Table 3.

Regression equation constants for predicting Achilles tendon stiffness from body mass and peak plantarflexor force and Young's modulus (YM) from age, body mass and peak stress in the form of Y = a(mass²) + b(mass) + c(force) + d(stress) + e(age²) + f(age) + Z. Coefficients of determination (adjusted R²) are also shown

Group	Dependent variable (Y)	Mass2a	Mass b	Force c	Stress d	Age2e	Age f	Constant C	Adj R2
Children	StiffnessREL	–	4.141	0.032	–	–	–	−28.375	0.66
	StiffnessABS	–	3.164	–	–	–	–	41.072	0.19
	YMREL	–	12.462	–	7.061	–	–	−124.507	0.45
	YMABS	–	6.783	–	6.538	–	–	35.294	0.29
All ages	StiffnessREL	−0.047	5.995	0.023	–	–	–	−30.792	0.78
	StiffnessABS	−0.031	0.649	0.029	–	–	−3.343	38.433	0.55
	YMREL	–	4.779	–	5.027	−1.760	57.313	−171.819	0.61
	YMABS	–	7.196	–	6.319	−0.559	–	69.736	0.47