Reliability and Validity of an Instrumented device for Measuring Functional Ankle Mobility

Elizabeth Dano, SPT, Tiffany Hopper, SPT, and Cole Miller, SPT

(Click on image to expand)

14 Comments on “Reliability and Validity of an Instrumented device for Measuring Functional Ankle Mobility

  1. Great work! What do you guys think might explain the lack of difference in measurements between the involved and uninvolved side? Do you think this was related to the instrument/examiners or the subjects?

    Like

    • Thanks for your question, Abby! We have discussed this extensively and came up with several possible explanations. One reason was the time limits that we set on our ankle sprains; we stated the sprain had to be at least 3 months old but had no upper limit. This resulted in us getting some ankle sprains that were up to several years old, by this time the majority of the patient had regained similar mobility to their uninvolved leg. Another contributor was that we had no limits on the severity of the sprain aside from the limitation of not having experienced a fracture. One would postulate that a more severe ankle sprain may result in more significant lasting impairments and less severe ankle sprain might result in no lasting impairments at all. While there could have been instrument/examiner error we did control for this to the best of our ability by completing practice trials on healthy individuals and ensuring that there was good inter-rater reliability for the examiners and device.

      Like

  2. If your research group had put a cap on how long ago the ankle sprain occurred, do you think the results would have been different? And if your research group had put an end date range on how long ago the sprain occurred, would that have affected the results?

    Like

    • Thank you for the question! We had a cap on one end, with requiring the sprain to occur at least 3 months prior, but putting a cap on the other end would have had a potential impact as well. Some participants had ankle sprains back as far as when they were a young kid and others had them just a year ago. Placing a greater limitation on how far back the injury occurred may have had an impact on our results with regards to finding a significant difference. In this case we were looking at chronic sprains in general without the timeline cap. It would be interesting to see how a stricter timeline would have affected the results, as there is the potential for different results based on time frame of injury. The limitation of this is if we had limited it to sprains 3 months ago but no older than 12 months, we would have had to limit the gernealization of the rehab ruler use to just the tested population, as that is the only population we could validated the results.

      Like

  3. Nice poster! I was wondering if you thought the small sample size in your study could have contributed to the lack in statistical difference you found between ankles and the FAAM score?

    Like

    • Thank you for the question Zack! It is likely that a small sample size contributed to the lack of significant differences in ankle ROM. Our target minimal sample size for the power we were aiming for was 34 participants, which was a number we could not reach at the time; however, if we had, we could be more confident either way with regards to the rehab ruler’s ability to detected a significant difference in ankle ROM differences between chronic sprained and non sprained ankles. With regards to FAAM scores, each participant self reported their perceived lasting deficits secondary to their sprain. In most cases the participant reported normal or near normal function, which did line up the lack of significant difference in ankle ROM.

      Like

  4. Awesome job on your poster! I think it would be interesting to know if some of the participants had other surgeries or injuries in either lower extremity as we have learned that the whole lower kinetic chain is connected. There may have been things that happened to either side which may have affected ankle mobility. For example, if they sprained their left ankle but also had patellofemoral pain in the right knee leading to compensations of restricted motion at the ankle, both sides may have restricted motion at the ankle but from different causes leading to no significant difference in ankle ROM. Just curious, did you guys inquire about any past surgeries or injuries? Just a thought that crossed my mind!

    Like

    • Thanks for the question, Justine. We did actually screen for past surgeries and injuries with participants. Before testing began, participants had to fill out a form containing both inclusion and exclusion criteria. Participants were included if they were between the ages of 18-40 and had a history of a unilateral ankle sprain over 3 months prior to testing. Participants were excluded if they were pregnant, had balance issues, suffered fractures or surgeries in the low back or lower extremities, or had any knee or hip impairments.

      Like

  5. Great job on the poster! Cole looks mighty handsome in those pictures. Did your team ever consider looking at dorsiflexion w/ knee extended in WB compared to knee flexed? In our retrospective research topic on pediatric patients we noticed a difference between DF w/ knee flexed vs knee extended so I was interested to see if yours was similar.

    Like

    • Well thank you for both the compliment and question, Tanner! In short, no, we did not consider looking at the dorsiflexion (DF) ROM in an extended position. While it would be interesting to assess this, for the method we utilized to assess DF ROM in a weight bearing position, I’m not quite sure how we would utilize the Rehab Ruler to do so in an extended knee position. For our assessment we looked at how far away someone’s foot would be away from the wall while completing the task of maintaining heel contact and touching their knee to the wall. If we were to keep the knee extended, we would have to utilize some other area of contact, such as the ASIS, to assess this utilizing the Rehab Ruler. If this were the case, at that point we would likely need a very long ruler as some individuals’ feet would be quite a ways from the wall. While this may have been a possibility, I do not think that this would have altered our results as all individuals underwent the same testing procedures bilaterally, which with the knee bent, mitigates gastrocnemius involvement and therefore, should allow for more ROM.

      Like

  6. Nice job! In your pre-test questionnaire for participants, did you ask about previous rehab or physical therapy for their ankle sprains? Were there participants who had multiple recurring ankle sprains on the same ankle?

    Like

    • Thanks for the question! We had a yes or no question regarding previous rehab for the ankle sprain; however, we did not look into duration of treatment or anything more specific. There were patients who had multiple reoccurring sprains on the affected side, but we did not see any impact on our results. We did not specifically ask how many times the patient sprained their ankle, but we did ensure they never sprained the opposite ankle.

      Like

  7. I like that your poster information is very concise and easily understood! My question for you; what is the advantage of using this tool in clinical, as opposed to the cheaper option of taping a ruler to the floor and to the wall? Will you personally utilize this tool in your practice if it is made available for purchase?

    Like

  8. Thanks for the question Micah. The advantage of this tool is that it has multiple uses. While you are correct that you could use a ruler on the wall, you would still need to place something on top of the individuals head to assess where they fall at on the ruler. In doing so, you would also have to take into consideration that it should be perfectly perpendicular to the wall; otherwise the measurement would not be accurate. With the rehab ruler, the portion that flips out and rests on the individuals head is exactly 90 degrees from vertical; ensuring an accurate measurement during the functional heel rise test. Throughout our time spent with Dr. Ness we have seen a few different variations of the rehab ruler, with some being comprised of entirely 3D printed parts. So if this tool were to become available for purchase and was at a reasonable price point, I believe that I would utilize it in my own practice.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s