Fig 1.
Mobility measures presented in a framework with physical performance and physical activity as domains of physical function.
Activity classes are determined and for all types of physical activity total duration, number of periods and mean duration of periods are calculated.
Fig 2.
Participant wearing the activity monitor, located at the lower trunk.
Fig 3.
Raw acceleration signals (top panel) and a Gantt chart of classes of activity (bottom panel).
The blue or dark grey line represents longitudinal (x), green or light black mediolateral (y) and red or light grey anterior-posterior (z) axis of the accelerometer. During lying, the person turns from prone to the left side.
Table 1.
Descriptive statistics of all measures averaged over 49 participants.
Physical Performance and Physical Activity outcomes are expressed in weighted mean, standard deviation (SD), minimum and maximum values.
Table 2.
Spearman rank correlations between Age, Physical Performance and Physical Activity measures.
Physical performance measures includes 3xSTS, TUG, the three sub-scores and the total score of the SPPB. Physical activity scores include lying, sitting, standing and locomotion and from these total duration (Dur.), number of periods (#), mean duration of periods (Mean) and movement intensity (MI). Note that 3xSTS and TUG are expressed in seconds, where higher values indicate worse performance, whereas SPPB scores are expressed in scores of 0–4, where higher values indicate better performance.
Table 3.
Rotated component matrix using varimax rotation displaying the factor loadings of each variable on each factor.
The physical performance parameters include the duration of 3xSTS at self chosen speed, duration of he TUG and the three sub scores of the SPPB. The physical activity parameters include the number of sitting periods, the mean duration of the sitting periods, the total duration of standing, the number of standing periods, the total duration of locomotion and the number of locomotion periods. Note that 3xSTS and TUG are expressed in seconds, where higher values indicate worse performance, whereas SPPB scores are expressed in scores of 0–4, where higher values indicate better performance.
Fig 4.
Mean Movement Intensity and standard deviations per class of activity.
Differences between classes of activity were all significant (P < 0.01).