Background:
Exercise is recommended as first line management for chronic non-specific low back pain (CLBP), the main cause for years lived with disability. The long-term benefits of exercise are evident, but short-term benefits are less explored. The phenomenon of exercise-induced hypoalgesia (EIH) describes a temporary decrease in pain sensitivity following exercise. Whilst several systematic reviews have confirmed that EIH occurs in asymptomatic people, there is a lack of research investigating people with spinal pain and the stability of the effects of EIH over repeated sessions.
Our recent rigorous systematic review (CRD42019145586) of 22 observational studies (n=807 participants) investigated whether EIH occurs for people with spinal. Specifically for people with CLBP, eight studies (n=352 participants) assessed eleven tasks with low-quality evidence for conflicting results (absent/altered EIH). These findings supported the need for low risk of bias studies assessing EIH in people with/without CLBP following local lumbar and remote tasks and thus informed this exploratory research.

Purpose:
To explore the occurrence and stability of EIH following different tasks and across repeated sessions in people with/without CLBP.

Methods:
A pragmatic observational study was conducted within a university setting according to the STROBE statement. Based on the sample size calculation, 30 participants with CLBP and 30 asymptomatic participants were allocated to six sessions of an individually tailored standardised task (n=15 each group): A) local dynamic lumbar resistance task (~12 minutes), B) remote brisk walking task (~15 minutes). Another ten asymptomatic participants did not exercise and rested instead (Task C). Changes in pain sensitivity indicative of EIH were assessed via an extensive quantitative sensory test battery immediately before and after each session. Lumbar pressure pain thresholds (PPT) were the primary outcome measure. A repeated-measures ANOVA was applied to determine the presence of EIH, and stability was assessed using the ICC (3,1).

Results:
Participants (n=70, 53% women, mean age 25±5 years, CLBP groups: minimal disability level) demonstrated EIH regardless of the task or the group (p≤ .035). Lumbar PPT changed following the local task A in participants with CLBP [mean PPT +42.30kPa, 95%CI 7.20;77.40] and asymptomatic participants [+63.44kPa, 28.33;98.54] and following the remote task B for CLBP [+35.39kPa, 5.58;65.21] and for asymptomatic participants [+39.03kPa, 9.21;68.84]. However, similar changes in lumbar PPT also occurred after rest only for task C [+35.46kPa, 16.36;54.55].
The stability of EIH effects was poor regardless of the group and task (ICC (3,1) ≤.303).

Conclusion(s):
In this study, significant changes indicative of EIH occurred in both CLBP and asymptomatic participants regardless of the nature of the task they were assigned (lifting (task A), walking (B), rest (C)). Furthermore, the poor stability of EIH requires further investigation.

Implications:

Current evidence supports inconsistent findings on whether EIH is altered in people with CLBP based on low-quality evidence. This exploratory research contributes to the understanding of EIH in people with/without CLBP, demonstrating EIH following local and remote tasks. Furthermore, it highlighted poor stability of EIH. This is critical, as stability is a prerequisite for future research to further elucidate EIH and the short-term benefits of exercise.

Background: Low back pain (LBP) represents a global burden, yet recovery from LBP is not well understood. There is no currently accepted definition for recovery from LBP, nor is there a gold standard for its measurement. In addition, it is currently unclear how the perspective of patients are used in making recovery determinations. While there has been some work to better understand recovery from LBP, no previous review has canvassed both surgical and non-surgical literature at the same time. By broadly surveying all available literature, it is hoped that a consistent definition of recovery in LBP can be created and therefore informed recommendations for measurement can be made.

Purpose: The purpose of this mixed study systematic review across quantitative and qualitative literature was to explore how recovery has been defined and measured for patients experiencing LBP, as well as examine how the perspectives of patients and providers for recovery of LBP align or differ.

Materials and Methods: Studies were eligible for inclusion if they included patients with musculoskeletal LBP and reported on recovery in either the abstract, methods or results. EMBASE, CINAHL, Cochrane, and PEDro databases were electronically searched from inception until February 20, 2023. Grey literature was searched through ProQuest Dissertations and Theses. Two reviewers independently evaluated studies for eligibility, performed quality assessment, and extracted relevant data. The Mixed Methods Appraisal Tool was used for quality assessment of included studies. Thematic analysis was used to explore definitions, measurements, and perspectives of recovery. Themes were developed in three phases for each of the objectives (definitions, measurements, perspectives), bringing themes from very specific to broad.

Results: 500 studies were included: 12 qualitative studies, 88 quantitative randomized control trials, 348 quantitative non-randomized studies, 16 quantitative descriptive studies, and two mixed methods studies. Most studies were rated as moderate (49%) or low (45.8%) quality. Across the corpus of literature, recovery was defined in seven main themes, and measured across six main themes. More than 1/3 of studies did not define recovery and used multiple measures to measure it. The perspectives of patients with LBP were largely not incorporated into making recovery determinations across surgical and non-surgical literature.

