How to Use a Knee CPM Machine: Phoenix 1850 and Kinetec Spectra Essential
Recovering from knee surgery or injury can feel challenging, but the right tools make a big difference. Continuous Passive Motion (CPM) machines—like the Phoenix 1850 and the Kinetec Spectra Essential—are designed to help your knee heal faster, stay flexible, and reduce stiffness.
This easy-to-follow guide explains how to set up and use both machines step by step. Whether you’re using one at home or in a clinic, you’ll learn how to get the most out of your CPM therapy safely and comfortably.
What Is a CPM Machine?
A Continuous Passive Motion (CPM) machine is a motorized device that gently moves your knee joint through a set range of motion. It helps reduce stiffness, improve circulation, and prevent scar tissue buildup after surgery or injury. Your doctor or physical therapist will tell you how long to use the machine and what settings are best for your recovery.
Using the Phoenix 1850 Knee CPM Machine

The Phoenix 1850 is simple, durable, and designed for comfort during rehabilitation.
Step 1: Set Up the Machine
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Place the machine on a flat surface, such as a bed or floor.
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Plug it in and make sure the remote control is nearby.
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Adjust the leg supports to fit your leg length so the ankle and thigh pads feel snug but not tight.
Step 2: Position Your Leg
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Sit or lie down comfortably.
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Place your leg in the cradle and align your knee with the hinge point of the machine.
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Secure the straps gently to keep your leg in place.
Step 3: Set the Movement Range
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Start at 0° to 25° of motion.
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Each day, increase the top (flexion) angle by 5° as directed by your therapist.
How to Increase the Flexion (Top) Angle
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Press and hold the “Flexion” button.
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While holding it, press the “+” button.
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The flexion angle will increase by 5°.
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Release both buttons.
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Press START to begin the session.
⚠️ Note: It won’t work if you press “+” without holding the Flexion button first.
Step 4: Begin the Session
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The machine will gently move your knee up and down through the set range.
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You should feel stretching, not pain. If it hurts, stop and lower the angle.
Step 5: End and Power Down
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When the session ends, press STOP, unstrap your leg, and unplug the machine if finished.
Tip: Clean the pads and straps regularly to keep them fresh and comfortable.
Using the Kinetec Spectra Essential Knee CPM Machine
The Kinetec Spectra Essential is lightweight and easy to use, with digital controls for simple adjustments.
Step 1: Get Ready

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Place the machine on a stable surface and plug it in.
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Adjust the leg carriage length so your knee lines up with the hinge.
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Make sure the padding and straps feel secure but not tight.
Step 2: Set the Movement Range
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Start at 0° to 25° of motion.
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Increase the flexion angle by 5° each day or as recommended.
How to Increase the Flexion (Top) Angle
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Press Flexion.
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Press the “+” button to raise the angle by 5°.
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Press START to begin the session.
Step 3: Begin the Motion
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The machine will gently bend and straighten your knee.
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If it feels uncomfortable, pause the session and adjust the settings.
Step 4: Finish the Session
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Press STOP when done, remove the straps, and turn off the power.
Safety and Comfort Tips
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Always follow your doctor or therapist’s instructions.
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Stop using the machine if you feel pain or unusual swelling.
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Keep the device clean and free of dust.
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Avoid changing settings without medical guidance.
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Use pillows or towels under your leg for added comfort.
The Bottom Line
Both the Phoenix 1850 and Kinetec Spectra Essential CPM machines are effective tools for knee rehabilitation. Regular use can help restore flexibility, reduce stiffness, and improve overall recovery after surgery or injury. By following your therapist’s instructions and using the machines correctly, you can make steady progress toward getting back to your normal activities.
