Table 3.

Linear regression model for repeated chair rise performance and alternative models to explore order effect, in older adults with CLBP (N = 50)^*

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	0.197	0.123	0.046**
2	Model 1 + flexion	0.190	0.315	0.001**
3	Model 2 + extension	0.027	0.329	0.179
4	Model 3 + average side-bending	0.001	0.313	0.777
Standardized β(P) for flexion, extension, & average side-bending = −0.385 (0.012),** −0.228 (0.253), & −0.058 (0.777)
Alternative model A: Altered order of trunk mobility variables with lumbar extension entered first
1A	Age, sex, BMI, current pain level	0.197	0.123	0.046**
2A	Model 1A + extension	0.114	0.230	0.012**
3A	Model 2A + flexion	0.103	0.329	0.011**
4A	Model 3A + average side-bending	0.001	0.313	0.777
Alternative model B: Altered order of trunk mobility variables with average side-bending entered first
1B	Age, sex, BMI, current pain level	0.197	0.123	0.046**
2B	Model 1B + average side-bending	0.083	0.195	0.033**
3B	Model 2B + flexion	0.115	0.307	0.008**
4B	Model 3B + extension	0.020	0.313	0.253

BMI = body mass index.

*Four outliers removed.

**P < 0.05.