From protection to non-protection: A mixed methods study investigating movement, posture and recovery from disabling low back pain

Attentional Distractions Do Not Influence Lumbar Spine Local Dynamic Stability during Repetitive Flexion-Extension Movements

The association between low back pain and lumbar spine local dynamic stability (LDS) appears to be modulated by if and how someone catastrophizes about pain, suggesting that the cognitive perceptions of pain may influence an individual's ability to control lumbar spine motion. Previous work also demonstrates that directing cognitive resources and attentional focus can influence movement performance. Therefore, we aimed to examine whether distracting attentional focus would influence lumbar spine LDS during repetitive flexion-extension movements. Sixteen participants performed repetitive spine flexion-extension movements under two baseline conditions (pre- and post-), and while attentional focus was distracted by either an external sensory stimulus or a cognitive-motor dual-task, both targeted at the hands. Lumbar spine LDS was examined over 30 continuous movement repetitions using maximum Lyapunov exponents. In comparison to both Baseline and Post-Baseline trials, the perceived mental workload was significantly elevated during the cognitive-motor dual-task trial but not the external sensory stimulus trial. The only statistically significant effect on LDS occurred in the Post-Baseline trial, where LDS was higher than in the cognitive-motor dual-task. In combination with previous work, these findings suggest that distracting attentional focus during repetitive lumbar spine flexion-extension movements does not have a negative influence on lumbar spine LDS.

Can training to dissociate trunk and pelvic motion influence thorax-pelvis coordination and lumbar spine dynamic stability?

BACKGROUND

The large number of articulating joints within the spinal column provides an abundance of options to control its movement. However, the ability of individuals to consciously manipulate these movement options is poorly understood.

OBJECTIVES

To determine if short-term training can improve the ability to consciously dissociate motion between the pelvis and thorax during repetitive pelvic tilting movements.

DESIGN

Cross-over design with young healthy individuals.

METHOD

Seventeen participants performed trials consisting of 35 continuous lift/lowers followed by 35 continuous anterior/posterior pelvic tilts while spine kinematics were recorded. Participants then underwent a 20-min training protocol designed to improve the control of pelvic motion and in particular the dissociation of pelvic and trunk motion. Post-training, the continuous pelvic tilt and lift/lower trials were repeated. Thorax-pelvis movement coordination was analyzed via vector coding and lumbar spine local dynamic stability was analyzed via Lyapunov exponents. Participants were grouped as being either high or low skill movers based on their ability to perform the pre-training pelvic tilt movements.

RESULTS

The low skill movement group demonstrated statistically significant increases in the time spent using in-phase pelvic dominant (p = 0.028) and anti-phase pelvic dominant (p = 0.043) coordination patterns during the pelvic tilt movements after the completion of the training protocol. The high skill movement group showed no differences in their movement patterns post-training.

CONCLUSIONS

Short-term training, targeted to improve the ability to dissociate pelvic from thorax motion, had a beneficial effect on the group of individuals who initially lacked skill performing the pelvic tilting task.

The relationships between spinal amplitude of movement, pain and disability in low back pain: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The role of spinal movement alterations in low back pain (LBP) remains unclear. This systematic review and meta-analyses examined the relationships between spinal amplitude of movement, disability and pain intensity in patients with LBP.

DATABASES AND DATA TREATMENT

We searched PubMed, CINAHL, Embase, Pedro and Web of Science for relevant articles until 14th March 2023. Risk of bias was assessed with the Quality in Prognostic Studies Tool. We analysed the relationships between amplitude of movement, disability and pain intensity with standard correlational meta-analyses and meta-analytic structural equation modelling (MASEM) in cross-sectional and longitudinal data.

