Strength, mobility, their changes, and pain reduction in active functional restoration for chronic low back disorders

The association between subjective experience in pain reduction and objective measurements in improvement of physical functioning was analyzed with chronic low back pain (CLBP) patients (n = 143) who attended a 12-week multidimensional back treatment program emphasizing active functional restoration. Low back flexion-extension, lateral flexion and rotation, isometric strength, and mobility and their changes were measured. The results showed that 79% of the subjects reported subjective decrease in LBP during the 12-week restoration program, and simultaneous increases in isometric strength and mobility also were measured in approximately 80% of the subjects. Concordance of these findings was high, i.e., the reduction of pain and improvement of function occurred mostly in the same subjects. However, the correlations between physical functioning parameters and pain reduction were low (rs below 0.22). Baseline strength and mobility values did not differ between those who benefited from the treatment regarding pain and those who did not. Thus, absolute levels at the baseline or magnitude of changes in the measurements of maximum isometric strength or mobility were not associated with pain reduction. The results indicate that subjective pain reduction is significantly associated with improvement per se in trunk muscle function and spinal mobility during active functional restoration, but not with the magnitude of the improvements. This should be considered when designing rehabilitation programs and outcome criteria for rehabilitation.