What is the Navicular Drop Test (NDT)?
The Navicular Drop Test (NDT) is a physical examination designed to assess a patient’s feet, specifically if they are overpronated. To determine if the foot is overpronated, the healthcare professional will observe and measure the navicular bone’s height when the foot is relaxed and again when the foot is bearing weight. The difference between the measurements will determine whether the foot is overpronated.
If the foot is overpronated, that means the foot tends to flatten more when bearing weight. This is not good because if the foot is flattened more than normal, that will strain the muscles and tendons that support it. If left unchecked for too long, the patient might develop foot conditions like Plantar Fasciitis (which will likely make them feel a stabbing pain in their plantar fascia), Achilles Tendonitis (the back of their legs right above the heel will ache), or the development of bunions (bony bumps at the joint of a big toe).
The Navicular Drop Test will help healthcare professionals determine what decisions they should make regarding their patients, like picking the necessary tests to further examine them, and choosing what should go into their care plan once all the testing is done (if a foot problem was confirmed and diagnosed).
Check out this video to see how the Navicular Drop Test is performed:
How to conduct the Navicular Drop Test (NDT)
Before you begin the Navicular Drop Test (NDT), you need to prepare two things: a non-permanent marker and a piece of paper.
The marker will record the measurements of the navicular drop on the piece of paper. A pen is fine, but we recommend using a marker instead because pens are sharp, and you don’t want to accidentally prick or slash your patient.
Once you have those ready, do the following:
- Have your patient sit down first.
- Tell them to keep their legs and feet relaxed. Being relaxed should make their feet maintain an arch.
- Locate their navicular tuberosity on one foot and mark it with your non-permanent marker.
- Once you’ve marked the navicular tuberosity, have the patient stand up without applying weight to their foot. This means that their subtalar joint is neutral.
- While the subtalar joint is neutral, measure the height of the navicular bone. This measurement is the starting position. Make sure to use a piece of paper and mark the starting position on it.
- After that, have your patient put weight on their foot. Remeasure the height of the navicular bone and mark it on the piece of paper.
- Repeat all of this for the other foot.
And that’s how you conduct the Navicular Drop Test (NDT)! Easy, huh?
How to interpret the findings of the Navicular Drop Test (NDT)
After recording the measurements of the navicular bone in neutral and while the foot is bearing weight, the last thing you’ll need to do is to calculate the difference between the two!
You will be measuring the difference by the millimeter. For the Navicular Drop Test, the foot is positive for overpronation if the difference is more than 10mm (1cm). This is not a diagnosis, though. If the foot is overpronated, the next step is to conduct a further examination. You will have to perform other foot-related physical examination techniques to determine if the patient is dealing with certain foot conditions like the ones mentioned earlier. If they test positive for those as well, imaging tests should be able to confirm things to make an official diagnosis.
Once you have an official diagnosis, you can determine how to treat your patient.
Navicular Drop Test (NDT) Example
The Navicular Drop Test usually doesn’t come with a test sheet where you can record your findings. The piece of paper that you will use for this test is not a test sheet. Given this, we are Carepatron took the liberty of making a Navicular Drop Test PDF template for physical therapists and adjacent professionals.
This contains the instructions (to serve as refreshers, just in case), fields where you can indicate the starting and ending positions of both feet’s navicular bones, fields for indicating the differences between the points for both, tickboxes for a positive or negative designation, and an additional comments box for you to indicate any comments you may have as well as detail your next steps.
If you like what you see and believe it’ll help you with your physical therapy work, feel free to download our template! You can print copies and fill them out physically, or go paperless and just engage with the editable parts of the Navicular Drop Test PDF template!
When is it best to conduct the Navicular Drop Test (NDT)?
The best times to conduct the Navicular Drop Test (NDT) are the following:
- Whenever a patient presents themselves during a consultation for foot problems. If they complain about problems with their feet, this is one of the standard physical examinations you can conduct to gauge the possible problem. If the results are positive, the next set of tests should deal with their Achilles tendon, heel, plantar fascia, etc. If their feet are overpronated, there might be a chance that they have issues related to those.
- Speaking of “the next set of tests,” it should always be included as part of a comprehensive examination because the Navicular Drop Test (NDT) alone is not enough to determine what foot problems the patient is dealing with. A positive test should be able to set the “roadmap” of tests to be conducted to narrow down the problem and make an official diagnosis. The collective results will then determine what goes into a patient’s treatment plan.
