Passive Movement Explained: Definition, Examples & Physiotherapy Role

Picture this. You’ve hurt your knee, and you’re lying on a therapy table. Your physiotherapist lifts your leg and gently bends it back and forth. You’re not doing anything just letting it happen. That’s passive movement.

It looks simple, right? But those slow, guided motions are powerful. They help your joints stay flexible, your muscles stay loose, and your body slowly remember how to move again.

When you’re injured, sore, or fresh out of surgery, even small movements can feel impossible. Your muscles aren’t ready to help yet — and that’s okay. That’s when your therapist steps in. They move your body for you, making sure you stay mobile while you heal.

Passive movement isn’t about building strength or pushing limits. It’s about keeping things working — gently, safely, and consistently. It keeps your joints from getting stiff, improves blood flow, and prepares you for the moment when you can start moving on your own again.

Find what passive movement really is, how it’s different from active movement, where it’s used in physiotherapy, and how devices like continuous passive motion machines support recovery.

What Is Passive Movement? — Clear Definition

Let’s start simple.

Passive movement happens when someone moves a part of your body for you. You’re not using your own muscles — instead, an external force like a physical therapist, personal trainer, or even a machine physically moves your joint through its available range of motion.

Think of your arm after surgery. It’s stiff and sore. You can’t lift it on your own yet. So your therapist gently lifts it, bends it, and straightens it — that’s passive range of motion (PROM). You stay relaxed; the therapist does the work.

Why Passive Movement Matters

When your body is healing from an injury, surgery, or medical condition, your joints and soft tissues can quickly lose flexibility. Joint stiffness, limited range, and even contractures can develop if you stay still too long.

Passive movement exercises prevent that. They help:

• Maintain joint mobility and prevent stiffness.
• Improve blood flow to healing tissues.
• Keep the soft tissues supple and elastic.
• Reduce the risk of complications after post-surgery recovery.
• Prepare your body for active rehabilitation later.

A systematic review published in the Journal of Physical Therapy Science (2022) found that regular passive range of motion exercises significantly reduce pain and improve early recovery in post-operative patients — especially after knee and shoulder surgeries.

How It’s Done

Passive motion exercises can be performed by:

• A physical therapist during treatment.
• A healthcare provider or trained family member at home.
• A continuous passive motion (CPM) machine that moves the joint slowly and steadily.

These exercises are gentle and controlled. They’re performed prior to active exercises, especially in the early stages of healing when the muscles are weak or the pain level is high.

Common examples include:

• Elbow flexion and extension while the patient relaxes.
• Shoulder abduction using a stretching strap.
• Knee or hip bending while lying flat or in an upright position.

Passive vs Active Effort (Quick Glance)

The Physiological Impact

During passive ROM, the body part being moved still benefits even though the muscles aren’t active. The gentle joint movement:

• Circulates synovial fluid, keeping the joint nourished.
• Reduces swelling and pain.
• Helps maintain soft tissue elasticity.
• Supports healing by improving blood flow and oxygen delivery.

Over time, this improves mobility, prevents stiffness, and makes it easier to transition to active range of motion (AROM) and strengthening work.

In short, passive movement is the quiet hero of rehabilitation. It’s the starting line — the safe zone — where healing begins before strength, endurance, and muscle development take over.

Types of Range of Motion — Where Passive Fits

Before diving deeper into passive movement, it helps to understand the bigger picture — the different types of range of motion (ROM) used in physical therapy.

In simple terms, range of motion (ROM) refers to how far a joint can move in different directions. Every joint — your shoulder, knee, or hip — has its own available range depending on flexibility, strength, and medical conditions.

When therapists talk about ROM, they usually mean three main types: passive, active, and resistive. Each plays a unique role in recovery.

1. Passive Range of Motion (PROM)

Here, movement is created by an external force — like a physical therapist, family member, or CPM machine.
You’re not using your own muscles. The goal is to maintain joint mobility, prevent stiffness, and improve blood flow without pain or strain.

