What is Knee Flexion? How Do We Strengthen It?

If your athletic journey is anything like mine, you had a deep desire to compete in sport but limited knowledge on how to “level up” your game (1999-2003 was my high school era, limited internet, no YouTube and I definitely wasn’t seeking answers there either way). Personally, I did everything I knew to do which was become a gym rat and live in the weight room. Truthfully, this approach took me from average (or slightly below) athlete to high school starter in two sports with an ability to keep up at cornerback with many wideouts on the gridiron, as well as be able to two hand dunk on the hardwood.

With that said, like many of us “old timers” I’m often saying to myself and clients while I’m training the next generation of “young athlete” - “If I knew then, what I know now.” Don’t get me wrong, I’m beyond grateful to have been able to preserve and in some cases increase my athletic ability in my mid-30s and now into my 40s, but it’s hard to think what could have been if I had known what I know now, back THEN. But…God is sovereign and had I not had those setbacks and ignorance around the human body, as well as sport and training in general; I’m certain I wouldn’t have the zeal and desire to serve the clients I currently have, the way I’m now able.

For this segment let’s focus on knee flexion and more specifically what strong knee flexion does in relation to speed and overall athletic performance.

The summer before my freshman year of college as an athlete on the basketball team, I was running sprints at a local football field with my “vet,” senior Johnny Angle. I can’t remember the distance but I feel like we were hitting around 50 yard sprints, resting for a large amount of time and repeating at similar distances. Without proper rest and recovery it’s impossible to reach max output so we were hitting top speeds during our sprints. I’d never done something like this before. All “sprint” work I’d done previously (and pretty much anytime) was fast but not top speed. Think traditional sport conditioning - you’re dog tired exhausted but not SPRINTING.

I digress. Long story short, my hamstrings were so sore after this football field sprint session, I couldn’t even run in open gym for a week - I was shocked and confused. Fast forward nearly 20 years and it’s starting to make sense.

Let’s start with the hamstring. The hamstring connects at the glute/hip and knee, this is the main mover when you’re doing movements like sprinting. That day on the football field I was putting so much force through KNEE FLEXION (flexing of the hamstring and upper calf) that my hamstrings were TORCHED. Unbeknownst to me then, there is a way to TRAIN for speed. Do genetics play a factor? Of course, I’ll never be an elite level wide receiver at 40, but I wonder how much faster I could have become in my late teens to 30s.

I’ll plan to do another post on speed and training for speed in depth, but for today let’s talk the best way to train knee flexion in my experience outside of actually sprinting.

The Standard & Nordic Hamstring Curls.

Most people are aware of the standard hamstring curl and many have seen the “nordic.” I’m not sure many understand the magnitude of how BENEFICIAL these exercises are though.

The concentric movement of a lift is the “way up.” So when you bench press, when you move the bar off your chest that is concentric or producing force. The way down is eccentric, in this case, when you’re bringing the bar to your chest. So in the case of the knee and knee flexion specifically, sprinting is the concentric movement but how do we train the eccentric movement? Enter: the hamstring curl.

Fighting the way down will help us handle and absorb force, while exploding “up” is what helps us create force. For many of us who haven't trained this way, holding the way down on a nordic hamstring curl will be enough. For a more in-depth visual. Check out these videos I’ve put together here (Nordic & Standard).

Whether you’re looking to build speed and athleticism or simply trying to have strong and healthy knees as you age, knee flexion is a MUST.

If you’re looking to pick up a Nordic Bench that adjusts for easy entry no matter the age or experience, check out the Nordic Back Extension from my guys The Tib Bar Guy’s.

The Nordic Back Extension

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Thanks for stopping by, I hope this is helpful. Please don’t hesitate to reach out with any questions. Let’s go get it!

For His Glory.

Joe Buys