Nordic Hamstring Curl: Technique, Benefits, and Injury Prevention

How to do a Hamstring Squat?

A "hamstring squat" most commonly refers to the Nordic Hamstring Curl (NHC), a highly effective bodyweight exercise that specifically targets and strengthens the hamstring muscles eccentrically, significantly enhancing their strength and resilience.

What is a Hamstring Squat?

The term "hamstring squat" is not a universally recognized exercise name in exercise science literature. However, within the fitness community, it is most frequently used to describe the Nordic Hamstring Curl (NHC). This exercise is distinct from traditional squats (like back squats or front squats) where the hamstrings act primarily as synergists for hip extension and knee flexion during the eccentric phase. The NHC, by contrast, isolates and primarily loads the hamstrings by resisting knee extension while the hips remain extended. While traditional squats certainly engage the hamstrings, the NHC provides a unique and intense eccentric overload specifically for these muscles.

Muscles Worked

The Nordic Hamstring Curl primarily targets the muscles of the posterior thigh and leg:

• Hamstrings: The primary movers, including the Biceps Femoris (long and short heads), Semitendinosus, and Semimembranosus. These muscles are responsible for knee flexion and hip extension. In the NHC, they work intensely to resist knee extension under bodyweight.
• Gluteus Maximus: Acts as a synergist, helping to maintain hip extension throughout the movement.
• Gastrocnemius: The calf muscle, which crosses the knee joint, also contributes to knee flexion and thus assists the hamstrings.

Benefits of Incorporating Hamstring Squats (Nordic Hamstring Curls)

Integrating Nordic Hamstring Curls into your training regimen offers several profound benefits, particularly for athletes and individuals seeking robust lower body strength:

• Enhanced Eccentric Strength: The NHC is renowned for its ability to build exceptional eccentric (lengthening) strength in the hamstrings. This is crucial for injury prevention and performance.
• Reduced Hamstring Strain Risk: Stronger hamstrings, especially eccentrically, are less prone to strains, particularly common in sprinting and explosive movements.
• ACL Injury Prevention: Research suggests that strong hamstrings can help stabilize the knee joint and counteract anterior tibial translation, thereby reducing the risk of Anterior Cruciate Ligament (ACL) injuries.
• Improved Athletic Performance: Greater hamstring strength translates to more powerful sprinting, jumping, and change-of-direction capabilities.
• Posterior Chain Development: Contributes to a balanced and powerful posterior chain, essential for overall athletic function and posture.

Proper Technique: The Nordic Hamstring Curl

Executing the Nordic Hamstring Curl safely and effectively requires strict attention to form. This exercise is challenging, so start with regressions if needed.

1. Setup:

• Positioning: Kneel on a padded surface (e.g., an exercise mat) with your torso upright and hips fully extended (straight line from knees to shoulders).
• Ankle Anchorage: Secure your ankles firmly. This can be done by:
  • Having a partner hold your ankles down.
  • Hooking your feet under a stable bar (e.g., a Smith machine bar set low, the pads of a lat pulldown machine, or a dedicated Nordic Hamstring Curl bench/GHD machine).
• Arm Position: Cross your arms over your chest or hold them out in front of you. You can also keep your hands ready to catch yourself on the floor.

2. Execution (Eccentric Phase):

• Controlled Descent: Slowly lower your entire body forward by resisting the movement primarily through your hamstrings. Maintain a rigid, straight line from your knees to your shoulders. Avoid hinging at the hips or arching your back excessively.
• Focus on Hamstrings: The goal is to control the knee extension as much as possible, feeling the intense stretch and contraction in your hamstrings.
• Go as Far as Possible: Continue lowering until you can no longer control the descent. For most beginners, this will be only a small range of motion. As you get stronger, you'll be able to lower further.

