Reverse Nordic Curl

The reverse Nordic curl, also called a kneeling quad extension, is a bodyweight quadriceps exercise performed from a kneeling position. Keeping your shoulders, hips and knees aligned, you lean backward by bending the knees and then use your quadriceps to return your body to the upright position.

During the descent, the quadriceps work eccentrically to control the increasing knee-flexion angle. During the return, they contract concentrically to extend the knees and bring the body upright. Because the hips remain extended, the movement trains the rectus femoris in a longer position than many seated knee-extension exercises.

Despite the similar name and starting position, the reverse Nordic curl is not a variation of the conventional Nordic hamstring curl. A Nordic hamstring curl involves leaning forward with the ankles secured and primarily trains the hamstrings. The reverse Nordic involves leaning backward without anchoring the ankles and primarily trains the quadriceps.

The reverse Nordic is also related to the sissy squat, since both exercises keep the hips extended while the knees bend. However, the reverse Nordic begins on the knees and removes the balance and ankle demands of the standing sissy squat.

An eight-week training study found changes in rectus-femoris muscle architecture following reverse Nordic training, including increases in muscle thickness and cross-sectional area. However, this was a small study and should not be interpreted as proof that reverse Nordics prevent quadriceps injuries. See the published reverse Nordic training study.

More recent research found that reverse Nordic curls did not produce greater eccentric quadriceps activation than every bodyweight squat-based alternative. They are best viewed as a useful equipment-free accessory exercise rather than a universally superior replacement for squats, split squats or other leg training.

The exercise requires comfortable kneeling, substantial knee flexion and enough quadriceps strength to control the backward lean. Begin with a short range and use thick knee padding. Stop if you experience sharp knee pain, instability or an uncomfortable pulling sensation that does not improve when the range is reduced.

The reverse Nordic curl primarily trains the four muscles of the quadriceps femoris. The glutes and trunk muscles work isometrically to keep the hips extended and maintain a rigid body position.

Primary Muscles

• Rectus femoris: The rectus femoris crosses both the knee and hip. It controls knee flexion during the backward descent and extends the knee during the return while remaining lengthened across the extended hip.
• Vastus lateralis: The outer quadriceps contributes to controlling the descent and producing knee extension during the ascent.
• Vastus medialis: The inner quadriceps contributes to knee extension and helps control the position of the patella as the knee bends and straightens.
• Vastus intermedius: This deeper quadriceps muscle lies beneath the rectus femoris and assists knee extension throughout the repetition.

A reverse Nordic training study reported changes in rectus-femoris thickness, cross-sectional area, pennation angle and fascicle length after eight weeks of eccentric training. These findings support the exercise’s ability to train the quadriceps but do not establish that it is superior to all other quadriceps exercises. See the original rectus-femoris study.

Secondary and Stabilizing Muscles

• Gluteus maximus: The glutes contract isometrically to keep the hips extended and prevent the body from folding backward at the waist.
• Rectus abdominis and obliques: The abdominal muscles resist lower-back extension and help keep the ribs positioned over the pelvis.
• Spinal stabilizers: The muscles surrounding the spine maintain a controlled torso position while the body leans backward.
• Hip adductors and abductors: These muscles help keep the thighs parallel and prevent the knees from spreading apart or collapsing inward.
• Foot and ankle muscles: These muscles provide minor positional support depending on whether the toes are tucked or the tops of the feet rest on the floor.

The reverse Nordic curl is more knee-extension dominant than the split squat, which combines knee and hip extension. The sissy squat uses a related hips-extended pattern but adds balance, ankle movement and a standing base of support.