Is breathing voluntary or involuntary motion? Breathing is voluntary.

Voluntary vs involuntary motion: the definitions

Radiography separates motion into two categories based on whether the patient can control it.

Voluntary motion is movement under conscious control. The patient can start, stop, or prevent it with instruction. Examples: breathing, gross body movement (shifting position), swallowing, blinking.

Involuntary motion is movement the patient cannot control, even if they try. It happens automatically or below conscious awareness. Examples: peristalsis (movement of food through the GI tract), cardiac pulsation (heartbeat), tremors, chills, and seizure activity.

The reason this distinction matters is the fix is completely different for each type.

The common wrong answer (and why it sticks)

Many study guides group breathing together with peristalsis as involuntary motion. This is the error the ARRT expects you to catch.

The reason it sticks is that breathing happens automatically most of the time. You breathe without thinking about it. So it feels involuntary, the way your heart beats without conscious effort. But automaticity is not the same as inability to control. You can hold your breath. Your heart, you cannot.

Breathing is automatic but voluntary. This is the standard definition in respiratory physiology and the definition the ARRT uses on the exam. If a study guide says breathing is involuntary, it is wrong, and you should correct it before exam day.

Examples of voluntary motion in radiography

In the radiography room, voluntary motion is any movement the patient could prevent with the right instruction.

• Breathing during exposure on a chest x-ray or thoracic CT. Fix: clear breath-hold instruction. “Take in a breath and hold it. Don’t let it out until I tell you.”
• Body movement during a long spine exam or extremity radiograph. Fix: proper positioning, immobilization aids, clear instruction: “Stay very still. Don’t shift your position once we start.”
• Swallowing during a chest x-ray (swallowing moves the shoulders and neck). Fix: ask the patient to swallow before the exposure, then hold breath and stay still.
• Fidgeting or shifting during fluoroscopy. Fix: communication, explain the procedure, keep the patient still with gentle immobilization.

All of these are prevented or reduced by clear communication and technical skill.

Examples of involuntary motion in radiography

Involuntary motion is anything that happens outside conscious control.

• Cardiac pulsation (heartbeat) during cardiac imaging or high-resolution chest CT. The heart beats whether the patient is conscious or cooperative. Fix: shortest possible exposure time, ECG gating, or imaging at a specific phase of the cardiac cycle.
• Peristalsis (GI tract movement) during abdominal radiography or fluoroscopy. The digestive system keeps moving. Fix: shortest exposure time. Some exams (like upper GI series) are timed to catch specific phases when motion is minimal.
• Tremors in elderly patients or those with essential tremor or Parkinson’s disease. Fix: shortest exposure time, proper positioning and support to stabilize the body, possibly multiple exposures to select the sharpest one.
• Chills or seizure activity in acutely ill patients. Fix: shortest exposure time, medical management of the underlying condition, immobilization if safe.

For all involuntary motion, the technical fix is exposure time. You cannot tell the heart to stop beating.

How to fix each type

Voluntary motion is preventable. Your fix has three parts:

1. Clear instruction: Tell the patient exactly what to do. “Take in a breath… hold it.” “Don’t move.” “Swallow now, then stay still.” Vague instruction (“Try not to move”) is less effective than specific instruction.
2. Minimize exposure time: Even with good instruction, the shorter the exposure, the less time there is for patient motion to blur the image.
3. Proper positioning: An uncomfortable position makes it harder for the patient to stay still. Use positioning sponges, arm supports, and footrests to maximize comfort and compliance.

Involuntary motion cannot be prevented by instruction. Your fix is technical:

1. Shortest possible exposure time: This is the primary control. Using faster film speed, higher mA, or pulsed fluoroscopy reduces the time the image is being acquired, minimizing the distance the moving structure travels during exposure.
2. Timing or gating: For cardiac imaging, ECG gating triggers exposure at the same point in each heartbeat. For GI imaging, timing the exposure during phases of reduced peristalsis (like right after barium reaches the stomach) helps.
3. Motion-compensating imaging: On some systems, motion-compensated reconstruction algorithms can reduce blur from involuntary motion, though this is more common in advanced modalities (MRI, CT) than in radiography.

The key insight: if the patient cannot control it, the fix must be technical, not behavioral.

Why this matters on the ARRT

The Image Production category on the ARRT Radiography Boards explicitly tests motion artifact and the distinction between voluntary and involuntary motion. The most common question patterns are:

1. Classification questions: “Which of the following is involuntary motion? A) Breathing, B) Peristalsis, C) Swallowing, D) Gross body movement.” Answer: B (peristalsis). Breathing is voluntary.
2. Fix questions: “The best method to reduce peristaltic motion artifact is to use the shortest possible exposure time. What method reduces breathing motion artifact?” Answer: Clear breath-hold instruction combined with shortest exposure time.
3. Misconception questions: “A patient holds their breath on command. This shows breathing is…” Answer: voluntary (under conscious control).

If you’ve been studying from materials that list breathing as involuntary, correct that before exam day. The ARRT treats voluntary motion as the right answer, and so does every authoritative source in radiography.

Quick reference table

Motion type	Examples	Patient control?	Fix strategy
Voluntary	Breathing, swallowing, movement	Patient can prevent it	Clear instruction + breath-hold + short time
Voluntary	Patient fidgeting, hesitation	Patient can prevent it	Positioning comfort + communication
Involuntary	Peristalsis, heartbeat	Patient cannot prevent it	Shortest exposure time + gating or timing
Involuntary	Tremors, chills, seizure activity	Patient cannot prevent it	Short exposure time + immobilization + support

ARRT exam tip

If you only memorize one thing from this page: breathing is voluntary motion because the patient can hold their breath on command. This is the rule the ARRT tests and the rule that aligns with respiratory physiology and every authoritative radiography source.

Study guides that list breathing as involuntary are incorrect. Correct them. On the exam, when you see a question about motion artifact, ask yourself: can the patient control this movement? If yes, it is voluntary (communication + instruction fixes it). If no, it is involuntary (short exposure time fixes it).

For a deeper look at motion artifact and image quality, see our chapter on image acquisition and technique. For how to communicate technical instructions clearly to patients, our section on patient communication and care covers best practices.