Sports Medicine Research: In the Lab & In the Field: Knee Goniometry? There’s an App for That. (Sports Med Res)
Wednesday, December 26, 2012

Knee Goniometry? There’s an App for That.

Validation of a Novel Smartphone Accelerometer-Based Knee Goniometer

Ockendon M & Gilbert RE.  J Knee Surg. 2012 Sep;25(4):341-5. 

Measuring knee range of motion (ROM) is a common clinical practice among most healthcare professionals, especially when monitoring ROM to track post-surgical outcomes.  Goniometers, accelerometers, and inclinometers are some examples of instruments that have been used to assess knee ROM.  Smartphones have built in accelerometers for various uses; therefore, the purpose of this study was to evaluate the reliability of a Smartphone knee goniometry application for assessing knee ROM.   The authors designed an application for the iPhone (“Knee Goniometer”) that estimates knee ROM by utilizing tibial incline measurements and basic trigonometry when placing the phone on the mid-shaft of the tibia.  Two independent and blinded clinicians measured 3 simulated joint angles bilaterally in 5 healthy males utilizing the iPhone application as well as a goniometer.  The intra- and inter-observer reliability of a traditional goniometer were excellent with correlations of 0.93 and 0.95 and standard errors of ± 9.6 degrees and ± 8.4 degrees, respectively.  In comparison, the intra-and inter-observer reliability of the iPhone application were mildly better with correlations of 0.98 and 0.99 and standard errors of ± 4.6 degrees and ± 2.7 degrees, respectively.  The authors found there was a high correlation between instruments (r = 0.95) and a mean difference of only -0.04 degrees.           

Clinically, the athletic trainer may have a valid and reliable application readily available in their pockets for clinical ROM knee measurements.  Truthfully, the smartphone may take out some of the ambiguity and user error often associated with the use of a traditional goniometer, potentially providing a more accurate and universally accepted method to measure ROM.   The possible implications of an application like this could mean more accurate interobserver results.  Furthermore, this method for measuring ROM could have implications on the compliance and monitoring of ROM during home exercise programs. Athletes may be able to track and report their ROM to the clinician daily, or even multiple times throughout the day. However, there results should be interpreted with mild caution.  Interestingly, the authors of the paper are the creators of the application “Knee Goniometer.” Curiosity led me to the App Store for independent investigation of this potentially useful application.  Much to my surprise, the application could be purchased for $4.99.  While the authors did demonstrate that this application was valid and reliable in comparison to currently utilized clinical knee ROM measures, they have a bias in conducting this research as it has a financial implication to them personally.  It would have been more interesting to see a third party, independent group investigate the clinical usefulness of this application.  Does anyone have any experience with an application like this?  Furthermore, does anyone have any smartphone applications that they find clinically useful?  

Written by: Nicole Cattano 
Reviewed by: Stephen Thomas

Related Posts:

Ockendon M, & Gilbert RE (2012). Validation of a novel smartphone accelerometer-based knee goniometer. The Journal of Knee Surgery, 25 (4), 341-5 PMID: 23150162

10 comments:

Michele Lorenzo said...

I think the idea of this app is fantastic! Having a goniometer right in your pocket at all times would be very beneficial, not to mention that it may in fact be more accurate that the traditional way of taking range of motion measurements. I also would like to have seen a third party investigate this app to eliminate bias. I think they should knock the price down a little so athletes are more inclined to purchase and use the app during home exercise. It could be a great tool for athletes to track their progress and could encourage them throughout their rehabilitation.

Nicole Cattano said...

Michele-I didn't even think if the possibility of athletes downloading for home exercise programs. That is a really neat possibility.

Does anyone know of any apps that Are clinically used?

Nic Philpot said...

I have never heard of a goniometer app. I have used a concussion app that used the SCAT on my phone so it is easier to administer the SCAT by letting the athlete sit on the bench and fill it out while I can pay attention to the game. It is NDBC, which stands for National Dizzy and Balance Center. That is the only app that I have found that is useful in the clinical setting. I am however very intrigued by this app. It gives a more concrete placement in order to do the measurement. I also really like the idea of the patient being able to do his/her own measurement. That would give them a tangible goal to shoot for that they can measure whenever they want.

Nicole Cattano said...

Nic-thanks for the recommendation to check out the NDBC app. I will have to check it out. I did a quick search and didn't see NDBC (any idea on who the developer would be listed as?)

I really think that we will only continue to see clinical app use grow, as there is a huge potential for it.

Becca Burkhart said...

I do not personally know of any apps that could be used clinically. The idea of having a goniometer on the go though is great. I think it would be interesting to see if this app truly is valid and reliable through a third party experiment. Technology is a huge part of daily life and to be able to use technology as a tool to help in the athletic atmosphere would be great.

Nicole Cattano said...

Becca-I agree. I think it was especially be useful to see that if there is interrater reliability....For instance, if the clinician shows the athlete how to do it once, and then the athlete goes home and does it, are they getting similar results?? But in my opinion, any objective finding is value added and can only help aid in compliance and accomplishments of short and long term goals.

Morgan Hooven said...

I have never heard of a goniometer app but I think it would be awesome to have and use in the athletic training room. I know for myself, goniometry is sometimes tricky. I'm not too sure if my measuments are correct and I find myself having to redo them numerous times. If there were an app that took measurements for you I really do think we could benefit from it. If athletes were to learn to use the goniometer app, if could help them track their gains in range of motion and help them stick to goals following a knee injury.

Marisa Rizzo said...

I have never heard of a goniometer app but i think the idea is great! Everyone always has their phone with them and it would make things easier outside of the training room where all your supplies are. Taking out the human error would be such a help for me with goniometry. I hate reading those little numbers and making sure the arms are in the right spot. I think having more apps to assist athletic trainers would be very useful

Alex Ruxton said...

As an athletic training student I had to measure knee ROM for a lab report. I was away from school and do not have a personal goniometer so I checked the app store on my phone and uploaded a free goniometer app. I used my smartphone app and when I was back at school I did the measurements again with a real goniometer. I was surprised of how close the readings were and I feel like I was able to get a better reading using the app. I think using the technology could be beneficial and take out the human error trying to decipher between the smaller line on the goniometer. I would be interested in seeing the app that the people made.

Brandon Green said...

I have seen various goniometer applications and have used one on a tablet. I find that it is much easier to use than the traditional goniometer. I do not remember the name of the application but I do remember the downside was the inability to record multiple measurements. The ability to record multiple measurements easily would be very beneficial for progressive rehab and treatment. An app that I have seen used in the clinic is a Scan to PDF app that allows the clinician to scan paperwork or scripts to record for personal use or send to another person via email.

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