Task-related and person-related variables influence the effect of low back pain on anticipatory postural adjustments

Abstract

Background People with low back pain exhibit altered postural coordination that has been suggested as a target for treatment, but heterogeneous presentation has rendered it difficult to identify appropriate candidates and protocols for such treatments. This study evaluated the associations of task-related and person-related factors with the effect of low back pain on anticipatory postural adjustments. Methods Thirteen subjects with and 13 without low back pain performed seated, rapid arm flexion in self-initiated and cued conditions. Mixed-model ANOVA were used to evaluate group and condition effects on APA onset latencies of trunk muscles, arm-raise velocity, and pre-movement cortical potentials. These measures were evaluated for correlation with pain ratings, Fear Avoidance Beliefs Questionnaire scores, and Modified Oswestry Questionnaire scores. Findings Delayed postural adjustments of subjects with low back pain were greater in the cued condition than in the self-initiated condition. The group with low back pain exhibited larger-amplitude cortical potentials than the group without pain, but also significantly slower arm-raise velocities. With arm-raise velocity as a covariate, the effect of low back pain remained significant for the latencies of postural adjustments but not for cortical potentials. Latencies of the postural adjustments significantly correlated with Oswestry and Fear Avoidance Beliefs scores. Interpretation Delayed postural adjustments with low back pain appear to be influenced by cueing of movement, pain-related disability and fear of activity. These results highlight the importance of subject characteristics, task condition, and task performance when comparing across studies or when developing treatment of people with low back pain.

Task-invariance and reliability of anticipatory postural adjustments in healthy young adults

“…Because this study investigated healthy participants, additional work utilizing multiple APA paradigms is needed to establish the extent of APA-task invariance in populations with clinical disorders that associate with modified anticipatory postural behavior [5,[28][29][30]. Indeed, the extent of task-invariance itself may be an indicator of disrupted control.…”

Postural Stability in Individuals with and without Sacroiliac Joint Dysfunction Before and After Pelvic Belt Application

“…Following our results, SIJD individuals showed lower values of APAs at the affected side before any interventions. As there were no similar studies in the literature, we could only compare the current results with those studies reported for CLBP (12,16,20,(33)(34)(35). Some of these studies reported increased postural sway while a few ones showed smaller postural sway for the CLBP group.…”

“…In other words, anticipatory reactions are launched by the individual, and then the CNS makes anticipatory corrections to predict postural perturbations. A group of studies suggested a complex relationship between LBP and APAs and decreased variability of APA onset latencies (16)(17)(18). Reaction time (RT) is the time interval from applying a stimulus to response, which could be increased in musculoskeletal disorders like LBP (19,20).…”

The Effect of Virtual Reality Training on Anticipatory Postural Adjustments in Patients with Chronic Nonspecific Low Back Pain: A Preliminary Study

“…Impaired postural control has been reported to involve APAs and CPAs of trunk muscles [ 28 , 29 ]. Most previous studies reported that delayed activation of abdominal muscles, especially TrA, in patients with CNLBP was commonly observed in patients with LBP in the postural control assessment, which may increase the recurrence of LBP in patients with CNLBP [ 4 , 30 , 31 ]. The potential reason was that the delayed muscle activation time of TrA in the APAs of patients with CNLBP was associated with remodeling of the motor cortex [ 32 ].…”