Table 1.

Irregular motion models.

Motion model	Motion pattern	Longitudinal range (mm)	Period (sec)
Slightly irregular (S‐I)	Period and amplitude variation ≤10%	18.6 ± 0.3	2.83 ± 0.10
Amplitude irregular (A‐I)	Amplitude variation ≥30%	16.9 ± 2.2	3.47 ± 0.35
Period irregular (P‐I)	Period variation ≥30%	17.8 ± 0.7	4.35 ± 0.78
Period and amplitude irregular (P+A‐I)	Period and amplitude variation ≥30%	13.3 ± 3.0	3.50 ± 1.07