A single-leg knee-extension that straightens one leg at the knee to load the quadriceps. It isolates the working thigh to train the quadriceps unilaterally.
How to do the Stability Ball Single Leg Extension#
- Sit upright with the working knee bent about 90° and your torso braced.
- Keep your thigh still and tighten your core to prevent the hips from shifting.
- Extend the knee by straightening the leg until it is nearly straight, avoiding a hard lockout.
- Lower the leg slowly and under control back to the starting bend.
- Complete the prescribed reps, then switch to the other leg.
Muscles worked#
- Primary: Quads (Quadriceps Femoris)
- Secondary: Abs (Rectus Abdominis), Hip flexors (Iliopsoas (Hip Flexors))
Common mistakes#
- Using momentum to swing the lower leg instead of controlled extension.
- Locking the knee at the top of the movement.
- Allowing the hips or thigh to lift or shift during the rep.
- Dropping the leg quickly on the eccentric phase.
