Signal | Category # | Parameter | Measure/parameter definition | Refs. |
---|---|---|---|---|
Angle | 1 | Onset Ang | Angle at the start of test response | [19] |
A0 | Knee angle at the beginning of the test during maximal limb extension | |||
αs initial angle | Initial Knee angle | [41] | ||
2 | F1 Ang | Angle at the end of initial movement into flexion | ||
F1 Amp | F1 Ang—Onset Ang | |||
Ex | First swing excursion: the difference between the starting angle (the position at which the examiner released the participant’s heel) and the first angle of reversal of the swinging limb | [59] | ||
P4 | First maximum of the oscillation | |||
FAR | knee angle when shank motion first switched from flexion to extension | [18] | ||
A1 | The amplitude of the first swing | |||
Magnitude of first drop | ||||
ϕmax | The first maximum of the goniogram after releasing the leg | [35] | ||
αp | The peak angle of the first swing | [41] | ||
Θ1 first reversal | First maximum of the oscillation | |||
3 | E1 Ang | Angle at the end of initial movement into extension | [38] | |
E1 Amp | F1 Ang—E1 Ang | [38] | ||
A2 | The angular change between the first minimum and second maximum | |||
4 | Rest Ang | Resting knee angle | ||
Rest angle (RA) θr | Knee angle at the end of oscillations | |||
Plat Amp | Rest Ang—onset Ang | |||
αf | Final position of the leg | [41] | ||
5 | Duration | Duration of oscillations | ||
T | Test duration | |||
Relative Swing Time | The time between the peaks, Normalized to the height of the person | |||
TFR | Time to first reversal: time interval between the start of shank motion and the first reversal from flexion to extension | [18] | ||
Test Duration | Duration from onset Angle to rest angle | [19] | ||
6 | F | Frequency of oscillations | ||
Frequency of the swing | ||||
C1 Freq | Initial cycle frequency = 1/duration of E1 Ang | [19] | ||
N | The number of sinusoidal waves produced by the swinging limb after the heel was released (minimum of 3 degrees) | |||
P2 | The Number of swings | |||
Ncyc | Number of cycles (full oscillations) was counted between start of motion and until the oscillation amplitudes is less than 3 degrees | [46] | ||
7 | RI | Relaxation index: (starting angle − first angle) / (starting angle − resting angle) | ||
F1 Amp / Plat Amp | [19] | |||
Θ1 / θr | [6] | |||
ERI | Extension Relaxation index = E1 Amp/ Plat Amp | |||
β | Damping ratio. Defined as the ratio of the logarithmic decrement (δ) to the period; expressed in sec | [43] | ||
λ | Defined as the natural log of the second to fourth peak amplitude ratio | [43] | ||
P1 | Normalized relaxation index | |||
P5 | Relaxation index at the half swing | |||
P6 | Average relaxation index of 10 successive swings | [38] | ||
Ratio 1 | Ratio 1: A1/(A1 − A2), where A1 is the amplitude of the first oscillation and A2 is the amplitude of the second oscillation | |||
Ratio R1 | Ratio R1: A/B, where A is the amplitude of the first oscillation and B is the amplitude of the second oscillation | |||
R1 ratio | The amplitude of the first swing (A) divided by the amplitude of the rebound angle | |||
Ratio 2 Ratio R2 R2 ratio | Ratio 2: A1/A0, where A0 is the final resting angle and A1 is the amplitude of the first oscillation | |||
R2: first swing (A) divided by the amplitude of the final position (C) | ||||
R2n | The normalized relaxation index. R2n: A1/1.6A0, where A0 is the knee angle between the full extension (starting position) and the neutral knee joint angle (end position), and A1 is the difference between the starting angle and the maximum flexion | |||
8 | AUC | Area Under Curve: area between the knee angle during oscillations and the resting angle; it is the integral of the absolute value of the knee angle | ||
P3 | ||||
Ptotal | The area between the goniogram and the time axis | [35] | ||
Relative area difference | Relative difference |P + − P-|/Ptotal between the positive and negative areas and the total area between the goniogram and the neutral line starting from the first minimum | [35] | ||
9 | PT | Total pendulum Score (combination of multiple parameters) | [35] | |
Angular velocity | 1 | ωmax | The maximum angular velocity of the shank | [35] |
Vmax | maximal velocity of the first swing (°/s) | |||
F1 Vel | Maximum velocity during F1 Amp | [19] | ||
P7 | First maximum of the tachogram | [38] | ||
2 | VFR | Velocity to first reversal: VFR = FAR / TFR | ||
3 | E1 Vel | Maximum velocity during E1 Amp | [19] | |
P8 | First minimum the tachogram | [38] | ||
ωmin | The minimum angular velocity of the shank | [35] | ||
Angular acceleration | 1 | F1 A/D ratio | Initial flexion acceleration/deceleration ratio = Max acceleration duration F1 Amp/ Max deceleration during F1 Amp | [19] |
First Maximum Acceleration | First Maximum Acceleration during flexion phase | [28] | ||
Max Acc on the rebound swing | Max Acceleration during extension phase | [28] |