# Calculate

In this section you can produce the STABLE balance profile by applying the online calculator. Please refer to the menu to chose one or two assessments.

The calculator is based on excel work sheets. To ensure using updated worksheets we recommend always doing calculations online but the worksheets can be downloaded for offline calculations as well. Using the calculator online you can change all values freely.

#### How to use the calculator

You only need to change the values in red, then the online calculator produces the balance profile.

The default values in red in SERIE 1 are the mean scores of the normative values. The default values in red in SERIE 2 (in two assessments) are the highest (best) values recorded in the normative values. If your test results differ drastically from these values please reconsider your results.

#### How to interpret the balance profile

The STABLE balance profile is the diagram showing the patient's scores in each of the six domains.

Essentially, higher values in the diagram reflects better performance and values of 0 reflects the mean scores of the normative values which the diagram is based on.

Please notice, when you enter the new values the points and the scale changes accordingly in the diagram.

#### How to interpret the calculated values

The calculated score of each domain is provided with its units.

In sensory orientation, two additional scores are provided the "visual" score and the "base" score. The score with the highest number indicates the patients sensory orientation. E.g. if visual=2.2 and base=1.5, this indicates that the patient is more challenged keeping balance standing without vision compared with standing on an unstable surface.

The z-score is provided for each domain. 0 equals the mean balance ability for the normative values. Positive values are above the mean. Negative values are below the mean. A z-score of 1 equals one standard deviation from the mean. The diagram is based on these scores (only the z-score for the motor component of cognitive-motor interaction is included in the diagram).

The average z-score expresses the patients' overall balance ability.

#### How the values are calculated

##### The scores

Each domain in STABLE are measured on a unique scale. The score of each domain is calculated by the online calculator as follows:

• The power score is calculated as the time in seconds to complete the adjusted sit to stand test.
• The stability limits score is calculated as the distance between the wall and the patients feet divided with the patients' height executing the maximal reach test.
• The anticipatory turning score is calculated as the time in seconds to complete the turn and touch test.
• the reactive stepping score is calculated as the time in seconds to complete the reactive four square step test.
• The overall sensory orientation score is calculated as the sum of all items in the test of reference frame interaction in balance divided by 120, producing a value between 0 and 1, with higher values indicating better performance.
• The visual score is calculated as the mean difference between equal standing tasks performed with eyes open and closed (in seconds).
• The base score is calculated as the mean difference between equal standing tasks performed standing on the floor and on foam (in seconds).
• The cognitive-motor interaction score is calculated as the relative dual task cost on the TUG (i.e. the difference between the TUG completion time performed with and without the kognitive task divided with the TUG completion time and multiplied by 100).
• Additionally the relative dual-task cost on the cognitive task is calculated as the difference between the number of words named per second with and without the motor task (TUG) divided with number of words named per second in sitting and multiplied by 100 (This value is not included in the diagram).
##### The z-scores

Because the scores of each domain are not measured on the same scale normalization is applied by transforming all scores to a z-score where μ is the mean of the normative values and σ is the standard deviation of the normative values.

Further, for measures where low scores equals "good" (RFSST, TAT, ASTS and CTUG) the z-score is multiplied by (-1) making scores comparable.

The average z-score is calculated as the mean of the z-scores of the six domains.

Please notice that currently the online calculator is only provided in danish and based on standard normative values. Language can currently be changed online manually.

The standard normative values applied are temporary results based on 527 primary elderly individuals  with balance impairment or dizziness (mean age is 79.4 years, 63.6 percent are women, 63.9 percent have fallen within 6 month before assessment).

We are currently undertaken studies to define precise normative values for various age groups, gender and pathologies.