The purpose of this study was to verify the influence of the hip flexion angle on isokinetic rotator torque and acceleration times of the hip medial and lateral rotator muscles. Twenty-one healthy women were included in this study. The hip rotator function was evaluated at 3 different hip flexion angles (10°, 40°, and 90°). The results showed that both eccentric and concentric hip lateral rotator torques were greater at 40° of hip flexion when compared with 90°. Moreover, both the eccentric and concentric hip medial rotator torques were greater at 90° of hip flexion than at 40° and 10°, and greater at 40° than at 10°. In addition, both the eccentric and concentric hip medial to lateral rotator torque ratios were greater at 90° of hip flexion than at 40° and 10°, and greater at 40° than at 10°. Finally, the acceleration times of the hip medial rotator muscles were smaller at 90° of hip flexion than at 10° and smaller at 40° than at 10°. The current results highlight the importance of evaluating the hip rotator muscles at different hip flexion angles to comprehensively assess their functions.
Rodrigo de M. Baldon, Leonardo Furlan and Fábio V. Serrão
Rodrigo de M. Baldon, Daniel F.M. Lobato, Leonardo Furlan and Fábio Serrão
The purpose of this study was to compare lower limb kinematics between genders during stair descent. Fifteen females and fifteen males who were healthy and active were included in this study. The lower limb kinematics (pelvis, femur and knee) in the coronal and transversal planes were assessed during stair descent at 30°, 40°, 50° and 60° of knee flexion. The study found that females showed greater knee medial rotation for all the knee flexion angles (P = .02−.001), greater femoral adduction (P = .01 for all variables), with exception for 30° (P = .13), and greater femoral lateral rotation at 60° (P = .04). Females also showed a trend to have greater knee valgus at all the knee flexion angles (P = .06−.11) as well as less contralateral pelvis elevation at 50° and 60° (P = .10 and .12, respectively). This study showed that females carry out the stair descent with a lower limb alignment that might predispose them to develop overuse knee injuries, such as the iliotibial band syndrome and patellofemoral pain syndrome. Further prospective investigations should be carried out to verify whether these variables are factors that could predict these knee injuries.