The BESS test protocol includes a combination of three stances (feet together, one foot, and tandem feet) and two standing surfaces (firm surface/floor or medium density foam). All of these stances are performed with the eyes closed, making this test a true balance challenge. The BESS test is conventionally scored using "Error" points. These points are given for specific behaviors, including opening eyes, lifting hands off hips, stepping, stumbling, or falling. These are difficult conditions, reflecting that the BESS test is designed specifically to ensure that most subjects will loose balance.
This is fundamentally different than the approach that Mobility Lab takes towards Sway tests, where we provide a very sensitive measure of the quantity and quality of sway while in a specific stance. For these measures to be accurate, it is important that the subject does not step, stumble, or fall. The measures may still have value, but due to the sensitivity of these measures, they will be far outside the normative range and highly variable.
To account for this, Mobility Lab instead implements the modified BESS (mBESS) test protocol. This protocol includes the 3 firm surface tests, which are much less likely to incur loss of balance in the subjects. Some researchers are still interested in collecting data from the full BESS, however. To accommodate this desire, we have provided a downloadable BESS protocol that can be imported into your Mobility Lab workspace. To install this protocol:
- Download the attached protocol file (BESS_Protocol.xml)
- From within Mobility Lab, switch to the subject group that you wish to make this protocol available to (you can do this from the icon in the top right corner of the application). Many users only have a single subject group, so this may not apply to you.
- Click on Tools->"Import Data"
- When prompted, select the BESS_Protocol.xml file you downloaded
- Click through the import process
- The BESS protocol will now be available as a test sequence that you can run. The new individual Sway trials can also be run independently.
- No normative data was collected for the foam surface conditions during our normative data study. The norms that will be provided in reports and data exports are for the default condition, which is "Feet Apart, Eyes Open, Firm Surface". This will likely result in normative values that are much smaller than the values you calculate for these trials.
- If you create a new subject group, the BESS protocol will have to be re-imported into the new subject group before it will be an available option.