Conclusions and Implications: Recovery from LBP currently is measured and defined in a myriad of ways and thus continues to lack consensus. Furthermore, determinations of recovery from LBP are largely made without patient input. Consensus-driven methods are required regarding how recovery should be defined and measured with incorporation of perspective from patients, clinicians, and researchers alike.

The aim of this study was to examine the associations of spinal kinematics and physical activity (PA) with bodily pain, physical functioning, and work ability among health care workers with low back pain (LBP). Spinal kinematics and PA were measured with a wireless Inertial Measurement Unit system (ValedoMotion®) and a waist-worn tri-axial accelerometer (Hookie AM20), respectively. Their association was assessed in relation to Work Ability Index (WAI), bodily pain and physical functioning (RAND-36) in 210 health care workers with recurrent LBP. Greater lumbar movement variability/less deterministic lumbar movement (in angular velocity) during a “Pick Up a Box” functional task was correlated with higher amounts of step counts (r = -0.29, p = 0.01) and moderate PA (r = -0.24, p = 0.03). A higher amount of PA (p = 0.03) as well as less movement control impairment (p = 0.04) and movement variability (p = 0.03) were associated with greater work ability, whilst greater vigorous PA was the only parameter to explain higher physical functioning (p = 0.02). PA and movement variability were relative to each other to explain bodily pain (p = 0.01). These findings show the importance of considering the interaction between lumbar kinematics and physical activity while planning strategies to improve bodily pain, physical functioning and work ability among health care workers with LBP.

Background:
Following an accident, individuals face many limitations and disabilities that present them with the dilemma of choosing which activities to resume or not. Classification according to activity patterns (avoidance, modulation and persistence), although useful, does not provide insight into patients' activity management strategies or the factors underlying them. Though many studies have examined these activity patterns, little research has looked at the factors that lead people to adopt particular activity behaviours. Knowing more about these factors may help to promote optimal pain and activity management in patients, and develop their ability to use appropriate strategies depending on the circumstances.
Aims:
This qualitative study aimed to explore the relationship with activity in people with chronic musculoskeletal pain after musculoskeletal trauma and to highlight the dynamics between the factors underlying their engagement in one or another pattern. This study aimed to shed light on the meaning attributed to such practices and the factors underlying their activity behaviour during rehabilitation and in their life context.
Methods:
Thirty-three patients (6♀/27♂, 44.9±10.6 years old, 26 unemployed, 7 working at a reduced rate, 11+/-2 months since the accident) were included in this qualitative research, which used observation of professional workshops and semi-structured interviews. The activity strategies adopted by people undergoing rehabilitation for chronic musculoskeletal pain and the factors underlying their choices were explored. Content analysis was carried out by an interdisciplinary team (physiotherapists, anthropologists, psychologists).
Results:
Analysis of observations and patients' discourses showed that any one patient will alternate between all three activity profiles: the same person may adopt a strategy of avoidance, pacing or persistence, depending on the context (private or professional), the importance and nature of the activity, personal goals, and representations of self, pain and activity. Participants combined different activity management strategies based on their experience, lay knowledge and education gained during their care. Those who were flexible in their strategies were better able to resume their activities. They weighed the expected consequences and the importance of an activity in their decision to undertake it or not.
Conclusion(s):
The relationship to activity is a dynamic process of constant negotiation with oneself and others (health professionals, relatives, health and social welfare system) rather than a personal trait. People establish a dynamic and flexible relationship with activity according to different logics that weigh up the stakes of the envisaged activity. A better understanding of these logics could help to improve the effectiveness of rehabilitation by targeting the mechanisms that limit activity. Future research should investigate whether this approach could effectively improve activity recovery after orthopaedic trauma.
Implications
These findings suggest that it would be appropriate to train the flexible use of a range of skills and activity management strategies in rehabilitation, in order to promote the performance of valued activities by minimising their undesirable consequences. Therapeutic approaches in the rehabilitation context could take into account these adaptive capacities to provide patients with optimal pain and activity management and develop their ability to use different strategies depending on the circumstances.

Background: Low back pain can affect movement throughout the body, potentially placing individuals at risk for a subsequent injury outside of the low back region. That rate at which individuals will go on to experience a distal joint injury (hip, knee, or ankle) after an episode of low back pain is unknown. Therapeutic exercise has been shown to be effective for low back pain, and can potentially reduce the risk of recurrent episodes, but it’s effect on subsequent distal joint injury after an episode of low back pain has not been investigated.

