Exercise guide
Side Plank Single Knee Drive
- Intermediate
- Compound
- Timed hold
- Lower legs
- Shoulders
- Upper legs
- Waist
This exercise combines lateral core stability with dynamic hip flexion to target the obliques, shoulders, and hip flexors. It improves functional core strength and pelvic stability by forcing the bottom side to stabilize while the top side moves.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Lie on your side with your forearm flat on the floor, elbow directly under your shoulder.
- Stack your feet or place the top foot slightly in front of the bottom foot for more stability.
- If using a wall, press the sole of your bottom foot against the baseboard to assist with balance.
- Lift your hips off the ground until your body forms a straight line from head to heels.
How to do it
- Exhale and drive your top knee toward your chest in a controlled motion, keeping your hips elevated.
- Inhale as you slowly extend the leg back to the starting position, maintaining a rigid torso.
- Maintain a steady tempo of 2 seconds for the knee drive and 2 seconds for the return.
- Complete all repetitions on one side before switching to the other side.
Form checklist
- Keep the elbow directly under the shoulder to avoid unnecessary joint strain.
- Ensure the hips remain stacked and do not rotate toward the floor during the knee drive.
- Keep the bottom hip pushed upward; do not let it sag as the top leg moves.
- Maintain a neutral neck position by looking straight ahead rather than at your feet.
Pro tips
- Actively push the floor away with your forearm to engage the serratus anterior and stabilize the shoulder complex.
- Squeeze the glute of the bottom leg throughout the set to keep the pelvis pushed forward and locked in place.
- Focus on 'crunching' the top oblique as the knee comes forward to maximize abdominal recruitment.
Make it harder
- Perform the exercise from a high side plank position (on your hand) to increase the stability demand on the shoulder.
- Add a 2-second pause at the peak of the knee drive to increase time under tension for the core.
Frequently asked
- What muscles does the side plank single knee drive work?
- The side plank single knee drive primarily targets the abs, deltoids, obliques, and pectorals, and also works the erector spinae and serratus anterior as secondary muscles.
- What equipment do you need for the side plank single knee drive?
- The side plank single knee drive requires no equipment — just your body weight.
- Is the side plank single knee drive good for beginners?
- The side plank single knee drive is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.
Related exercises
- 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals
- Bosu Ball Plank HoldIntermediate · abs, deltoids, obliques, and pectorals
- Explosive Dynamic PlankIntermediate · abs, deltoids, obliques, and pectorals
- Knee Tap Sky ReachIntermediate · abs, calves, deltoids, obliques, and pectorals