Core stability in crook with opposite elevated LL and UL extension (Core/pelvic floor stabilization, lifting arm overhead/extending opposite leg, lifted, supine, feet standing)

Lie on your back with your legs bent and feet flat on the floor.
Ensure your feet and knees are hips width apart.
Tighten your abdominal and pelvic floor muscles, and then lift one leg just off the floor.
Slowly straighten your leg out ensuring it remains off the floor.
Simultaneously lift your opposite arm up and stretch it above your head.
Ensure you keep your body and hips level throughout this movement.
Control the movement as you slowly bring your arm and leg back up to the starting position.
Repeat this movement with the other opposite pair.