We have all been in the gym and seen someone doing a squat with their toes pointing out, or maybe if they are flexible, their toes pointing forward. There might even be a few bros that have zero idea what we are talking about here… well, just read this and learn something important. In the world of lifting there has been a common belief that by changing the position of a joint, you can, therefore, alter the muscle activity. This would be called, changing the line of pull on a muscle by shifting the natural length-tension of the muscle. The core of what a muscle, the inner parts, are what controls the scale of force formed by that muscle. These are the actin and myosin filaments of the sarcomere. The more actin-myosin cross bridges that are available, the higher the amount of force. However, if the muscle is too elongated then the actin-myosin cross bridges will have a reduction in the force. There is a point of the length of the sarcomere for the optimal number of actin-myosin cross bridges.
We are going to look over a Study that tests the quadriceps femoris muscle to see if different feet / toe placements could result in different muscle activation. 20 people were used for this study, 13 males and 7 females. Electromyography (EMG), surface electrodes were attached at the muscle belly to measure muscle activation of the superficial quadriceps muscles: Vastus Medialis Oblique, Vastus Lateralis Oblique, and Rectus Femoris. Noraxon software and hardware and MyoResearch XP version 1.06 software were used to retrieve, process, and measure the EMG activity of the subjects.
- Neutral: feet at shoulder-width apart and the toes pointed forward (12 o’clock).
- Internally: toes rotate towards the center of the body (roughly 11 o’clock).
- Externally: toes rotate to the outside of the body (roughly 1 o’clock).
- Staggered: Both feet pointing neutral, but one foots toes are inline of the others heal.
- One legged: foot pointed neutral.
Five different foot / toe placements were measured: Neutral position, internally rotated position, externally rotated position, staggered foot position, and one legged squat foot position (for a control). Each person has performed the squats on a power tower set at 35 degrees, with 55% of their body as resistance*, five repetitions per foot placement, squatting to 90 degrees of flexion at the knee joint, and given two minutes recovery after each foot placement. *The angle of the power tower and the subject’s body weight was equal to approximately 55% of the each person’s own body weight.
Let’s break down what was found by this study, first, the Vastus Medialis Oblique and Vastus Lateralis Oblique during the neutral, internal, external, and staggered stance were across the board with about the same amount of muscle activation. However, here is where the finding is different. While the neutral, internal, and external were at the same levels, no matter the muscle; the neutral has a slight more activation then the internal and external while the internal had a little more activation then the external. Now for most of us, we have only done the neutral or external stance for a squat. The idea of a staggered stance squat just sounds “dumb”. In this study, the finding shows that the staggered stance squat yielded more muscle activation, by around 0.15 more normalized EMG activation. The Rectus Femoris, on the other hand, while having similar results, had one key difference. The neutral and internal foot placements had the same activation, but the external foot placement resulted in a higher activation then both of the neutral and internal. Yet, just as the Vastus Medialis Oblique and Vastus Lateralis Oblique the staggered stance squat was shown to have more muscle activation. The staggered stance squat was the only foot position to have a significantly more muscle activation in the four-foot positions.
This was should be expected because the staggered stance puts a majority of the weight being bared on the back leg (support leg). If you were to do a staggered stance squat with your right foot forward, you would want to follow up that set with another set with the left foot forward. The staggered stance squat activates the quadriceps femoris similar to a single leg squat. Thus, the-the amount of muscle activation from the back leg (support) leg should increase when compared to a regular squat. If the Staggered position is not considered, the neutral foot position is the best foot position for Vastus Medialis Oblique and Vastus Lateralis Oblique activation. Altering the foot position, Internal or External rotation, established little to no effect with the quadriceps femoris.
When we look at the anatomy of how the tibia to move superiorly in relation to the femur, it is an open kinematic chain that gives the distal portion of the leg free to move space. It is when the distal segment is not fixed that greater tibial rotation occurs with full extension. This could be the cause of the musculature activation and why it could have been altered. With this, the staggered squat could be a way of training a single leg before progressing to a single leg squat. It is important to point out that multiple factors could have caused the results. The Q-angle of the people in the study was not measured, meaning if the Q-angle was exaggerated, muscle activation could have been altered. Especially in the Vastus Lateralis Oblique and could lead to a change in the overall muscle activation. Also, the people in the study could have had fatigue could potentially alter the muscle activation. Last, keep in mind that the squats in this study were preformed on a “power tower”.
To end this write-up lets break down a few factors. When we look at this study, we are just looking at superficial quadriceps muscle activation. Most of use train squats as a full lower body movement. Meaning we are trying to train our hips, posterior chain, and legs, not just one muscle group. For an athletic performance, to do a staggered stance squat over a normal stance squat, would not make sense. While if the goal was to body build the quadriceps or for a rehabilitation reason, staggered stance would be the way to go. We should all remember, deep normal squats are the king.
Nicholas Murray, Daniel Cipriani, Denise O’Rand, and Rebecca Reed-Jones. “Effects of Foot Position during Squatting on the Quadriceps Femoris: An Electromyographic Study” International Journal of Exercise Science. P115-125 www.intjexersci.com. <http://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=1446&context=ijes>