3. Controlled Return (Concentric Phase):

• Assist if Necessary: Once you reach your maximum controlled range, use your hands to push off the floor and assist your hamstrings in returning to the starting upright kneeling position. This is known as a "spot-assisted" or "push-off" concentric.
• Focus on Control: Even with assistance, try to engage your hamstrings to help initiate the return.
• Full Extension: Return to the starting position with your torso upright and hips fully extended.

4. Progression and Regression:

• Regression (Easier):
  • Limited Range of Motion: Only go down as far as you can control.
  • Assisted Push-Off: Use your hands heavily to push off the floor for the concentric phase.
  • Resistance Band: Loop a resistance band around your chest/shoulders and anchor it to something in front of you to provide assistance during the eccentric phase.
  • Incline: Perform the exercise on an incline bench with your feet secured at the top, reducing the leverage and making it easier.
• Progression (Harder):
  • Increased Range of Motion: Aim to lower your entire body until your chest is close to the floor while maintaining control.
  • Minimal/No Push-Off: Reduce or eliminate the hand assistance for the concentric phase, relying purely on hamstring strength to pull yourself back up (this is extremely difficult and a sign of advanced strength).
  • Weighted: Hold a weight plate or dumbbell against your chest.

Common Mistakes to Avoid

• Hinging at the Hips: A common error is to bend at the hips instead of resisting the fall primarily through knee extension. This shifts the load away from the hamstrings and onto the glutes and lower back.
• Loss of Body Rigidity: Allowing your back to arch or sag, or your hips to pike, indicates a loss of core stability and proper form. Maintain a straight line from knees to shoulders.
• Going Too Fast: The eccentric phase should be slow and controlled. Rushing the movement reduces the time under tension and the effectiveness of the exercise.
• Not Controlling the Descent: Letting yourself "fall" rather than actively resisting the movement negates the primary benefit of the NHC, which is eccentric strength.
• Improper Anchorage: Insecure ankles can lead to instability and potential injury. Ensure your feet are firmly held in place.

Incorporating Hamstring Squats into Your Routine

Given its intensity, the Nordic Hamstring Curl should be programmed thoughtfully:

• Frequency: 1-2 times per week is often sufficient, especially when starting out or if performing other intense lower body exercises.
• Sets and Reps:
  • Beginners: Start with 2-3 sets of 3-5 reps, focusing solely on the eccentric phase with a controlled push-off for the concentric.
  • Intermediate/Advanced: Progress to 3-4 sets of 5-8 reps, aiming for more control on the concentric phase.
• Placement: Can be done as part of a warm-up (lighter versions), as an accessory exercise after main lifts, or on a dedicated posterior chain day.
• Prioritize Quality: Due to the high eccentric load, prioritize perfect form and controlled movement over the number of repetitions.

Who Should and Shouldn't Do Hamstring Squats?

• Who Should:
  • Athletes involved in sports requiring explosive running, jumping, or rapid changes of direction (e.g., soccer, football, track and field).
  • Individuals looking to improve hamstring strength, size, and injury resilience.
  • Those with a history of hamstring strains seeking to strengthen the area preventatively.
• Who Shouldn't (or Should Exercise Caution):
  • Individuals with acute knee pain or pre-existing knee injuries without clearance from a medical professional or physical therapist.
  • Those with severe hamstring strains or tears that are not fully rehabilitated.
  • Beginners with very weak hamstrings should start with less intense hamstring exercises (e.g., glute-ham raises, Romanian deadlifts, good mornings) before progressing to NHCs. Always start with the easiest regression.

Conclusion

While the term "hamstring squat" may be ambiguous, its most common interpretation, the Nordic Hamstring Curl, stands as a cornerstone exercise for developing unparalleled eccentric hamstring strength. By meticulously adhering to proper technique, understanding its benefits, and integrating it strategically into your training, you can significantly reduce injury risk, enhance athletic performance, and build a truly resilient posterior chain. As with any demanding exercise, listen to your body, progress gradually, and prioritize impeccable form over sheer volume.