stX, stY, stZ

Static acceleration (body posture) in each separate axis

[17, 54,55,56]

dyX, dyY, dyZ

Dynamic acceleration in each separate axis

[23, 54, 55, 57]

PBDAx, PBDAy, PBDAz

Partial dynamic body acceleration (absolute acceleration in each axis)

[40, 58, 59]

ODBA

Overall dynamic body acceleration

[60, 61]

VeDBA, VeDBAs

Vectorial dynamic body acceleration, smoothed
 
ratioX, ratioY, ratioZ

Ratio of VeDBA to PDBA

[25]

jerkX, jerkY, jerkZ

Jerk, derivative of acceleration, in each separate axis

[18]

jerkN

Norm of jerk in all axes
 
Pitch, Roll

Pitch and roll in radians

[54]

PSD1x, PSD1y, PSD1z

Primary dominant power spectrum density in each axis

[25, 62]

PSD2x, PSD2y, PSD2z

Secondary dominant power spectrum density in each axis
 
Freq1x, Freq1y, Freq1z

Frequency corresponding to the primary dominant power spectrum density in each axis
 
Freq2x, Freq2y, Freq2z

Frequency corresponding to the secondary dominant power spectrum density in each axis
 