The psoas muscle, often pronounced “so-as,” is a deep core muscle that plays a significant role in movement and posture. It is a long, ribbon-shaped muscle that connects the lower spine (T12 to L5) to the top of the femur (thigh bone). This connection makes the psoas the primary muscular link between the torso and the lower body, helping to stabilize the core, flex the hip, and lift the upper leg. Because of its location and function, maintaining a healthy, relaxed psoas is integral to preventing discomfort in the lower back, hips, and pelvis. This muscle is frequently the source of tension, making it useful to understand which positions encourage its relaxation.
Why the Psoas Muscle Becomes Tight
The psoas muscle frequently develops chronic tension due to modern lifestyle habits. Prolonged sitting is a primary factor, as it keeps the muscle in a continuously shortened position, leading to stiffness and discomfort when standing or walking.
Another significant contributor to psoas tightness is its connection to the nervous system. The psoas has a deep link to the body’s protective “fight or flight” response. Emotional stress and anxiety can physically manifest as chronic tension in this muscle, causing it to tighten as a primal, defensive mechanism.
The Foundational Position for Passive Psoas Relaxation
The single most effective position for passively relaxing the psoas muscle is known as the Constructive Rest Position (CRP) or semi-supine position. This pose is designed to allow gravity to neutralize the pelvis and spine, releasing the habitual contraction of the psoas. The goal is complete stillness, which signals to the nervous system that the body is safe and can let go of tension.
To enter this position, lie on your back on a firm, flat surface with your knees bent and your feet flat on the floor. The feet should be placed parallel, about hip-distance apart, with the heels positioned approximately 12 to 16 inches away from the buttocks. This specific angle of knee flexion allows the pelvis to settle into a neutral position without the effort of muscle engagement.
For optimal release, the arms should rest by the sides, or gently on the stomach, and the head should be aligned with the spine. Because the skeletal structure is supported, the psoas is no longer required to work to maintain posture, allowing it to shorten slightly and relax. It is recommended to remain in this position for 5 to 20 minutes, breathing gently.
Gentle Movements and Supported Postures for Release
Once the psoas has had time to partially relax in the foundational position, gentle movements and supported postures can be introduced for a deeper, yet safe, lengthening. These techniques involve external support or slight muscular engagement, differentiating them from the completely passive nature of Constructive Rest.
Supported Bridge Pose
One beneficial method is the Supported Bridge Pose, which encourages lengthening without strain. To perform this, lie on your back in the semi-supine position, then lift the hips slightly and place a yoga block or firm cushion directly underneath the sacrum. Resting the pelvis on the support allows the front of the hips and the psoas to lengthen with gravity, without requiring active effort. Choose a block height that feels like a deep stretch but does not cause a sharp pull in the lower back or front of the hip.
Modified Half-Kneeling Stretch
Another helpful, supported posture is a modified half-kneeling hip flexor stretch, also known as a Low Lunge. Begin in a kneeling position and step one foot forward so the knee is directly over the ankle. The back knee remains on the ground, and the focus should be on tucking the pelvis slightly to maintain a neutral spine. This gentle pelvic tuck ensures the stretch is directed toward the psoas of the back leg, promoting lengthening in a controlled manner.