NIH Toolbox V3 Standing Balance

The NIH Toolbox V3 Standing Balance test is an assessment of balance. Participants ages 3 and older are asked to perform a series of poses on the ground and on a foam pad. The participant is asked to wear a gait belt with an iPhone attached, which measures the participant’s postural movement/sway during each pose. This second device—an iPhone with a current iOS—must have the “Balance by NIH Toolbox V3” app installed to measure the participant’s sway. It is important to install the correct app; the “BalancePod” app that was used to measure balance in NIH Toolbox V2 will not work with the NIH Toolbox V3 Standing Balance test. Likewise, the “Balance by NIH Toolbox V3” app will not work with the NIH Toolbox V2 Standing Balance test.

If possible, use an iPhone protective case that has a screen cover, as accidental touches to the screen may inadvertently interrupt and end the test.

NEW V3 FEATURE: The “Balance by NIH Toolbox V3” app saves raw accelerometer data which can provide more details about the participant’s performance. This accelerometer data is saved in the “Files” app on the iPhone that collected the data, and will also be uploaded to the iCloud drive if that feature is enabled on the device. Please note that you may need to view the .txt files on your computer.  

Raw data consists of pairs of X and Z axis accelerometer measurements, and are reported in increments of the gravitational acceleration in the given direction, 50 seconds at 50Hz; for more details, please refer to: https://developer.apple.com/documentation/coremotion/getting_raw_accelerometer_events).  

Each trial is saved as a separate file (i.e., maximum 10 files per test). File names are titled in the following format: “001567-VBBAMp1T2-2023-07-13 18/17/57 GMT.txt”. The first set of characters represents the Participant ID. The pose number and trial number are at the end of the second batch of characters (e.g., here “p1T2” indicates the file has data for trial 2 of the first pose). The date and time follow, where time is in GMT.  

Regarding security, the only participant data that is sent from the NIH Toolbox V3 app to the “Balance by NIH Toolbox V3” app is the Participant PIN so the data can be linked to the participant. No other demographic information is sent to the iPhone. 

Troubleshooting

• Touching the iPhone screen during administration may inadvertently interrupt the test. To avoid this, please use a protective case that has a screen cover.
• If you are unable to connect the NIH Toolbox V3 app to the Balance app, please try the following steps:
  • On the iPhone, open the iPad’s Settings app.
  • Scroll down the left sidebar until you see the “BalanceV3” app and tap on it.
  • Ensure the “Local Network” option is toggled on.