The Relationship between Subjective and Objective Measurements of Strength

Abstract

Manual muscle testing is utilized by physicians and physical therapists to aid in the diagnosis and evaluation of pathology.' The basis of a diagnosis or the modification of a treatment program is dependent upon the clinician's perception of a patient's strength. This inherent subjectivity of manual muscle testing often leads to questionable findings in a medical examination. Factors such as sex, age, height, and weight serve only to increase the subjectivity of this evaluation This study demonstrates the use of a new manual muscle testing unit (MMTU) to quantify muscle strength objectively. The results of the MMTU were compared to a clinician's subjective evaluation of the stronger limb. In addition, the data obtained with the MMTU were analyzed to investigate further what constitutes a significant strength deficit. The MMTU's ability to differentiate strength differences and deficits demonstrates how manual muscle testing can assume a refined role in the evaluation of muscle strength. J Orthop Sports Phys Ther 1980;2(1):15-19.