Can Exercise Positively Influence the Intervertebral Disc?

Roles of organokines in intervertebral disc homeostasis and degeneration

The intervertebral disc is not isolated from other tissues. Recently, abundant research has linked intervertebral disc homeostasis and degeneration to various systemic diseases, including obesity, metabolic syndrome, and diabetes. Organokines are a group of diverse factors named for the tissue of origin, including adipokines, osteokines, myokines, cardiokines, gastrointestinal hormones, and hepatokines. Through endocrine, paracrine, and autocrine mechanisms, organokines modulate energy homeostasis, oxidative stress, and metabolic balance in various tissues to mediate cross-organ communication. These molecules are involved in the regulation of cellular behavior, inflammation, and matrix metabolism under physiological and pathological conditions. In this review, we aimed to summarize the impact of organokines on disc homeostasis and degeneration and the underlying signaling mechanism. We focused on the regulatory mechanisms of organokines to provide a basis for the development of early diagnostic and therapeutic strategies for disc degeneration.

Impact of Running Exercise on Intervertebral Disc: A Systematic Review

CONTEXT

Running is one of the most popular sports worldwide. However, controversies exist regarding how running affects runner's intervertebral discs (IVD).

OBJECTIVE

The purpose of this study was to systematically review studies that evaluated IVD morphology or composition changes in response to running exercise, to determine the impact of running exercise on IVD.

DATA SOURCES

A systematic literature search was performed for 4 major databases: PubMed, Cochrane, Embase, and Web of Science.

STUDY SELECTION

Inclusion criteria were as follows: (1) healthy people without known IVD disease or major complications such as tuberculosis (IVD degeneration or low back pain are considered as minor complications); (2) subjects performed 1-time or regular running exercises; (3) pre and post comparison of runners or comparison between runners and healthy control subjects; (4) direct or indirect IVD morphology or composition measured; (5) IVD assessed before and after either acute or chronic running exercise, or compared cross-sectionally between runners and controls. Exclusion criteria were as follows: (1) reviews, editorials, letters or abstracts only; (2) animal studies; (3) subjects performed exercise other than running.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The extracted data included study design and primary outcomes of the included studies. The Newcastle-Ottawa scale (NOS) was used to evaluate study quality and risk of bias.

RESULTS

A total of 13 studies with 632 participants were included in the final analysis; 4 studies measured IVD changes using stature or spinal height, and the other 9 measured IVD changes using magnetic resonance imaging; 6 studies found that running acutely and negatively impacts IVD; 3 out of 5 cross-sectional studies found that IVD parameters are better for runners than controls; 1 longitudinal study found no significant difference in IVD before and after training for marathon in runners; 1 longitudinal study found no significant difference in changes of IVD between runners and controls after 15 years of follow-up.

CONCLUSION

Negative changes in IVD exist for a short period of time after running, which may be due to the temporary compression pushing water content out of the disc. Cross-sectional studies suggest that long-term running exerts a mild positive effect on IVD; however, this inference has not been confirmed by high-quality longitudinal studies.

Causal association of physical activity with low back pain, intervertebral disc degeneration and sciatica: a two-sample mendelian randomization analysis study

Objective: Previous studies are insufficient to confirm a causal association between physical activity (PA) and low back pain (LBP), intervertebral disc degeneration (IDD), and sciatica. The present study used a two-sample Mendelian randomization (MR) analysis method to demonstrate whether or not there was a causal connection. Methods: First, four PA phenotypes were selected [accelerometer-based PA (average acceleration), accelerometer-based PA (acceleration fraction >425 mg), self-reported moderate-to-vigorous PA, and self-reported vigorous PA], setting thresholds for single nucleotide polymorphisms (SNPs) significantly concerned with PA p < 5 × 10-8, linkage disequilibrium (LD) r 2 < 0.01, genetic distance >5,000 kb, and F-value >10. SNPs associated with the outcome and confounding factors were then excluded using the PhenoScanncer database. Finally, after coordinating the genetic instruments from genome-wide association studies (GWAS) effect alleles for exposure and outcomes, multiplicative random effects inverse variance weighting (IVW), MR-Egger, weighted median method (WMM), and weighted mode method were used to assess exposure-outcome causality and perform sensitivity analysis on the estimated results. Results: The current study's IVW findings revealed proof of a causal connection between PA and LBP. While there was a positive causal tie between accelerometer-based PA (acceleration fraction >425 mg) and LBP [OR: 1.818, 95% CI:1.129-2.926, p = 0.012], there was a negative causal link between accelerometer-based PA (average acceleration) and LBP [OR: 0.945, 95% CI: 0.909-0.984, p = 0.005]. However causal relationship between PA and IDD or sciatica was not found. Conclusion: Increasing average PA but needing to avoid high-intensity PA may be an effective means of preventing low back pain. Although PA is not directly causally related to disc degeneration and sciatica, it can act through indirect pathways.

