Table 2. Difference of average RMSSD (ms) of horses between the experienced rider (regular reins) and beginner rider (regular reins & buffer reins)

	Rider	Reins	Walk	Rising trot	Sitting trot
RMSSD (ms)	Experienced rider (E)	Regular (a)	26.51 ± 6.50 (100.00%)	10.05 ± 3.68 (37.91%)	11.05 ± 3.34 (41.68%)
	Beginner rider (B)	Regular (a)	20.32 ± 5.54 (76.65%)	8.29 ± 3.16 (37.27%)	6.43 ± 1.831) (24.25%)
	Beginner rider (B)	Buffer (b)	22.84 ± 8.42 (86.16%)	17.46 ± 10.83 (65.86%)	8.97 ± 2.87 (33.84%)

Significantly different (p < 0.05) from sitting trot of experienced rider equipped regular reins.
RMSSD, root mean square of successive differences.