The rear foot elevated split squat: Maximise its use for training and testing

Another debate that never ceases is the unilateral versus bilateral one. One exercise that has become very popular for those programming unilateral exercises is the rear-foot elevated split squat. We wanted to find out more about the exercise, how much of a unilateral exercise it actually is, can it be used for testing unilateral strength and does it even matter if asymmetries exist when our athletes perform it. We asked Mark Helme who looked at this exercise extensively in his PhD.

Does lower limb strength symmetry really matter for performance and injury risk?

When I started my Ph.D., I shared the view I hear frequently in the S&C community that we should all be symmetrical, but I have come to the idea that asymmetry is perfectly natural.

At the moment, I would say the simple answer is no, I haven’t seen enough consistent evidence that symmetry is a big concern. If someone has a large asymmetry in strength, power, flexibility or some other output, it is probably because one limb is dysfunctional. Sorting out that dysfunction is the important part, not “restoring” symmetry. There’s been a lot of research other the last 10 years on asymmetry (mostly by Chris Bishop), and it shows that asymmetry is highly variable between days and changes between tasks. It is the definition of a moving goal post.

Most of my work has been around leg strength – when you improve this, you perform better and get injured less. The closing line of my Ph.D. viva was “just get stronger.” Considering asymmetry has become a distraction from the real goal of increasing function. I now advocate for less comparison between limbs within the same person. Instead, treat each limb in its own right and compare that to an external standard.

For example, in my research an average 5RM in the rear foot elevated split squat (RFESS) was 1x body weight (BW). If a player had scores of 1.1x BW and 1.25x BW for left and right legs, I wouldn’t be at all thinking about asymmetry. If, however, the scores were 0.8 and 1.25, I would be saying that they have one weak leg that needs improving.

Is the rear foot elevated split squat an appropriate exercise to measure unilateral strength and symmetry?

It depends!

The exercise has some key advantages compared to a traditional squat test, which I still use as needed. First, I can measure single leg strength anywhere as long as there are weights and a squat rack. Second, by observing the test, as a coach I can see deficiencies that bilateral testing wouldn’t show.

During my research participants typically failed a lift for two reasons. The first is that their legs were not strong enough to move the weight, as you’d expect. Second, participants were not able to stabilise the load enough to allow their legs to squat the weight.

I encourage coaches to ask themselves: Are these pieces of information useful to your sport? Sometimes they will be, and others not. I have worked in Rugby League a lot and I felt that understanding a player’s ability to express strength on one leg and maintain stability was helpful in understanding how they may tackle, carry into contact, change direction etc. However, it’s not going to tell me what I would need to know as a weightlifter, which is the maximum weight that can be lifted bilaterally.

After that, the coach must consider who they are testing. I have used the test both in my research and coaching practice. There are some players who can do this extremely well but others cannot, especially those at the end of their careers who aren’t as robust or mobile. I kept them away from it.

All tests require the athlete to be familiar with the exercise, but that is particularly the case with the RFESS. My research outlines a protocol to follow. Most people took 2-3 sessions to get to grips with it and had big leaps in performance between those early sessions. So if you want to test with it, train with it first.

Do anthropometrics affect the contribution of the rear leg in the rear foot elevated split squat?

I haven’t seen any evidence for it. Pretty much every person I have tested using force plates had approximately 15% of their total force (that’s everything including body weight, bar load and pushing) going through the back foot with very little variance. That can be pretty much explained by the weight of the rear leg. Alex Natera found the same thing when he had his athletes do the same thing. All of those that I tested used the same height box, so every test was a different percentage of height or leg length, yet the numbers stayed consistent.

The box can be closer or further away, but lots of people hop around to get into position before starting a set, so there is good amount of self-organisation that takes place. I always perform the RFESS inside a full or half rack for safety. So as long as the bars are at the right height to catch the bar and prevent the athlete from getting hurt, the set up is pretty much the same for everyone with no change in lead foot demands.

If we want to maximise the contribution of the front leg and minimise it for the rear leg, is there anything we can do when setting up the exercise?

