Fig. 5

MR images of the gluteus minimus and joint capsule under internal rotation in hip flexion. Coronal section images of the hip in the control (a-d) and flexion adduction internal rotation (FADIR)-positive groups (e-h). The locations of each coronal section are indicated by black lines in each upper right panel, which is a schematic illustration of the lateral aspect of the right hip (90° flexion). Images were acquired at 0° external/internal rotation (ER/IR 0°; a and e) and 10° internal rotation (IR 10°; b-d and f-h) in 90° hip flexion. Asterisks (*) indicate the proximal spaces between the gluteus minimus (GMi) and joint capsule (Cap), which are prominent in the control group. GMa = gluteus maximus, GMe = gluteus medius, GT = greater trochanter, H = head of femur, Ip = iliopsoas, MR = magnetic resonance, N = neck of femur, OE = obturator externus, QF = quadratus femoris, RF = rectus femoris, RFr = reflected head of the RF, Section mark (§) = anterior inferior iliac spine, Lat = lateral and Sup = superior