The relationship between subjective and objective measurements of strength *

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.