Experimental determination of three-dimensional cervical joint mobility in the avian neck

Table 2 Regression results

Joint	Rotation	Variable	Coefficient	St. Err.	T value	p-value	Adj. r²	p-value
Cranial	axial rotation excursion	PC1 PC2 PC3	−5.8268 7.971 −6.5223	0.4825 0.7522 1.4763	−12.076 10.597 −4.418	<.001 <.001 <.001	0.9093	<.001
	lateroflexion excursion	PC1 PC2	−1.4410 6.112	0.6853 1.1422	−2.103 5.351	0.0449 <.001	0.5041	<.001
	dorsoventral excursion	PC2	−1.6532	0.8461	−1.954	0.0608	0.0886	0.06078
	mean dorsoventral flexion	PC1 PC2 PC3	6.6402 −5.8441 6.4364	0.6137 0.9567 1.8777	10.820 −6.108 3.428	<.001 <.001 0.0020	0.8627	<.001
Caudal	axial rotation excursion	PC1 PC2 PC3	−4.1545 7.6497 4.3237	0.8023 1.1911 2.2359	−5.178 6.422 1.934	<.001 <.001 0.0641	0.7681	<.001
	lateroflexion excursion	PC2 PC3	4.30274 3.955	1.3482 2.422	3.192 1.633	0.0037 0.1141	0.2957	0.003358
	dorsoventral excursion	PC3	−2.854	1.585	−1.801	0.0825	0.0718	0.08246
	mean dorsoventral flexion	PC1 PC2 PC3	4.9342 −7.6029 2.2219	0.5378 0.7984 1.4988	9.174 −9.522 1.482	<.001 <.001 .15	0.9025	<.001

Results of regressing range of motion on principal component scores for vertebrae. Each regression was run twice for the joint cranial to and then caudal to the vertebra. Rotation excursions are the differences between maximum and minimum angular values, while mean dorsoventral flexion is the average/midpoint between the maximum and minimum value. Only significant terms are shown. An adjusted R-squared and p-value is given for each model, and for each term the value of the coefficient, the standard error, and the t value and its p-value are given.

ISSN: 1742-9994