Frontal Plane Pelvic Drop in Runners: Causes and Clinical Implications

摘要

Running is becoming an increasingly popular sport; however, runners have a high rate of injury and are therefore often treated in the orthopedic or sports medicine setting. One current focus of these patientsu27 treatment is gluteus medius muscle (GM) strengthening and gait retraining, with the goal of decreasing frontal plane pelvic drop. Unfortunately, there is a research void assessing the role of GM function on pelvic drop, and the effect of an increased pelvic drop on running performance. The specific aims of this research were to investigate a link between frontal plane pelvic drop and (1) isometric GM torque, (2) GM surface electromyography (sEMG) peak amplitude and onset timing, and (3) GM fatigue; and (4) to study the relationship between frontal plane pelvic drop and increased metabolic energy demands. Subjects were recreational runners who ran an average of five or more miles per week. Data from an initial ten subjects were collected, followed by an additional eleven subjects tested for Specific Aims #1, 2, and 3. GM maximal isometric torque was obtained prior to the run. Subjects ran on a treadmill for thirty minutes while three-dimensional pelvic kinematics, GM sEMG, and metabolic data were collected. Pearsonu27s Correlations and scatter plots of the variables showed no relationship between GM maximal isometric strength, GM peak amplitude and onset timing, or GM fatigue rate and frontal plane pelvic drop. The change in pelvic drop also had no effect on the change in running economy (RE) from the start to end of the run. Clinicians should not employ a GM centered treatment approach when treating frontal plane pelvic instability in runners. Future research into additional core stabilizing muscles and their interactions could provide insight into which muscles should be the focus of treatment in runners with proximal instability. These studies should also include kinetic as well as lower extremity (LE) kinematic analysis of running gait to investigate the link between these variables, their relationship to muscle performance, as well as to running performance.