Fitness Mythbuster: Squatting with Knees in Front of Toes

Yesterday, I watched a personal trainer approach a gym member and caution him about letting his knees travel in front of his toes while doing squats. Being a polite Canadian, Mr. Squat acknowledged the trainer’s concern and thanked him for the advice. After the trainer split, I caught Mr. Squat’s eye and we exchanged a knowing roll of the eyes.

Another young trainer spreading half-truths he learned during his weekend personal training certification.

Fast forward to this morning – I get an alert about some new research published in the Journal of Strength and Conditioning Research entitled - Effect of Squat Depth and Barbell Load on Relative Muscular Effort in Squatting …. which got me thinking about Mr. Squat & The Trainer and inspired me to look for research investigating squatting and joint angles and torques – Here’s what I found:

• Effect of knee position on hip and knee torques during the barbell squat
• Comparison of the Angles and Corresponding Moments in the Knee and Hip During Restricted and Unrestricted Squats

What did the research say?

It said that when you restrict the travel of your knees so that they do not travel past your toes, you end up with:

• Vertically oriented shins
• A smaller moment / Less torque at the knees
• A larger moment / More torque at the hips
• An increased anterior lean of the trunk
• A greater internal angle at the knees and ankles.

Which results in:

• Reduced strain on the knee joints
• Increased strain on the hip joints
• Increased stress on the lumbar joints

Conversely, the unrestricted (toes in front of knees) squat resulted in:

• Increased strain on the knee joints
• Decreased strain on the hip joints
• Decreased stress on the lumbar joints

And what did the researchers conclude from their research?

1. Although restricting forward movement of the knees may minimize stress on the knees, it is likely that forces are inappropriately transferred to the hips and low-back region. Thus, appropriate joint loading during this exercise may require the knees to move slightly past the toes.
2. The higher moments in the hip during restricted squats suggest a higher load of the lower back. Athletes that aim to strengthen their quadriceps should consider unrestricted squats because of the larger knee load and smaller back load.

Conclusion

When it comes to knee position while squatting, our young PT was wrong to declare unrestricted squats universally wrong.

Right or wrong is subjective and depends on a few different factors:

• Current state of joint health – Does Mr. Squat have a bad back / bad knees / bad hips???
• Goals – Muscular development of hip muscles vs knee muscles – training for power vs training for appearance
• Fitness Program Design – I often divide up leg training days by hip-dominant exercises vs knee dominant exercises

None of which Mr. Personal Trainer considered before spreading his Fitness Myth