Why Does My Back Still Hurt Months After Having a Baby?

Postpartum back and hip pain months after birth is common — but not something you're stuck with. A physiotherapist explains the causes and what helps.

Your baby is eight months old. You're sleeping in longer stretches. You've stopped counting weeks. And yet — the ache is still there. Low back, one side of your pelvis, maybe deep in a hip. It shows up when you stand up from the floor, when you've been carrying the baby on one hip, when you roll over in bed at 3am.

And somewhere along the way you probably decided this is just what your body is now.

I want to gently push back on that. Persistent back and hip pain after birth is extremely common — but common is not the same as normal, and it's definitely not the same as permanent. In most cases, this pain is a load problem, not a damage problem. Your body is being asked to do a great deal of lifting, bending, and one-sided carrying with a core and pelvis that haven't yet been retrained to share that load. That's a fixable setup.

Here's what's usually going on, and where to start.

Is postpartum back and hip pain normal?

It's very common. Research following women after pregnancy has found that pregnancy-related low back and pelvic girdle pain is still present for a meaningful proportion of women a year or more after birth — this is not a fringe experience, and you are not imagining it.

Most people do improve over the first few months. But "most people improve" is cold comfort if you're the one still hurting at month eight. The useful question isn't is this normal — it's what is still driving it, and what haven't I addressed yet?

Why did it start months after birth instead of right away?

This is the part that confuses people most, and it's the most important thing to understand.

In the first weeks postpartum, your world is small. You're sitting, feeding, shuffling to the kitchen. The demand on your body is low. Then, gradually, life scales back up — you're lifting a heavier baby, hauling a car seat, pushing a stroller up hills, picking up a toddler, going back to work, maybe returning to exercise.

The load goes up. But nobody ever restarted the capacity side of the equation. So the pain doesn't show up when the tissue is most vulnerable — it shows up months later, when demand finally overtakes capacity.

That's why "it came out of nowhere at seven months" is one of the most common stories I hear. It didn't come out of nowhere. It came from a gap.

What actually causes postpartum back and hip pain?

From a physiotherapy perspective, there are usually four contributors, and most people have more than one.

1. The pelvis and its joints changed shape and job description. Pregnancy hormones increase laxity in the ligaments supporting the pelvis and sacroiliac (SI) joints. Those joints then have to be stabilised more by muscle than by ligament — and if the muscles aren't up to it, you get that sharp, one-sided, deep-in-the-back-pocket ache.

2. The deep core isn't sharing the load. Your deep abdominal wall and pelvic floor are meant to work with your diaphragm as a pressure system that supports your spine. Studies of postpartum women have found reduced abdominal muscle thickness, endurance, and control persisting for months after birth. When that system is offline, your low back and hips take the shift.

3. Your daily positions are relentless and one-sided. Feeding hunched forward for 40 minutes. Baby parked on the same hip every time. Twisting to lift a 9-kg car seat out of a low car door with your arms out in front of you. Bending over a cot with a straight back and locked knees. None of these are dangerous once. All of them, thirty times a day, for months, are a training program — just not one you chose.

4. Sleep and stress are turning the volume up. Pain sensitivity genuinely rises with sleep deprivation and sustained stress. This isn't "it's all in your head." It's that the same tissue load hurts more when your nervous system is running on four broken hours.

Where do the pelvic floor and deep core fit into back pain?

More centrally than most people expect.

Think of your trunk as a canister: the diaphragm is the lid, the deep abdominals are the walls, the pelvic floor is the base. When you lift, that canister is supposed to pressurise and support your spine from the inside — before your back muscles ever have to grip.

After birth, that canister frequently isn't coordinating. The lid is stuck (shallow chest breathing), the walls are stretched and slow to switch on, and the base is either overworking or not responding in time. So every time you lift, the job defaults to whatever can do it — usually your low back extensors and the outside of your hips. They grip. They fatigue. They ache.

This is why back pain, leaking, and that "my core feels disconnected" feeling so often show up in the same person. They're the same system.

What can I change this week?

Small, boring changes to the load side pay off faster than anything else. Try these five:

1. Switch hips. If you always carry on the right, deliberately alternate. Set a rule: every second pick-up is the other side.
2. Bring the baby to you. Raise the change table, use a nursing pillow so you're not curling forward for 40 minutes, sit back into the chair rather than perching on the edge.
3. Lift with your legs and your breath. Before you pick up the car seat, exhale gently as you lift. That single cue helps the canister pressurise instead of leaving your back alone with it.
4. Practise diaphragmatic breathing, 5 minutes a day. Not as relaxation — as reconnection. It's step one of retraining the whole system.
5. Add one strength stimulus. A sit-to-stand from a chair, 10 reps, twice a day. Your hips and glutes need to be asked to work in a way that carrying a baby doesn't ask them to.

None of these are dramatic. That's the point. Persistent postpartum pain usually improves through consistent, unglamorous changes to how your body is loaded — not through one perfect stretch.

When should I see someone about it?

Please see a licensed provider where you live if any of the following apply:

• Pain that's severe, worsening, or waking you every night
• Pain with numbness, pins and needles, or weakness down a leg
• Any change in bladder or bowel control, or new saddle-area numbness
• Pain with fever, or that started with a fall or injury
• Pain that hasn't budged at all despite months of sensible self-management

And more broadly: a pelvic-health physiotherapist in your area can assess your pelvic floor, deep core, and hips together, which is exactly the combination that gets missed when back pain is treated as a back-only problem.

Frequently asked questions

Where to start

If you want the ordered plan — breathing, deep core, pelvic floor, then real-life load — that's exactly what the free 6-Week Postpartum Movement Roadmap lays out. It's the sequence I wish every mom was handed at her six-week check.

Written by Harleen Kalra, Registered Physiotherapist (BC, Canada).

This article is general education from a physiotherapist's perspective. It is not individualized physiotherapy advice, does not create a therapist-patient relationship, and is not a substitute for care from a licensed healthcare provider in your area. Harleen Kalra is a physiotherapist registered in British Columbia, Canada. For personalized assessment and treatment, please see a licensed pelvic-health provider where you live.