Table 3.

Mixed effect multivariable linear regression modelling the association of jockey head displacement (m) with predictor variables; speed, days experience and TRIMP with the random effect of jockey interacting with ride type (exercise or trial riding).

Fixed effects	Estimates	CI		S.E		d.f	t-value	p
(Intercept)	0.18	0.16–0.20		9.7e-3		35	18.9	< 0.001
Days experience	-3.1e-6	-7.3e-6–1.2e-6		2.2e-6		17	-1.4	0.16
Speed	-8.3e-3	-9.6e-3 – -6.9e-3		6.5e-4		35	-12.7	< 0.001
TRIMP	0.012	0.003–0.021		4.5e-3		323	2.7	0.007
Random Effects
σ2 (residual variance)	5.7e-4
τ00 (Jockey: Ride Type) Between subjects variance	1.5e-4
ICC	0.21
N (Jockey)	14
N (Ride Type)	2
Observations	413
Marginal R2	0.66
Conditional R2	0.73