Which muscles are primarily responsible for trunk flexion?

The muscles primarily responsible for trunk flexion are the rectus abdominis, internal oblique, and external oblique. The rectus abdominis, known as the "six-pack" muscle, plays a major role in flexing the spine forward. The internal and external obliques assist in this flexion while also contributing to lateral flexion and rotation of the trunk.

Understanding the function of these muscles is important for assessing core strength and stability, which are crucial in various physical therapy interventions and exercises. The strong engagement of these muscles during trunk flexion makes them essential for movements such as sitting up from a supine position or performing abdominal exercises. They work synergistically to allow for efficient movement and stability of the trunk during various activities.