Use of the Medical Research Council Muscle Strength Grading System in the Upper Extremity

Abstract

P N u t i a b t b r M s a t m i s t c o w e e e T M m c i t o M l t t istory of Muscle Strength Grading he Medical Research Council of Great Britain MRC) system is the best known and most comonly used muscle strength grading system for manal muscle testing (MMT) worldwide. Dyck et al race the development of the MRC system to the reatment of war injuries and poliomyelitis. S.W. itchell, a Civil War surgeon, recognized nerve amage as a cause of muscle weakness in 1872. itchell and M.J. Lewis were later responsible for he first known effort to grade neuromuscular signs hen they classified ataxic gait in 1886. In 1917, .W. Lovett, a Boston orthopedist, published the uscle scoring system later adapted by the MRC ased on his experience treating poliomyelitis; he redited W. Wright, a physical therapist, with develping the muscle testing methods. As a result of heir experiences treating World War II injuries, 12 urgeons formed the Nerve Injuries Committee of the ritish Army (G. Riddoch [Chair], W.R. Bristow, .W.B. Cairns, E.A. Carmichael, M. Critchley, J.G. reenfield, J.R. Learmonth, H. Platt, H.J. Seddon, .P. Symonds, J.Z. Young, F.J.C. Herrald) and deeloped the classic handbook Aids to the Investigaion of Peripheral Nerve Injuries. This manual ilustrates the major actions of limb muscles and how hey should be tested; defines the concepts of prime overs, synergists, and antagonists; and includes the uscle grading scale familiar to all orthopedic sureons (Table 1). A modified version of this manual, ids to the Examination of the Peripheral Nervous ystem, fourth edition, was published in 2000. Beause the MRC system was intended to be used to rade recovery from paralysis (grade 0) attributable o nerve repair, the greatest emphasis is placed on evere degrees of weakness (grades 1, 2, 3); although his system is ordinal, the difference in strength beween different grades was not assumed to be contant. In general, the intertester and intratester relig