Lower back pain with cycling and seat position are intimately related. Height, fore/aft, and tilt will all affect the pelvic position, hip range and capability, and forces placed through the low back. In this article, we will discuss how each variable affects lower back pain and how to optimize your seat position for you.

Height:

Your saddle should be at a height where if you were to measure the angle of your knee at the bottom of your pedal stroke (your crank arm at 12 o’ clock), the angle would measure around 145-155 degrees.

If your saddle is too heigh:

Your hips will start to rock in order to reach to the bottom of the pedal stroke. This will cause your back to have to stretch and move more, resulting in lower back pain.

If your saddle is too low:

Your hips will be restricted when they get to the top of the pedal stroke, causing them to have to externally rotate. This puts extra stress through the hip and pelvic muscles and pulls on the low back.

Fore/Aft:

The saddle should be in a position such that when your knee is bent at the forward-most position (3 or 6 o’ clock), your knee should be relatively over the pedal spindle, within 1-2 cm. 

If your saddle is too far forward (fore):

Your pelvis will have to posteriorly tip, causing stretch through the low back. It will also require increased hip range of motion, which will place extra stress through the lower back.

If your saddle is too far backward (aft):

Your pelvis will anteriorly tip, resulting in increased force through the low back. This will also increase your reach, will further make the low back have to work to support yourself if you lack core strength. A saddle that is too far backward may also place more pressure on the soft tissue of the pubis, causing discomfort, shifting on the saddle, and further lower back issues.

Saddle tilt:

There is no set saddle tilt/angle recommendation. The most important thing with saddle tilt is that it best fits your pelvis. The “sits” bones should be gently cradled in the last 1/3 of the saddle. There should not be excessive pressure through the soft tissue at the front of the pelvis.

 If the saddle is tilted too far down:

Gravity will continually cause the pelvis to slide down the nose of the saddle, and therefore you will have to constantly shift yourself back up the saddle, causing friction, stress through the hips, and typically more pain into any soft tissue areas. This constant shifting up and down the saddle will also create stress through the lower back.

 If saddle is tilted too far up:

This will cause the pelvis to posteriorly tilt, as in with a saddle that is too far forward. This will require the low back muscles to lengthen. If the lower back is tight, this will result in continued low back pain on the bike.

Examine these three variables of your saddle on your bike to improve your lower back pain on the bike. To further assess the other components of your bike fit, download my free Essential Bike Fit Checklist, which covers the other aspects of bike fits such as cleat, knee, and hip positioning.

 Lastly, I always tell my cyclists that lower back pain with cycling needs to be addressed in two ways: How the bike supports the body, but also how the body supports itself on the bike. If you continue to experience back pain on the bike, make sure you check out my free e-book that provides the beginning exercises I take all of my cyclists through to get rid of their back pain. You can download that here.  

My next steps for you:

1. Further explore bike fit and how it impacts your body by reading my blogs: Hamstring Pain With Cycling and Saddle Height and Groin Pain from Cycling? What to do About It.

2. Make sure to follow Chain Reaction on Instagram for exercise suggestions, performance and bike fit info, and general bike tomfoolery.