Exercise guide
Straight Arm Double Knee Drive
- Beginner
- Compound
- Timed hold
- Hips
- Lower legs
This standing core exercise combines explosive hip flexion with a torso crunch to target the abs and obliques while improving balance and glute stability. It is a dynamic compound movement that builds functional core strength and coordination without requiring equipment.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Stand tall with your feet hip-width apart and your core engaged.
- Extend both arms straight overhead, reaching toward the ceiling with palms facing forward.
- Shift your weight onto your left leg and extend your right leg back, resting only your toes lightly on the floor.
How to do it
- Exhale and explosively drive your right knee toward your chest while swinging your straight arms down in a wide arc to meet your thigh.
- Inhale and quickly tap your right toe back to the starting position, then immediately perform a second powerful knee drive on the same side.
- Switch your weight to the right leg and repeat the double knee drive sequence with the left leg.
- Maintain a brisk, rhythmic tempo, ensuring each drive is performed with maximum intent.
Form checklist
- Keep a slight bend in the standing knee to maintain balance and joint safety.
- Avoid rounding the lower back; focus on crunching the ribs toward the pelvis.
- Keep your chest lifted and avoid collapsing your shoulders forward during the arm swing.
- Ensure the standing foot remains flat and rooted to the floor throughout the movement.
Pro tips
- Visualize breaking a branch over your knee to increase the mind-muscle connection and the intensity of the abdominal contraction.
- Squeeze the glute of the standing leg hard to create a stable base and improve hip extension on the trailing side.
Make it harder
- Hold a light medicine ball or a single dumbbell with both hands to increase the rotational and vertical resistance.
- Incorporate a small hop on the standing leg during each knee drive to turn the movement into a high-intensity plyometric exercise.
Frequently asked
- What muscles does the straight arm double knee drive work?
- The straight arm double knee drive primarily targets the abs and obliques, and also works the adductors and hamstrings as secondary muscles.
- What equipment do you need for the straight arm double knee drive?
- The straight arm double knee drive requires no equipment — just your body weight.
- Is the straight arm double knee drive good for beginners?
- Yes. The straight arm double knee drive is a beginner-friendly movement and a strong foundation to build on.