Which exercise involves flexion from an erect position, typically with straight legs?

The exercise that involves flexion from an erect position, typically with straight legs, is the roll down. This movement starts with the individual standing or sitting tall, and it transitions to producing spinal flexion as the individual lowers their torso towards their legs. During the roll down, the engagement of the core is crucial to control the spine and pelvis as you move through flexion, ensuring the lower back does not lead the movement.

In this exercise, the straight legs align the body to facilitate a deeper stretch in the hamstrings and further articulate the spine as the person rolls down. This activity emphasizes proper spinal articulation and core stability, foundational elements in Pilates practice.