The hip flexors are considered to be the most important muscle in the running process.
The hip flexors are (in order of importance to the action of flexing the hip joint):
The effects of different sit- and curl-up positions on activation of abdominal and hip flexor musculature.(Report)
Oct 01, 2008; Introduction Well-developed abdominal musculature is important in maintaining trunk and spine stability to reduce low back pain...