Kinetec Spectra 'The CPM Concept' knee therapy machine, $15

CPM stands for continuous passive motion, and the type of therapy a CPM machine like this Kinetec Spectra CPM Concept provides can mean all the difference in the world when it comes to recovering from an injury or surgery.

CPM machines like this Kinetec are often used by to help patients recover after an injury or surgery involving a joint. Think about it - a patient often experiences pain after surgery, which can naturally cause the patient to not want to move the joint enough to regain its full range of motion. When this happens, the tissue around the joint can become stiff because of the lack of movement, and scarring can begin to develop.

When a CPM machine is used, the joint can be automatically manipulated through a predetermined range of motion, and for long periods of time. This movement can greatly reduce recovery time by increasing the range of motion, promoting healing of the joint surfaces and soft tissues, reducing the tendency for adhesions and / or scar tissues to develop and decreasing the joint's stiffness.

Now that you have an idea what a CPM machine like this Kinetec Spectra is used for, and how vitally important it is for the eBay buyers who will be searching for it, how do you test one when you find it? I'll admit that I didn't test this machine before I bought it, and for several reasons. First of all, it was in perfect physical shape. Second, these machines cost thousands to buy new, and used examples sell for hundreds on eBay. Third, it was only $15. So with my risk to reward ratio tipping so strongly in my favor, the deal was a go.

The great thing about machines like the Kinetec Spectra is that its operation is pretty straightforward. I turned it on, waited for the software to load, and started playing with a few of the machine's various settings.

• The ON/OFF button is self-explanatory, but note that there's also a power switch on the side of the machine.
• The two LIMIT buttons set the range of motion that the machine will move the patient's joint through.
• The SPEED button adjusts how quickly the machine cycles through its bending and straightening cycle.
• The FORCE button adjusts the amount of pressure the machine applies to the joint as it tries to cycle through its preset range of motion.

Note that I didn't play around with the other buttons, and I stated so when this machine was listed on eBay. I simply stated that I tested it as best I could and was selling it precisely that way.

Please also check out the Gallery entry on the Breg 'Flex Mate' CPM machine that I got with this Kinetec and note these machines' similar 'profiles'. 

This Kinetec Spectra 'The CPM Concept' continuous passive motion knee therapy machine sold on eBay for $405.