The use of statistical parametric mapping to determine altered movement patterns in people with chronic low back pain

Kinematics studies have generally focused on the quantity of movement using discrete parameters such as maximum and minimum angles to compare between people with chronic low back pain (CLBP) and healthy individuals. However, discrete parameters cannot be used to fully describe movement patterns and segmental contributions. This study aimed to explore the use of Statistical Parametric Mapping (SPM) to characterize quality of movement by examining if differences in movement patterns exist between groups, and within-group segmental contributions, during active movement tests. Twenty-one individuals with CLBP and nine healthy individuals were recruited. Inertial Measurement Unit (IMUs) were attached at thoracic (T3) and lumbar (L1) spine, and pelvis (S1) to collect active trunk flexion, extension, rotation, and lateral bend. SPM was used to analyze between-group movement patterns and within-group segmental contributions. SPM revealed no significant differences (P > 0.05) between groups. However, a greater lumbar contribution (P < 0.001) was observed during 10-40% of flexion followed by a greater pelvic contribution (P < 0.001) during 60-90% of flexion, while a greater lumbar than thoracic contribution (P < 0.001) was observed during flexion and the return to upright position in individuals with CLBP. Individuals with CLBP used a greater thoracic contribution compared to lumbar contribution (P < 0.001) during rotation, while a greater lumbar contribution compared to pelvic contribution was observed (P < 0.001) during lateral bending. Our findings suggest that SPM approach was able to detect differences in thoracic, lumbar, and pelvic velocity contributions and timings between segments in individuals with CLBP. These findings may help improving inter-rater reliability of clinical observations.