Manual muscle testing: does it meet the standards of an adequate screening test?

In class we have discussed the validity of MMT as a unique clinical skill for PTs. As I was looking through journal articles, I stumbled upon something very interesting. Here is a copy of the article summary:

Bohannon RW. Manual muscle testing: does it meet the standards of an adequate screening test? Clin Rehab 2005; 19: 662/667

Objective: To describe the sensitivity, specificity, positive predictive value, negative
predictive value and diagnostic accuracy of manual muscle testing.
Design: Secondary analysis of cross-sectional strength data.
Setting: Acute rehabilitation unit.
Participants: Convenience sample of 107 consecutive qualifying rehabilitation
inpatient.
Intervention: Not applicable.
Main outcome measures: Knee extension forces measured by manual muscle
testing and hand-held dynamometry.
Results: The ability of manual muscle testing to detect 15, 20, 25 and 30% between side
differences and deficits in knee extension force was described. Although the
specificity of manual muscle testing was acceptable (mostly/80%), its sensitivity to
differences between sides and to deficits relative to normal never exceeded 75%. Its
diagnostic accuracy was never greater than 78%.
Conclusion: The results of this study cast doubt on the suitability of manual muscle
testing as a screening test for strength impairments.

I was impressed to think about the discussions we had in Biomechanics on how to increase reliability. The inter-rater reliability earned a C+, and as we well know, that doesn't meet "mastery" requirements. The best option is having the same person perform the test, instead of several trying to repeat it. In the clinic this may mean that one therapist will test the patient throughout the treatments and re-evaluations. I was impressed to think about my own skills and how much they need to be better. I have set a goal of practicing more my evaluation skills. I will soon be posting scenarios to work on at school on the weekends.