Best for:

• Post-surgery recovery (knee, shoulder, hip)
• Patients with limited range or pain
• Early rehab, before active movement begins

Example: A therapist gently bends your elbow into flexion and extension while you relax. You don’t help — you just allow the movement to happen.

2. Active Range of Motion (AROM)

In active range, you create the motion using your own muscles.
No external help. It’s all your effort.

Best for:

• Later stages of recovery
• Improving muscle strength and control
• Building coordination and confidence

Example: Lifting your arm overhead or bending your knee on your own during ROM exercises.

Active range of motion improves mobility, circulation, and prepares you for strength training and active rehabilitation.

3. Resistive Range of Motion (RROM)

This type takes active movement a step further. You move your joint against some resistance — like a therapist’s hand, a band, or a weight.

Best for:

• Restoring muscle strength
• Enhancing joint stability
• Progressing toward full functional recovery

Example: Using a stretching strap or resistance band for shoulder or hip exercises.

Quick Comparison Table

Measuring Range of Motion

Therapists often assess and measure range using a goniometer — a small tool that measures angles of joint movement.
It helps them track improvement over time and decide when to progress from passive to active or resistive exercises.

For example:

• A healthy shoulder joint usually flexes up to 180°.
• After an injury, it might only move 90°.
• With consistent motion exercises, you can improve range safely over several weeks.

The Clinical Relevance

Each type of ROM serves a purpose in the treatment process:

• Passive movement prevents complications and keeps joints healthy.
• Active ROM builds muscle strength and prepares for daily tasks.
• Resistive exercises restore full function and performance.

In short, passive range starts the process, active range develops it, and resistive range completes it — all working together to bring your body back to full motion.

Passive Movement Examples (Practical, Clinical & Everyday)

Now that you know what passive movement is, let’s look at how it actually happens in real life.
You’ll find it in physical therapy clinics, hospitals, rehab centers, and even at home with help from a family member or a continuous passive motion machine.

The idea is always the same — the joint moves, but the muscles stay relaxed.

Clinical Examples

In a rehabilitation or physical therapy setting, passive movement is part of almost every recovery plan.
Here are some common examples used by physical therapists:

These ROM exercises are performed slowly and within a pain-free range.
The goal isn’t to push limits  it’s to maintain mobility and prepare for active rehabilitation later.

Everyday Examples

You don’t have to be in a clinic to see passive movement in action.
It happens in daily life more often than you’d think.

• A caregiver helping an elderly parent stretch their leg while they sit in an upright position.
• A family member gently moving your arm after surgery so the joint doesn’t lock up.
• Using a stretching strap to lift your knee or shoulder when you’re unable to move it yourself.
• A personal trainer assisting a client with passive stretching to improve mobility and soft tissue flexibility.

In all these cases, the body part moves, but the effort comes from someone or something else — not from your own muscles.

Mechanical or Machine-Assisted Examples

Technology now helps perform motion exercises when human assistance isn’t available.
That’s where CPM machines (Continuous Passive Motion) come in.

• These machines physically move the joint at a controlled speed and range.
• They’re often used after surgery on knees, hips, or shoulders.
• The machine keeps the joint in motion, reducing stiffness and helping tissues heal faster.

According to research published in the Journal of Orthopaedic & Sports Physical Therapy, patients who used CPM machines after knee surgery showed better early joint mobility and reduced swelling compared to those who didn’t.

Why These Movements Matter

Even simple passive movement can have major benefits:

• Keeps joints lubricated with synovial fluid.
• Enhances blood flow and oxygen delivery.
• Prevents soft tissues from shortening.
• Reduces pain and stiffness.
• Helps maintain range of motion during immobilization or limited activity.

A 2023 systematic review in Clinical Rehabilitation found that patients performing regular passive range of motion exercises had significantly better joint mobility and lower pain scores during the first six weeks of recovery.

