Hello everyone! This is Linnea, the pelvic floor physical therapist here at CSCM. Today, I would like to discuss the effects of hormones released during pregnancy and lactation on the musculoskeletal system. Certain hormones make structural changes to the skeleton to improve laxity during pregnancy and allow for delivery.
Relaxin
Relaxin is a hormone released during ovulation and continues to climb throughout pregnancy. Relaxin levels peak at about 12-14 weeks during pregnancy, and the hormone allows for relaxation of the uterus to prevent early labor and creates laxity in the blood vessels to accommodate increased blood volume. Relaxin also helps loosen structures around your pelvis to allow for delivery. Since relaxin is a hormone, it influences the entirety of the musculoskeletal system, resulting in decreased muscle tension and increased laxity in all ligaments, which can lead to weakness and pain in other structures, such as the lower back, neck, and shoulders.
Prolactin
Most people don’t realize that another essential hormone is released during lactation, which can also create continued changes in the musculoskeletal system during the postpartum phase. During lactation, your body releases prolactin, which also changes how the muscle loads tension, decreasing how efficiently the muscle recruits during contraction. What ends up happening is that most people who are lactating continue to feel weak and have increased difficulty with motor recruitment while lifting, squatting, and carrying, which are all activities that are completed while caring for an infant. As a result, a person can be at increased risk for injury during the postpartum phase between a combination of decreased musculature stability and an increase of repetitive motion coupled with poor sleep.
Strength Training
Understanding why your body might feel a certain way during pregnancy and postpartum is important. This knowledge can guide you in taking appropriate measures to improve function and reduce the possibility of injury. The exciting part is that strength training has been proven to reduce symptoms and pain severity. So, even though you can’t change these hormones, you can change how you feel! If you’re in the prenatal or postpartum population and want an individualized training program for a confident return to daily and recreational activity, check out our pregnancy programs at CSCM.
