BACKGROUND: Chest expansion is simple and quantitative measurement that can be used to determine a baseline respiratory function i.e. chest mobility, respiratory muscle strength and lung function. A simple and inexpensive technique for measuring chest expansion is by using measure tape.

OBJECTIVE: To obtain and compare changes in chest expansion when adopting two different instructions in relation to age and sex.

METHOD: A prospective study was conducted over a period of 1 year. Chest expansion measurement of 280 subjects was done by traditional and additional/new instructions.

RESULT:The mean chest expansion value among all the age group was greater with additional/new instruction when compared to the traditional instruction in both the genders. (p< 0.001).

CONCLUSION: Study concludes significant difference in mean chest expansion between traditional and new instructions. The verbal instruction during measurement of chest expansion is also important.