Side Jackknife
Side Jackknife is a strength - lateral torso-and-leg tuck exercise involving Internal and external obliques. Use these steps to learn the movement and work with your coach to choose a suitable level.
Last updated: · DynPerformance
- Primary muscles
- Internal and external obliques
- Secondary muscles
- Gluteus medius, Hip adductors, Iliopsoas
- Exercise type
- Strength - lateral torso-and-leg tuck
Exercise technique
- Position
Lie on your side with your legs extended and stacked.
- Lower arm
Establish light floor support with your lower forearm or palm.
- Upper hand
Hold your upper hand beside your head or reach it toward your legs.
- Tuck
Lift your upper torso and both legs toward each other.
- Emphasis
Shorten your side abdominals by bringing your ribs toward the upper hip.
- Pause
Balance briefly under control on the side of your hip.
- Return
Lower your shoulder and legs slowly, then switch sides.
Key technique points
- Stay in the side plane.
- Move both legs together.
- Use only light assistance from the lower hand.
- Do not pull on your neck.
- Exhale as you close.
- Bend your knees to reduce the range if needed.
Common mistakes
Rolling onto the back
Do not turn the side tuck into a standard V-up.
Pushing with the arm
Do not raise your torso through lower-arm strength and reduce the oblique load.
Swinging the legs
Do not turn the tuck into a momentum-driven side kick.
Pulling the head
Do not use your upper hand to force your neck toward your legs.
Landing hard on the hip
Do not finish the return without braking.
Separating one leg
Do not disrupt balance by opening the two-leg alignment without control.
Frequently asked questions
Side Jackknife: why is “Rolling onto the back” a mistake?
Do not turn the side tuck into a standard V-up.
Side Jackknife: why is “Pushing with the arm” a mistake?
Do not raise your torso through lower-arm strength and reduce the oblique load.
Side Jackknife: why is “Swinging the legs” a mistake?
Do not turn the tuck into a momentum-driven side kick.
Side Jackknife: why is “Pulling the head” a mistake?
Do not use your upper hand to force your neck toward your legs.
Side Jackknife: why is “Landing hard on the hip” a mistake?
Do not finish the return without braking.
Side Jackknife: why is “Separating one leg” a mistake?
Do not disrupt balance by opening the two-leg alignment without control.
What should I focus on when doing Side Jackknife?
Stay in the side plane. Move both legs together. Use only light assistance from the lower hand. Do not pull on your neck. Exhale as you close. Bend your knees to reduce the range if needed.
Related exercises
- Band Pallof Press
- Bicycle Crunch
- High-to-low Cable Woodchop
- Short-lever Copenhagen Plank
- Alternate Heel Touchers
- Exercise Guide
Add this exercise to your program with your coach
If you have a health condition, consult a qualified professional.