TABLE 4.

A. Contribution of total activity score and other factors to cortical area at the midshaft femur (N = 239).^†

Contributors	Cortical Area	Cortical Thickness
Model R2	0.132**	0.052
Total activity score	0.161*	0.145*
Body mass	0.189**	NS
Leg length	0.215**	NS

B. Contribution of physical scores and other factors to peripheral quantitative computed tomography measures at the midshaft femur using Iowa State University subjects only (N = 122).†‡
Contributors	Periosteal Circumference	Endosteal Circumference	Polar Moment of Inertia	Strength–Strain Index
Using peak strain score
Model R2	0.306**	0.233**	0.336**
Peak strain score	–0.206*	–0.210*	–0.189*	NS
Body mass	0.216*	0.140	0.280**
Leg length	0.356**	0.333**	0.329**
Using hip BLE score
Model R2			0.335**	0.320**
Hip BLE score	NS	NS	–0.190*	–0.222**
Body mass			0.281**	0.259**
Leg length			0.299**	0.262**
YSM			–0.162	–0.179*

C. Contribution of total activity score and other factors to peripheral quantitative computed tomography measures at the midshaft femur using University of California–Davis subjects only (N = 117).†
Contributors	Cortical Area	Polar Moment of Inertia
Model R2	0.241**	0.493**
Total activity score	0.208*	0.142*
Body mass	0.164	0.266**
Leg length	0.350**	0.550**

^*P < 0.05

^**P < 0.01.

^†Values are standardized regression coefficients. Models were generated using stepwise regression analysis and accounted for calcium and vitamin D intake, body mass, leg length, age, and years since menopause. Only outcome variables for which a physical activity scoring method was a significant contributor are shown.

^‡Total activity score was not a significant contributor to any peripheral quantitative computed tomography femur measure among Iowa State University subjects.