PROM in Physical Therapy: Goals and Evidence-Based Uses

If you’ve ever been to physical therapy after an injury or surgery, chances are you’ve experienced PROM — Passive Range of Motion exercises. They may seem simple — your therapist moving your limb for you — but there’s a lot of science and strategy behind it.

Let’s break it down in plain, human language.

What PROM Means in Therapy

PROM (Passive Range of Motion) is when your therapist or sometimes a machine moves your joint without your muscles helping.

Your job? Stay relaxed.

Their job? Move your limb carefully through its natural range — without pain.

Think of it as the first step in your recovery ladder.

When your body isn’t ready for active exercise, PROM keeps your joints, tendons, and muscles from stiffening up or weakening.

Main Goals of PROM

Therapists don’t use PROM randomly. Each movement is purposeful and based on your injury stage, tissue healing, and mobility goals.

Here’s what they’re trying to achieve:

1. Maintain Joint Mobility
   Even when you can’t move, your joints still need motion to stay healthy. PROM keeps the synovial fluid flowing — that’s the natural lubricant that prevents stiffness.
2. Prevent Contractures
   When muscles and tissues stay in one position too long, they shorten and stiffen — that’s called a contracture. PROM gently stretches those tissues to keep them flexible.
3. Reduce Pain and Swelling
   Gentle motion improves circulation and helps reduce edema (swelling), especially after surgeries like knee or shoulder repair.
4. Enhance Healing
   Movement promotes better nutrient delivery to healing tissues. Studies show it can even speed up recovery in post-operative cases.
5. Restore Normal Movement Patterns
   PROM helps re-educate your body — it reminds your joints and brain how movement should feel, setting the stage for active rehabilitation later.

When PROM Is Used

PROM is common during the early rehabilitation phase — when active movement is too risky.
Therapists often use it after:

• Orthopedic surgeries (like ACL repair, shoulder rotator cuff, or joint replacement)
• Neurological injuries (such as stroke or spinal cord injury)
• Severe fractures or immobilization
• Arthritis flare-ups causing pain or stiffness

In hospitals, PROM may even be done daily for bedridden patients to prevent joint stiffness and maintain basic flexibility.

What the Research Says

Evidence strongly supports the benefits of passive range of motion in recovery.
For instance:

• A 2022 review in Clinical Rehabilitation found that PROM exercises significantly improved joint flexibility and reduced pain levels in post-surgical patients during the first 4–6 weeks of rehab.
• Another study in the Journal of Orthopaedic & Sports Physical Therapy reported that early PROM, when done under guidance, leads to better long-term mobility and less scar tissue formation.
• PROM is especially helpful in neurological rehab, as it prevents muscle shortening and keeps joints mobile even when voluntary control is limited.

So, while it may look “passive,” it’s actually active therapy for your joints, circulation, and tissue health.

Passive vs Active Movement — Clinical Decision Making

In physical therapy, understanding the difference between passive and active movement is more than just theory — it’s what guides every decision a physical therapist makes. Both have their place, but knowing when to use each is the key to safe and effective recovery.

Let’s unpack this in a simple, practical way.

What’s the Core Difference?

The difference comes down to who’s creating the movement.

When a therapist physically moves your arm or leg, that’s passive movement.
When you move it yourself — using your own muscles — that’s active movement.

Both aim to improve range of motion (ROM), but they target different goals depending on your recovery stage.

How Therapists Decide Between Passive and Active

A therapist doesn’t randomly pick one or the other.
Their choice depends on several key factors:

• Stage of Healing: In the first few weeks after surgery or injury, passive movement is safer. As tissues heal, the therapist shifts to active range of motion (AROM) and strengthening.
• Pain and Swelling Levels: If moving your own joint causes pain or swelling, the therapist will use PROM to maintain mobility without stressing healing tissues.
• Muscle Strength and Control: Weak or paralyzed muscles can’t move a limb effectively. PROM keeps the joint mobile until muscle strength returns.
• Joint Stability: After procedures like knee ligament repair or shoulder stabilization, active motion might be restricted early on. PROM helps maintain the available range safely.
• Functional Goals: Once the patient can perform active motion exercises without pain, AROM becomes the priority for restoring function and coordination.

