Roll Up
Plane of Motion
Sagittal
Muscle Focus
Spinal Flexors
Rectus Abdominis, External Oblique, Internal Oblique
To flex the spine when rolling up & down.

Other Muscles at Play
The transversus abdominis aids with control through articulation.
Spine extensors receive a stretch when over the legs and stack the spine when sitting tall.
Hip flexors assist with rolling up and flexing over the legs.
Hip extensors aid in creating length through the legs and an anchor to the floor.
Dorsiflexors flex the feet.
Shoulder flexors resist gravity when holding the arms during the roll up/down and move the arm up overhead.
Shoulder extensors help anchor the shoulder down and move the arm down from overhead.
Scapular depressors stabilize the scapula and shoulder throughout the entire exercise.
Elbow extensors keep the arm straight and reaching long.
Objectives
The deeper core, spinal flexors and abdominals are strengthened while focusing on the deep internal connections from the inner thighs and pelvic floor up to the sternum to improve pelvic stability and spinal mobility and flexibility.
Stretches and lengthens the posterior chain from head to heel.
This exercise requires substantial core strength and should first be introduced in a modified version (half roll up) until the client can fully activate the entire core, avoiding back strain.
The lower back is imprinted while the pelvic remains in neutral to ensure a strong connection to the core. Cueing to work from the pelvic floor muscles helps to provide lumbo-pelvic stabilization.
Focus on breathing to synchronize the movement.