As great an exercise as leg raises are, many of us face the exact same problem when we perform them.
I am of course talking about your tailbone and lower back hurting.
If your tailbone hurts when doing leg raises you should press your spine into the floor. This will ensure that you don’t have anterior pelvic tilt during the movement, which will typically see your lower back arch. You should also contract your abs and core during leg raises, and use these muscles to raise your legs instead of using your hip flexors. If you still experience lower back pain you should try easier variations, such as single leg lifts or with your knees bent.
1. You’re Not Pressing Your Spine into The Floor
One of the main reasons your tailbone hurts when you do leg raises is because you’re not pressing your spine into the ground.
This is especially true when you lower your legs back down to the floor.
In fact, there is a tendency to relax somewhat on the lowering portion of leg raises.
In effect, many people view this as a “rest period” during the movement.
However, by “relaxing” as you lower your legs your lower back will typically arch.
And it is this that can cause you lower back pain.
I would go as far to say that you should probably control the lowering part of leg raises more than when you raise your legs.
But, in truth, you should have complete control throughout the entire movement.
You should really squeeze your abs into your stomach as you lower your legs and this will help you to press your spine into the ground.
2. You Have Anterior Pelvic Tilt
You should maintain posterior pelvic tilt during ab exercises.
Posterior pelvic tilt involves tucking your butt under towards the front of your body.
By doing this you will no longer have the arch in your lower back, which is usually the cause of tailbone pain during leg raises.
Posterior pelvic tilt also engages the abs much more, which will actually make the exercise harder.
Additionally, posterior pelvic tilt places far less stress on the lower back.
You should actually maintain slight posterior pelvic tilt on most ab exercises, even planks, to ensure that you engage your abs properly and can feel them working.
But, I’m sure you’re aware that the harder your abs have to work and the less pressure on your spine the better it will be for you.
Unfortunately, many people maintain anterior pelvic tilt during ab exercises, and this is especially true with leg raises.
This will automatically create an arch in your lower back.
Plus, it also reduces the effectiveness of leg raises and other ab exercises.
Basically, anterior pelvic tilt will place far more stress on the lower back and it won’t allow you to engage the abs and core properly.
3. You’re Not Contracting Your Core
One of the most obvious things to do during any ab exercise is to contract your core muscles.
And yet it is typically the one thing that many people forget to do.
You actually stand a better chance of targeting the abs and core if you squeeze the muscles tight.
In effect, you’re almost telling your brain, “This is the part of the body where I want to feel it most.”
You’ll find that by contracting your core and really squeezing your abs during leg raises you’ll also provide your lower back with additional support.
And in truth, if any ab exercise causes you lower back pain it’s probably because you’re not contracting your core for additional stability.
Furthermore, this will help you to avoid anterior pelvic tilt and arching your lower back.
Therefore, it will aid you in keeping your spine pressed into the floor.
And as we’re already aware this will ensure that your tailbone doesn’t hurt during leg raises.
So, as you set yourself up in the correct position on the floor make sure you really contract your core and squeeze those abs before any hint of movement with your legs.
4. You’re Using Your Hip Flexors to Raise Your Legs
Something else to consider is that you’re not actually using your abs at all during leg raises.
You may in fact be using your hip flexors to raise your legs, more specifically the psoas muscle.
The psoas muscle is connected to the pelvis and the top of the thighbone.
You will work the psoas muscle whenever you flex at the hip joint and lift your upper leg towards the body.
So, in reality the hip flexors and psoas muscle will have a role to play during leg raises.
However, if you concentrate more on hip flexion, as opposed to spinal flexion, your psoas muscle will end up doing most of the work.
This is typically why you may have sore hip flexors whenever you perform leg raises, or any other ab exercise for that matter.
This will often lead to tight or painful hip flexors, which can impact on your mobility in this area of the body.
Plus, if you use your hip flexors rather than your abs to lift and lower your legs you’ll end up putting far more pressure on the spine.
And this of course could be the reason for the pain you feel in your tailbone.
5. You Should Try Easier Leg Raise Variations
Something else to consider would be variations of leg raises.
Basically, the further your feet are away from the “pivot point” of the exercise, i.e.. the hips and abs, the harder the exercise becomes.
So, in effect when your legs are completely straight during leg raises you are performing the most difficult variation.
It could be a case that your abs and core just aren’t strong enough yet to perform this movement.
Look, I know that most of us want to perform the “hardest” exercise possible because we believe it will provide the greatest benefits.
However, sometimes you have to modify an exercise to fit in with your own abilities.
And there’s no shame in that.
I would rather perform an exercise well and safely than risk a potential injury with poor technique.
So, when it comes to leg raises, if you shorten the distance between your feet and the “pivot point” the exercise becomes much easier.
Therefore, you can bend at the knees and perform leg raises that way.
You will still be targeting the abs and core to great effect, and you will receive the benefits of working the movement safely.
And as you become stronger at performing bent-knee leg raises you can always move onto the straight leg variation.
Another variation of leg raises that is even easier is single-leg raise.
This involves you keeping one leg straight and raising and lowering it.
Your other leg should be bent at the knee with your foot flat on the floor.
This will provide a lot more stability for your lower back.
Plus, you will still be working the abs and core.
Key Learning Points
- Always ensure your spine is pressed tight into the floor when performing leg raises. There is a tendency to arch the lower back when lowering your legs. This immediately puts more stress onto the tailbone.
- If you perform leg raises with anterior pelvic tilt you will automatically arch the lower back, thusexposing the tailbone to more pressure.
- You should squeeze and contract your core during ALL ab exercises. This gives your brain a focal point, which can increase mind-muscle connection.
- Many people actually use their hip flexors, as opposed to their abs, when performing leg raises. Unfortunately, this places much more stress on the spine.
- While working on improving your core strength you can use easier leg raise variations.
Hi, I’m Partha, owner and founder of My Bodyweight Exercises. I am a Level 3 Personal Trainer and Certified Strength & Conditioning Specialist through the Register of Exercise Professionals, United Kingdom. I have been a regular gym-goer since 2000 and coaching clients since 2012. My aim is to help you achieve your body composition goals.