Nordic Curls: Preventing Hamstring Injuries

Hamstring strains are the bane of runners, sprinters, and team sport athletes everywhere. They are painful, they linger, and they have a notoriously high recurrence rate. However, recent sports science points to one specific movement that offers the best defense against these tears: the Nordic Hamstring Curl. This exercise is not just for elite bodybuilders; it is a functional necessity for anyone who wants to bulletproof their posterior chain.

What is the Nordic Hamstring Curl?

The Nordic Hamstring Curl (NHC) is an eccentric-focused leg exercise. Unlike a standard machine leg curl where you pull a weight toward your glutes, the Nordic curl involves anchoring your ankles and lowering your entire upper body toward the floor.

The movement relies on “eccentric loading.” This means your hamstring muscles are strengthening while they are lengthening. This is critical because most hamstring injuries occur during the eccentric phase of running—specifically the moment your leg swings forward and extends just before your foot strikes the ground. By training the muscle to handle high loads while fully extended, you directly prepare it for the exact stress that causes injuries.

The Science: Why It Drastically Reduces Injury Risk

The effectiveness of the Nordic curl is backed by significant data. A landmark systematic review and meta-analysis published in the British Journal of Sports Medicine analyzed data from over 8,000 athletes. The results were staggering. Teams that included the Nordic Hamstring Curl in their training protocols saw a reduction in hamstring injuries by up to 51%.

Here is specifically what happens physiologically when you perform this movement:

  • Fascicle Lengthening: The exercise physically increases the length of the muscle fiber bundles (fascicles) in the biceps femoris. Longer fibers can generate force over a greater range of motion.
  • Shift in Torque Angles: Untrained hamstrings often fail when the leg is fully extended. Nordics shift the point of peak torque to a longer muscle length. This means your hamstrings remain strong even when stretched to their limit during a sprint.
  • Neural Adaptation: Your nervous system learns to recruit more muscle fibers rapidly to act as a “brake” for your knee joint.

How to Perform the Exercise Correctly

Executing a Nordic curl with poor form renders it useless. The goal is not just to reach the floor but to control the descent for as long as possible.

The Setup

  1. Kneel Down: Start on a soft surface like a yoga mat or a padded gym floor to protect your knees.
  2. Secure the Ankles: Have a training partner hold your ankles down firmly. If you are alone, use a dedicated piece of equipment like a “Nordstick” that slides under a door, or wedge your feet under a heavy, immovable object like a loaded barbell rack or a couch.
  3. Align the Body: Your knees, hips, and shoulders should form a straight line. Engage your glutes and brace your core.

The Movement

  1. The Descent: Slowly lower your torso toward the ground. The movement must come strictly from the knee joint.
  2. Maintain Tension: Resist gravity with your hamstrings. Do not let your hips shoot back; keep your glutes squeezed tight to keep your hips extended.
  3. The Break Point: Eventually, gravity will win. When you can no longer control the fall, put your hands out to catch yourself in a push-up position.
  4. The Return: Push yourself back up explosively with your hands to the starting position. Do not try to curl yourself back up using your hamstrings unless you are an advanced athlete. The benefit is in the lowering (eccentric) phase.

Equipment and Home Alternatives

You do not need a commercial gym to perform this movement. While dedicated Nordic benches exist, several cost-effective alternatives work just as well.

  • The Lat Pulldown Machine: In a commercial gym, kneel on the seat of the lat pulldown machine facing away from the stack. Hook your heels under the knee pads/rollers. This is often the most secure setup in a standard gym.
  • Door Anchors (The Nordstick): Several brands produce a simple strap-and-hook device called a hamstring curl strap. You slide it under a closed door, hook your heels in, and perform the curl on the floor. This typically costs between $20 and $40.
  • Smith Machine: Set the bar of a Smith machine to the lowest setting. Place a barbell pad on the bar. Kneel on a mat and wedge your heels under the bar. Note that you may need to put heavy plates on the machine to prevent it from lifting.

Common Mistakes to Avoid

Because the exercise is difficult, the body naturally tries to “cheat” to make it easier. Watch out for these errors:

  • Breaking at the Hips: This is the most common error. As you lower yourself, you might stick your butt out (flexing the hips) to shift the center of gravity. This removes the tension from the hamstrings. You must keep a straight line from knee to shoulder.
  • Hyperextending the Back: Do not arch your lower back to compensate for weak hamstrings. Keep your ribcage tucked down and your core braced.
  • Speeding Through the Rep: Dropping to the floor quickly negates the benefits. Fight for every inch of the descent. A 3 to 5-second lowering phase is ideal.

Recommended Programming

The Nordic curl is intense. It induces high levels of muscle damage (which leads to growth), so you should not do it every day.

For Beginners: Start with low volume.

  • Frequency: 1 to 2 times per week.
  • Volume: 2 sets of 4 to 5 repetitions.
  • Note: You will likely experience significant soreness (DOMS) for the first two weeks. This is normal.

Progression: Once you can control the descent for the full range of motion, you can increase volume to 3 sets of 8 to 10 reps. Advanced athletes can eventually eliminate the push-up and curl themselves back up using only hamstring strength.

Frequently Asked Questions

Can beginners do Nordic curls?

Yes, but they should use regression techniques. Using a resistance band tied to a rig behind you can assist the movement. Hold the band as you lower yourself to reduce the load on your hamstrings. Alternatively, limit the range of motion and only lower yourself halfway before pushing back up.

Is this exercise bad for your knees?

The movement puts pressure on the kneecap (patella) because you are kneeling. However, it is not damaging to the knee joint itself if performed correctly. Always use a thick foam pad or folded yoga mat under your knees to prevent discomfort. If you have a history of patellar tendonitis, consult a physical therapist first.

How is this different from a seated leg curl?

A seated leg curl is an open-chain exercise that isolates the hamstring but usually focuses on the concentric (shortening) phase. The Nordic curl is a closed-chain movement that emphasizes the eccentric (lengthening) phase. The Nordic curl mimics the mechanics of sprinting and injury scenarios much more closely than a seated machine.

Do I need to warm up before doing Nordics?

Absolutely. Because the intensity is high, you should never do these “cold.” Perform 5 to 10 minutes of light cardio or dynamic leg swings, followed by a few sets of glute bridges or light leg curls to get blood flowing to the posterior chain before attempting Nordic curls.