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Comparison of programs for determining temporal-spatial gait variables from instrumented walkway data: PKmas versus GAITRite.

Egerton T, Thingstad P, Helbostad JL - BMC Res Notes (2014)

Bottom Line: There were systematic differences for Base Width (PKmas® values 1.6 cm lower than GAITRite®) and Foot Angle (PKMAS® values 0.7° higher than GAITRite®).The study demonstrated that for most variables the outcomes from both programs can be used interchangeably for evaluation of gait among older people collected with GAITRite® hardware.However, validity and reliability for Base Width and Foot Angle derived by PKMAS® would benefit from further investigation.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. thor@sutmap.com.

ABSTRACT

Background: Measurement of temporal-spatial gait variables is common in aging research with several methods available. This study investigated the differences in temporal-spatial gait outcomes derived from two different programs for processing instrumented walkway data.

Method: Data were collected with GAITRite® hardware from 86 healthy older people and 44 older people four months following surgical repair of hip fracture. Temporal-spatial variables were derived using both GAITRite® and PKmas® processing programs from the same raw footfall data.

Results: The mean differences between the two programs for most variables were negligible, including for Speed (mean difference 0.3 ± 0.6 cm/sec, or 0.3% of the mean GAITRite® Speed). The mean absolute percentage difference for all 18 gait variables examined ranged from 0.04% for Stride Duration to 66% for Foot Angle. The ICCs were almost perfect (≥0.99) for all variables apart from Base Width, Foot Angle, Stride Length Variability, Step Length Variability, Step Duration Variability and Step Width Variability, which were all never-the-less above 0.84. There were systematic differences for Base Width (PKmas® values 1.6 cm lower than GAITRite®) and Foot Angle (PKMAS® values 0.7° higher than GAITRite®). The differences can be explained by the differences in definitions and calculations between the programs.

Conclusions: The study demonstrated that for most variables the outcomes from both programs can be used interchangeably for evaluation of gait among older people collected with GAITRite® hardware. However, validity and reliability for Base Width and Foot Angle derived by PKMAS® would benefit from further investigation.

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Related in: MedlinePlus

Associations between GAITRite® and PKMAS® data. Scatter plots showing the associations between GAITRite® and PKMAS® data, and Bland-Altman plots showing mean difference and 95% limits of agreement for Speed, Base Width, Step Length Variability and Stride Duration Variability. ● = healthy older people, ○ = post hip fracture patients.
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Fig1: Associations between GAITRite® and PKMAS® data. Scatter plots showing the associations between GAITRite® and PKMAS® data, and Bland-Altman plots showing mean difference and 95% limits of agreement for Speed, Base Width, Step Length Variability and Stride Duration Variability. ● = healthy older people, ○ = post hip fracture patients.

Mentions: Scatter plots and Bland-Altman plots are shown for Speed, Base Width, Step Length Variability and Stride Duration Variability in Figure 1. The plot for Base Width shows >95% of differences were negative indicating that PKmas® Base Width values were systematically lower than the GAITRite® values. The plots for Stride Duration Variability (not shown) and Step Duration Variability showed greater differences for lower values of variability which affected only a small number of healthy participants. Apart from these two variables the plots showed even spread of differences over the range of values.Figure 1


Comparison of programs for determining temporal-spatial gait variables from instrumented walkway data: PKmas versus GAITRite.

Egerton T, Thingstad P, Helbostad JL - BMC Res Notes (2014)

Associations between GAITRite® and PKMAS® data. Scatter plots showing the associations between GAITRite® and PKMAS® data, and Bland-Altman plots showing mean difference and 95% limits of agreement for Speed, Base Width, Step Length Variability and Stride Duration Variability. ● = healthy older people, ○ = post hip fracture patients.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4150969&req=5

Fig1: Associations between GAITRite® and PKMAS® data. Scatter plots showing the associations between GAITRite® and PKMAS® data, and Bland-Altman plots showing mean difference and 95% limits of agreement for Speed, Base Width, Step Length Variability and Stride Duration Variability. ● = healthy older people, ○ = post hip fracture patients.
Mentions: Scatter plots and Bland-Altman plots are shown for Speed, Base Width, Step Length Variability and Stride Duration Variability in Figure 1. The plot for Base Width shows >95% of differences were negative indicating that PKmas® Base Width values were systematically lower than the GAITRite® values. The plots for Stride Duration Variability (not shown) and Step Duration Variability showed greater differences for lower values of variability which affected only a small number of healthy participants. Apart from these two variables the plots showed even spread of differences over the range of values.Figure 1

Bottom Line: There were systematic differences for Base Width (PKmas® values 1.6 cm lower than GAITRite®) and Foot Angle (PKMAS® values 0.7° higher than GAITRite®).The study demonstrated that for most variables the outcomes from both programs can be used interchangeably for evaluation of gait among older people collected with GAITRite® hardware.However, validity and reliability for Base Width and Foot Angle derived by PKMAS® would benefit from further investigation.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. thor@sutmap.com.

ABSTRACT

Background: Measurement of temporal-spatial gait variables is common in aging research with several methods available. This study investigated the differences in temporal-spatial gait outcomes derived from two different programs for processing instrumented walkway data.

Method: Data were collected with GAITRite® hardware from 86 healthy older people and 44 older people four months following surgical repair of hip fracture. Temporal-spatial variables were derived using both GAITRite® and PKmas® processing programs from the same raw footfall data.

Results: The mean differences between the two programs for most variables were negligible, including for Speed (mean difference 0.3 ± 0.6 cm/sec, or 0.3% of the mean GAITRite® Speed). The mean absolute percentage difference for all 18 gait variables examined ranged from 0.04% for Stride Duration to 66% for Foot Angle. The ICCs were almost perfect (≥0.99) for all variables apart from Base Width, Foot Angle, Stride Length Variability, Step Length Variability, Step Duration Variability and Step Width Variability, which were all never-the-less above 0.84. There were systematic differences for Base Width (PKmas® values 1.6 cm lower than GAITRite®) and Foot Angle (PKMAS® values 0.7° higher than GAITRite®). The differences can be explained by the differences in definitions and calculations between the programs.

Conclusions: The study demonstrated that for most variables the outcomes from both programs can be used interchangeably for evaluation of gait among older people collected with GAITRite® hardware. However, validity and reliability for Base Width and Foot Angle derived by PKMAS® would benefit from further investigation.

Show MeSH
Related in: MedlinePlus