Should I Measure My Knee Bending and Straightening With My Phone
The Short Answer
Yes! Using a smartphone to measure range of motion (ROM) has been repeatedly shown by research to be accurate.[1][2][3]
The Longer Answer
Why Should You Care
Range of Motion (ROM) is an important measure of your recovery following your surgery or injury. For more information on the recovery timeline for a knee replacement, check out this blog here!
ROM provides a good indicator of recovery and joint function following surgery[1]. To learn more about what ROM is check out our earlier blog posts here.
Previously, measuring your joint range of motion yourself was nearly impossible! The most common way to have your knee or hip ROM was to have your physical therapist or surgeon measure it using a big compass protractor hybrid-looking device called a goniometer. Now thanks to the technology in your smartphones and apps like Curovate, you can measure and track your range of motion by yourself at home! You can also complete the thigh girth measurement, which is also a simple way to measure your progress by measuring the circumference of your thigh muscles.
Is it Accurate?
The answer to that question….. it is actually very accurate! A good source for healthcare information are studies that examine the results of multiple studies done on a particular topic. One such study from 2019 looked at the results from 37 studies that assessed the quality of smartphone ROM measures and found the following:
- 11 of the studies included reported on the consistency of the ROM measure when different people measured the same joint. 6 of those studies report less than a 10 degree variation in those repeated measures[2].
- 17 of the studies reported on the consistency of the ROM measure when the same person repeatedly measured a joint. 13 of those studies reported less than a 10 degree difference in the repeated measures[2].
A study that compared goniometric measurement of joint ROM to other methods reported the values to fall within a 10 degree range as well [1].
Overall findings from research suggest that using a smartphone to measure ROM is comparable in accuracy to the measurement typically performed by a physical therapist in a clinical setting[1][2][3].
You can measure your knee or hip ROM at home! Download the Curovate app for iOS or Android to try it for yourself! For step-by-step instruction and a video on how to measure range of motion using Curovate, check out this blog!
If you need further customized assistance during your surgery or injury recovery check out our Virtual Physical Therapy page to book your 1-on-1 video session with a physical therapist.
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