We're so used to hearing about having a "strong core" that it's easy to forget just how important it is to maintain strength in the muscles that surround the pelvis. These gluteal (buttock) muscles are responsible for stabilising and holding our pelvis (and therefore legs) in alignment. They also stabilise the lower back, enabling an upright posture and are key players in powering walking, running and climbing.
So when there's weakness in the glutes, there's often instability in the pelvis which throws things out of alignment, contributing to all sorts of issues down through the legs. Glute weakness is linked to problems in the knees, ITB, calves and achilles.
It's easy to have strong hamstrings, quadriceps and calves, but without isolating and working on the glutes, these other large muscles become disproportionately stronger. Another issue can be attributed to tight hip flexors which can inhibit the glutes from firing correctly.
So what exactly are the "glutes"?
The gluteus maximus is the biggest muscle in the human body, by volume. The gluteal muscle group - commonly known as the glutes - includes 3 muscles located at the back of each hip. The glutes are the major components of each buttock. Gluteus maximus is the largest and most superficial (closest to the surface) of the gluteal muscle group, which also include gluteus medius and gluteus minimus.
The good news is that there are plenty of exercises that will strengthen your glutes and provide you with a great looking butt!
Check out this Runner's World article for how to test your glute strength and what to do about it.