What is the best method for measuring mid arm circumference (mid upper arm circumference)?

From the Guidelines

The best method for measuring mid-arm circumference (MAC), also called mid-upper arm circumference (MUAC), is to use a flexible, non-stretchable measuring tape on the non-dominant arm at the midpoint between the acromion process of the shoulder and the olecranon process of the elbow, as described in the study by 1.

Key Steps for Measuring Mid-Arm Circumference:

• Have the person stand with their arm hanging relaxed at their side.
• Locate the acromion process (the bony protrusion at the top of the shoulder) and the olecranon process (the bony point of the elbow).
• Mark the midpoint between these two landmarks.
• With the arm relaxed and hanging, wrap the measuring tape around the arm at this midpoint, ensuring it's snug but not compressing the tissue.
• The tape should be perpendicular to the long axis of the arm.
• Read the measurement to the nearest 0.1 cm.

This measurement is valuable because it provides information about muscle mass and subcutaneous fat, making it useful for nutritional assessment, as noted in the study by 1. MAC is particularly important in settings where weight and height measurements are difficult to obtain, such as in bedridden patients or during humanitarian emergencies, and it serves as a reliable indicator of malnutrition, especially in children and the elderly, as discussed in the study by 1.

From the Research

Measuring Mid Arm Circumference

To measure mid arm circumference, the following steps can be taken:

• Use a measuring tape to measure the mid-upper arm circumference (MUAC) 2
• The measurement should be taken at the midpoint of the upper arm 2
• The MUAC can be used as a quick and inexpensive measurement for nutritional assessment 2

Best Method for Measuring Mid Arm Circumference

The best method for measuring mid arm circumference is by using a measuring tape, as it is an accessible and quick method 2

• The measurement can be taken at the bedside with a measuring tape 2
• The use of MUAC tapes can help identify cases of malnutrition 3

Factors to Consider

When measuring mid arm circumference, the following factors should be considered:

• The use of different MUAC tapes can result in different measurements 3
• There is no one universal MUAC tape specification 3
• The measurement method and references used can be inconsistent 4

Cut-off Values

Cut-off values for mid arm circumference can vary depending on the population being measured:

• For women, a cut-off value of ≤ 28 cm can be used to identify malnutrition 2
• For men, a cut-off value of ≤ 30 cm can be used to identify malnutrition 2
• A cut-off value of 240 mm can be used to identify undernutrition and higher rates of illness in adult males 5