Lying Crunch (Straight Legs)
Lying Crunch (Straight Legs) Exercise Description
The Lying Crunch (straight legs) is a bodyweight trunk-flexion exercise that targets the rectus abdominis with the obliques assisting in stabilization. Extending the legs on the floor lengthens the lever, increasing the demand on lumbopelvic control while keeping the motion focused on the upper trunk. The movement occurs primarily through controlled thoracic flexion: you curl the ribcage toward the pelvis until the shoulder blades lift from the floor, while the hips and legs stay quiet. A gentle posterior pelvic tilt and light contact of the lower back with the floor help minimize hip motion and keep the effort on the abdominal wall. Proper execution emphasizes smooth, segmental curling rather than reaching with the chin or yanking the neck. Consistent form reinforces abdominal bracing, spinal alignment awareness, and precise control through a small, repeatable range of motion.
- Muscle Groups: Abs, Core, Waist
- Target Muscles: Rectus Abdominis
- Assisting Muscles: External Obliques, Internal Obliques
- Stabilizing Muscles: Multifidus, Quadratus Lumborum, Transversus Abdominis
- Body Area: Upper Body
- Body Parts: Core, Torso
- Body Surface: Front
- Body Symmetry: Other
- Equipment: Bodyweight
- Exercise Patterns: Other
- Exercise Type: Strength
- Functional Grouping: Trunk Flexors
- Joint Involvement: Single-joint
- Muscle Location: Stomach
- Movement Direction: Other
- Muscle Position: Anterior
- Gender: Male
How To Do The Lying Crunch (Straight Legs) Exercise
‘- Lie supine on a firm surface; extend legs together with heels on the floor and knees softly unlocked.
– Place fingertips lightly behind ears or cross arms over the chest; keep shoulders down and wide.
– Set the pelvis with a gentle posterior tilt so the lower back lightly contacts the floor; brace the abdomen.
– Keep the chin slightly tucked, gaze toward the ceiling, and maintain a fist-width space between chin and sternum.
– Exhale as you initiate the curl by drawing ribs toward the pelvis; lift head, neck, and shoulders until shoulder blades just clear the floor.
– Keep elbows wide if hands are behind the head; do not pull on the head or lead with the chin.
– Pause briefly at the top with steady tension; keep legs heavy on the floor and hips still.
– Inhale as you lower with control, returning the spine to the mat one segment at a time while maintaining the pelvic position.
Lying Crunch (Straight Legs) Tips
‘- Set up with legs extended together, heels on the floor, and knees softly unlocked before you start.
– Gently posteriorly tilt the pelvis so the lower back lightly contacts the floor, then brace the abdomen.
– Place fingertips lightly behind the ears or cross arms over the chest, keeping the shoulders down and wide.
– Keep the chin slightly tucked, gaze toward the ceiling, and maintain about a fist-width space between chin and sternum.
– Initiate the curl by exhaling and drawing the ribs toward the pelvis, lifting head, neck, and shoulders until the shoulder blades just clear the floor.
– Focus on curling through the upper trunk (thoracic flexion) while keeping the hips and legs quiet and heavy on the floor.
– If hands are behind the head, keep elbows wide and avoid pulling on the head or leading the movement with the chin.
– Pause briefly at the top with steady abdominal tension before lowering.
– Inhale as you lower with control, returning the spine to the mat one segment at a time while maintaining the pelvic position.
Lying Crunch (Straight Legs) Beginner Introduction
The Lying Crunch (straight legs) is a simple floor-based move that uses only body weight to challenge the abs while the side abs help steady the torso. With the legs stretched out along the ground, the body acts like a longer lever, so the center of the body and hip area work harder to control the lift. The action centers on a small curl of the upper spine, where the chest gently moves toward the hips and the shoulder blades rise slightly away from the surface, while the pelvis, hips, and legs remain settled.
Throughout the motion, the lower back rests softly into the floor with a mild rolling under of the hips, which directs the work into the front of the midsection rather than the legs. The neck and head travel as part of the trunk instead of leading the movement, promoting relaxed shoulders and reduced strain in the upper body. This exercise highlights deliberate, smooth rounding of the spine, steady abdominal tension, and consistent alignment awareness through a compact, repeatable range of motion.