I just got excited with this old paper by Eva Andersson and my graphic designs (not really) with Adobe Illustrator. Below are some graphics that explain the muscle activation workings of the hip flexors during running. Figure 1 shows muscle activation and hip range of motion during running at 4 metres per second (about a 20:50 5km run). Please note, raw EMG does not look like my blue scribbles - it is just a schematic so back off. As physiotherapists we love to talk about analyzing gait. But I am not sure we really know much about it. I often hear some brutal concepts about running that fly in the face of some pretty old research. This post along with a million to follow will slow build some good foundations of running biomechanics literature.
Figure 2 shows when all of the hip flexors are active during the running gait cycle. (more…)