TABLE 1.

Logistic regression equations and regression coefficients of the four injury risk functions utilized in the prediction of injury, where α and β are the regression coefficients and x is the measured acceleration for the Pellman, linear, and rotational risk functions.

Equation	Logistic regression equation	Risk function	Regression coefficients
(2)	$R[a]=\frac{1}{1+e^{-\alpha +\beta x}}$	Linear (NFL)	α = −4.897, β = 0.0606
		Linear (Collegiate)	α = −9.805, β = 0.0510
		Rotational	α = −12.531, β = 0.0020
(3)	$\text{CP}=\frac{1}{1+e^{-({\beta }_o+{\beta }_1\alpha +{\beta }_2\alpha +{\beta }_3\alpha \alpha )}}$	Combined Probability (CP)	β0 = −10.2, β1 = 0.0433, β2 = 0.000873, β3 = −9.2E–07

β₀, β₁, β₂, and β₃ are the regression coefficients, a is the measured linear acceleration, and α is the measured rotational acceleration for the combined probability risk function.