The leg press, whether seated or incline, is typically viewed as one of the best exercises for quad hypertrophy.
However, this doesn’t mean it comes without its problems, and lower back pain is quite common.
With that being said, if you adhere to a few “rules” you’ll be able to take the pressure off your lower back, while really focusing on your lower body muscular development.
Here’s what you need to know.
The main reason that your lower back hurts when you leg press is that your pelvis has gone into posterior tilt (hips pushed forward and butt tucked under) and your lumbar spine has flattened (your lower back is no longer maintaining its natural curvature). This can often be made worse if you allow your butt or lower back to come away from the seat. Unfortunately, due to the position of your pelvis and lumbar spine you will have placed the discs in your lower back into herniation position.
Your Butt’s Coming Off the Seat
As I’ve mentioned, the leg press is a fantastic exercise for hypertrophy.
However, it’s not exactly a functional movement.
What I mean by this is that squatting, as an example, is a basic human movement pattern.
In other words, we typically all squat in our everyday life, even without probably realising it.
Okay admittedly, you won’t often squat with a heavy load placed across your back, but you still squat on a daily basis.
With that being said, it’s not often, if ever, that you’ll need to push a heavy weight away from your body with your legs.
Yes, there are many exercises that you’ll perform in the gym that don’t transfer to your daily life, but they may not place as much stress on the body as leg presses.
The main issue with the leg press machine and lower back pain is the position that you get yourself into.
If you think about it, at the bottom of the movement your quads are more or less parallel to your torso.
So, this would be the equivalent of squatting and then allowing your torso to fall forwards until it’s almost parallel to the floor.
In effect, you’re squatting and performing a Good Morning at the same time.
This position immediately places the lower back under a lot of pressure.
This can be a very precarious position to be in, especially if your core isn’t activated properly (more on this in a moment).
To make matters worse, if you allow your butt or lower back to come away from the seat you’ll place even more stress on your lower back.
In fact, you will have placed the discs in your lower back into herniation position.
And it is for this reason that your lower back hurts, so ensure your butt does not lift off the seat when you leg press.
How to Position Yourself & Use the Leg Press Machine (Infographic)
Your Body Has No Internal Stability
I’ve just mentioned the importance of core activation when performing the leg press.
In truth, whenever you perform any exercise you should activate and stabilise your core first.
Basically, this provides you with a solid base, plus the fact that most movements originate from our core.
However, there are certain gym exercises when you may not activate your core.
This is especially true of the exercises that I would call “non-athletic” movements.
What I mean by this is exercises where you’re either sitting or lying down.
When it comes to the leg press, the machine itself will provide external stability.
In other words, your body isn’t challenged in a way that requires you stabilise anything.
If we look at squats again, then you’ll need to stabilise yourself internally.
By doing so you can squat with a heavy weight on your back without falling forwards or falling backwards.
Plus, not only will you need to activate your core during squats, but also many other smaller stabilising muscles.
Therefore, in order to protect your lower back when you leg press always ensure that you both activate and stabilise your core.
You’re Lowering the Weight Down Too Far
Something else to consider is how far you lower the weight down when you leg press.
Obviously, when performing any exercise you’d like to go through the full range of motion.
By doing so you give yourself the best chance of fully activating the target muscles, which in turn will lead to better muscle and strength gains.
With that being said, the further you lower the weight plate during leg presses, the more pressure you’re putting on your lower back.
I’ve already discussed that the leg press forces the body into a fairly unnatural position.
And unfortunately, this is made worse the lower you bring the weight down.
In fact, depending on your height and especially the length of your legs, you could in effect be completely doubled-over at the bottom of the leg press.
Plus, don’t forget that you’ll typically perform leg presses with more weight than just about any other exercise you do.
So, it makes a great deal of sense to not lower the weight plate too far down when doing leg presses.
Essentially, once the bend in your legs is at 90 degrees, and your upper legs are more or less parallel to the weight plate, STOP, don’t go any further.
Alternatives to Leg Press For Lower Back Pain
If you are struggling with lower back issues from the leg press then it’s probably best to avoid the exercise.
This doesn’t mean that you can’t ever perform leg presses again, but rather that you simply want to give your lower back a bit of a break.
If this is the case, there are a few alternatives that you could try.
Firstly, most gyms will have either an incline or seated leg press machine, or indeed both.
However, some gyms may also have a supine leg press machine.
This involves you lying down completely flat and then performing leg presses from this position.
This immediately places your spine in a more neutral position, so you won’t have to worry about forcing your discs into a herniated position.
If you don’t have access to a supine leg press then the hack squat is a great alternative.
Once more, your spine is allowed to stay in a neutral position, plus the hack squat is much more of an athletic movement.
Plus, the hack squat is awesome for quad hypertrophy.
Finally, you could focus on Swiss ball squats.
