The Validity and Reliability of a Sphygmomanometer in Assessing Isometric Muscle Strength of Shoulder Flexors and Abductors

Abstract

ABSTRACT:

Background: A sphygmomanometer is a medical instrument which is normally used to measure blood pressure in an individual. This instrument has a potential of being used as a device for measuring isometric strength of muscles in the shoulder and to be used in clinical settings for this purpose.

Objective: To measure the validity and reliability of sphygmomanometer in assessing the isometric strength of shoulder flexor and abductor muscles.

Methods: A study was performed in which isometric strength of shoulder flexors and abductors of 30 university students who were healthy, was measured using a handheld dynamometer (HHD) and a commonly available sphygmomanometer. Isometric strength of right and left sides was measured. The values were analyzed for within day reliability, between days reliability and criterion validity.

Results: The results exhibited that the validity of the sphygmomanometer was excellent for shoulder abduction and flexion isometric strength measures of both right and left sides (Pearson’s r = 0.964-0.979). The sphygmomanometer showed good within day (ICC = 0.994-0.998) and between days (ICC = 0.993-0.998) intra-rater reliability for shoulder flexion and abduction of both sides. The within day and between days intra-rater reliability calculated for handheld dynamometer was also good. (ICC = 0.996-0.998 and ICC = 0.995-0.998 respectively).

Conclusion: A sphygmomanometer is an easily accessible instrument which is both inexpensive and present in most clinics which allows clinicians to analyze isometric shoulder strength providing objective values for assessment.