Regaining coordinated function of the deep trunk muscles requires effort! The muscles do not just snap back post birth.Genetic differences in connective tissue, weight gain, sustained stretch of abdominal muscles and hypertension of the back muscles affect recovery of the body post childbirth.
First, each component of the deep intrinsic trunk muscle synergy usually must be facilitated. In order for the muscles to work efficiently and effectively, women are able to exercises better if they understand the anatomy and physiology of muscles. Often one muscle can enhance other muscles in performing a functional task. For instance, when contracting the pelvic floor muscles with a sequential contraction of the deep abdominal muscle, the contraction of the pelvic floor muscles is greater in motor units recruited and endurance. These two muscle groups create stability of the pelvis.
The four components of the deep trunk muscle synergy are the transversus abdominis, deep back paraspinal muscles ( spinalis, longissimus, and iliocoastalis), superficial and deep pelvic floor muscles, and the diaphragm. First, the pelvic floor muscles are composed of 70% deep, and 30% superficial. They often work in concert, supporting the pelvic organs and reducing the size of the pelvic outlet offering more integrity of the pelvis. One component of the abdominal muscles offers approximation of the two side of the pelvis in the anterior portion of the body. The abdominals and deep back muscles perform lumbar stabilization when contracted. Intra-abdominal pressure increases when a person holds their breath causing the muscles of the pelvic floor and abdominals to work more intensely at first. However, fatigue occurs and less support of the organs and skeletal structure is offered from the muscles.
Individualized deep intrinsic trunk muscles exercises can be developed by a women’s health physical therapy specialist after an assessment of the postpartum woman is done. Exercises are based on posture alterations, abdominal strength and integrity, pelvic floor muscle strength and endurance, with consideration of any comorbidities such as incontinence of bowel or bladder, prolapsed pelvic organs, back pain including sacroiliac joint dysfunction. Individual exercises are started for all components of the synergy starting with proper breathing, especially exhalation with execution of a contraction.
Next, the basic pelvic floor contractions, quick flicks of the superficial muscle fibers, and long holds of the deep diaphragm will be started. As soon as these two muscle groups are performing the correct contraction, short lever arm or leg movements are added to the base of the pelvic floor and abdominal co-contractions. As the postpartum woman is able to progress, the exercises are made to be more challenging with longer lever arms of resistance in different positions such as quadruped versus prone or supine. In addition, functional carry over is always addressed with ergonomics and correct integration of deep intrinsic trunk synergy.
Correct rehabilitation and recruitment of the deep intrinsic trunk muscles will support the spine and pelvis. Due to pregnancy hormones continuing to circulate for three months post birth or at the completion of breast feeding, the ligaments are loose; therefore, requiring even more coordinated, strong, good endurance and well timed muscle function to prevent back and pelvic pain.