Upper Arm Muscle Circumference

Circumferences can be used as indicators for the quantity of fat and muscle mass in the body. The upperarm muscle circumference (S) is a measure for muscle mass in the body measured together with the triceps skinfold (T). In this method the assumption is that the measured muscle circumference is representative for the rest of the body.

Besides that it is assumed that there is an equal distribution of fat around the arm and that there is a constant amount of bone compared to the muscle area.


 

Upperarm fat mass (F), also measured by upperarm circumference measured together with the triceps skinfold (T), provides a better determination of the total body fat mass than a single skinfold measurement. The thickness of the triceps skinfold and the area of the upperarm diminish if the patient has malnutrition. Repeated measurements can give us an indication about changes in body composition and nutritional state of the patient.

Malnutrition: when?

Frisancho A.R. (1981) has published some tables with percentiles, which can be used to compare the measured values with the values of a general population. As a patient can be compared to the low percentiles, than he or she belongs to the skinny people.

McWhirter (1994) demonstrated in his research that an upperarmmusclecircumference below P15 shows that we can speak about malnutrition. Below the 5th percentile its severe malnutrition.

These values are, however, not a very reliable measure. When a patient has a constant upperarm muscle circumference (for example p60) and it drops to P50, malnutrition is a possibility although the muscle circumference is not below P15. The change in time is a better measure for the nutritional state.

 
Reliability
The disadvantage of this method is that the results are not reliable patients with oedema in the upper extremities or people who are immobile by muscle disease or something else.
 
Formulas
 

c = upperarmcircumference in mm

T = triceps skinfold in mm

p = 3.14

  • upperarmmusclecircumference S in mm   
    S = c - ( T * 3.14)
= Upperarmcircumference (c) in mm

= Triceps skinfold (T) in mm



= Result (S)
  • upperarmarea A in mm   
    A =  c / 12.56

    = Upperarmcircumference (c) in mm



    = Result (A)

  • upperarmmusclearea M in mm  
    M = S / 12.56 
     
    = upperarmmusclecircumference (S) in mm



    = Result (M)

  • upperarmfatarea F in mm  
    F = A - M
    = upperarmarea (A) in mm2

     = upperarmmusclearea (M) in mm2



    = Result (F)

Reference-tables
 
Reference-tables in percentiles Frisancho A.R. (1981):  click on the links.
  • Triceps skinfold in mm: Tabel 1.pdf
     
  • Upperarm circumference and  upperarm muscle circumference in mm : Tabel 2.pdf
     
  • Upperarm area in cm (!) : Tabel11.pdf
     
  • Upperarm muscle area in mm and upperarm fat area in mm : Tabel 3.pdf

Measurements of the upperarm circumference and triceps skinfold:

Measuring the upperarm circumference and triceps skinfold is easy to perform, not painful for the patient and cheap.

The middle of the upperarm is measured using a measuring tape (Frisancho: right arm).

  1. Determine the middle between the shouldertop and the point of the elbow and mark this point.
  2. At this point you measure the upperarm circumference, the measuring tape gently around the arm, do not pull.
  3. Measure the triceps skinfold at the back of the arm at the same height as the upperarm circumference, using a skinfold calliper.
  4. Take the skinfold in a vertical position between thump and pointing finger.
  5. Ask the patient to stretch his arm and strain his muscles, so the muscles are no part of in the skinfold.
  6. Ask the patient to relax his arm and let it hang down along the body.
  7. Place the calliper on the skinfold.
  8. Let go the handgrip and wait two seconds before reading the value.
  9. Repeat this measurement three times.
  10. Calculate the mean of the three measurements.
The triceps skinfold in mm is measured in the middle on the backside of the right upperarm (Frisancho).
 

Reference values for upperarm circumference, upperarm muscle circumference and triceps skinfold are also published by Jelliffe (1966) and are often used as a reference. These reference value however are often criticised and references published by Frisancho (1974/ 1981) were recommended because the values were taken by a more representative population. Comparison is made by Harries (1982) and showed that there is no similarity between the two. Its always important to mention which reference is used.

Ravasco (2002) describes in his article that upperarm circumference is a useful tool to determine the nutritional state of ICU patients. The criteria from Mcwhirter (1994) and Blackburn (1977) were used. Muscle mass was measured on the non-dominant arm and was classified in three categories: normal, middle and severe depleted.

Literature
  • Frisancho A. Triceps skinfold and upper arm muscle size norms for assessment of nutritional status. Am. J. Clin. Nutr. (1974) 27, 1052-1058.
     
  • Frisancho A. New norms of upper limb fat and muscle areas for assessment of nutritional status. Am. J. Clin. Nutr. (1981) 34, 2540-2545.
     
  • Frisancho A.R. Anthropometric standards for the assessment of growth and nutritional status. The University of Michigan Press, 1990. (-> uit Shenkin, 1996)
     
  • Ravasco P., Camilo M.E., Gouvela-Oliveira A., Adam S., Brum G.. A critical approach to nutritional assessment in critically ill patients. Clinical Nutrition 2002; 21(1): 73-77.
     
  • Blackburn G.L., Bistrian B.R., Miani B.S., Schlamm H.T., Smith M.F. Nutritional and metabolic assessment of the hospitalised patient. JPEN 1977;1: 11-22.
     
  • McWhirter J.P., Pennington C. R. Incidence and recognition of malnutrition in the hospital. BMJ 1994; 308: 945-948.
     
  • Harries A.D., Jones, L.A., Heatley R.V., Rhodes J. Assessment of nutritional status by anthropometry: a comparison of different standards of reference. Human Nutrition: Clinical Nutrition (1983) 37c, 227-231.
     
  • Jelliffe D.B. The assessment of the nutritional status of the community (with special reference to field surveys in developing regions of the world). Monogr-Ser-World Health Organ. 1966; 53, 3-271.
     
  • Bishop, C.W., Bowen, P.E., Ritchey S.J. Norms for nutritional assessment of American adults by upper arm anthropometry. Am. J. Clin. Nutr 34; 2530, 1981.
     
  • Bishop C.W., Bowen P.E., Richey S.J.. Comparison of two newly developed sets of upper arm anthropometric norms for American adults. Am. J. Clin. Nutr. 1982 sep 36 (3) 555-560. MG T 0044
     
  • Heymsfield S.B., Baumgartner R.N., Pan S.F.. Nutritional assessment of malnutrition by anthropometric methods. In: Shils M.E., Olson J.A., Shike M., Ross A.C., Eds. Modern nutrition in health and disease. 9th ed. Baltimore: Williams and Wilkins, 1998: 903-921.