- Follow-up assessments. Naturally, you will want to know how your patient is doing after you’ve implemented a treatment plan. If overpronation is the cause of their foot problems, then you can repeat this test to see if the navicular drop length has lessened.
Who can conduct the Navicular Drop Test (NDT)?
Since the Navicular Drop Test (NDT) is a physical examination of the foot, the healthcare professionals that can conduct this should be knowledgeable regarding assessing and treating foot-related ailments. These professionals include the following:
- Podiatrists - These healthcare professionals specialize in diagnosing and treating problems related to the feet and ankles. They are trained in conducting physical examinations such as this, and because feet and ankles are the focus of their practice, you can trust that their interpretations and decisions are well-informed and backed by years of extensive training and experience.
- Orthopedists - These professionals are well-versed in the musculoskeletal anatomy of people. While Podiatrists focus on the feet, these cover the feet and more. They can conduct this test and more, interpret the findings well from their tests and those from others, are equipped to make official diagnoses, and can implement treatment plans. If the patient requires surgery, orthopedic surgeons can perform surgical procedures to fix whatever the foot or ankle problem is.
- Physical Therapists and Occupational Therapists - These professionals can also conduct the Navicular Drop Test (NDT) and other physical examination techniques for assessing feet. They can also assist with creating a treatment plan by providing rehabilitation to restore the patient to tip-top shape.
What are the benefits of the Navicular Drop Test (NDT)?
It can be used for planning early intervention.
Let’s say that you conducted the Navicular Drop Test (NDT), and the patient’s results turn up positive for overpronation, but based on other examinations, the patient doesn’t have any foot conditions as of now. You can take the opportunity to develop plans for early intervention so that the patient can manage their overpronated feet and restore them to normal. Doing so can prevent actual foot problems like Plantar Fasciitis from developing (or worsening if the problem is still mild).
It can help healthcare professionals monitor their treatment plans.
Earlier in this guide, we mentioned that one of the best times to conduct the Navicular Drop Test (NDT) is to monitor the patient’s feet during routine check-ups. If the length of the navicular drop is decreasing, then the pronation of their feet is slowly becoming normal. That also means they’re getting better. Repeating this test to monitor the patient also monitors the treatment plan. If the patient is getting better, it’s safe to say that your treatment plan is going well! Cool! If not, you might want to make some changes and see if said changes are effective.
It can help with creating custom orthotic items.
One of the possible treatments that you can give is to have an orthotic item created for the patient. What this item will be will depend on the foot or ankle problem that the patient is dealing with. Since the Navicular Drop Test is for the foot, specifically the arch, you can use the results to help create a custom orthotic foot pad to help patients maintain their foot arch while wearing shoes.
Why use Carepatron for podiatric and physical therapy-related work?
If you are a podiatrist, orthopedist, physical therapist, or an adjacent healthcare professional, we recommend taking the time to browse around the Carepatron platform! Hoo boy, do we have some features you will surely find valuable.
One of our defining features is our resource repository. It’s filled with a massive amount of worksheets, assessments (including the Navicular Drop Test!), survey templates, general treatment plan templates, and much more! It even covers numerous healthcare fields, including your respective practice(s)!
If you recall our point about the Navicular Drop Test not being the best test when used alone? Well, we’d like you to know that we have numerous physical examination templates you can download to help you conduct comprehensive examinations.
Since you will be looking at the patient’s foot, we recommend checking our Windlass Test guide and template! It also revolves around the plantar fascia of the patient and can check for the possibility of Plantar Fasciitis. Since overpronation of the foot can lead to that condition, it might be a big help! If you take the time to check out our roster of resources, you’ll surely find more assessments that you can add to your comprehensive examination.
Besides our clinical resources, we also have a nifty storage room that you can take advantage of. This system will allow you to store your clinical documentation with us in a HIPAA-compliant manner! This means that you have full control over who can access your files. Even if you’re storing them with us, we can’t access them! If you downloaded our Navicular Drop Test sheet template, you can store filled-out copies with us! We recommend that you share access with your team so they can easily check the results and share their results.
Storing your clinical documents with us is the same as creating digital backups. If you somehow lose all the physical copies of your documents but stored digital copies with us, you can redownload and reprint them!
We at Carepatron are all about helping healthcare professionals with their work, so take advantage of our platform so we can help streamline your workflows and help you preserve your work!