Absolute dimensions (e.g. body height, abdominal girth) generally increase when clothing is worn. This increase affects all percentile values. Functional dimensions such as the arm reach may be reduced by clothing.
Whereas measurements of the human body are generally performed for the most part with the body unclothed, persons wear everyday clothing or work clothing similar it, special work clothing, or protective clothing during the work process. This clothing changes the body dimensions. The following figures for allowances for clothing were taken from the Handbuch der Ergonomie. All values stated are estimates; they permit close approximation, however.
All length dimensions on the body when standing such as the body height, eye height, shoulder height, elbow height above the floor, height of the hand (grip axis) above the floor, height of the ribcage (sternum), and also the seat surface height, become greater independently of other factors when footwear is worn. The Handbuch der Ergonomie adds 35 mm to each standing length dimension when heavy footwear is worn.
The body height also increases when headgear is worn: depending upon the type of headgear, figures of between 10 and 35 mm (safety helmet) are stated. The headgear has no influence upon the other dimensions measured with the subject standing, such as the eye height. For safety dimensions, the influence of the hair must be considered (see Hair, hairstyle, fingernails), in order to prevent moving parts from catching the hair, or comfort being impaired by contact.
The clothing must also be considered where applicable in all length and breadth measurements of body regions (e.g. shoulder-elbow length, buttocks-knee pit length, hip breadth, pelvic breadth, chest depth, shoulder height sitting). Around 5 mm must be added for light clothing, approximately 8-10 mm for heavy clothing.
Depending upon the magnitude of a dimension (ribcage girth, waist girth, thigh girth) in the unclothed state, light clothing has the effect of increasing it by 20 mm (thigh girth), heavy clothing by approximately 110 mm (waist girth).
Clothing, particularly heavy protective clothing, may constrain movement considerably. Many functional and movement dimensions are therefore comparatively smaller when heavy clothing is worn.