Criss-Cross — Both Knees Bent: A Complete Guide
Quick Intro
Criss-Cross — Both Knees Bent is a mat Pilates exercise performed curled up with the hands behind the head and both knees held in tabletop throughout, rotating the ribcage so one elbow reaches toward the opposite knee while both legs stay bent and stacked. Keeping both knees bent, with no leg extending out, is what makes this the easier way into Criss-Cross.
Equipment Needed
No equipment is required. A Yoga Mat underneath is an optional way to cushion the shoulders during the rotation.
Why It Matters
Holding both knees fixed in tabletop while the ribcage rotates asks for sustained abdominal effort and spinal mobility, plus the coordination to rotate the torso without disturbing the legs. The waist muscles along the side of the torso (obliques) drive the rotation from shoulder to opposite knee, and the abdominal muscles running down the front of the stomach (rectus abdominis) hold the curled-up position through every rep. A deep core muscle that wraps around the torso like a corset (transverse abdominis) keeps the movement controlled, and the deep hip flexor (hip flexors, iliopsoas) holds both knees fixed in tabletop throughout.
When to Do It
Criss-Cross — Both Knees Bent works well in the supine abdominal portion of a Pilates mat session, usually placed as the entry point before a leg extends into the full rotation. Two to three sessions a week is a reasonable pace for building this rotational pattern.
Anyone with a current lower back or neck issue should get individual guidance before adding this exercise, since a rotating torso loads the spine even with both knees bent.
Getting Ready
A few rounds of holding both knees in tabletop confirm the position feels stable before any rotation begins. A single slow rotation to one side, held briefly, previews the range the full set will use.
Step-by-Step Instructions
1. The setup. Curl up with the hands behind the head, both knees held in tabletop.
2. The rotation. Rotate the ribcage, bringing one elbow toward the opposite knee while both knees stay fixed.
3. The return. Bring the ribcage back to centre with control.
4. The switch. Rotate to the other side, repeating the same fixed-knee rotation.
How Many, How Often
Criss-Cross — Both Knees Bent is dosed by reps, with each rotation to one side counting as one.
| Level | Where you’re at | What to do |
|---|---|---|
| Beginner | New to keeping both knees fixed through the rotation | 2 sets of 6 to 8 reps per side, with a smaller rotation |
| Intermediate | The knees stay fixed through a fuller rotation | 2 to 3 sets of 8 to 10 reps per side |
| Advanced | Comfortable with a full rotation and steady tabletop legs | 3 sets of 10 to 12 reps per side |
The knees staying fixed in tabletop matters more here than how far the ribcage rotates, since legs that shift or sway to help the rotation trade oblique work for a bigger-looking twist.
Modifications and Variations
The step up from this version extends one leg on each rotation.
Compared to Criss-Cross, this version keeps both knees at a fixed 90-degree tabletop throughout, which lets the rotation be learned without the added coordination of a moving leg. Once the rotation feels smooth and controlled with both knees fixed, extending one leg gradually toward Criss-Cross’s full pattern is the natural next step.
Common Mistakes to Avoid
Letting the stationary knees drift or sway during the rotation. Allowing the tabletop legs to shift toward the rotating side, even slightly, borrows help from the hips that should be coming from the torso alone. Keeping both knees fixed leaves the rotation to the torso.
Letting the head lead the twist ahead of the ribcage. The head turning first, with the ribcage staying mostly square behind it, skips the spinal rotation this exercise depends on. The ribcage turns first and the head goes with it.
Pulling on the neck with the clasped hands. Using the hands behind the head to yank the torso around shifts the strain onto the neck when the obliques should be doing the driving. The hands should support the head lightly, not pull it through the movement.
After Your Set
Drawing both knees to the chest and holding for a few slow breaths settles the lower back after a set spent rotating with the legs held fixed. A slow neck rotation in each direction finishes releasing any tension the twisting motion left behind.
Going Deeper
This exercise usually works well as a way to build the rotational control the full extending-leg version needs, without the added coordination demand of a moving leg testing that control before it exists. The tabletop legs tend to start swaying toward the rotating side to make the twist feel bigger. Keeping the legs still, even if that means a smaller rotation, builds oblique strength faster than letting the legs assist.
Someone new to this exercise generally manages a smaller rotation with steady legs within a few sessions, then works toward a fuller rotation over two to three weeks.
How to Know You’re Improving
- Knees that stay fixed in tabletop through the whole rotation
- A rotation that comes from the ribcage, not the head or neck
- Hands that support the head lightly, without pulling it through the twist
- A rotation range that grows while the legs stay still
Legs that never sway to help the rotation matter more than how far the torso turns.
Muscles Worked
- Obliques (the waist muscles along the side of the torso, driving the rotation from shoulder to opposite knee)
- Rectus Abdominis (the abdominal muscles running down the front of the stomach, holding the curled-up position through every rep)
- Transverse Abdominis (a deep core muscle that wraps around the torso like a corset, keeping each rotation controlled from start to finish)
- Iliopsoas (the deep hip flexor, holding both knees fixed in tabletop throughout)
FAQ
Why keep both knees bent through the whole rotation? Holding both knees fixed in tabletop lets the rotational pattern be learned on its own, without the added coordination of a leg extending and returning with each switch.
When is it time to extend a leg? When the rotation feels smooth and controlled to both sides with the knees fixed, start extending one leg gradually toward the full Criss-Cross.
Is some oblique or hip flexor fatigue after this exercise normal? Yes, fatigue through the obliques and hip flexors after several reps per side is expected. Sharp pain that settles into the neck or lower back is a separate matter, worth a doctor or physical therapist’s opinion if it lingers.
Is it normal for the rotation to feel easier on one side? Yes, a control difference between the two directions is common. Matching the rep count on the harder direction to the easier one is a reasonable way to train that gap closed.
How often should the bent-knee Criss-Cross be practiced? Two to three times a week, as part of the supine abdominal portion of a broader mat session, is enough repetition to build this rotational pattern.
Related to Criss-Cross as the harder version that extends one leg on each rotation.