A common proclamation for doing single leg exercises is, “We walk, run, etc. with one leg on the ground, we should perform exercises in this fashion to be “functional.””
Let’s look at the poor logic of this statement for one moment:
1) Uhh, we don’t walk, run, etc. with bars / dumbbells in our hands either. I guess we should never use them in the gym, right?
2) Here are some of the commonly suggested single leg exercises to be “functional”:
Nearly the entire duration of all these exercises entails both feet, in some way shape or form, being in contact with the ground.
So much for being “functional.”
Anyways, there IS merit in performing exercises where only one leg/foot is in contact with the ground. This is especially true for those who have a significant imbalance between legs. For instance, someone coming out of knee surgery (hey, that’s me) could definitely benefit from such exercises.
The reason exercises where both feet on the ground can become inadequate is because the person will –often unconsciously- favor the stronger leg.
Take a rearfoot elevated split squat:
Some internet gods out there claim this is the greatest exercise ever. One of the reasons being it isolates one leg and is a true indicator of how strong each leg is.
Well, that’d be great, if it were true.
These same people completely ignore the fact the back leg can do an awful lot of work. Again, especially in those who are having trouble achieving symmetrical strength between legs.
Thus, we have our reason for trying to get one leg completely out of the way i.e. in a position where it cannot help the struggling leg. The reason being if it can help…it will.
This is a bit easier when trying to train the backside of the legs. (Hamstring and glutes.) Exercises like single leg bridges, hamstring curls, and RDLs get the job done quite well. (They remove the opposite leg from helping.) However, this can be a lot harder when trying to train the quad.
1) No, leg extensions are not good for this. This is because leg extensions suck. ESPECIALLY for those with a knee pain / surgery history i.e. those who are going to be most interested in achieving balance.
2) This is where some people will advocate things like Pistol Squats.
This is a lot better, and the type of thinking we’re going for. The opposite leg is completely off the ground and out of the way; it just can’t really help. There is one problem I’ve run into consistently with this though: People often have a hell of a hard time controlling the hip when trying to strengthen a lagging leg.
Here’s how this becomes apparent. Watch the hips rotate as the person performs a pistol squat:
Notice how far the left hip is outside the left foot. Ideally, they’d be more straight like so:
Now of course you can simply cue the person, or yourself to not the let the hips twist. I’ve found this to be hard for people, as well as myself though. It’s just really hard to know exactly when your hips are twisting. This, coupled by the fact you are working a leg that is notoriously weak for you, makes it hard to concentrate on the hip.
Again, it’s not bad, but I think there is a better way. Try putting yourself up against a wall:
You can also do this where you incrementally lower yourself as much as you can (without pain!) and then hold yourself in that position. You’ll probably notice you’re able to go lower on one leg than the other.
(Make sure when you straighten the opposite knee (to bring the foot off the ground) you don’t lift the knee. Both knees should be at the same height, or basically touching one another.)
The wall helps the person immensely with noticing compensations and weaknesses. If their hips are rotating at all the person immediately knows because they will feel one side of their hips come out of contact with the wall.
You’ll likely notice a hell of a lot more quad work (probably burning) in this exercise than in the pistol too.
Furthermore, many will notice a difference in what they feel in their abs on one leg compared to the other. In other words, often times on the weak leg the person will feel like they are going to fall over, whereas on the strong leg the person will feel nice and stable. This illustrates an imbalance in the strength of the obliques between sides.
If the person is having a really hard time with not tilting over then I’ll let them put their hands on the wall to help the stomach out. (See the videos.) This way the stomach doesn’t limit their quads from getting some work too.
You won’t get this same sensation in the pistol because people are just too likely to lean/tilt/rotate in order to accomplish the knee bending. They are essentially doing everything they can, using every compensation they can, to accommodate the weak leg. The wall prevents any compensation and throws all of the work on the muscles that truly need it.
Once this is mastered you have yourself a nice progression to a pistol without wall support.
Brice
April 22, 2017
Hello Brian,
I just saw this exercise and tried it. I am wondering if i should leave some space or not between my legs. In the videos, people have their knees together but i tend to get internal rotation of my knees doing so and it hurts. When leaving some space (hips wide) i can t keep my balance. Also, what amount of bending are we aiming for ? I cant do more than what the person in the first video does but i suppose the objective is to progressively go lower ? Is their a max we shouldn t go beyond ?
Thanks a lot for your wonderful knowledge sharing.
Brice
reddyb
April 25, 2017
Hey Brice,
-Using the hands on the wall should help with the balance.
-Having the knees apart is fine. They look fully together in the video due to the pants, but that wasn’t intentional.
-Depth I usually aim for 90 degrees or so. Whether a person can go lower than that depends. For instance, not everyone’s hips bend more than that.
Or if there is knee pain, then I won’t have the person go to a depth which causes pain.
But I don’t have a set depth in mind e.g. “A person has to go such and such deep.”
Thanks for the nice words.
Joe
October 19, 2019
I like the idea. What do you think of single leg skater squats for those with strength imbalances and acl rehab? What do you also think of single leg step down?
b-reddy
October 22, 2019
Similar ideas there, but those will involve more hip & torso flexion (torso will lean forward in your movements). That will be fine for many, but hip mobility / structure can come into play for many as well i.e. flexing your hip and torso that much, with the femur purely in the sagittal plane, won’t agree with everybody due to how their hip is built e.g. a retroverted hip won’t agree with that. This could be more noteworthy in an ACL / athletic population, as in my experience larger males are more likely to have hip structures which don’t love deep hip flexion in the sagittal plane.
With the single leg exercise and the back against a wall, the flexion issue is mitigated.
However, balance is much more of a factor in the exercises you mentioned. If someone is coming off an ACL injury, that is paramount to work on. You might do those movements, but not with as much ROM.
They’re all good in terms of true single leg exercises. What’s best will depend on the context.