Study Design: Retrospective cohort study

Methods: Participants were adults 18 to 65 years of age seeking care for low back pain in the US Military Health System from 2015-2019, and followed for 1 year. Cases with red flags were excluded (fracture, cauda equina syndrome, systemic arthropathies, infection, cancer). Care utilization in medical records were extracted from the Military Health System Data Repository (MDR), to include follow-on visits that included therapeutic exercise for low back pain within the first 90 days from injury, and any future visits with a diagnosis code for a hip, knee or ankle injury. Cox proportionate hazards models were run for each of the three adjacent injury types independently looking at days to adjacent injury. Adjustments were made for sex, age, and socioeconomic status.

Results: There were 650,993 participants that met all criteria and included into the cohort. The majority were male (65.2%) with a mean of 35.5 years of age (SD 12.3). Of these, almost 1 in 4 (23.3%) sustained a distal joint injury during the 1-year follow-up (8.4% ankle, 7.2% knee, 4.4% hip, and 3.3% to multiple joints). Receipt of therapeutic exercise for low back pain resulted in significantly reduced likelihood of a subsequent knee injury (HR 0.87; 95CI 0.85-0.99), ankle injury (HR 0.92; 95CI 0.89-0.93), or hip injury (HR 0.97; 95CI 0.95-0.999).

Conclusion: Distal joint injury in the lower extremity was common in the year following a low back pain episode, but those who received therapeutic exercise as part of their treatment plan were less likely to sustain a follow-on injury. These may be potential downstream health effects associated with low back pain that merit consideration when establishing a treatment plan.

Low back pain (LBP) is the world’s most disabling condition and leading cause of work absenteeism. Manual workers are exposed to repeated lifting tasks and lifting is a common risk factor for LBP. Engaging in manual tasks that are repeated or awkward has been reported to increase the risk of LBP persistence. Strategies targeted at reducing lifting-related LBP have not been effective.

Strategies to prevent and manage lifting related LBP have had a biomechanical focus. Advice to lift with a straight back, use the legs, lift slowly and tense the core are the dominant paradigm. These strategies are not evidence based. Recent systematic reviews have found that people with LBP follow this advice more than people without LBP.

Muscle activity around the core during lifting remains a topic of contention. The evidence surrounding how people with and without LBP lift from a muscle activity perspective is limited to few studies, where pain and fatigue were low and lift repetitions were less than 10, not replicating a manual workplace environment.

This study addressed a number of previous limitations in the research. A 12 sensor trunk muscle EMG protocol was used to compare peak and average muscle activity over a 100 lift task between manual workers with and without a history of LBP. This task induced pain and fatigue and therefore associations between trunk muscle activity, pain and fatigue in manual workers with and without a history of LBP could be explored.

We found no differences in trunk muscle activity between people with and without LBP during a 100-lift task. There were within group changes across the 12 channels over time in both groups. These changes were inconsistent and only involved few muscle channels. There was also no relationship with fatigue or pain and trunk muscle activity.

This study was a comprehensive EMG study of a 100-lift task that compared muscle activity between manual workers with and without a history of LBP. It adds to recent systematic reviews suggesting that the dominant paradigm to prevent and manage lifting-related LBP has no research evidence to support it at a group level.

At a group level, trunk muscle EMG during lifting does not seem important, as people with and without LBP lift similarly despite differences in lifting kinematics, pain and fatigue. This study addressed important gaps in the literature but ultimately adds to a growing body of evidence suggesting the focus of preventing and managing lifting-related LBP requires reconsidering.

