Lower back pain on the bike: why it happens and how to prevent it
You’ve probably had your bike fitted by a bike fitter, perhaps more than one. You’ve moved the saddle up, down, forward and back. You’ve raised the stem, tilted the brake levers and asked every rider you know for advice. But your back still hurts. Could the problem be partly with you, but also with your bike?
First of all, you’re not alone. Cold comfort perhaps, but lower back pain caused by cycling appears to be universal. In one study of professional riders, 45% reported back problems during their career. More striking still, 58% said they had suffered back pain in the last year.
Watch any professional rider step off the bike after a long race and you’ll see the discomfort as they struggle to straighten up fully.
Why does cycling cause lower back pain?
Essentially, it’s the position you’re in and the amount of time you spend in it. Unfortunately, there’s no way around that. Unless you want to take on the aerodynamic properties of a wall, you have to lean forward. Stooping for long periods has been linked to back pain, whether on the bike or simply sitting in a chair.
This is thought to cause something called the flexion-relaxation phenomenon, a situation in which the spinal muscles simply switch off. Instead, the body relies on passive structures such as ligaments to help maintain position. This could be an energy-preservation strategy of the central nervous system (CNS), or it could be down to a lack of endurance in those muscles.
There’s not much we can do about the first, but the second can be improved.
Not all flexion is equal
Research shows that your position on the bike can make a difference. In the traditional cycling position, two different types of flexion are at play: hip flexion and lumbar spine flexion.
Hip flexion is the narrowing of the angle between the thigh and the trunk. Lumbar spine flexion involves bending the spine itself. Note the difference in the images below. Filippo Ganna (Team Ineos) achieves the position by flexing more at the hip, whereas Rigoberto Urán (EF) flexes more through the spine.
It’s Rigo’s position in particular that’s associated with lower back pain in riders.
Are you sitting with a straight back?
A research group found a significant relationship between increased lumbar flexion and spinal rotation in riders who experienced lower back pain. Although the sample size was relatively small, every subject who developed back pain while cycling had weakness in the muscles that rotate the trunk to one side or the other.
Solutions for back pain while cycling
So it seems that lower back pain while cycling is associated with increased lumbar flexion and perhaps also with a rotational component. That being the case, I’ll point you towards a few solutions to the problem.
If you think you’re more of a back-bender than a hip-flexor, there are a couple of things you can work on:
1. Train your hip flexors
Hardly anyone recommends training the hip flexors for cycling. The general wisdom is that they adapt to the activity and need to be stretched in riders. This is based on little more than observing the position riders spend their time in.
You can’t assess which muscles are tight and which are weak simply by observing a posture. It’s the equivalent of a mechanic telling you what’s wrong with your car as it rolls into the workshop without even speaking to you. It’s more effective to assess the performance of the hip flexors directly.
Here’s a video with some fairly comprehensive exercises.
2. Check your hip flexion range of motion
Try this for a second. Lie on your back and stretch your arms out parallel to your body. Now bring one bent knee towards your chest and stop when you feel the pressure increase on your hands. That’s your available active hip flexion range of motion.
How far did you get? Take a photo and check the progress after doing the exercises for a few weeks.
Now, take a photo on the bike and compare the angle between your thigh and your trunk when you’re gripping the drops.
If that angle is much smaller when you’re on the bike, then you’re exceeding your active hip flexion range of motion. That explains why your lower back is causing problems.
There’s also a fairly simple exercise to improve hip flexor performance. Lie on a weights bench with the backrest tilted slightly upwards. Bear in mind that the greater the incline, the harder the exercise. Keep one foot firmly planted on the floor and slowly bring the other leg towards your chest. Raise the leg as high as you can, before lowering it slowly until your foot almost touches the floor. It’s important to make sure the knee and hip stay aligned throughout.
Repeat until you start to feel fatigue around the front of the hip. Now do the exercise with the other leg and notice whether there’s a difference between the two.
3. Train your back extensors
Another possibility is that the muscles of the lower back aren’t able to hold a flexed position for long periods of time. A great deal of research suggests that people with back pain have weakness in the lumbar muscles. This effect has also been shown in cyclists. There’s also plenty of research indicating that strengthening these muscles reduces back pain — which is logical, and something we don’t really need research to tell us.
From a performance perspective, a stronger spine will also help you transfer more power to the pedals. What’s not to like? Less pain and better performance. It’s a win-win! The hard part is choosing the right exercise and performing it at exactly the level of your current ability.
The best results come from isolating the lower-back muscles as much as possible, especially if they’re weak. This reduces the risk of your body using other muscles to compensate.
However, it’s hard to do this without specialised equipment, because these muscles are quickly overpowered by the large hip extensor muscles. That’s why exercises like the back hyperextension and the deadlift don’t always produce the best results.
If you don’t have access to a lumbar extension machine, use the following exercise. While it has its limitations, it’ll provide a valuable starting point.
The aim of this exercise is to isolate the muscles that extend the lumbar spine as much as possible. We also want to train them through their available range of motion.
A Bosu ball will help you do this because it lets you introduce flexion into the lumbar spine. It’s preferable to a Swiss ball because it’s stable and lets you keep your knees bent. This will stop you from using the hamstrings to assist the movement.
Position yourself on the ball so your navel is level with the top of the dome. Squeeze your stomach muscles as if you were doing a crunch and slowly curl your abdomen downwards over the ball. When your stomach muscles can’t take you any further, stop. It’s important not to go past this point. If you can’t contract into a position, it’s very hard to contract out of it without compensating.
Keeping the gluteus maximus (the buttock muscle) relaxed, slowly extend your spine as far as it’ll go. Hold the top position for one or two seconds before squeezing your stomach muscles to come back down.
Bear in mind that changing the position of your arms will alter the result. Keeping them at your sides makes the exercise easier. If you place them next to your head, the exercise will be harder. This lets you increase the intensity as needed.
Repeat the exercise until you feel slight fatigue in your lower back muscles.
4. Assess your trunk rotation range of motion
To check whether trunk rotation might also be an issue, use the following range-of-motion assessment. Sit upright on a bench with your feet firm on the floor. Cross your hands loosely over your chest and slowly rotate your trunk to one side. Don’t let your hips or pelvis move. Note how far you get and repeat in the other direction.
If you’re more limited on one side, that’s an indication you have weakness in the muscles responsible for movement in that direction.
Try the following isometric exercise (muscle contractions without movement) to improve movement on the restricted side.
Conclusion
There are two options: swap your bicycle for one with a basket and a bell for leisurely rides, or tolerate the flexed position of the road bicycle. For the second option, the exercises I’ve explained above are designed to help you hold that position for longer and with less discomfort.
They’ll also help you improve your performance on the bike.