Anatomy of a Runner

By Dr. Lisbeth Hoyt

When most people think about running, the first body part attributed to the movement are our legs. While our legs do the majority of the work, running is actually a full body exercise. Our legs move us forward, our trunk stabilizes our body, and our arms assist our legs with forward propulsion.

Here’s a quick breakdown of the anatomy of running and some major muscle contributors:

Legs: quadriceps, hamstrings, calves, gluteal muscles, and hip flexors.

Arms: biceps, shoulders, and upper back.

Core: paraspinals, abs, and obliques.

Let's start with the legs. The quadriceps are the muscles in the front of your thigh from your hip to your knee that cause the knee to straighten while walking and running. Additionally, one of the quad muscles helps to bend the hip. While running, the quads help to propel forward motion, stabilize the knee, and absorb the shock of impact on landing. Directly above the quads are your hip flexors, located in the front of your hip. The hip flexors help to stabilize your hip, in addition to assisting with forward movement.


The muscles in the back of your thighs are your hamstrings. They work opposite of your quads to bend your knee as you move forward. Above your hamstrings is the gluteal group (your butt) which is made up of three different muscles. Your gluteus maximus, the big muscle, extends your hip as you run and is your main source of power. Your gluteus medius and minimus help keep your hips stable and maintain proper alignment while running.


Lastly in the legs are your calves, located behind your shins. The calves assist with foot control, providing a spring motion as you push off the ground and reduce ground shock impact as you land.


While your legs do the majority of the work, we can't neglect the other muscles that assist with stability and control while running: your arms and core. Your core muscles help to engage your legs throughout your stride, maintain your upright posture, and protect your lower back and spine from ground impact. Your core includes both the muscles in the front and back of your trunk: rectus abdominals, obliques, and paraspinals to name a few.


Finally, your arms, and more importantly your arm swing, helps to propel you forward, decrease energy expenditure from your legs, and maintain the rhythmic motion of running. Your biceps (front of your arm) keep your arm bent and contribute to the amount of power you can swing your arm with. Your shoulder muscles: deltoids, traps, rotator cuff, lats and pecs, all assist with bending your elbow and upright posture in addition to driving the forward and backward movements of arm swing. Your back muscles maintains upright posture throughout all running.


Next time you’re on a run, don’t just thank your legs for carrying you through, thank your whole body!