BACKGROUND- Hip abductor weakness is a major risk factor for lower extremity (LE) pathologies. Gluteus medius (Gmed) insufficiency leads to compensatory tensor fasciae latae (TFL) activity, altering LE movement. Previous studies focused on TFL/Gmed-ratios using surface electromyography (EMG) without assessing Gmed subdivisions (anterior [AGM], intermedius [IGM], posterior [PGM]). Moreover, trunk stability’s impact on lumbopelvic control during hip functional movement has not been sufficiently evaluated.
PURPOSE- This study’s purpose was to explore TFL’s, AGM’s, IGM’s, and PGM’s neuromuscular activity and lumbopelvic kinematics during side-lying hip abduction (SLHA) with and without volitional preemptive abdominal contraction (VPAC).
METHODS- A within-subjects, repeated measures design was incorporated. Nineteen healthy male and female subjects aged 27 ± 7 years performed SLHA in an internal rotation (SLHA-IR) versus external rotation (SLHA-ER) pre-position. Hip abduction activities were performed with and without VPAC using an abdominal bracing maneuver (ABM). Outcome measures included muscle output amplitudes (% maximum voluntary isometric contraction) collected through surface and indwelling fine-wire EMG. Three-dimensional lumbopelvic kinematics were measured using the Vicon Nexus system.
RESULTS- Performing SLHA produced a significant interaction for hip pre-position and hip muscle during the no-VPAC and yes-VPAC conditions (each p < .001). The 2(VPAC) x 2(hip pre-position) within-subject repeated measures ANOVAs revealed significantly higher TFL (p < .001) and PGM (p = .010) EMG amplitudes during the yes-VPAC versus no-VPAC-condition. The same analyses reported significantly greater AGM (p < .001) and IGM (p < .001) EMG amplitudes with hip IR versus ER pre-position. For kinematics, no significant (VPAC) x (hip pre-position) interactions or main effects were found for lumbopelvic complex range-of-motion (ROM). VPAC-use produced a significant reduction (p < .025) in: sagittal plane minimum pelvic angle; transverse plane (TP) maximum and minimum lumbar spine (LS) angles; and TP maximum pelvic angle. Several significant hip pre-position main effects (p < .025) were found, where IR reduced minimum LS angles in all three planes, as well as TP and frontal plane maximum LS angles and both maximum and minimum pelvic angles.
CONCLUSION- This study suggests SLHA with pre-positioned hip IR and/or ER cannot be thoroughly recommended to emphasize Gmed while de-emphasizing TFL. The myofascial chain model may explain the significant increase in TFL and PGM activity during VPAC-use, but more data are needed to support this. The overall increased muscle activation levels with VPAC-use suggest ABM could enhance hip muscle performance during SLHA-IR and SLHA-ER. Finally, VPAC-use during SLHA-IR and SLHA-ER performance does not limit functional ROM but enhances lumbopelvic anterior-posterior and rotational stability.
IMPLICATIONS: This study widens clinicians' understanding of the most effective means to activate and optimize Gmed function without simultaneously allowing TFL compensatory dominance in response to insufficient Gmed activation. Such knowledge is essential for adequately supervising patients with lower extremity disorders and reducing the consequences associated with hip sensorimotor dysfunction.

Background
Low back pain (LBP) may lead to sensorimotor alterations such as disturbed proprioception and balance. Balance is commonly assessed with posturography on a force plate in a movement science laboratory. However, affordable technology such as the Wii Balance Board (WBB) can be used in the clinical setting. Although proprioception is vital for balance, balance tests are not specific tests of proprioception since it involves all parts of sensory and motor control functions. In the cervical spine, the influence of proprioception on postural sway has been explored using posturography with the cervical spine in a torsioned position. This was proposed to adversely affect the afferent input from the cervical proprioceptors and showed increased sway in people with neck pain. It is possible that similar torsion test, but directed to the lumbar spine, can be useful in the assessment of people with low back pain.

Purpose:
The study aims were to assess if a lumbar torsion postural stability test using a WBB could identify postural sway difference between participants with mechanical LBP compared to healthy controls (CON), and to assess the test-retest reliability of the lumbar torsion postural stability test.

Methods:
Fifty-five participants (42.3 ±9.8 years, 67% females), 27 with mechanical LBP and 28 CON participated in this cross-sectional test-retest study. Postural sway during quiet stance, eyes closed, was evaluated in a neutral and torsioned (rotated) lumbar position tests for 60 seconds for path velocity, medio-lateral amplitude and antero-posterior amplitude. The procedure was repeated one hour later to evaluate test-retest reliability. Data was analysed with independent T-test or Mann-Whitney U-tests to explore group differences. Test-retest reliability was analysed using intra class correlation (ICC) and standard error of measurement (SEM).

Results:
There was a significant increased postural sway in LBP compared CON in neutral position in antero-posterior amplitude (p=0.03, effect size 0.6) while the other outcome variables showed no significant differences. Interestingly, all sway measures were smaller in torsioned position compared to neutral position for both groups. This difference (i.e., between torsioned and neutral position) was close to significantly larger for LBP compared to CON in antero-posterior amplitude (p=0.08, effect size 0.5). Test-retest reliability of postural sway in neutral and torsioned positions was moderate to excellent.

Conclusion(s):
The WBB is useful for clinical measure of postural sway in neutral quiet stance. The fact that the sway decreased in torsioned position compared to neutral, and that this decrease was larger (although not significantly) in the group with mechanical LBP, was unexpected and needs further investigation. Are there differences in postural strategies that can be revealed using this test? Future research should investigate other groups of LBP, e.g., neuropatic pain (sciatica), but also more challenging tests such as standing on soft surface or various types of perturbations to the postural control.

Implications:
Clinical evaluation of postural sway in quiet stance in neutral and lumbar torsioned position using a WBB has acceptable reliability. Neutral posture is more useful compared to torsioned position to identify postural disturbance in mechanical LBP.