Table 3.

Trunk stiffness and damping coefficients normalized to body mass, onset times of the lumbar (OnTime_lumb) and thoracic (OnTime_thorac) erector spinae muscles after release and maximum Lyapunov exponent (λ_max) for the four groups of participants: elite athletes (athletes), with (LBP) and without (healthy) chronic non-specific low-back pain and participants of the general population (non-athletes), also with and without chronic non-specific low-back pain (means ± standard deviation).

	Non-athletes		Athletes
	Healthy (n = 14)	LBP (n = 15)	Healthy (n = 15)	LBP (n = 15)
Trunk stiffness coefficient [Nm/(rad∗kg)]	15.06 ± 5.63	11.51 ± 2.33	12.34 ± 2.60	12.73 ± 4.64
Trunk damping coefficient [Nm∗s/(rad∗kg)]∗	0.01 ± 0.47	0.32 ± 0.37	0.17 ± 0.31	0.36 ± 0.45
OnTimelumb [ms]∗	79 ± 5	78 ± 9	81 ± 7	74 ± 5
OnTimethorac [ms]∗	82 ± 8	77 ± 8	78 ± 2	73 ± 8
λmax	1.91 ± 0.33	1.69 ± 0.31	1.84 ± 0.33	1.90 ± 0.36

^∗Significant (p < 0.05) low-back pain effect (healthy vs. low-back pain participants) in both groups (athletes and non-athletes).