A crunch performed with the legs lifted, knees bent and ankles crossed. With the legs up the hip flexors can't help, so the upper abs do the curl.
Primary muscles
Secondary muscles
This information is general fitness guidance, not medical advice. Stop if you feel pain and consult a qualified professional.
Main muscles working (thicker lines)
Lie on your back with your ankles crossed, thighs raised to vertical and knees bent, and your arms crossed on your chest.
Brace your abs and press your lower back into the floor.
Curl your head and shoulders up toward your knees without moving your legs.
Pause at the top.
Lower slowly back to the floor.
Breathing: Exhale as you curl up, inhale as you lower.
Legs stay still
Ribs to hips
Lower back stays down
Rocking the legs toward the chest
Pulling with the neck
Dropping back down fast
Tuck your chin slightly to keep the neck relaxed.