Red, Bruised or Dark Knees From Crawling: What's Normal and What Helps

Red, bruised or dark knees are common once babies start crawling, and they're usually harmless: most bruises fade in about 2 weeks. Call your pediatrician if a bruise isn't improving by then or bruises keep appearing for no clear reason. For babies under 1, the American Academy of Pediatrics' symptom checker advises calling about any cut, scrape or bruise.

Knees and shins take a lot of knocks once your baby is on the move. As researchers at Cardiff University put it, accidental bruises are most likely over bony spots "such as knees and shins," and on the front of the body.

Is it normal for babies' knees to bruise when crawling?

Yes. Bruises become more common as babies get moving, and the lower legs are where they show up most.

In the Cardiff study, parents of 328 young children checked them for bruises once a week for up to 12 weeks. At least one bruise turned up in 45.6% of the weekly checks on babies who were crawling or cruising, compared with 6.7% of checks on babies who weren't crawling yet. The most common spot at every stage was below the knees.

Those rates ran higher than in earlier studies, which the researchers say may be partly because parents recorded even faint bruises. Either way, a bruise on the knee or shin of a crawling baby fits the usual pattern. Where bruises show up, and how often, tells you more than any single bruise.

Do babies' knees hurt when they crawl?

They can be sore if there's a bruise or a scrape. Your baby can't tell you, so watch how they react. KidsHealth's guide to bruises describes a bruise as "tender to the touch," so fussing when the spot is touched is a clue.

To ease a fresh bruise, KidsHealth suggests a cold pack wrapped in a towel, which can help keep bruising and swelling small.

A baby who can't move the leg is a different story. KidsHealth says to call the doctor if a child can't move a joint or you think a bone may be broken.

If hard floors are your worry, we looked at whether crawling on hardwood hurts babies.

Red knees or bruised knees? How to tell

Red, rough patches right where the knee meets the floor point to friction or rug burn, and our guide to baby knees red from crawling covers how to soothe them.

A bruise is blood from tiny damaged blood vessels trapped under the skin. It can look reddish at first too, so the tell is what happens next. According to KidsHealth, a bruise usually fades in about 2 weeks, changing color as the body breaks down and reabsorbs the blood:

• At first: reddish.
• Within 1 to 2 days: bluish-purple or even black.
• After 5 to 10 days: green or yellow.
• After 10 to 14 days: yellow-brown or light brown, before it fades.

Why are my baby's knees dark from crawling?

Three things can make a crawling baby's knees look dark: floor dirt, a bruise, or skin that stays darker after it's been irritated. Each one looks a little different.

Floor dirt

Crawling knees pick up whatever is on the floor. If the gray or black tint washes off in the bath with a soft washcloth, that's all it was.

A bruise

A fresh bruise can look bluish-purple or even black within a day or two. Over the next 2 weeks it moves through green or yellow to light brown, as in the timeline above.

Darker skin after irritation

When a rash or irritated patch heals, the skin can stay darker than the skin around it. The American Academy of Pediatrics (AAP) calls this post-inflammatory hyperpigmentation and says it's harmless. It's often more visible on skin of color.

The spots can look brown, tan or blue-gray and often fade on their own over months to years. So knees that were red and irritated can stay darker for a while after the redness settles. Eczema is one of the common causes the AAP lists, and treating a rash as soon as you see it can often lessen or prevent dark spots.

When to call about dark knees

• A dark mark that looks like a bruise isn't improving after 2 weeks.
• You see a rash on or around the knees. Your pediatrician can tell you what it is and how to treat it.
• Dark patches persist or are bothering your family. The AAP says a dermatologist can talk through treatment options.

How to protect your baby's knees while crawling

Bruises are hard to avoid completely, as KidsHealth puts it, so aim for a softer layer between knees and floor rather than a bump-free baby.

• Cover the knees. Soft pants, leggings or a onesie with padded knees put fabric between skin and floor. Here's more on protecting baby knees on hardwood floors.
• Soften the main crawling zone. A rug or play mat where your baby spends the most floor time gives knees a softer landing.
• Look after dry or rough patches. The red-knees guide linked above has a care routine for that.
• Thinking about knee pads? Here's our take on whether babies need knee pads.

When to talk to your pediatrician

Most minor bruises and scrapes heal on their own. Call your pediatrician if you notice any of these:

• A bruise that isn't improving after 2 weeks, or one that's swelling and seems to hurt a lot.
• Bruises that show up often or for no clear reason, or a bruise 2 inches (5 cm) wide or larger after a minor bump.
• Bruises in spots that were rare in the Cardiff study: the ears, neck, hands or genitals, or the bottom, chest or belly of a baby who isn't walking yet.
• Your baby can't move the leg, or you think a bone may be broken.
• A scrape that's deep, covers a large area or shows signs of infection, such as spreading redness, a red streak, pus or a fever.
• A scrape that hasn't healed by 10 days.

The AAP's symptom checker for cuts, scrapes and bruises is more cautious with the youngest babies. It lists "age less than 1 year old" under "Call Doctor or Seek Care Now," so if your baby is under 1, the AAP's advice is to call about a cut, scrape or bruise.

KidsHealth notes that bruising also depends on things like certain health conditions and medicines. If your baby has a bleeding disorder such as hemophilia, follow your care team's advice. We've also written about crawling with hemophilia.

Common questions

Why are my baby's knees black from crawling?

Start with a bath, since crawling knees pick up floor dirt. If the dark color stays, it may be a fresh bruise, which can look bluish-purple or even black within a day or two, or skin that stayed darker after irritation, which the AAP says is harmless. Call your pediatrician if a bruise isn't improving after 2 weeks or bruises keep appearing for no clear reason.

Is it normal for a crawling baby to have bruises on their legs?

Yes. In a Cardiff University study of 328 young children, the area below the knees was the most common place for bruises at every stage, and parents found at least one bruise in 45.6% of weekly checks on babies who were crawling or cruising. Bruises on the ears, neck, hands or genitals were rare at every stage, so marks there are worth a call to your pediatrician.

What should I do about my baby's bruised knees?

For a fresh bruise, KidsHealth suggests a cold pack wrapped in a towel to help keep bruising and swelling small, and most bruises fade in about 2 weeks. Soft clothing over the knees and a rug or play mat where your baby crawls most can soften future bumps. If your baby is under 1, the AAP's symptom checker advises calling your pediatrician about a bruise.

If you'd like a soft layer on those knees every day, that's what our padded crawling onesie is for. It's 100% organic Peruvian Pima cotton, padding included, with diamond-quilted pads sewn in at the knees, elbows and bottom, in sizes 6-9M, 9-12M and 12-18M. It won't stop every bump (nothing will), but it puts something soft between your little explorer and the floor.