Reliability of manual muscle testing with a computerized dynamometer

The purpose of this study was to investigate the reliability of manual dynamometry. Three testers participated and performed the doctor- and patient-initiated testing methods as described in the applied kinesiology literature. Three muscles from each subject were tested. Fifteen normal volunteer adults had their muscles tested by the doctor-initiated method and another 15 had their muscles tested by the patient-initiated method. Each tester took two observations per muscle. The testing procedures were repeated 7 days later. The results showed that the intratester reliability coefficients were 0.55, 0.75 and 0.76 for testers 1, 2 and 3, respectively, when the doctor-initiated method was used; 0.96, 0.99 and 0.97 when the patient-initiated method was used. The intertester reliability coefficients were 0.77 and 0.59 on day 1 and day 2, respectively, for the doctor-initiated method; 0.95 and 0.96 for the patient-initiated method. It is concluded that manual dynamometry is an acceptable procedure for the patient-initiated method and is not acceptable for the doctor-initiated method.