What muscles are typically weak in a person with sway back posture?

In individuals with sway back posture, there is often a specific muscular imbalance that leads to the characteristic alignment of the spine and pelvis. Typically, those with sway back posture exhibit weakened abdominal muscles, particularly the rectus abdominis and other core stabilizers. This weakness contributes to the excessive anterior pelvic tilt and lordosis in the lumbar spine, as the abdominal muscles are not adequately supporting the pelvis and lower back.

Additionally, the upper back extensors may also be weak, which can lead to a forward position of the shoulders and upper body. This further exacerbates the sway back alignment since those muscles are responsible for maintaining an upright posture in the thoracic region. Therefore, the combination of weak abdominals and upper back extensors is a hallmark of this postural condition. This insight into muscle weakness is crucial for designing effective interventions in Pilates, focusing on strengthening these areas to improve overall stability and posture.