Musculoskeletal pains among amateur and professional athletes of five disciplines in Senegal: a preliminary study

BACKGROUND

Musculoskeletal pains (MSPs) in sport are cause of poor performances and loss of competition in athletes. The present study aimed at determining the prevalence of MSPs with regard to sport disciplines and athletic status.

METHODS

A cross-sectional study was conducted among 320 Senegalese professional and amateur athletes practicing football, basketball, rugby, tennis, athletics, and wrestling. Rates of MSPs in the past year (MSPs-12) and week (MSPs-7d) were assessed using standard questionnaires.

RESULTS

Overall proportions of MSPs-12 and MSPs-7d were 70 and 74.2%, respectively. MSPs-12 were more frequently reported on shoulders (40.6%), neck (37.1%) and hips/thigh (34.4%), while MSPs-7d were predominant on hips/thigh (29.5%), shoulders (25.7%), and upper back (17.2%). Proportions of MSPs-12 and MSPs-7d varied significantly by sport disciplines, with highest values among basketball players. Again, highest MSPs-12 proportions on shoulders (29.7%, P = 0.02), wrists/hands (34.6%, P = 0.001), (40.2%, P = 0.0002), and knees (38.8%, P = 0.002) were seen among basketball players. High proportions of MSPs-7d were seen on shoulders (29.6%, P = 0.04) for tennis players, wrists/hands (29.4%, P = 0.03) for basketball and football players, and hips/thigh (38.8%, P < 0.00001) for basketball players. Football players had reduced risk of MSPs-12 by 75% on lower back (OR = 0.25; 95% CI. 0.10-0.63; P = 0.003) and by 72% on knees (OR = 0.28; 95% CI. 0.08-0. 95; P = 0.04). In contrast, tennis players were more at risk of MSPs-12 on shoulders (OR = 3.14; 95% CI. 1.14-8.68; P = 0.02), wrists/hands (OR = 5.18; 95% CI.1.40-11.13; P = 0.01), and hips/thigh (OR = 2.90; 95% CI. 1.1-8.38; P = 0.04). Professionals were protected from MSPs-12 on neck pain with a significant reduction of risk by 61% (OR = 0.39, 95% CI. 0.21-0.75, P = 0.03).

CONCLUSION

MSPs are a reality among athletes and their risk is modulated by sport disciplines, athletic status and gender.

Effect of trunk exercise upon lumbar IVD height and vertebral compliance when performed supine with 1 g at the CoM compared to upright in 1 g

Background

Spinal unloading in microgravity is associated with stature increments, back pain, intervertebral disc (IVD) swelling and impaired spinal kinematics. The aim of this study was to determine the effect of lateral stabilization, trunk rotation and isometric abdominal exercise upon lumbar IVD height, and both passive and active vertebral compliance when performed supine on a short-arm human centrifuge (SAHC)—a candidate microgravity countermeasure—with 1 g at the CoM, compared to that generated with equivalent upright exercise in 1 g.

Methods

12 (8 male) healthy subjects (33.8 ± 7 years, 178.4 ± 8.2 cm, 72.1 ± 9.6 kg) gave written informed consent. Subjects performed three sets of upper body trunk exercises either when standing upright (UPRIGHT), or when being spun on the SAHC. Lumbar IVD height and vertebral compliance (active and passive) were evaluated prior to SAHC (PRE SAHC) and following the first SAHC (POST SPIN 1) and second Spin (POST SPIN 2), in addition to before (PRE UPRIGHT), and after upright trunk exercises (POST UPRIGHT).