RESULTS

A total of 106 studies (9001 participants) were included. In cross-sectional data, larger amplitude of movement was associated with lower disability (pooled coefficient: -0.25, 95% confidence interval: [-0.29 to -0.21]; 69/5899 studies/participants) and pain intensity (-0.13, [-0.17 to -0.09]; 74/5806). An increase in amplitude of movement was associated with a decrease in disability (-0.23, [-0.31 to -0.15]; 33/2437) and pain intensity (-0.25, [-0.33 to -0.17]; 38/2172) in longitudinal data. MASEM revealed similar results and, in addition, showed that amplitude of movement had a very small influence on the pain intensity-disability relationship.

CONCLUSIONS

These results showed a significant but small association between amplitude of movement and disability or pain intensity. Moreover, they demonstrated a direct association between an increase in amplitude of movement and a decrease in pain intensity or disability, supporting interventions aiming to reduce protective spinal movements in patients with LBP.

SIGNIFICANCE

The large meta-analyses performed in this work revealed an association between reductions in spinal amplitude of movement and increased levels of disability and pain intensity in people with LBP. Moreover, it highlighted that LBP recovery is associated with a reduction in protective motor behaviour (increased amplitude of movement), supporting the inclusion of spinal movement in the biopsychosocial understanding and management of LBP.

Understanding Discrepancies in a Person's Fear of Movement and Avoidance Behavior: A Guide for Musculoskeletal Rehabilitation Clinicians Who Support People With Chronic Musculoskeletal Pain

BACKGROUND: Generic self-report measures do not reflect the complexity of a person's pain-related behavior. Since variations in a person's fear of movement and avoidance behavior may arise from contextual and motivational factors, a person-centered evaluation is required-addressing the cognitions, emotions, motivation, and actual behavior of the person. CLINICAL QUESTION: Most musculoskeletal rehabilitation clinicians will recognize that different people with chronic pain have very different patterns of fear and avoidance behavior. However, an important remaining question for clinicians is "How can I identify and reconcile discrepancies in fear of movement and avoidance behavior observed in the same person, and adapt my management accordingly?" KEY RESULTS: We frame a clinical case of a patient with persistent low back pain to illustrate the key pieces of information that clinicians may consider in a person-centered evaluation (ie, patient interview, self-report measures, and behavioral assessment) when working with patients to manage fear of movement and avoidance behavior. CLINICAL APPLICATION: Understanding the discrepancies in a person's fear of movement and avoidance behavior is essential for musculoskeletal rehabilitation clinicians, as they work in partnership with patients to guide tailored approaches to changing behaviors. J Orthop Sports Phys Ther 2023;53(5):1-10. Epub: 9 March 2023. doi:10.2519/jospt.2023.11420.

Distinction of non-specific low back pain patients with proprioceptive disorders from healthy individuals by linear discriminant analysis

The central nervous system (CNS) dynamically employs a sophisticated weighting strategy of sensory input, including vision, vestibular and proprioception signals, towards attaining optimal postural control during different conditions. Non-specific low back pain (NSLBP) patients frequently demonstrate postural control deficiencies which are generally attributed to challenges in proprioceptive reweighting, where they often rely on an ankle strategy regardless of postural conditions. Such impairment could lead to potential loss of balance, increased risk of falling, and Low back pain recurrence. In this study, linear and non-linear indicators were extracted from center-of-pressure (COP) and trunk sagittal angle data based on 4 conditions of vibration positioning (vibration on the back, ankle, none or both), 2 surface conditions (foam or rigid), and 2 different groups (healthy and non-specific low back pain patients). Linear discriminant analysis (LDA) was performed on linear and non-linear indicators to identify the best sensory condition towards accurate distinction of non-specific low back pain patients from healthy controls. Two indicators: Phase Plane Portrait _ML and Entropy _ML with foam surface condition and both ankle and back vibration on, were able to completely differentiate the non-specific low back pain groups. The proposed methodology can help clinicians quantitatively assess the sensory status of non-specific low back pain patients at the initial phase of diagnosis and throughout treatment. Although the results demonstrated the potential effectiveness of our approach in Low back pain patient distinction, a larger and more diverse population is required for comprehensive validation.