The psoas muscle, often pronounced “so-as,” is a deep-seated muscle that significantly influences lower back and hip function. As a major hip flexor, it is frequently implicated in discomfort for those who spend long periods sitting or engaging in repetitive movements. Understanding how to properly lengthen this muscle is important for maintaining mobility and reducing undue strain on the spine. The following techniques provide practical, safe, and effective methods to target the psoas.
Understanding the Psoas Muscle
The psoas major muscle is unique because it is the only muscle that connects the upper body to the lower body. It originates along the sides of the last thoracic vertebra (T12) and all five lumbar vertebrae (L1-L5), then inserts into the lesser trochanter on the inside of the thigh bone. This anatomical path allows the psoas to perform its primary actions, which include flexing the hip joint and contributing to lateral movement of the trunk. The psoas also plays a role in stabilizing the spine and maintaining posture. When a person sits for extended periods, this muscle remains in a shortened position, which can lead to chronic tightness over time. This consistent shortening can contribute to issues such as lower back pain or hip stiffness, making targeted stretching beneficial for restoring its intended length and function.
Step-by-Step Psoas Stretches
Kneeling Hip Flexor Stretch
Begin this stretch in a half-kneeling position, with one knee resting on a soft surface and the opposite foot flat on the floor directly in front of the hip. Ensure the front knee is positioned at approximately a 90-degree angle, with the ankle aligned directly beneath the knee joint. The goal is to lengthen the psoas on the side of the back knee.
To maximize the stretch and protect the lower back, slightly tuck the pelvis underneath you and consciously squeeze the gluteal muscle of the back leg. This action prevents the lower spine from arching excessively, a common error that reduces the effectiveness of the stretch on the psoas. Once the pelvis is stabilized, gently shift the hips forward a minimal distance until a deep sensation is felt in the front of the hip and thigh of the trailing leg. The intensity of the stretch should be controlled by the forward hip shift and the strength of the gluteal contraction, not by forcing the body into an uncomfortable position.
To deepen the stretch further, raise the arm on the side of the kneeling leg straight overhead, gently leaning the torso away from the kneeling hip. Hold the position steady before slowly returning to the start and repeating on the other side.
Supine Psoas Release
This variation uses gravity and a stable surface to achieve a passive, gentle lengthening of the muscle. Lie on your back on a firm surface, positioned so that one leg hangs completely off the edge. The leg remaining on the surface should be bent, with the foot flat, or pulled toward the chest to help flatten the lower back against the surface.
The leg dangling off the side should hang relaxed and straight, allowing gravity to gently pull the hip into extension. The sensation should be felt along the front of the hip of the dangling leg, but should not involve sharp pain in the lower back or groin. This stretch is a good option for those with limited mobility or who find kneeling difficult.
Ensuring Safe and Effective Stretching
Proper form is paramount to ensure the stretch targets the psoas muscle without causing strain or injury to the lower back. The most frequent error is allowing the lumbar spine to arch, which can result from pushing the hips forward too aggressively without engaging the core and glutes. Actively engaging the glutes and tilting the pelvis posteriorly is required to stabilize the spine and direct the stretch to the hip flexor insertion point.
When performing any static stretch, a sustained hold time is necessary for the nervous system to allow the muscle to lengthen effectively. Holding each stretch for a minimum of 30 to 60 seconds is generally recommended to engage the stretch reflex mechanism within the muscle. Avoid bouncing or pulsing movements, as this can trigger the muscle’s protective reflex, causing it to contract instead of relax and lengthen.
For maximum benefit, incorporating psoas stretches into a routine multiple times a week or even daily is suggested, particularly for individuals who sit for long durations. If any stretch produces sharp, radiating, or excessive pain, the position should be immediately released and the movement should not be forced. Using props, such as a rolled towel under the kneeling knee or a chair for balance, can modify the stretch to accommodate differing mobility levels while maintaining correct, safe alignment.