Thank you for viewing! We will ship nationwide for free. No need to comment before purchasing, so if you like it, please purchase it as is. ✳️ The Role of the 3 Muscles Around the Waist and Their Relationship to Lower Back Pain The abdominal and back muscles related to lower back pain include the rectus abdominis, iliopsoas, quadratus lumborum, and erector spinae. When these muscles weaken or become stiff, the burden on the lower back increases, leading to pain. ❇️ Iliopsoas (chouyoukin) This is a deep inner muscle of the hip joint, a general term for the three muscles: the psoas major, iliacus, and psoas minor. It is a representative abdominal muscle. It is used when bending the waist forward, but if you are in a desk work-centered posture, the iliopsoas will shrink, causing swayback and pelvic distortion. The iliopsoas is a deep muscle, so it is considered difficult to approach with external massage. ❇️ Quadratus Lumborum (youhoukeikin) This is a rectangular muscle located deep in the lower back, supporting the lumbar vertebrae from both sides. It plays an important role in stabilizing posture. Since the quadratus lumborum is a symmetrical muscle, if its balance is lost, only one side of the lower back may hurt, or pain may occur when twisting the waist. ❇️ XL: Flat length approx. 112cm / Waist approx. 108-128cm ❇️ 2XL: Flat length approx. 112cm / Waist approx. 128-148cm ❇️ 3XL: Flat length approx. 112cm / Waist approx. 148-168cm ・ A support belt for the waist that firmly fixes and supports the lower back ・ Firmly supports the lumbar spine with 4 steel bones and a double belt ◎ ・ The waist area is made of breathable mesh fabric for excellent breathability ◎ ・ Comfortable even when worn for long periods ◎ New ✅ Standard mail ✅ Ships within 24 hours at the earliest ⚠️ Regarding Delivery ・ We will ship by standard mail or click post. ・ There is no tracking number. ・ We cannot ship on Saturdays, Sundays, and holidays because the post office is closed. ・ Shipping will be the day after the purchase and payment are completed. ※ We take care when photographing the colors and textures, but the colors and textures may look different depending on the smartphone you are viewing. Please make your own judgment based on the images. ⚠️ Made in foreign countries (*Although we measure by hand, there may be some errors or the size may be slightly smaller. Thank you for your understanding in advance.)