From: Review of fall risk assessment in geriatric populations using inertial sensors
Category | Variable | Sensor location |
---|---|---|
Position and Angle Variables | AP peak to peak amplitude | LB [52] |
ML peak to peak amplitude | LB [52] | |
V peak to peak amplitude | LB [52] | |
AP and ML postural sway length during stance | ||
Trunk tilt | St [44] | |
Angular Velocity Variables | Min, mean, max AP | Sha [50] |
Min, mean, max ML | Sha [50] | |
Min, mean, max V | Sha [50] | |
AP peak to peak amplitude | LB [52] | |
ML peak to peak amplitude | Sha [50] | |
V peak to peak amplitude | LB [52] | |
Postural sway velocity during stance | ||
Mean squared modulus ratio for postural sway | ||
AP RMS during stance | LB [51] | |
ML RMS during stance | LB [51] | |
V RMS during stance | LB [51] | |
3D RMS during stance | LB [51] | |
ML variability | UB [73] | |
Linear Acceleration Variables | Median AP | LB [74] |
SD of AP | ||
Peak AP | UB [75] | |
Peak V | UB [75] | |
AP peak to peak amplitude | LB [52] | |
ML peak to peak amplitude | ||
V peak to peak amplitude | LB [52] | |
AP RMS | ||
ML RMS | ||
V RMS | ||
AP RMS during stance | LB [51] | |
ML RMS during stance | LB [51] | |
V RMS during stance | LB [51] | |
2D RMS (ML and AP) during stance | LB [43] | |
3D RMS | ||
3D RMS during stance | LB [51] | |
Jerk | St [42] | |
Sit to stand AP range | LB [74] | |
Stand to sit AP range | LB [74] | |
Sit to stand Jerk | LB [74] | |
Dissimilarity of AST subcomponents | ||
Dissimilarity of STS subcomponents | ||
Spatial Variables | Number of steps | |
Step length | ||
Temporal Variables | Gait Speed | |
Cadence | ||
Step duration | ||
Step duration variability | ||
Stride time | Fo [71] | |
SD of stride time | Fo [71] | |
% GC double support | Sha [50] | |
TUG time | ||
TUG subcomponent time | ||
TUG: number of gait cycles | Sha [50] | |
STS time | LB [66] | |
STS subcomponent times | ||
SD of STS subcomponent times | LB [66] | |
Normalized SD of STS subcomponent times | ||
Sit/stand transition duration | ||
Sit/stand SD of transition duration | St [17] | |
AST time | LB [66] | |
AST subcomponent times | ||
SD of AST subcomponent times | LB [66] | |
Normalized SD of AST subcomponent times | ||
Energy Variables | Kinetic Energy | LB [49] |
Local wavelet energy | St [45] | |
Summed magnitude area of acceleration | ||
25% quartile frequency | ||
50% quartile frequency | ||
75% quartile frequency | ||
Sway frequency during stance | LB [51] | |
Number of FFT peaks | ||
Dominant FFT peak parameters | ||
1st FFT peak parameters | ||
Ratio of magnitude of even harmonics to odd harmonics | ||
Area under 1st 6 harmonics divided by remaining area | ||
Ratio of 1st 4 harmonics to magnitude of 1st 6 harmonics | ||
ML spectral edge frequency | St [42] | |
Entropy of power spectrum | LB [53] | |
Correlation between left and right arm signals | ||
Maximum V acceleration Lyapunov Exponent | ||
Maximum AV Lyapunov Exponent | ||
Autocorrelation coefficients of acceleration signal | ||
Trunk level forces | St [45] | |
Continuous wavelet transform | LB [63] | |
Discrete wavelet transform | ||
Detrended fluctuation fractal scaling index of acceleration derived stride time | Fo [69] | |
Fractal dimension of acceleration versus AV | St [45] | |
Number of abnormal sit/stand transitions | St [17] |