The supine hip extensor manual muscle test: A reliability and validity study

Perry J, Weiss WB, Burnfield JM, Gronley JK. The supine hip extensor manual muscle test: a reliability and validity study. Arch Phys Med Rehabil 2004;85:1345-50. Objectives To define the relative hip extensor muscle strengths values identified by the 4 grades obtained with a supine manual muscle test (MMT) and to compare these values with those indicated by the traditional prone test. Design Comparison of 4 manual supine strength grades with isometric hip extension joint torque; κ statistic-determined interrater reliability, and analyses of variance identified between grade differences in torque. Setting Pathokinesiology laboratory. Participants Adult volunteers recruited from local community and outpatient clinics. Reliability testing: 16 adults with postpolio (31 limbs). Validity testing (2 groups): 18 subjects without pathology (18 limbs), and 26 people with clinical signs of hip extensor weakness (51 limbs). Interventions Not applicable. Main Outcome Measures Supine hip extensor manual muscle grade and isometric hip extension torque. Results Reliability testing showed excellent agreement (82%). Subjects with pathology had significant differences in mean torque (P<.01) for the assigned grade 5 (176Nm), grade 4 (103Nm), grade 3 (67Nm), and grade 2 (19Nm). Healthy adults showed significant differences between grade 5 (212Nm) and grade 4 (120Nm) in mean torque (P<.05). Conclusions The supine MMT is a reliable and valid method with which to assess hip extension strength.