Table 1. Results of stepwise multiple regression predicting the inter-trial variability of the individual inter-keystroke intervals (IKIs).

		Kinematics of the striking finger at the moment of a keypress						Correlation coefficient of the finger movements during two successive keystrokes
								between a striking finger and the first finger from the radial			between a striking finger and the second finger from the radial			between a striking finger and the third finger from the radial
		Joint angle			Joint angular velocity			Joint angular velocity			Joint angular velocity			Joint angular velocity
		DIP	PIP	MCP	DIP	PIP	MCP	DIP	PIP	MCP	DIP	PIP	MCP	DIP	PIP	MCP
First IKI	coef.	0.072	0.020	-0.127	0.083	0.181	-0.210	0.030	-0.107	-0.125	-0.088	-0.051	-0.109	0.082	-0.064	-0.041
	p	0.386	0.817	0.122	0.381	0.030	0.012	0.720	0.193	0.142	0.292	0.535	0.182	0.327	0.483	0.620
Second IKI	coef.	-0.144	-0.036	0.216	0.065	-0.005	0.003	0.130	0.183	-0.097	-0.115	-0.020	-0.057	0.001	0.043	0.003
	p	0.087	0.699	0.010	0.433	0.952	0.975	0.115	0.028	0.244	0.170	0.812	0.493	0.989	0.620	0.968
Third IKI	coef.	-0.093	0.099	0.018	-0.056	0.231	0.002	-0.146	-0.034	-0.257	-0.144	-0.079	-0.038	0.074	0.326	0.074
	p	0.254	0.217	0.822	0.494	0.009	0.976	0.092	0.687	0.002	0.075	0.348	0.649	0.365	0.000	0.375
Fourth IKI	coef.	-0.028	-0.074	-0.089	0.033	0.098	-0.082	0.115	-0.079	0.015	0.088	0.015	-0.008	0.094	-0.006	0.052
	p	0.747	0.385	0.293	0.696	0.249	0.333	0.176	0.354	0.863	0.301	0.862	0.926	0.271	0.948	0.544
Fifth IKI	coef.	-0.090	-0.016	0.143	0.045	0.071	-0.252	0.096	0.046	0.080	-0.054	-0.013	0.146	-0.075	-0.033	0.053
	p	0.275	0.851	0.084	0.591	0.400	0.003	0.251	0.575	0.337	0.513	0.876	0.091	0.371	0.693	0.523
Sixth IKI	coef.	-0.058	0.159	0.030	0.202	-0.139	-0.102	0.083	0.099	0.112	-0.025	-0.016	0.123	-0.016	0.089	0.092
	p	0.508	0.057	0.723	0.017	0.096	0.229	0.326	0.241	0.186	0.763	0.849	0.152	0.853	0.294	0.282
Seventh IKI	coef.	0.008	-0.103	-0.031	0.131	0.147	-0.009	-0.093	-0.024	-0.233	0.099	0.003	0.001	0.153	0.028	-0.029
	p	0.922	0.224	0.719	0.115	0.076	0.913	0.269	0.771	0.006	0.242	0.971	0.993	0.064	0.738	0.724

A number in bold indicates p < 0.05.