How the Single-Leg Hip Extension Hamstring Curl Can Help Build Injury-Resistant Legs

When it comes to building strong, muscular hamstrings, most lifters perform heavy RDLs or leg curls variations, often neglecting the fact that bodyweight exercises can still pack a hamstring punch.

However, resistance is resistance, whether it’s from a dumbbell or the pull of gravity. Your hamstrings don’t care about the type of resistance you’re using. They respond to tension, resistance, and movement quality—and the single-leg hip extension hamstring curl on a stability ball delivers all three in spades.

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This challenging bodyweight move combines hip extension and knee flexion, demanding your glutes and hammies work together while your core keeps it tight. Whether you’re training at home, rounding out a lower-body day, or looking to enhance your posterior, this move deserves a spot in your workout rotation.

Let’s dive in.

What is the Hip Extension Hamstring Curl?

The single-leg hip extension hamstring curl is a bodyweight exercise performed on a stability ball that combines two movements: hip extension and knee flexion—both primary functions of the hamstrings. Many hamstring exercises train just the curl, but this variation starts with a hip extension and finishes with a hamstring curl.

One foot is on a stability ball, then you drive your hips up and curl the ball toward your glutes using your hamstring. It’s a move that trains your glutes, hamstrings, and core simultaneously, while you fight instability.

Next, let’s learn how to perform this exercise with good form.

How To Do the Hip Extension Hamstring Curl

1. Begin by placing one foot on the stability ball, then bend the other knee and bring it toward your chest.
2. Activate your working glute to keep a neutral lower back position.
3. Perform a single-leg hip extension, pause, then curl the ball towards you till your foot is flat on the ball and your body forms a straight line from hips to shoulders.
4. Perform an eccentric hamstring curl, lower your hips to the floor, then reset and repeat.

Hip Extension Hamstring Curl Benefits

When your hamstrings are burning and you wish the set were over already, keep these benefits in mind to remember how beneficial this exercise is for you.

Runner Friendly

The combination of hip extension and knee flexion in a single movement mirrors the mechanics of a running stride. You’re not just building hamstring strength—you’re training the glutes and hamstrings to activate together, exactly as they should during running.

Mimics Actual Instability

Unlike machines, the stability ball creates a shifting surface, similar to the unpredictable terrain of roads, trails, or tracks. Every rep requires you to stabilize against rotational and lateral drift—much like what happens with every foot strike. This instability teaches the hamstrings to be reactive and resilient, reducing injury risk and improving stride efficiency.

Glute-Hamstring Coordination

Weak glutes and hamstrings are a recipe for injury and reduced performance with any exercise involving these two muscles. This move requires both muscles to contract in harmony, raising the hips and pulling the ball in. That neuromuscular coordination enhances your ability to stabilize the pelvis under fatigue and stress.

Injury Prevention

Hamstring strains don’t occur during concentric knee flexion; they happen when the muscle lengthens during the eccentric contraction. Studies show that eccentric knee flexor exercises like this lower the risk of hamstring strains by improving eccentric knee flexor strength and increasing the length of the hamstrings.

Common Hip Extension Hamstring Curl Mistakes and Fixes

It’s easy to lose focus, especially when there isn’t any weight. However, doing so would be a mistake because tension and focus drive this exercise.

Sagging Hips

As fatigue sets in, lifters often lose hip extension while curling the ball in, which reduces tension on the glutes and hamstrings—and defeats its purpose.

The Fix: Keep your glutes tight throughout and think about driving your hips toward the ceiling as you curl. If you can’t maintain hip height, regress to the two-leg version until your strength improves.

Unnecessary Rotation

The combination of instability and training one side at a time can cause loss of control and twisting of the hips. This mistake compromises the movement and overloads one side of the lower back.

The Fix: Keep your torso square and core braced. The non-working leg should stay in line with the hips, not flailing off to the side. Imagine balancing a glass of water on your pelvis—don’t let it spill.

Rushing It

I get it. The exercise is challenging, and you’re getting tired. Then it becomes a tendency to speed through reps to survive the burn, using momentum instead of muscle.

The Fix: Slow down. Use a 2-second curl and a 3-second lowering. The slower you move, the more time under tension you create—which is key for muscle and strength.

How To Program the Hip Extension Hamstring Curl Into Your Routine

The single leg hip extension hamstring curl works well as an accessory exercise on lower body days or as part of a core circuit. Here are the set and rep suggestions for strength and muscle.

• For Strength: 4 sets of 6 reps per side, focused on controlled eccentrics and maximum hip engagement.
• For Bigger Muscle: 3 sets of 8-12 reps per side, adding a 2-second squeeze at the top of each curl to increase time under tension.