. Cambridge, UK, Cambridge University Press.
Eston, R. & Reilly, T. (Eds) (2001) Kinanthropometry and exercise physiology lab manual, volume 1. London: Routledge