The iliopsoas muscle, more commonly known as the psoas muscle, is the primary muscle that connects the spine to the legs. If the psoas muscle is tight or weak, it can cause strain in the lower spine, leading to back pain. Relief of back pain caused by the psoas muscle can be found through massage therapy, chiropractic treatment and trigger point therapy or by stretching and strengthening the psoas muscle.
The psoas muscle is attached to the bottom of the thoracic spine and top of the lumbar spine, and reaches through the abdomen to attach to the top of the top of the thigh. It is considered the primary hip flexor and helps to stabilize the lumbar spine. The iliopsoas is composed of three muscles: the psoas major, psoas minor and iliacus. Sitting shortens the psoas muscle and back bending lengthens it. Approximately 40 percent of people do not have a psoas minor muscle, which may be a result of modern sedentary lifestyles.
Because the psoas muscle shortens when you sit, sitting for long periods of time can cause the psoas to remain short, even during other activities. Short psoas muscles pull on the lumbar spine, increasing the lumbar curve and compressing the vertebrae. This compression can cause back pain. Back pain may also be caused by psoas muscle spasms, which occur when a weak psoas is overworked.
Back pain caused by the psoas muscle is usually a generalized aching in the lower back, which can spread to the hip region. Pain may be worsened by standing upright, twisting at the waist or by extending your leg while sitting. Back pain caused by psoas muscle spasms may appear gradually over a few days; back pain caused by a shortened psoas may appear as chronic acute back pain that worsens over time.
When a shortened psoas muscle compresses the lumbar spine, it can lead to degeneration of the intervertebral discs. This degeneration can lead to an increased risk of tears or bulging discs, and it can create pain in the sciatic nerve. If the psoas is tighter on one side of the body, your body may be slightly twisted to one side. Psoas spasms, which can cause lower back pain, may be caused by sacroiliac problems or intervertabral disease, which require longer professional treatment than regular psoas tightness.
Gentle stretching can help relieve back pain from psoas muscle spasms and help strengthen the psoas muscle to prevent and reduce lower back pain. Yoga poses such as One-Legged Pigeon (eka pada rajakapotasana), Wind-Relieving Pose (pavanamuktasana), Crescent Lunge (anjaneyasana), Warrior One (virabhadrasana 1) and Reverse Plank (purvottanasana) target the psoas and can help relieve lower back pain. Chiropractic and massage therapy techniques that focus on the psoas rather than the spine itself can relieve tightness and release the psoas for greater flexibility and relief of lower back pain.