MMT vs MVIC Low-tech scores high?

How should we measure muscle strength to evaluate new therapies in progressive disorders such as amyotrophic lateral sclerosis (ALS)? Compared to many complex functions evaluated by neurologists, measurement of muscle strength should be straightforward. Unfortunately, this is not so. For multicenter studies in which different evaluators test many subjects with diverse patterns of weakness over long periods, the problems of achieving consistency are formidable. One way to deal with these difficulties is to opt for high technology in the hope of increasing the sensitivity of the measure and increasing the power to detect change over time. On the other hand, as the article by Sorenson et al.1 in this issue of Neurology emphasizes, simple, low technology solutions treated in a sophisticated way may be as good as (or better than) more complex, technical, expensive, and (for investigators and patients alike) time-consuming and arduous approaches. The techniques compared in this article— manual muscle testing (MMT) based on the Medical Research Council (MRC) scale2 (familiar to all clinicians) and maximal voluntary isometric contraction (MVIC) using the technique originally incorporated in the Tufts Quantitative Neuromuscular Examination (TQNE)3,4⇓—are emblematic of the two approaches to clinical measurement. The former requires only a trained evaluator, a subject, and a serviceable couch. The latter requires a trained technician, dedicated space, and a specially designed examination frame in which a limited range of muscles can be tested via a fixed …