Results

No significant effect upon IVD height (L2–S1) when performed UPRIGHT or on the SAHC was observed. Trunk muscle exercise induced significant (p < 0.05) reduction of active thoracic vertebral compliance when performed on the SAHC, but not UPRIGHT. However, no effect was observed in the cervical, lumbar or across the entire vertebral column. On passive or active vertebral compliance.

Conclusion

This study, the first of its kind demonstrates that trunk exercise were feasible and tolerable. Whilst trunk muscle exercise appears to have minor effect upon IVD height, it may be a candidate approach to mitigate—particularly active—vertebral stability on Earth, and in μg via concurrent SAHC. However, significant variability suggests larger studies including optimization of trunk exercise and SAHC prescription with MRI are warranted.

Trial Registration

North Rhine ethical committee (Number: 6000223393) and registered on 29/09/2020 in the German Clinical Trials Register (DRKS00021750).

Exercise-induced FNDC5/irisin protects nucleus pulposus cells against senescence and apoptosis by activating autophagy

Intervertebral disc degeneration (IVDD) is a major cause of low back pain (LBP), and excessive senescence and apoptosis of nucleus pulposus (NP) cells are major pathological changes in IVDD. Physical exercise could effectively delay the process of intervertebral disc degeneration; however, its mechanism is still largely unknown. Irisin is an exercise-induced myokine released upon cleavage of the membrane-bound precursor protein fibronectin type III domain-containing protein 5 (FNDC5), and its levels increase after physical exercise. Here, we show that after physical exercise, FNDC5/irisin levels increase in the circulation and NP, senescence and apoptosis are reduced, autophagy is activated in NP tissue, and the progression of IVDD is delayed. Conversely, after knocking out FNDC5, the benefits of physical exercise are compromised. Moreover, the overexpression of FNDC5 in NP tissue effectively alleviated the degeneration of the intervertebral disc (IVD) in rats. By showing that FNDC5/irisin is an important mediator of the beneficial effects of physical exercise in the IVDD model, the study proposes FNDC5/irisin as a novel agent capable of activating autophagy and protecting NP from senescence and apoptosis.

Stem Cell Therapy and Exercise for Treatment of Intervertebral Disc Degeneration

As part of the motor system, intervertebral disc (IVD) is a complicated tissue with multiple components. The degeneration of IVD may result in low back pain (LBP), which strongly impairs quality of life. Various causes are related to the degeneration of IVD, including cell senescence, hydration lost, and inflammation. Stem cells founded in different tissues have attracted the interest of the researchers and clinicians to study the implication of these cells in the treatment for tissue injury and degeneration. In this report, we will review the study of stem cells in the treatment for IVD degeneration. On the other hand, the effect of exercise on IVD degeneration and the relationship between IVD degeneration and musculoskeletal disorders like sarcopenia are discussed.

Knowledge and management of low back pain as running-related injuries among Italian physical therapists: findings from a national survey

OBJECTIVES

To investigate the beliefs, knowledge, attitudes, behavior, and the clinical management procedures of the Italian physical therapists specialized in orthopedic manipulative physical therapy (OMPT) toward running and its correlation with low back pain (LBP).Design: A cross-sectional online survey was conducted in 2019, according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES) and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.Setting: Italy.Participants: One thousand two hundred and eighteen Italian OMPTs.

METHODS

Survey Monkey software was used to administer the survey. The questionnaire was self-reported and included 26 questions. Descriptive statistics were used and related to the effective respondents for each question.

RESULTS

One thousand two hundred and eighteen questionnaires (60.9%) were included in the analysis. A considerable cohort of OMPTs working in private practice clinical settings (n = 845; 69.4%; 95% CI 66.7-71.9) has indicated running not to be a relevant risk factor for the onset of LBP (n = 806; 66.2%; 95% CI 63.4-68.8). Moreover, most of the participants (n = 679; 55.7%; 95% CI 52.9-58.5) adopted a combination of manual therapy techniques and therapeutic exercise for the management of runners with LBP.

CONCLUSIONS

Widespread knowledge of clinical and theoretical management of LBP in runners-patients has emerged among Italian OMPTs. The OMPTs' academic background agrees with the recent literature and therefore highlights the paucity of studies related to LBP as running-related injuries.

