Last updated on March 4th, 2024 at 05:00 pm
No, there is no need for the back knee to touch the ground during lunges. For most people, leaving the back knee 1-3 inches off the ground would be ideal. This allows for an adequate range of motion, as well maintaining sufficient muscle tension throughout the movement.
You Can Still Achieve Full Range of Motion Without Touching the Ground
Firstly, I will say that there is no definitive right answer.
This is a matter of personal preference.
So, you can in fact touch your knee to the ground during lunges, but I prefer not to.
In fact, I advise against it, and will explain why in the remainder of this article.
One of the main reasons that you may hear that you should is in order to achieve a full range of motion.
We all know that performing any exercise through the full range of motion is the best way to get positive results.
Whether you’re looking to gain strength, build muscle, or lose fat, never half-rep or “cheat” an exercise.
However, in my mind, the full range of motion when it comes to performing lunges can be achieved without your knee touching the ground.
At the bottom of the movement, as long as both legs form a 90 degree angle at the knee, you have achieved an adequate range of motion.
In fact, dropping your knee to the floor will typically lessen this angle.
You Have More Control Over The Descent if Your Knee DOESN’T Touch the Ground
People will often talk about whether lunges are bad for the knees.
However, this is generally aimed at the front knee, whereby the knee shoots past the toes.
By doing this, your front leg will go beyond the “perfect” 90 degree angle I’ve mentioned above, and this can put additional pressure on the knee.
With that being said, I frequently see people performing lunges and literally dropping their back knee into the ground.
In fact, it’s almost as though they are reaching for the ground in order to finish the movement.
Basically, there is absolutely no control over the descent, and this can often lead to the back knee “banging” into the ground.
I’m sure you don’t need me to tell you that this is not going to do your knees any favours.
And this could be a precursor for an injury, but for the back knee rather than the front knee.
So, I prefer to avoid touching my knee to the ground in favour of a more controlled descent.
Lunges should be performed slowly and under full control.
This is not a speed-based exercise, as many people believe.
Loss of Muscle Tension
Another problem with dropping the knee to the ground is that many people tend to relax once they hit the floor.
I agree that a lunge should be performed slowly, and that you will achieve better results by having a brief pause at each change of movement.
By this I mean:
- Lunge forward (or backwards)
- Slight pause
- Drop into lunge until both legs form a 90 degree angle
- Slight pause
- Push back up to the top of the movement
- Slight pause
- Repeat
By performing lunges in this way, you increase time-under-tension, plus you keep muscle tension throughout the movement.
This is fantastic irrespective of whether you’re once again training for strength, muscle, or fat loss.
However, there is a tendency to completely relax when your knee touches the floor.
It’s almost as though the lunge has been made into two separate movements.
A lowering movement, then completely relax, and then a raising movement.
But if your knee touches the ground during lunges and you completely relax, you’re defeating the object of the exercise.
This will immediately cause you to lose muscle tension.
So, in other words, you have decreased the time-under-tension, and therefore the exercise becomes less effective.
The reason I mentioned earlier that there is no real “right” answer is because I see nothing wrong with the knee briefly touching the floor.
Literally just grazing it.
However, many people tend to come to a complete stop once their knee touches the floor, thus removing all muscle tension.
Do You Have Tight or Weak Hip Flexors?
Another reason not to allow your knee to touch the ground during lunges is if you have tight hip flexors.
This is certainly something that I am familiar with, so I know only too well why “ground-touching” should be avoided.
Many people struggle with lunges due to a variety of factors.
This could range from instability in the hips, ankles, or even the feet.
Remember, the lunge is a single-leg movement, so there is a certain amount of balance required.
Plus, the lunge requires a bend at the knee and at the hips.
So, this brings the hip flexors into play.
I often see people overstretching the hip flexors when performing lunges, and this is never a good thing.
However, if you’re someone who suffers with tight or even painful hip flexors then you need to be even more careful when doing lunges.
If this is an issue for you check out the Unlock Your Hip Flexors program.
Maintain a Slight Forward Torso Lean
In fact, I would recommend that if you do have tight hip flexors that you ensure that your knee stays at least 2-3 inches off the ground.
Whenever performing lunges, the torso should always remain in exactly the same position.
The ideal torso position is leaning slightly forward, and as you go up and down, this position should be maintained.
However, when tight or sore hip flexors come into play there is a tendency to arch the lower back, and the torso leans into more of a backward position.
This will stretch the front hip flexor, and provides some light relief in terms of tightness or pain.
But, this goes against the correct body mechanics of performing a lunge.
So, always ensure that your torso is leaning ever so slightly forward and maintain that position.
As soon as you feel your upper body starting to move backwards you know you have reached your full hip flexor flexibility.
Be Careful When Fatigued
The final reason I would suggest that you avoid your knee touching the ground during lunges is due to fatigue.
Whether you’re using a barbell or dumbbells to lunge, kettlebells or even your own bodyweight, fatigue can play a part.
Let’s say that you’re performing high-rep bodyweight lunges, 20 reps per leg.
As you begin to tire, you may find that rather than your back knee barely touching the ground, you have manifested into a bouncing movement.
By this I mean the back knee literally bounces off the ground to keep the movement flowing.
This actually takes into consideration practically everything I have mentioned so far.
There is the most obvious, but as you fatigue, this “bouncing” movement could see you banging your knee hard into the ground.
A potential for injury.
Although not directly related to knee placement, I would also be wary of maintaining a neutral spine whenever you lunge, but pay especially close attention to this when you’re fatigued.
Next, you’re making the exercise slightly easier with the “bounce”.
But, rather than completely relaxing at the bottom, you’re now using momentum to get your knee back up from the floor.
Either way, this will have an impact on muscle tension.
Finally, by bouncing off the ground from fatigue you are no longer controlling the descent of the lunge.
So, your lunge form has pretty much gone out of the window.
Key Learning Points
- No, your knee shouldn’t touch the ground during lunges.
- Some trainers claim it is okay, but in reality your knee should only ever graze the ground while you maintain perfect form.
- For most people, whle using a full range of motion, your knee should remain 1-3 inches above the ground.
- Don’t fall into the trap of “bouncing” or “banging” your knee into the ground, as this shows that you don’t have control over the descent.
- Many trainees “relax” when they allow their back knee to rest on the floor, which means that muscle tension is released, i.e. not good for strength and muscular development.
- A limited range of motion may point to tight or weak hip flexors.
- Maintain a slight forward torso lean when you lunge.
- Be wary of your lunge form when fatigued.
That’s you back knee sorted, now for another common issue, namely, your toes hurting whenever you lunge.
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.
Hey Partha,
I am so pleased that you have written and shared this article. I have told you before that I do twenty lunges every day on each leg, and I do not touch the floor with my knee. The reason I didn’t touch the floor was because I saw it as resting and I wouldn’t get the full benefit of the exercise. But, there are also the other reasons that you describe so I am even happier now.
I am going to continue with the lunges and I will ensure to not put my knee on the floor. Especially when you say it is a definite NO.
Thank you for sharing another inspirational article that has made me happy. Keep coming with more inspirational articles my friend.
All the best,
Tom
Hey Tom,
Thanks for stopping by.
I’m glad to hear that you’ve been performing your lunges “My Way”, LOL, although I know not everyone will agree with me.
As I’ve mentioned it could be viewed as “resting” simply because muscle tension may be released.
However, there are those who will say that in order to achieve full range of motion that the knee should touch the floor.
But, I’m definitely not in that camp.
I’m glad to hear you enjoy the articles Tom, that’s always lovely to hear.
Thanks
Partha