Clinical observation of standing trunk movements: what do the aberrant movement patterns tell us?

Clinical measurement, cross-sectional study.

To investigate the reliability of observation of aberrant movement patterns (altered lumbopelvic rhythm, deviation from sagittal plane, instability catch or judder, and painful arc of motion) and to determine whether each pattern is associated with current low back pain (LBP).

Identification of aberrant movement patterns during trunk motion is an important component of subclassifying patients with LBP and prescribing evidence-based interventions. However, reported reliability for observation of specific aberrant patterns is low, and observation of any aberrant pattern (clinical definition of positive test) has ranged from poor to moderate. In addition, the validity of the association of clinical observations of aberrant movements during forward bending with LBP or dysfunction has yet to be determined.

Experienced physical therapists simultaneously observed trunk movements of 102 subjects with no LBP, current LBP, or history of LBP. Kappa statistics were used to evaluate interrater agreement in identifying different types of aberrant patterns. Associations were used to determine the validity of the hypothesized relationship between aberrant patterns and LBP.

Interrater reliability of identifying the different types of aberrant patterns in subjects with LBP ranged from fair (κ = 0.35; 95% confidence interval: 0.00, 0.71) to excellent (κ = 0.89; 95% confidence interval: 0.69, 1.00). Using the clinical definition of 1 observation of any aberrant motion, interrater agreement was substantial (κ = 0.65; 95% confidence interval: 0.00, 1.00). Significant association was found between judder, deviation, and LBP. The frequency of observed aberrant patterns was significantly associated with LBP.

Simultaneous observation for specific aberrant movement patterns suggests that identification can be performed with at least fair interrater agreement, and observation of any pattern with substantial agreement. Aberrant patterns are more frequently observed in patients with current complaints of LBP; however, they also appear in individuals with a history of LBP and no LBP.