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Table 3 Significant inertial-sensor-based variables (p < 0.05) with associated sensor location

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

LB [43, 51]

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

LB [43, 51]

Mean squared modulus ratio for postural sway

LB [46–48]

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

He [18], LB [74], Hi [18]

Peak AP

UB [75]

Peak V

UB [75]

AP peak to peak amplitude

LB [52]

ML peak to peak amplitude

LB [49, 52, 60]

V peak to peak amplitude

LB [52]

AP RMS

He [55], LB [55]

ML RMS

He [55], LB [55]

V RMS

He [55], LB [55, 71]

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

LB [1, 57]

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

LB [57, 67]

Dissimilarity of STS subcomponents

LB [67, 68, 70]

Spatial Variables

Number of steps

LB [60], Sha [50]

Step length

He [64], LB [60, 64, 72]

Temporal Variables

Gait Speed

He [55, 64], LB [40, 44, 55, 64, 72, 74]

Cadence

He [64], LB [39, 58, 64], Kn [41], Sha [50], An [41]

Step duration

LB [74], Sha [50]

Step duration variability

He [55], LB [55]

Stride time

Fo [71]

SD of stride time

Fo [71]

% GC double support

Sha [50]

TUG time

LB [66, 74], Sha [50]

TUG subcomponent time

LB [57, 66], Sha [50]

TUG: number of gait cycles

Sha [50]

STS time

LB [66]

STS subcomponent times

LB [57], Th [42]

SD of STS subcomponent times

LB [66]

Normalized SD of STS subcomponent times

LB [58, 66]

Sit/stand transition duration

St [17, 45]

Sit/stand SD of transition duration

St [17]

AST time

LB [66]

AST subcomponent times

LB [57, 58, 68, 70]

SD of AST subcomponent times

LB [66]

Normalized SD of AST subcomponent times

LB [67, 68, 70]

Energy Variables

Kinetic Energy

LB [49]

Local wavelet energy

St [45]

Summed magnitude area of acceleration

LB [57, 58, 67]

25% quartile frequency

He [18], Hi [18]

50% quartile frequency

He [18], Hi [18]

75% quartile frequency

He [18], Hi [18]

Sway frequency during stance

LB [51]

Number of FFT peaks

LB [61, 62]

Dominant FFT peak parameters

LB [59, 61, 62]

1st FFT peak parameters

Sho [41], El [41], Wr [41], Kn [41], An [41]

Ratio of magnitude of even harmonics to odd harmonics

He [55, 64], UB [44, 75], LB [44, 50, 52, 53, 59, 72]

Area under 1st 6 harmonics divided by remaining area

LB [57, 58]

Ratio of 1st 4 harmonics to magnitude of 1st 6 harmonics

LB [57, 58]

ML spectral edge frequency

St [42]

Entropy of power spectrum

LB [53]

Correlation between left and right arm signals

Sho [41], El [41], Wr [41]

Maximum V acceleration Lyapunov Exponent

Hi [56], Kn [56], An [56]

Maximum AV Lyapunov Exponent

UB [73], Hi [56], Kn [56], An [56]

Autocorrelation coefficients of acceleration signal

LB [39, 65]

Trunk level forces

St [45]

Continuous wavelet transform

LB [63]

Discrete wavelet transform

St [45], LB [63]

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]

  1. An, ankle, AP, anteroposterior, AST, Alternating Step Test, AV, angular velocity, COP, center of pressure, CoV, coefficient of variation, El, elbow, FFT, Fast Fourier Transform, Fo, foot, He, head, Hi, hip, GC, gait cycle, Kn, knee, LB, lower back, ML, mediolateral, RMS, Root Mean Square, SD, standard deviation, Sha, shank, Sho, shoulder, St, sternum, STS, sit-to-stand transitions, Th, thigh, TUG, Timed Up and Go, UB, upper back, V, vertical, Wr, wrist.