What Is Serial Casting?

Medically Reviewed by Nayana Ambardekar, MD on March 13, 2022
Written by Steven Brown
4 min read

If your child has a joint that can’t flex or extend as far as it should, that might be because one of the muscles connected to it is too short or tight. Your doctor may recommend putting a series of casts on the joint. Each one would turn the joint a little farther in the direction it needs to go.

You may hear this technique called serial casting, and doctors mainly use it on wrists and ankles. It might help your child walk better or gain better use of their hands and arms.

Serial casting can sometimes help adults, too.

The first cast holds the joint in a position where it stretches the muscle just a little. A week or so later, your child’s medical team puts a new cast on them. This one turns the joint a little more, so that it pulls the muscle farther. Each week, a fresh cast increases the stretch.

When the muscle gets stretched over a period of weeks, it adds cells that make it longer and more flexible.

How long this takes depends on how much the muscle needs to expand. The average time is around 4 to 6 weeks. If your child needs serial casting because of a condition that affects their nerves, they might need more than one round of it.

Sometimes, people also get shots of Botox, a muscle-relaxing medication, to target the muscle that’s getting stretched.

Serial casting can benefit kids affected by:

Serial casting may also help adults whose muscles have tightened after a brain injury. The process has helped people get more motion in their elbows, wrists, knees, and ankles. For them, switching the casts every few days works better than waiting a whole week each time.

Each cast is made of fiberglass. Cotton and padding go between it and your child’s skin.

It could take around an hour to put on the cast. The medical team may need around double that time if they also give your child a shot of Botox.

If the cast goes on your child’s foot, they may also get a special sock and shoe to help them walk. But they’ll have to wait at least 2 hours after they get the cast before they put their weight on it.

When the time comes to take off a cast, the doctor will probably use a tool with a blade that vibrates quickly back and forth. Your child should only feel a tickling sensation and a little warmth.

Some casts are so easy to remove that the medical team may ask you to take off each one just before you bring your child back for the next one.

Serial casting comes with both advantages and challenges. The pluses are:

  • It spares your child from having an operation.
  • The casts don’t cause pain.
  • It can be repeated if need be.

The challenges:

  • It takes several weeks.
  • Some muscles may get weaker for a while.
  • You and your child have to be very careful not to get the cast wet.

Your child may need a little time to get used to the weight and bulk of the cast. But they can walk around, go to school, and do their regular activities. It’s good for them to stay active.

Meanwhile, keep these things in mind:

The cast must stay dry. This is the most important of all. If the lining gets wet, it can blister or irritate your child’s skin. When it’s time for a bath, they could take sponge baths, or else hold the cast outside the tub. Or before they get in the tub, wrap the cast in plastic wrap, then put a plastic bag over that, then another layer of plastic wrap.

Don’t try to scratch. The cast is snug and warm, and it doesn’t let dead skin cells fall away. So your child will probably itch sometimes underneath it.

Never stick anything into the cast to scratch. Instead, try to keep that part of your child’s body dry and cool. An ice pack or fan might help. Or you could put a hair dryer on the cool setting and blow air into the cast. If the itching is bad, you could ask your doctor if it’s OK to try an over-the-counter medicine like Benadryl.

Keep dirt out. When your child is outdoors or being active, slip a sock over the cast for protection.

Be ready for soreness. Your child might get sore from going around with the extra weight and bulk of the cast. An over-the-counter pain reliever like acetaminophen or ibuprofen (Advil, Motrin, Nuprin) could help.

The treatment might not be over, but different.

Your child may need to use a brace or splint. The medical team may give them a removable cast to wear at night.

Also, your child will probably need to get physical therapy. If the therapist gives them exercises to do at home, encourage them to stick with them. If they need to get used to their new and better way of walking, their physical therapy may last several months.