What is the primary muscle focus of the Flat Back exercise in the Short Box Series?

The primary muscle focus of the Flat Back exercise in the Short Box Series is indeed on the abdominal muscles and back extensors. This exercise is designed to improve core stability while also engaging the spinal extensors, which helps in maintaining an upright posture throughout the movement. The abdominals work to stabilize the pelvis and lower back as the torso moves into a flattened position, promoting awareness of spinal alignment and core activation. Simultaneously, the back extensors are activated to support the torso and counterbalance the actions of the abdominals, ensuring that both muscle groups work in harmony to control movement and support the spine. This dual focus on the abs and back extensors is essential for building overall core strength, which is a key benefit of this particular exercise within the Pilates framework.