Core · Stability Ball
Leg Extension Crunch with Stability Ball
How to do the leg extension crunch with stability ball, the muscles it works, and the mistakes to avoid. Pulled straight from the Kovo app's exercise library.
- Equipment
- Stability Ball
- Difficulty
- Intermediate
- Logged as
- Weighted reps
- Movement
- Flexion
- Mechanic
- Isolation
How to do it
Sit on a stability ball and lean back so it supports your lower back, hands behind your head. Crunch your torso up while extending both legs out straight, then lower back and bend the knees in a controlled, combined motion.
- 1Your abs crunching as your shoulders curl up
- 2Your quads extending the legs out straight
- 3The ball supporting you while your core stays in control
Common mistakes
- Pulling on your neck to lift your head
- Letting the ball roll or your balance slip
- Swinging the legs out with momentum
Muscles worked
The leg extension crunch with stability ball mainly works the upper abs and lower abs, with the quads, hip flexors, and obliques assisting.
- Upper AbsPrimary
- Lower AbsPrimary
- QuadsSupport
- Hip FlexorsSupport
- ObliquesSupport
- Lower BackMinor
- HamstringsMinor
Kovo programs the leg extension crunch with stability ball for you and tracks it every session.
We build your whole program, drop the right lifts into each workout, and adjust your weights as you get stronger. Free on iOS and Android.
More abs & core exercises
- How to do the ab wheel rollout
- How to do the ankle tap plank
- How to do the ankle taps
- How to do the resistance band dead bugs
- How to do the resistance band pallof press
- How to do the rollout
Last reviewed June 2026.