How accurate are visual assessments by physical therapists of lumbo-pelvic movements during the squat and deadlift?

OBJECTIVES

To investigate the accuracy of visual assessments made by physical therapists of lumbo-pelvic movements during the squat and deadlift and how much movement is considered injurious.

DESIGN

Quantitative Cross-sectional.

PARTICIPANTS

14 powerlifters, 10 Olympic weightlifters and six physical therapists.

SETTING

The lifters were recorded simultaneously by video and an inertial measurement unit (IMU) system while performing squats and deadlifts. The physical therapists assessed the videos and rated whether specific lumbo-pelvic movements were visible during the lifts and whether the movement amplitude was considered injurious.

MAIN OUTCOME MEASURES

The nominal visual assessments, if there was a movement and if it was considered injurious, were compared to the degrees of movement attained from the IMU system.

RESULTS

During the squat, a posterior pelvic tilt of ≥34° was required to visually detect the movement. For other lumbo-pelvic movements, there was no significant difference in the amount of movement between those who were assessed as moving or not moving their lumbo-pelvic area, nor was there a difference in movement amplitude between those who were assessed as having an increased risk of injury or not.

CONCLUSIONS

Physical therapists did not consistently detect lumbo-pelvic movements during squats and deadlifts when performed by competitive lifters.

Changes in physiotherapy students' beliefs and attitudes about low back pain through pre-registration training

BACKGROUND

Implementation of best-practice care for patients with low back pain (LBP) is an important issue. Physiotherapists' who hold unhelpful beliefs are less likely to adhere to guidelines and may negatively influence their patients' beliefs. Pre-registration education is critical in moving towards a biopsychosocial model of care. This study aimed to investigate the changes in 2nd year physiotherapy students' beliefs about LBP after a module on spinal pain management and determine whether these changes were maintained at the end of academic training.

METHODS

During three consecutive calendar years, this longitudinal cohort study assessed physiotherapy students' beliefs with the Back Pain Attitudes Questionnaires (Back-PAQ) in their 1st year, before and after their 2nd year spinal management learning module, and at the end of academic training (3rd year). Unpaired t-tests were conducted to explore changes in Back-PAQ score.

RESULTS

The mean response rate after the spinal management module was 90% (128/143 students). The mean (± SD) Back-PAQ score was 87.73 (± 14.21) before and 60.79 (± 11.44) after the module, representing a mean difference of - 26.95 (95%CI - 30.09 to - 23.80, p < 0.001). Beliefs were further improved at the end of 3rd year (- 7.16, 95%CI - 10.50 to - 3.81, p < 0.001).

CONCLUSIONS

A spinal management learning module considerably improved physiotherapy students' beliefs about back pain. Specifically, unhelpful beliefs about the back being vulnerable and in need of protection were substantially decreased after the module. Improvements were maintained at the end of academic training one-year later. Future research should investigate whether modifying students' beliefs leads to improved clinical practice in their first years of practice.

Mechanical loading influences the lumbar intervertebral disc. A cross-sectional study in 308 athletes and 71 controls

There is evidence in animal populations that loading and exercise can positively impact the intervertebral disc (IVD). However, there is a paucity of information in humans. We examined the lumbar IVDs in 308 young athletes across six sporting groups (baseball, swimming, basketball, kendo, soccer, and running; mean age 19 years) and 71 nonathletic controls. IVD status was quantified via the ratio of IVD to vertebral body height (IVD hypertrophy) and ratio of signal intensity in the nucleus to that in the annulus signal (IVD nucleus hydration) on sagittal T2-weighted magnetic resonance imaging. P values were adjusted via the false discovery rate method to mitigate false positives. In examining the whole collective, compared to referents, there was evidence of IVD hypertrophy in basketball (P ≤ .029), swimming (P ≤ .010), soccer (P = .036), and baseball (P = .011) with greater IVD nucleus hydration in soccer (P = .007). After matching participants based on back-pain status and body height, basketball players showed evidence of IVD hypertrophy (P ≤ .043) and soccer players greater IVD nucleus hydration (P = .001) than referents. Greater career duration and training volume correlated with less (ie, worse) IVD nucleus hydration, but explained less than 1% of the variance in this parameter. In this young collective, increasing age was associated with increased IVD height. The findings suggest that basketball and soccer may be associated with beneficial adaptations in the IVDs in young athletes. In line with evidence on other tissues, such as muscle and bone, the current study adds to evidence that specific loading types may beneficially modulate lumbar IVD properties.

