Chest percussion is a form of physical therapy used frequently in chronic obstructive pulmonary disease (COPD) and other conditions, such as cystic fibrosis, to help clear the airways from mucus. It involves a therapist or loved one clapping on your chest or back to help loosen the thick mucus in your lungs so you can cough it up. Chest percussion also can be performed using electronic devices or other instruments that vibrate your chest.

Purpose

Conditions like COPD and cystic fibrosis can result in major mucus build-up in your airways, making it hard to take a deep breath. While there are several medications that can help loosen mucus, making it easier to breathe, chest percussion is often used to help achieve this goal. Strategic clapping on the chest or back shakes the sticky mucus loose.

Chest percussion is considered a part of chest physical therapy (CPT), which also incorporates postural drainage and vibration, both of which can help loosen and drain mucus as well.

Risks and Contraindications

Chest percussion is a very safe procedure if performed correctly and carefully. Complications are unusual but may include:

An increase in hypoxemia (a drop in blood oxygen saturation levels)
Severe bronchospasm
Choking on loosened mucus secretions from other lung lobes
Damage to internal organs

Before Therapy

Your doctor or respiratory therapist will give you specific instructions on how and when to have someone perform chest percussion on you. You should always follow the instructions from your healthcare team, but here are some general guidelines on how the procedure typically is performed.

Timing

The best time to perform chest percussion is in the morning since it's likely that your lungs will have built up mucus during the night. If you have a problem with coughing overnight, you can consider performing it right before you go to bed as well.

Your doctor will advise you on the best times to perform the technique. Chest percussion works best after a bronchodilator treatment, so you might want to keep that in mind.

It's not a good idea, though, to perform chest percussion right after you've eaten; banging on your chest or back following even a small meal could make you sick.

Location

Chest percussion can be performed while standing, sitting upright, reclining, or lying down on a firm, flat surface. Ask your therapist or healthcare provider which position is right for you.

What to Wear

Note that the procedure shouldn't be performed on bare skin. Make sure you're wearing a shirt or use a towel to cover the area being treated.

During Therapy

You'll likely be instructed to perform chest percussion at least once per day in several different positions:

Seated
On your back with a pillow under your chest, so that your head tilts downward
On your stomach, also with your head tilted downward

It's important that the person performing manual percussion uses correct hand positioning: The hand should be in a cupped position, with fingers and the thumb together. They will then quickly and repeatedly clap you on the back of the chest with their hand.

The percussion should be relatively vigorous and rhythmic, but it should not be painful. If pain occurs, the hand may not be properly cupped and should be adjusted.

You'll know that the person performing this technique is using proper hand positioning when you hear a hollow sound with each percussion.

Chest percussion should only be done in specific areas:

Over the ribs
On the sides of the chest
On the sides of the back

Care must be taken to avoid the breastbone, spine, and lower back, as percussing could harm internal organs. Your physician can show you exactly where to perform chest percussion.

If you're using postural drainage with chest percussion, you should hold your position for at least five minutes (or as long as your doctor advises) to allow as much mucus as possible to drain from your lungs. Combining chest percussion with coughing or other methods of bringing up loosened mucus can also be helpful.

Should you opt to use a mechanical airway clearance device instead of manual chest percussion, speak with your doctor about how to properly use it.

A Word From Verywell

The ultimate goal of chest percussion is to loosen mucus secretions enough so that they may be coughed up. One of the benefits of this manual technique is that it can be performed in adults and children as young as 5. While clinical trials have not successfully illustrated its effectiveness in an evidence-based study, chest percussion remains an important part of treatment plans for many with COPD and cystic fibrosis due to anecdotal evidence of its benefit.