Ortho Impact Mobile App

Announcing Ortho Impact. This app is to help people understand the impact to their body doing various activities.

When I got a new artificial hip, I was frustrated that there was not more clarity on how to take good care of my hip. I was told to avoid basketball and running if I want to maximize the life of the hip. But there is a lot of grey area. Like many, I got the hip in order to be more active.

What if you play basketball without jumping? What if you run across the street before the pedestrian light turns red? What about tennis with a partner who hits to you? What about skiing in moguls? What about hiking with a backpack on? What about roller blading? What about playing tag with grandkids? What about …?

This app’s goal is to give you more information about how much force you are putting on your hip doing various activities. With this information you can decide which activities you want to pursue and which you might want to minimize or change the way you do them.

If your hip lasts 30 years and you get 10,000 steps a day, you will put over 100 million steps on your hip. The goal of this apps is to provide you information about how much these steps impact your hip.

This only works for weight bearing exercises. If you are riding on a roller coaster you will have lots of acceleration but they will not be born by your hip since you are sitting down.

How to use

The first step after you install this app is to understand how much acceleration you undergo with various activities (walking on flats, hiking uphill, hiking downhill, jogging, …). Since everyone is different, this will give you an understanding of how these activities compare and what acceleration this puts on your body. To start a recording session, just start the app, put it in your pocket and do your activity. When you are done or while you are still doing it, you can look at the maximum acceleration and view a graph to see when the impact was the highest.

The next step is to determine what threshold values to set on your app. The threshold is the level that you want to know when you exceed it. The app can play a sound when you exceed the threshold and you can also view how many times you exceeded the threshold during a session.

The IPhone accelerometer reads twice the value of the Android. Although they both have the same value for gravity(no motion).

The threshold can be set based on acceleration or force. Acceleration is easier to use but is not based on your weight so should be more generally applicable. According to this research paper, “Loading of Hip Measured by Hip Contact Forces at Different Speeds of Walking and Running” https://pubmed.ncbi.nlm.nih.gov/25704538/ Walking generates 4.22 to 5.41 times your body weight while running generates 7.48 to 10.01 times your body weight. Given that running is considered bad for your hip, one approach would be to set the threshold at 6 times your body weight.

Threshold can also be set based on force. Force should be a more accurate measurement of the wear of the hip liner. For this you will need to enter your weight and determine what force is considered harmful based on your artificial hip manufacturer. Force is usually expressed in Newtons and is the product of your mass (more commonly thought of as weight) and the acceleration you put on your hip.

To avoid your phone turning off iPhone:

  1. Go to settings
  2. Tap on Display and Brightness
  3. Tap on Auto-lock
  4. To turn if off, select “Never”

Android:

  1. Open settings
  2. Tap on Security & Location
  3. Tap the Smart Lock entry and confirm your current PIN or password.
  4. Select on-body detection
  5. Tap continue once you have read the security message.

Support

For questions or comments please send mail to alpineapp@gmail.com.