Table 4.

Linear regression model for TUG performance and alternative models to explore order effect, in older adults with CLBP (N = 54)

Model	Independent variables	R2 change	Adjusted R2	P change
Regression model: Lumbar flexion entered first into regression analysis
1	Age, sex, BMI, current pain level	0.390	0.340	< 0.001*
2	Model 1 + flexion	0.089	0.425	0.006*
3	Model 2 + extension	0.039	0.456	0.057
4	Model 3 + average side-bending	0.001	0.446	0.769
Standardized β(P) for flexion, extension, & average side-bending = −0.230 (0.085), −0.259 (0.112), & 0.051 (0.769)
Alternative model A: Altered order of trunk mobility variables with lumbar extension entered first
1A	Age, sex, BMI, current pain level	0.390	0.340	< 0.001*
2A	Model 1A + extension	0.096	0.432	0.004*
3A	Model 2A + flexion	0.033	0.456	0.081
4A	Model 3A + average side-bending	0.001	0.446	0.769
Alternative model B: Altered order of trunk mobility variables with average side-bending entered first
1B	Age, sex, BMI, current pain level	0.390	0.340	< 0.001*
2B	Model 1B + average side-bending	0.064	0.397	0.022*
3B	Model 2B + flexion	0.038	0.426	0.069
4B	Model 3B + extension	0.028	0.446	0.112

TUG = timed up-and-go test; CLBP = chronic low back pain; BMI = body mass index.

*P < 0.05.