Table 2: Pearson product-moment correlations between the relative motion index (RMI) during the active-instructed condition and subject characteristics, clinical findings, and laboratory findings.

RMI, active-instructed condition
People with LBPPeople without LBP
CorrelationsP valueCorrelationsP value

Gender0.5700.0270.2730.244
Age −0.1150.682−0.1200.613
Weight −0.1640.560−0.3180.171
Height −0.3930.149−0.3070.188
Spine length −0.4570.087−0.2950.206
Shank length −0.2510.368−0.4450.049
Passive hip lateral rotation*0.0280.9220.0300.900
Femoral anteversion 0.0220.9430.1910.420
Generalized joint hypermobility 0.2420.3840.0870.715
RMI , passive condition0.873<0.0010.1440.544
RMI, active condition0.6540.0080.2290.331

Abbreviations: HLR, hip lateral rotation; RMI, relative motion index.
Significant correlations indicated in bold-face type.
Passive hip lateral rotation with pelvis stabilized, measured in prone with an inclinometer.
Femoral anteversion measured with a goniometer using methods described by Ruwe et al. [37].
Generalized joint hypermobility measured with Beighton Hypermobility Scale [38].
Relative motion index calculated as the amount of HLR angular motion completed prior to the start of lumbopelvic motion.