When Passive Movement Takes the Lead

PROM is especially beneficial when:

• You’re recovering from surgery (like ACL reconstruction or shoulder repair).
• You’re dealing with neurological conditions that limit voluntary control.
• You’re on bed rest or immobilized after injury.
• Pain prevents you from using your own muscles effectively.

In these situations, passive movement prevents complications such as joint stiffness, limited range, or muscle shortening.

When Active Movement Becomes Essential

Once healing has progressed, active range of motion exercises take over.
This is where active rehabilitation begins — you’re now retraining your body to move, stabilize, and build strength.

Active movement helps:

• Improve muscle strength and coordination
• Enhance blood flow and tissue healing
• Increase flexibility and control
• Prepare for resistance training or functional tasks

Passive Insufficiency — What It Is & an Example

You’ve probably heard the term passive insufficiency in anatomy or movement science, but it’s one of those phrases that can sound more complex than it really is.

In simple words, passive insufficiency happens when a muscle is stretched so far that it can’t allow full movement across all the joints it crosses.

Let’s break that down with a practical example you can visualize.

Understanding the Concept

Some muscles in your body cross more than one joint — these are called biarticular muscles.
For example:

• The hamstrings cross both your hip and knee.
• The biceps cross your shoulder and elbow.

When these muscles are stretched at both joints at the same time, they eventually reach a point where they can’t lengthen any further. That’s passive insufficiency.

In other words, the soft tissues — like muscles, tendons, and fascia — reach their maximum stretch, and that limits joint movement, even though the joint itself could move more.

A Simple Example: Hamstring Stretch

Imagine lying on your back during a leg stretch.
Your therapist lifts your leg up while keeping your knee straight — that’s a passive movement.

At first, your hip flexes easily, but as your leg rises higher, you start to feel a tight pull behind your thigh. That’s your hamstring reaching its limit.

The hamstrings are now stretched across both the hip joint (flexed) and the knee joint (extended). The muscle can’t stretch further, so your hip flexion stops — even though the joint itself could move more if the muscle wasn’t tight.

That’s passive insufficiency in action.

Why It Matters in Physical Therapy

For a physical therapist, understanding passive insufficiency is crucial for joint assessment and exercise programming.
Here’s why:

• It helps identify whether limited range is due to joint restriction or muscle tightness.
• It guides the use of passive stretching and ROM exercises to improve flexibility.
• It prevents overstretching or injury by respecting the body’s natural limits.

For example, when performing a range of motion exercises, a therapist might support the leg with a stretching strap to control tension and avoid pushing past the muscle’s safe stretch point.

Clinical Relevance and Treatment Approach

A systematic review on flexibility training highlighted that passive stretching — when done consistently — can increase muscle length and improve mobility over time. However, it must be done gradually to avoid micro-tears or soreness.

That’s why PROM exercises are often performed prior to active training sessions — they warm up the tissues, reduce joint stiffness, and prepare muscles for active range of motion work later.

In Real-Life Terms

You don’t need to be in a clinic to experience passive insufficiency. It can show up in everyday life:

• When you reach forward to touch your toes and feel your hamstrings resist.
• When your arm can’t fully extend backward because of tight biceps.

It’s your body’s way of saying, “That’s as far as I can stretch — for now.”

Understanding passive insufficiency helps both therapists and patients appreciate how movement works — not just in theory, but in the way muscles, joints, and soft tissues interact during every motion.

