Original living room, Kangaroo Point House, Kangaroo Point, Brisbane

Original living room, looking through to new outdoor room.

Original living room, Kangaroo Point House, Kangaroo Point, Brisbane

As seen from outdoor room.

Individual calibration for estimating free-living walking speed using the MTI monitor

Purpose: This study was conducted to devise a new individual calibration method to enhance MTI accelerometer estimation of free-living level walking speed. Method: Five female and five male middle-aged adults walked 400 m at 3.5, 4.5, and 5.5 km(.)h(-1), and 800 in at 6.5 km(.)h(-1) on an outdoor track, following a continuous protocol. Lap speed was controlled by a global positioning system (GPS) monitor. MTI counts-to-speed calibration equations were derived for each trial, for each subject for four such trials with each of four MTI, for each subject for the average MTI. and for the pooled data. Standard errors of the estimate (SEE) with and without individual calibration were compared. To assess accuracy of prediction of free-living walking speed, subjects also completed a self-paced, brisk 3-km walk wearing one of the four MTI, and differences between actual and predicted walking speed with and without individual calibration were examined. Results: Correlations between MTI counts and walking speed were 0.90 without individual calibration, 0.98 with individual calibration for the average MTI. and 0.99 with individual calibration for a specific MTI. The SEE (mean +/- SD) was 0.58 +/- 0.30 km(.)h(-1) without individual calibration, 0.19 +/- 0.09 km h(-1) with individual calibration for the average MTI monitor, and 0.16 +/- 0.08 km(.)h(-1) with individual calibration for a specific MTI monitor. The difference between actual and predicted walking speed on the brisk 3-km walk was 0.06 +/- 0.25 km(.)h(-1) using individual calibration and 0.28 +/- 0.63 km(.)h(-1) without individual calibration (for specific accelerometers). Conclusion: MTI accuracy in predicting walking speed without individual calibration might be sufficient for population-based studies but not for intervention trials. This individual calibration method will substantially increase precision of walking speed predicted from MTI counts.

Outdoor room, C House, Coorparoo, Brisbane

As seen from upper level of house.

Outdoor room, C House, Coorparoo, Brisbane

Looking towards pool deck, Hanging Basket top right.

Outdoor room, C House, Coorparoo, Brisbane

As seen from upper level of house.

Outdoor room, C House, Coorparoo, Brisbane

Looking towards Iwan from within outdoor room.

Outdoor room, Q House, Chelmer, Brisbane

View from front of property through main entrance to double-height outdoor room. Existing house on right.

Side boundary wall, Q House, Chelmer, Brisbane

Stepped out lower section of wall houses seating, shelving and water features to outdoor room and living areas.

Outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Looking towards section of original house from outdoor room area. Hand-made spotted gum columns on edge of outdoor room on right.

Battened roof to outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Timber battened concave roof and supporting structure over outdoor room area.

Outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Dining setting, sculptures, timber columns and curved roof in outdoor room