Welcoming a new baby into your family is an incredible, life-changing milestone. However, the physical toll of pregnancy, labor, and the newborn phase is often severely underestimated. While most mothers anticipate the sleep deprivation and the pelvic recovery, very few expect to wake up with creaky, unstable, and deeply aching joints.
If you find yourself wincing when you stand up from the rocking chair, or feeling like your knees might give out when carrying your baby down a flight of stairs, you are not alone. Postpartum joint pain is incredibly common. More importantly, it is highly treatable once you understand the biomechanics behind the ache.
Why Do My Knees and Joints Hurt After Having a Baby?
Postpartum knee and joint pain is rarely the result of a sudden, isolated joint injury. Instead, it is primarily driven by lingering relaxin hormones—which keep your ligaments loose and flexible for up to 5 to 6 months postpartum, and even longer if you are breastfeeding. When you combine this hormonal ligament laxity with weakened core and glute stabilizers, and the altered biomechanics of carrying a growing newborn, your joints are forced to absorb massive amounts of daily stress they are temporarily unequipped to handle.
The 3 Hidden Causes of Postpartum Joint and Knee Pain
Understanding why your joints feel so vulnerable is the first step toward reclaiming your strength. Our clinical team regularly identifies these three primary drivers of postpartum knee and joint dysfunction:
1. The Relaxin Effect on Ligament Laxity
During pregnancy, your body produces a hormone called relaxin, which loosen the ligaments in your pelvis to prepare for childbirth. However, relaxin does not only target the pelvis; it systematically affects every joint in your body, including your knees, ankles, and wrists.
Because ligaments act as the “duct tape” holding your joints tightly together, this hormonal laxity leaves your knees feeling loose and unstable. If you are breastfeeding, your body continues to produce relaxin, meaning this joint vulnerability can last well into your baby’s first year.
2. Glute Amnesia and Pelvic Tilt Shifting Load to the Knees
As your baby grows during pregnancy, your center of gravity drastically shifts forward. To compensate, your lower back arches, your pelvis tilts anteriorly, and your glute muscles essentially “turn off”—a phenomenon clinicians playfully call “glute amnesia.”
Your glutes are the primary stabilizers for your knees. When they are weakened and failing to fire correctly postpartum, your knee joints lose their structural support. Consequently, every time you take a step, the raw mechanical force bypasses the glutes and goes straight into the delicate cartilage and tendons of your knees.
3. Repetitive Strain from Nursery Ergonomics
New motherhood is an extreme endurance sport. You are repeatedly lifting a heavy car seat, bending over a low crib, rocking for hours, and sitting in awkward, asymmetrical positions to feed your baby.
This repetitive strain places a massive, localized burden on your lower body. Constantly relying on your knees to lift your baby from the floor, rather than using your core and hips, rapidly accelerates joint inflammation and leads to chronic aches.
5 Safe, Low-Impact Exercises for Postpartum Knee Relief
To eliminate postpartum knee pain, you must strengthen the muscles around the joint without overstretching your already-loose ligaments. Perform this gentle, low-impact routine 3 to 4 times a week to safely rebuild your lower body stability.
1. Supported Glute Bridges (with block/pillow squeeze)
This exercise reactivates your “sleeping” glutes while simultaneously engaging your pelvic floor and inner thighs.
- How to do it: Lie on your back with your knees bent and feet flat on the floor. Place a firm pillow or yoga block between your knees.
- The Movement: Squeeze the block gently. Exhale, engage your core, and push through your heels to lift your hips toward the ceiling until your body forms a straight line.
- Clinical Cue: Do not arch your lower back at the top. Squeeze your glutes, hold for two seconds, and slowly lower down. Perform 2 sets of 15 reps.
2. Straight Leg Raises with Quad Set
This isolated movement strengthens the quadriceps (the muscles on the front of the thigh) to help support the kneecap, without bending the knee joint and causing friction.
- How to do it: Lie on your back with one knee bent (foot flat on the floor) and the painful leg extended straight out.
- The Movement: Flex your toes toward your nose and tighten the thigh muscle of the straight leg (pressing the back of your knee firmly into the floor).
- Clinical Cue: Slowly lift the straight leg to the height of the opposite bent knee. Slowly lower it back down without fully relaxing the thigh muscle. Perform 2 sets of 12 reps per leg.
3. Wall Sits with Pelvic Floor Engagement (shallow depth)
Wall sits build immense isometric strength in your quads and glutes, providing immediate stability for your knees when you stand or walk.
- How to do it: Stand with your back flat against a wall. Step your feet about two feet away from the baseboard, keeping them shoulder-width apart.
- The Movement: Slowly slide down the wall into a shallow squat (do not drop your hips lower than a 45-degree angle).
- Clinical Cue: As you hold the position for 20 to 30 seconds, gently perform a Kegel (pelvic floor lift) and draw your belly button toward your spine. Repeat 3 times.
4. Clamshells with Neutral Spine
Clamshells target the gluteus medius, a crucial hip muscle that prevents your knees from caving inward when you walk or climb stairs.
- How to do it: Lie on your side with your hips and knees stacked and bent at a 45-degree angle. Rest your head on your lower arm.
- The Movement: Keeping your ankles glued together and your pelvis completely still, slowly lift your top knee open like a clamshell.
- Clinical Cue: Do not let your lower back roll backwards. The movement should be small and controlled. Perform 2 sets of 15 reps per side.
5. Sit-to-Stand with Chair Assistance
This functional movement trains your body to use your hips and glutes, rather than just your knees, when standing up with your baby.
- How to do it: Sit on the edge of a firm chair. Place your feet hip-width apart, slightly pulled back toward the chair.
- The Movement: Hinge your torso slightly forward at the hips. Push firmly through your heels and squeeze your glutes to stand straight up.
- Clinical Cue: Focus on keeping your knees tracking directly over your second toes (do not let them cave inward). Slowly reverse the motion to sit back down softly. Perform 2 sets of 10 reps.
Movements New Moms Should Avoid in the Early Months
While movement is medicine, the wrong kind of movement can severely exacerbate postpartum joint issues. Due to the presence of relaxin and reduced core stability, try to avoid the following until your doctor or physical therapist gives you the green light:
- Deep, Unweighted Squats: Dropping your hips below your knees places massive shearing force on the knee capsule. Keep squats shallow and controlled.
- High-Impact Plyometrics: Jumping jacks, box jumps, or heavy running send intense shockwaves through lax joints, risking acute ligament tears and pelvic floor strain.
- Aggressive Hamstring Stretching: Because your ligaments are hormonally loosened, aggressive static stretching can easily lead to overstretching and permanent joint instability. Focus on strength, not extreme flexibility.
Reclaim Your Strength with Intecore Physical Therapy
Joint pain should never simply be accepted as an inevitable “part of motherhood.” You deserve to care for your baby without wincing in pain every time you stand up or climb the stairs.
If your knees feel unstable, ache consistently, or interfere with your daily life as a new mom, it is time for a professional intervention. The women’s orthopedic and postpartum rehabilitation team at Intecore Physical Therapy is highly trained in navigating the unique biomechanical challenges of the postpartum body.
We invite you to step into one of our clinics for a personalized movement and pelvic-stabilization assessment. Our clinical experts will identify your specific imbalances and build a customized, safe recovery plan tailored to your lifestyle.
Contact us today to schedule an evaluation at our Aliso Viejo, Foothill Ranch, or San Juan Capistrano clinics, and let us help you find your strength again.
