Today, we're diving deep into the realm of squatting, specifically addressing the age-old debate about squat depth and its impact on knee health. I know there have been some wild claims made about squatting low, but hopefully, I can help debunk some of those myths and shed light on why squatting deep is not only safe but actually beneficial for most people's knees.
Let's kick things off by addressing a common misconception: the notion that squatting to a 90-degree angle at the knee and hip is the safest option for your knees. Many individuals, including some trainers, have propagated this belief, but the science tells a different story.
First and foremost, let's talk about biomechanics. When you squat to parallel or higher (90 degrees), you're essentially stopping short of engaging the full range of motion of your hip and knee joints. This limited range can lead to muscle imbalances, reduced mobility, and increased risk of injury over time. Oddly enough, your ACL is under the most stress during the first 30-50 degrees of your squat rep! But stress is a normal part of training. It’s all about giving your body appropriate amounts of stress in a full range of motion, allowing it to recover through proper rest, and gradually increasing the stress/demands by increasing weight or reps slowly over time. Deep squats are a biomechanically sound part of a proper training program.
Research published in the Journal of Strength and Conditioning Research highlights the importance of full-depth squats in promoting balanced muscle development and improved joint health. The study found that deep squats (where the thighs are below parallel to the ground) activate a greater number of muscles, including the glutes, hamstrings, and quadriceps, compared to shallow squats.
But what about the concern that deep squats place excessive stress on the knees? Contrary to popular belief, several studies have shown that deep squats do not increase the risk of knee injury when performed with proper technique and - this is key - appropriate loading.
A study published in the European Journal of Applied Physiology compared the biomechanics of deep squats to partial squats and found that deep squats resulted in lower knee joint stress and greater muscle activation in the quadriceps. Additionally, a systematic review published in Sports Medicine concluded that deep squats can actually improve knee stability and reduce the risk of anterior cruciate ligament (ACL) injuries by strengthening the surrounding muscles and enhancing proprioception.
Furthermore, deep squats have been shown to improve functional performance and enhance athletic abilities. Research published in the Journal of Sports Sciences found that athletes who regularly performed deep squats experienced greater gains in sprinting speed, jumping ability, and agility compared to those who only performed partial squats.
It's also important to address the flawed studies commonly cited by proponents of shallow squatting. One such study, often referenced, suggested that deep squats may increase the risk of knee injury due to higher compressive forces. However, further analysis revealed significant flaws in the study design, including the use of untrained subjects and improper squatting technique. Many things you hear about studies involving joint angles are using cadaver joints…and some of them aren’t even human cadavers! I’m pretty sure your nervous system, muscles, and ANY training history will allow your joints to work better than a dead pig’s joints being bent by a machine in a laboratory for a confirmation bias study…but we won’t get more into that right now, lol.
The evidence overwhelmingly supports the benefits of squatting deep for most individuals, including improved muscle activation, joint health, and athletic performance. As personal trainers, it's our responsibility to educate our clients and promote evidence-based practices that maximize results while minimizing the risk of injury. If you have a current or prior knee injury, maybe you need to work on finding a range that works for you right now, and that’s totally fine. The goal should be to work towards the max depth your knee wants to bend and train with appropriate weights as you work towards improving your body’s ideal range of motion.
If you want a comprehensive program to improve your knee health and function, check out our free ebook here: Train Away Your Pain
Or check out our Remote Coaching service if you’d like us to design you a custom program!
So, the next time you hit the squat rack, don't be afraid to go deep. Your knees will thank you for it in the long run!
Stay strong,
Jonny
References:
Caterisano, A., Moss, R. E., Pellinger, T. K., Woodruff, K., Lewis, V. C., Booth, W., & Khadra, T. (2002). The effect of back squat depth on the EMG activity of 4 superficial hip and thigh muscles. Journal of Strength and Conditioning Research, 16(3), 428-432.
Escamilla, R. F., Fleisig, G. S., Zheng, N., Lander, J. E., Barrentine, S. W., & Andrews, J. R. (2001). Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Medicine and Science in Sports and Exercise, 33(2), 351-360.
Hartmann, H., Wirth, K., Klusemann, M., Dalic, J., Matuschek, C., & Schmidtbleicher, D. (2012). Influence of squatting depth on jumping performance. Journal of Sports Sciences, 30(9), 1-7.
Kritz, M., Cronin, J., & Hume, P. (2009). The bodyweight squat: A movement screen for the squat pattern. Strength & Conditioning Journal, 31(1), 76-85.
McKean, M. R., Dunn, P. K., & Burkett, B. J. (2010). The lumbar and sacrum movement pattern during the back squat exercise. Journal of Strength and Conditioning Research, 24(10), 2731-2741.
Simenz, C. J., Dugan, C. A., & Ebben, W. P. (2005). Strength and conditioning practices of National Football League strength and conditioning coaches. Journal of Strength and Conditioning Research, 19(3), 486-492.