First, make sure the athletes understand that it is a unilateral exercise, and they should try to use the lead leg. That said, there are some elements that can minimise the athlete’s ability to use the rear leg. It is normal for people to self-organise and find whatever way they can to complete the task, so ensure the set up limits how they could use that rear leg.

• Box height: We used 40 cm. Anything close to that would work, and box height doesn’t need to be scaled to the participants. Once the rear leg is elevated beyond 30 cm, it’s very difficult to use it.
• Box type: Using a flat ply box is a great tool. First, it is slightly soft so any force the rear foot produces will compress the box and not contribute to lifting the bar. Second, the flat surface prevents any “hooking.” If you use some type of bar to elevate the rear leg, the athlete can pull with the rear foot to try to help themselves up. You would see a repetition that looks different than the required vertical up and down, as the athlete would be pulling themselves backwards instead of pushing up.
• Foot Placement: We use toe contact only, rather than a flat foot with the laces down, simply because it is harder to apply force in that position.
• Stride length: My desired technique is a near vertical shin and torso angle with the rear foot placed quite far back and the hips, therefore, in a very extended position. This end range set up again limits the potential for the rear limb to express force.

Bilateral vs. unilateral exercises is one of the most debated topics in S&C, with people like Mike Boyle putting himself firmly in the unilateral camp. Is this debate warranted, and is there ever a place for being all in one camp?

Listening to Mike Boyle was the initial spark for what became my Ph.D. I thought he talked a lot of common sense, but at the time there was no evidence for or against it.

Mike makes some great points, especially around loading the spine, but I think there are loads of people who can safely do bilateral training and have great success. I am big fan of Squat University, and their content is making great strides in helping people avoid some pitfalls of heavy bilaterals. I think most people should have the capacity to do both and be able to pick an exercise that drives their optimal performance adaptation.

We are governed by the principle of adaptation, so if we know that an athlete will be exposed to large external forces in a bilateral stance, such as an NFL lineman or Rugby Union prop, then unilateral exercises aren’t going to cut it. On the flip side, unilateral exercises have always been viewed as being light. As my research and coaching progressed, I was seeing a lot more weight on single leg exercises than before, creating huge systems loads on one leg. However, the movements are not the same I haven’t seen anyone have a range of movement in a single leg exercise comparable to what happens in a full ass-to-grass deep squat – something I should get around to researching!

As an example, in any split squat variation, athletes don’t achieve full hip extension, so they do less work. This may or may not be an issue for you, but it’s important to understand the limitations of all exercises before going all in. I still use both modalities in training.

What are the biggest mistakes you see young practitioners / clinicians make? What advice would you give them to help?

“Mistakes” is the wrong word here. All novices should make mistakes. That is largely what makes someone a novice. Novices need to accept mistakes as a helpful event. I’d prefer to use the word “challenges” instead.

I’ve reflected on the journey from being a novice to an expert and the importance of trial and error on that path.

Novice practitioners should make lots of mistakes and be in a space that knows and encourages that. For example, starting out with an athlete eight months before the Olympics is not a free space to make a mistake. On the other hand, leading the warm-up for a group of under-15 sprinters might be. They won’t succeed or fail based on those warm-ups, but what the novice coach learns and experiences could set them up for a successful career.

Part of being a novice is being rules and process driven, blaming the athletes or clients for any mistake – something I did early on. In this early stage, the novice coach isn’t aware of their influence on what didn’t go well. The biggest challenge is the journey to developing a sense of self-awareness and vulnerability to acknowledge their part in those errors. The students and young coaches I meet are increasingly less likely to admit something did not go well or that they lacked knowledge, expertise or preparation. Developing self-awareness is key for coaches to transition from novice to competent to expert, knowing what they need to know, when the textbooks work and when they are a hindrance.

Therefore, a novice coach needs an “apprenticeship” that blends the right degree of accountability with space to watch and learn from experts, who will challenge them to reflect.

Too many novice coaches are chasing tracksuits, working for free, picking cones for a convoluted title, but not developing. They aren’t watching experts go about their role and they aren’t responsible for an element of a program where they can make their own mistakes.

This is equally a challenge laid at the door of more experienced coaches and organisations that aren’t providing those kinds of experiences.