Continuous Passive Motion (CPM): Definition, Devices, and Use

After surgery or a serious joint injury, movement is often the last thing on your mind. But for your body, even gentle movement is essential. That’s where Continuous Passive Motion (CPM) steps in — a clever blend of rehab science and technology that helps restore your range of motion safely.

What Is Continuous Passive Motion?

Let’s start with the basics.

Continuous Passive Motion (CPM) refers to a mechanical therapy technique where a device continuously moves a joint through a controlled passive range of motion — without any effort from the patient.

In other words, it’s a machine that performs passive movement for you.
Your muscles stay relaxed, while the device gently flexes and extends the joint — often for hours each day.

This process is called passive because the movement is caused by an external force, not by your own muscles.

Continuous Passive Motion Definition (Simplified)

If you had to define passive movement in this context, it’s the repeated, rhythmic motion of a body part performed by a machine or therapist to keep a joint flexible when active movement isn’t possible.

So when people ask, “What is a continuous passive motion device?”, the answer is simple:

It’s a motorized machine designed to move your joint continuously within a safe, pre-set range to prevent stiffness, reduce pain, and promote healing.

How CPM Machines Work

A CPM device works by cradling the limb (like your leg, knee, or elbow) and moving it gently through a controlled arc.
It mimics what a physical therapist might do manually — only it can do it for longer durations and with consistent speed.

Here’s how it typically works in practice:

It’s like having a gentle, tireless therapist helping your joint stay active — even when you can’t move it yourself.

When Are CPM Machines Used?

CPM devices are most often used post-surgery, particularly after:

• Total knee replacement (TKR)
• ACL reconstruction
• Rotator cuff repair
• Joint fracture surgeries

They’re also helpful for patients who are unable to perform PROM in physical therapy due to severe pain, muscle weakness, or immobilization.

In these early stages, continuous passive motion ensures that joint movement begins immediately — even when active rehabilitation must wait.

Benefits of Continuous Passive Motion

Research and clinical experience both highlight several benefits of using CPM in recovery:

• Prevents joint stiffness: Keeps soft tissues flexible and prevents scar tissue from restricting movement.
• Improves circulation and reduces swelling: Gentle movement helps maintain healthy blood flow.
• Decreases postoperative pain: Continuous motion can help reduce pain levels and the need for medication.
• Promotes faster healing: Improves joint mobility and encourages tissue regeneration.
• Helps maintain joint nutrition: The movement keeps synovial fluid circulating, which nourishes the cartilage.

What the Research Says

Multiple studies have examined the physiological impact of CPM machines.
For example:

• A systematic review published in the Journal of Rehabilitation Medicine found that continuous passive motion improved early joint flexibility and helped patients achieve better ROM outcomes within the first six weeks post-surgery.
• Another review comparing passive vs active movement found that using CPM early after surgery reduced the risk of joint stiffness and shortened hospital stays for knee replacement patients.
• However, therapists agree that CPM is most effective when combined with traditional physical therapy — it should complement, not replace, manual PROM and active ROM exercises.

Example: Knee Surgery Recovery

After a knee replacement, the therapist may begin CPM therapy on day one.
The machine gently bends and straightens the knee, usually between 0° and 40° of flexion at first.
As pain and swelling decrease, the range is increased daily, helping the patient improve mobility while avoiding strain.

Once the joint tolerates movement without discomfort, active exercises begin — marking the shift from passive motion to active rehabilitation.

Conclusion

Passive movement is a cornerstone of rehabilitation. By allowing a therapist or CPM device to move a joint through its passive range of motion, it maintains joint mobility, prevents stiffness, and improves blood flow to soft tissues.

It’s essential in early recovery when active movement isn’t possible, setting the stage for active ROM and strengthening exercises later. Understanding passive vs active movement and concepts like passive insufficiency ensures safe, effective therapy.

Combined with tools like continuous passive motion machines, PROM in physical therapy helps patients recover faster, maintain flexibility, and regain functional movement, making it a vital part of any rehabilitation program.