Diastasis recti is a separation of the abdominal muscles along the fascia line of the linea alba. The function of the line alba is to maintain the abdominal muscles at a certain proximity to each other. Diastasis recti commonly occurs during pregnancy as the abdominal muscular wall stretches and increases tension on the fascia whilst accommodating for the growing fetus. Other causes are high level abdominal training, obesity, inadequate abdominal muscle development (e.g. young children).
Normal width of the linea alba is considered to be 1.5cm at the xiphoid, 2cm above the umbilicus and 1.6cm below the umbilicus in nulliparous women. (Beer et al,2009). Rectus diastasis commonly occurs at the level of the umbilicus and up to 5-6 cm above that however variations can occur, (see diagram below.)
The abdominal wall consists of four muscular layers and has a large role in providing stability for the trunk and pelvis as well as support for the pelvic organs and maintaining bladder continence. In a recent study (Spitznagle 2007), 66% of women with a diastasis also experienced pelvic floor dysfunction (either urinary incontinence, painful intercourse or a loss of pelvic organ support.) As part of your post- pregnancy recovery it is important to learn how to strengthen your abdominal wall correctly to avoid low back, hip, or pelvic pain.
To test your rectus diastasis, lay on your back with your knees bent and feet on the floor, place your one hand behind your head and the other hand over your umbilicus (belly button). Curl your head and chest up off the floor. Move your finger side to side to feel the edges of the rectus abdominal muscle group then measure the gap by noting how many fingers needed to bridge the gap. (ie. half finger width, one – three finger width). A diastasis of 2-4 finger width is very common in the post-natal period even at 6 months post-natal.
All four layers of the abdominal wall need to be strengthened to improve the tension across the linea alba. Your Physiotherapist is trained to teach you how to correctly activate these muscles so there is a balance between the four layers to optimise tension across the linea alba. With correct recruitment patters, most women will be able to narrow their diastasis to normal limits. Pilates is a great form of exercise to improve core musculature.
Surgical correction is an option with persistent separation greater than 5cm at 18 months post natal or who have a separation between 3-5cm but are unable to achieve core control. The rectus abdominal muscle is brought back together with recti plication and then the loose skin is repaired with an abdominoplasty. The most common surgery uses non-absorbable suture (+/-mesh) to take the anterior rectus sheaths together. More recently the anterior and posterior sheaths are repaired and demonstrate to have a better result.
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