This involves placing a Swiss ball between your back and a wall, and then squatting from this position.
You can perform this movement with just bodyweight, dumbbells or kettlebells in either hand, or in the goblet position.
Your spine and lower back in general is far more protected in this position, and you’ll generally find that Swiss ball squats are extremely intense.
All these exercises can produce some fantastic results, while also protecting your lower back.
Key Learning Points
- Lower back pain during leg press usually comes down to “posterior pelvic tilt” and “lumbar flexion”. Essentially, your hips are pushed forward, while your butt is tuck inwards, and you’re no longer maintaining the natural curvature of your lower back.
- Ensure that your butt and lowe back always remain in contact with the seat.
- Keep your heels flat of the weight plate and always push through your heels and big toes.
- Ensure you always maintain a “bend” in your knees, Never fully extend your knees.
- Create “internal stability” when you leg press by activating and stabilizing your core muscles. This will provide “protection” for your lower back.
- The further you bring the weight plate down (towards your body) the more pressure you apply to your lower back. So, if leg press hurts your lower back on a regularly basis don’t take the bend in your leg past 90 degrees.
- Realistically, if performing the leg press gives you lower back pain try using alternative lower-body exercises which will relieve the pressure on your lower spine, e.g. supine leg press, hacks squats, stability ball squats.
Frequently Asked Questions
What follows are some of the most frequently asked questions in terms of leg press and back pain.
Is Leg Press Safer For Your Back Than Squats?
In truth, neither exercise should cause you back pain, and if they do it’s usually your form that is off.
That being said, both exercises have been known to lead to back injuries, and although form is the likely issues, this can also be caused by your body shape, limb length, or injury history.
However, if you were to compare leg press to squats, due to the external stability and fixed range of motion provided by the leg press, this places less stress on your lower back than squats.
Why Does My Lower Back Round When I Leg Press?
Your lower back may round if you haven’t properly engaged and stabilised your core.
However, potentially the most common cause of “back rounding” on the leg press machine is tight hamstrings.
So, when you extend your legs out in front you there is a tendency to lean forward and extend the lower back in order to compensate the lack of hamstring mobility.
Obviously, it makes sense to work on your overall hamstring flexibility.
But, something that I always due before performing a quad-dominant exercises, e.g. barbell squats, hack squat, leg press, etc. is to perform stability ball hamstring curls.
I find that this “loosens” my hamstrings enough that I can perform the above exercises with good technique and pain-free.
What Are the Most Common Leg Press Injuries?
There are two injuries most commonly associated with the leg press, namely lower back injuries and knee injuries.
When it comes to the lower back this typically comes down to rounding the lower back or going into posterior pelvic tilt.
The reasons for this are usually that you’re using too much weight, plus you haven’t stabilized your core.
As for knees, injuries can be caused by fully extending your knees at the top or allowing your knees to track further forward than your toes.
Now, you’ll often hear than you shouldn’t allow your knees to pass your toes when you leg press or squat, although this isn’t strictly true,
The greater the bend in your knees the greater the quad activation will be. However, weak or tight glutes or hamstrings may mean that your technique is poor, which is what can cause a knee injury.
Finally, you should be wary of your knees collapsing inwards when you leg press. This is an unnatural position for your knees to be in (especially when weighed down with a heavy load) and is extremely unstable.
Should I Avoid The Leg Press?
Realistically, all exercise will have their “good” and “bad” points, and not everyone will be able to perform the same exercises with the same ease.
While the leg press isgreat for hypertrophy it ddefinitely isn’t a functional movement.
In other words, there are very few (if any) occasions in “the real world” where you would be required to push a very heavy load away from you by using your feet.
Furthermore, your body may not be adept for performing leg presses, as an example, someone with long legs will find the movement far more difficult than someone with shorter legs.
This mainly comes down to the increased range of motion, but a long-legged leg-presser will also find that they get cramped and bent over at the beginning of the movement.
Therefore, it may be advisable for a long-limbed trainee to avoid the leg press.
Additionally, someone who has a previous history of knee or back injuries may also wish to avod the leg press unless they can ensure they perform every single rep with perfect form.
So, whether leg press should be avoided will always be a personal thing.
Should Leg Presses Be Fast or Slow?
In order to get the best out of the leg press machine you should perform your reps at a slow pace.
This provides a greater time under tension which is ideal for muscle growth.
Additionally, performing leg presses at a fast pace can lead to poor form.
More often than not, this frantic pace of leg pressing can cause you to hyperextend your knees, which can lead to an injury.
Then again, if your concentration is on speed you may decrease the range of motion in order to perform your reps quicker, which will impact on potential hypertrophy.
The leg press is definitely a movement that calls for slow and controlled reps.
What Shall I Read Next?
I’ve mentioned both exercise in this article already, so discover exactly what I have to say about whether you should squat and leg press on the same day.
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.