Lie on your back on the Reformer with your head supported and feet hip-width apart on the foot bar (heels or balls of feet, as prescribed).
Keep your arms relaxed by your sides, palms down.
Inhale to prepare. As you exhale, press through your feet and peel your spine off the carriage, lifting into a bridge until shoulders, hips, and knees are in line.
Maintain your hips in this lifted position.
Inhale and press the carriage away by straightening your knees into a leg press while keeping hips stable and lifted.
Exhale and bend the knees to bring the carriage back in, still holding the bridge.
After completing the desired press, lower your spine back to the carriage one vertebra at a time.
Complete repetitions as prescribed by your physiotherapist.