The Muscles that Support the Pelvis
What if I told you that you could exercise to prepare your body for labor, and that helping your baby find an optimal position for birth begins during pregnancy? If we understand what muscles support the pelvis and influence it’s movement, we can ensure that we focus our fitness programming on ensuring these muscles are balanced.
Baby’s will go where there is space, as fetal positions are not random. If the muscles on one side of the pelvis are tighter or overlengthened compared to the other side, it influences the shape of the pelvis, and can change the shape of the space available for the baby.
Let’s focus on the lower body musculature that supports the pelvis and influences it’s movement.
The lower body has multiple muscles that attach to the pelvis and influence it’s position/movement capability. The main muscles are the: glutes, quads, hamstrings, adductors, hip flexors, and pelvic floor. Let’s break these down in more detail along with the function of each of these muscles with exercise examples.
The Glutes
The glutes attach on the posterior and lateral side of the pelvis. There are three components to the glutes: max, med, and min. The tensor fasciae latae (TFL) is also a component of the gluteal group.
The main function of the glute max is external rotation and hip extension. The glute med and min work together for thigh abduction, internal rotation, and pelvic/hip stability. The glute max is what turns on for squats and hip thrusts. The glute med/min are what turn on when you do a single leg movement to help stabilize your hip.
Usually, the right glute is a little weaker than the left side, so focusing a few extra reps on the right, or adding resistance bands to emphasize the right external rotation could also help.
Hip thrusts can be modified throughout pregnancy to support strengthening of the glutes!
The Quads
The quads consist of four muscles: rectus femoris, the vastus lateralis, the vastus medialis, and the vastus intermedius. The rectus femoris is the only of the four that cross both the hip and knee joint and influences movement at both joints, while the other three only cross the knee joint. The quad muscles are responsible for hip flexion (rectus femoris only) and knee extension. Tight quad muscles would pull the pelvis into an anterior pelvic tilt.
Exercises that would strengthen the quads would include the eccentric portion of squats (lowering) and the concentric portion of squats (raising) and lunges.
The Hamstrings
The hamstring group consists of three muscles: bicep femoris, semitendinosus, and semimembranosus. The hamstring group contributes towards hip extension, knee flexion, and stabilizes the pelvis. The hamstring group contributes towards internal rotation of the hip except for the bicep femoris which contributes towards external rotation at the hip. Tight hamstrings would pull the pelvis into a posterior pelvis tilt. The hamstring is more activated in hinge motions (deadlift or kettlebell swings). Focus on both feet being parallel and roughly hip distance (widen the stance and externally rotate in the feet as belly grows). A helpful cue is to focus on pushing the butt towards the wall behind you and keep the shins relatively vertical.
We may find that the left hamstring and adductor are weaker than the right side, so emphasizing asymmetrical movement could be helpful.
Understand how to approach training clients throughout pregnancy, prepare for birth, and then recover in the postpartum as they return to fitness!
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The Adductors
The inner thigh consists of the following muscles: pectineus, adductor magnus, adductor minimus, adductor longus, adductor brevis, and gracilis. The adductors bring the legs together (adduction), contribute towards hip flexion, and stabilizes the pelvis. When feeling pelvic pain, sometimes activating the adductors (such as, a ball squeeze between the thighs) helps to stabilize the pelvis and decrease pain. The adductors tend to get weaker throughout pregnancy as women tend to move towards a widen stance and external hip rotation. Exercises that would strengthen the adductors include Copenhagen plank, squats, and movements that involve side lunges, squeeze a ball between the thighs or lateral resistance at the thigh.
The adductors play a large role in helping us find internal rotation, which is key for labor preparation! Internal rotation helps us create more space in the lower midpelvis and outlet.
Hip Flexors
The hip flexors include: the psoas major/minor and iliacus, and contribute towards hip flexion. The hip flexors, particularly the psoas run posterior to the uterus, runs over the pubic bone, and attaches to the femur. If these muscles are tight, it tends to cause the pelvis to move into an anterior tilt, and restrict space in posterior portion of the uterus (usually more on one side than the other). Exercises that strengthen the hip flexor include: banded bridge marches and step ups with balance.
Pelvic Floor
The pelvic floor includes a lot of different muscles (levantor ani and coccygeus), ligaments, and fascia in a several layers. The piriformis and obturator internus are near the pelvic floor but not included in the muscle group. These muscles support external hip rotation and hip stability. The pelvic floor is similar to a trampoline; it energetically lengthens and loads and then bounces back upwards or contracts. The pelvic floor supports the pelvic organs, aids in continence (preventing leakage), and aids in childbirth. If the pelvic floor is tight, it can cause functional issues and make childbirth more difficult, as baby needs to push their way through a tight muscle. If the pelvic floor is weak, it can cause functional issues, such as leakage or pelvic organ prolapse.
Exercises that help strengthen the pelvic floor include kegels coordinated with diaphragmatic breathing.
Diaphragmatic breathing is also a great way to help learn to relax the pelvic floor. The pelvic floor is a part of our deep core and helps to stabilize our spine along with the other components of our deep core (diaphragm, transverse abs, obliques, and multifidus). We need to learn how to coordinate this component with the entire system for it to be effective for function and childbirth.
Watch our breathing drill that helps coordinate the pelvic floor with the rest of the deep core.