Can Haglund's Syndrome Be Misdiagnosed as Low Back Pain? Findings from a Case Report in Physical Therapy Direct Access

Background: Haglund’s syndrome (HS) is a painful condition that is caused by an exostosis of the posterior superior part of the calcaneus coupled with Achilles tendinopathy and retrocalcaneal bursitis. Both for the proper musculoskeletal assessment and for the differential diagnosis process of possible concurrent diseases deriving from other anatomical areas, the diagnosis of HS is still a challenge. Case Presentation: A 41-year-old male amateur runner was diagnosed and treated for low back pain and referred leg pain by his general practitioner. Due to ineffective results, he self-presented to a physical therapist (PT) with intense right heel pain, radiating up to the leg and to the lumbopelvic region. Results: The PT’s examination and interview relating to the sports activities led to the correct diagnosis and a proper orthopedic referral. At the one-year follow-up, the patient reported regular pain-free marathon running. Discussion: This case report highlights the central role of PTs working in direct access environments as primary care healthcare professionals for the management of musculoskeletal diseases, and their abilities in identifying patients with suspected pathologic conditions that may need referral for imaging, medical assessment or surgical intervention.

Prevalence of low back pain in young Brazilians and associated factors: Sex, physical activity, sedentary behavior, sleep and body mass index

BACKGROUND

Low back pain (LBP) has become increasingly common, but the prevalence of this complaint and associated factors in young people remains controversial.

OBJECTIVE

This study aimed to identify the prevalence of LBP and to explore the existence of associated factors (sex, physical activity, sedentary lifestyle, sleep, body mass index and waist circumference).

METHODS

This study considered all complaints of the lumbar region (acute or chronic) as LBP, which can irradiate to the backside and legs, lasting a minimum of 24 hours. Youngsters aged 15 to 18 years from a school in the south of Brazil were evaluated. Descriptive statistics was used, in particular Chi-square, Mann-Whitney U tests and binary logistic regression. A significance level of p< 0.05 was adopted.

RESULTS

A total of 330 youngsters answered a questionnaire and had their anthropometric measurements measured (response rate 84%). The prevalence of LBP in the present was 30%, quarterly 63% and throughout life 77%. There was a significant association between LBP and sex: girls have an increased risk of LBP in the last three-month period (PR = 1.3, 95% CI 1.06-1.56) and throughout life (PR = 1.2, 95% CI 1.04-1.43). The practice of physical activities was also associated with LBP, but as a protection factor in the present and in the last three-month period (PR = 0.7, 95% CI 0.47-0.90). Physical education at school has demonstrated a protective factor regarding LBP throughout life (PR = 0.9, 95% CI 0.77-0.97). Most of the students did not comply with recommendations related to sleep and time spent doing activities in front of a screen, and no association of these factors with LBP was detected. This exposure (physical activity, sleep time, sedentarism) did not present significant association with LBP when adjusted by the confusion factors (sex, age, BMI).

CONCLUSIONS

Youngsters reported a high prevalence of LBP. Girls were at greater risk of LBP than boys. It is recommended that prevention strategies focus on the practices of physical activities and scholar physical education. No association of LBP with sedentary lifestyle (TV and computer use time, sleep time), anthropometric measures and sleeping duration was observed.

Long-term effect of physical inactivity on thoracic and lumbar disc degeneration-an MRI-based analysis of 385 individuals from the general population

BACKGROUND CONTEXT

The correlation between physical inactivity, thoracolumbar disc degeneration, and back pain remains unclear.

PURPOSE

This study investigated the relationship between short- and long-term physical inactivity and degenerative changes of the thoracic and lumbar spine in a southern German cohort from the general population over a time period of 14 years.

STUDY DESIGN/SETTING

This study was designed as a cross-sectional case-control study, nested in a prospective cohort from the "Cooperative Health Research in the Region of Augsburg/Kooperative Gesundheitsforschung in der Region Augsburg" (KORA) study.

