Method

The Instrumented Six Minute Walk Test can be performed in the same way as a the non-instrumented version. The instrumented Six Minute Walk Test is performed on a straight walking trajectory with a length between 10 and 50 meters. At both ends of this trajectory the subject turns 180 degrees and continues walking in the opposite direction towards the turning point at the other end of the trajectory. The objective is to cover as much distance as possible within 6 minutes. The use of a walking aid and intermittent resting during the Instrumented Six Minute Walk Test are allowed.

Outcomes

Step Frequency and Step Length

Two more walking parameters are calculated for each trajectory: step frequency (Hz) and step length (m). The mean and SD for both parameters are given in het summary overview. A scatter plot is displayed for each parameter as well.

Number and Duration of Stops

Certain freedom is allowed when performing the 6-Minute Walk Test. It is e.g. allowed for subjects to take short intermittent breaks during the test. Both the number and duration of these stops are visually and numerically displayed.

Direction of Turns

An arrow alongside each turn graphically depicts whether the turn around the pylon was taken clockwise or anticlockwise.

Walking Speed

The average walking speed (kmh) over all trajectories is displayed in the summary overview. The walking speed of each individual trajectory (km/h and m/s) over time is displayed in a scatter plot. A trend line is fitted through the plot. Colours indicate how the walking speed of each trajectory compares to 'healthy' walking speed.

Comparison with Guidelines

The walked distance is compared with 6 widely used guidelines. The norm distance of each guideline is age, weight and height-dependent and hence varies per subject. Most guidelines are based on a walking trajectory of ± 30m. Therefore a guideline which gives a good representation of the walking distance for a trajectory length of 10m is added [1]. The walked distance is expressed as a percentage of the norm distance and colours indicate whether the norm was achieved, not achieved or if the lower limit was achieved (if applicable).

Total Distance Walked

The trajectory length should be given as input parameter before the start of the test. The trajectory length can vary between 10 and 50 meter. The total distance walked is automatically calculated based on the number of trajectories. The length of the final -incomplete- trajectory is estimated based on the time of the last incomplete walking trajectory and the previous walking speeds.

1. Beekman, E., Mesters, I., Gosselink, R., Klaassen, M. P. P., Hendriks, E. J. M., van Schayck, O. C. P., & de Bie, R. A. (2014). The first reference equations for the 6-minute walk distance over a 10 m course. Thorax Published Online First: 24 April 2014. doi: 10.1136/thoraxjnl-2014-205228.