1. Lay on your side on a soft workout surface with your upper hand resting lightly behind your head, and your legs straight out below with one leg on top of the other
2. As you exhale, contract your oblique muscles to bring your head and shoulders toward your hip on the corresponding side
3. Simultaneously lift your legs upwards to increase the flex
4. After reaching a solid contraction, slowly relax your oblique muscles and return to the starting position to complete one rep
The primary muscles used in Oblique Jackknife Crunches are the Abs and Obliques.