Person-specific Characteristics of People with Low Back Pain Moderate the Preferred Movement Pattern within Motor Skill Training and Strength and Flexibility Exercise

Background People with chronic low back pain (LBP) display an altered movement pattern where the lumbar spine moves more readily into its available range of motion relative to other joints when performing a movement. Recently a randomized controlled trial was completed to compare the effects of motor skill training (MST) to strength and flexibility exercise (SFE). MST improved the altered pattern to a greater extent than SFE. However, there was substantial variability in the baseline and the change over time in the pattern. Understanding factors that influence this variability may ultimately be used to better target treatment strategies to the person. Objective Examine if gender, age, LBP duration, and the movement pattern at baseline moderate the baseline movement pattern and the change over time in the pattern within MST and SFE. Design: Secondary analysis of kinematic data from a single-blind, randomized controlled clinical trial. Setting Institutional Patients 154 patients with chronic LBP. Interventions Motor skill training and strength and flexibility exercise. Main outcome measures lumbar contribution (LC) to total movement. Results There was not a significant difference in baseline LC between MST and SFE (β=-2.39, CI=[-7.74, 2.96], p=0.38). SFE did not change LC over time (β=-0.11, CI=[-0.47, 0.24], p=0.53). However, there was a significant change over time in LC within MST (β=-2.13, CI=[-2.54, -1.48], p<0.001). Irrespective of treatment group, there was a trend for gender (β=-5.29, CI=[-10.34, 0.30], p=0.05) and age (β=-0.22, CI=[-0.46, 0.00], p=0.05) to moderate baseline LC. Age (β=0.01, CI=[0.00, 0.02], p = 0.04) and baseline LC (β=-0.07, CI=[-0.10, -0.04], p<0.01) were associated with the change over time in LC within MST only. Conclusions Person-specific characteristics moderate the baseline altered movement pattern within MST and SFE, as well as the change over time in the pattern within MST.