PATIENT SAMPLE

All participants in the population-based KORA study were assessed using a physical activity questionnaire to establish a baseline in 1999-2001 (exam 1), within an initial follow up questionnaire in 2006-2008 (exam 2), and a second follow-up questionnaire between 2013 and 2014 (exam 3). A subsample of this group (400 subjects) underwent full body MR scan performed on a 3T magnetic resonance imaging scanner current with exam 3.

OUTCOME MEASURE

Data regarding physical inactivity over a time period of 14 years and back pain, and quantification of thoracic and lumbar disc degeneration on magnetic resonance imaging.

METHODS

Quantification of thoracic and lumbar disc degeneration was performed using the Pfirrmann score. Physical activity was grouped as no physical activity, irregularly for 1 hour, regularly for 1 hour, or regularly for ≥2 hours. This was used to calculate another variable "physical inactivity," with the options of irregular activity ≤1 hour per week or regularly ≥1 hour. Physical labor, walking, and cycling activity were additionally investigated. Correlations between physical inactivity measurements and thoracic and lumbar disc degeneration were analyzed via linear regression models adjusted for age, sex, BMI, hypertension, diabetes, and back pain.

RESULTS

In total, 385 individuals (mean age: 56 years, SD ± 9.19; 58.2% male) were included in this study. Mean summed Pfirrmann score was 2.41 (SD ± 4.19) in the thoracic and 1.78 (SD ± 1.81) in the lumbar spine. The level of current exercise in our cohort varied with 113 (29.4%) subjects exercising regularly ≥2 hours per week, 118 (30.7%) regularly 1 hour per week, 57 (14%) irregularly for about 1 hour per week, and 97 (25.2%) stated not to exercise at exam 3. Disc degeneration was more apparent in those with irregular activity <1 hour compared to those with regular activity of ≥1 hour and more per week (p<.01) and in those with no activity compared to those with regular activity of ≥2 (p<.001) measured using exam 3. Less physical activity over a time period of 14 years correlated with an increase of disc degeneration of the thoracic and lumbar spine after adjustment for age, sex, BMI, hypertension and diabetes mellitus (p<.05). There was no statistically significant association between physical labor, walking activity, or cycling activity with disc degeneration. Additionally, no significant correlations between degree of disc degeneration (p=.990), degree of physical inactivity (p=.158), and back pain were observed.

CONCLUSION

Degree of physical inactivity as measured over a time period of 14 years demonstrated a strong correlation with disc degeneration of the thoracic and lumbar spine.

Characterization of Intervertebral Disc Changes in Asymptomatic Individuals with Distinct Physical Activity Histories Using Three Different Quantitative MRI Techniques

(1) Background: Assessments of intervertebral disc (IVD) changes, and IVD tissue adaptations due to physical activity, for example, remains challenging. Newer magnetic resonance imaging techniques can quantify detailed features of the IVD, where T2-mapping and T2-weighted (T2w) and Dixon imaging are potential candidates. Yet, their relative utility has not been examined. The performances of these techniques were investigated to characterize IVD differences in asymptomatic individuals with distinct physical activity histories. (2) Methods: In total, 101 participants (54 women) aged 25–35 years with distinct physical activity histories but without histories of spinal disease were included. T11/12 to L5/S1 IVDs were examined with sagittal T2-mapping, T2w and Dixon imaging. (3) Results: T2-mapping differentiated Pfirrmann grade-1 from all other grades (p < 0.001). Most importantly, T2-mapping was able to characterize IVD differences in individuals with different training histories (p < 0.005). Dixon displayed weak correlations with the Pfirrmann scale, but presented significantly higher water content in the IVDs of the long-distance runners (p < 0.005). (4) Conclusions: Findings suggested that T2-mapping best reflects IVD differences in asymptomatic individuals with distinct physical activity histories changes. Dixon characterized new aspects of IVD, probably associated with IVD hypertrophy. This complementary information may help us to better understand the biological function of the disc.

Prevalence and incidence of low back pain among runners: a systematic review

Background

Running is one of the most popular sports worldwide. Despite low back pain (LBP) represents the most common musculoskeletal disorder in population and in sports, there is currently sparse evidence about prevalence, incidence and risk factors for LBP among runners. The aims of this systematic review were to investigate among runners: prevalence and incidence of LBP and specific risk factors for the onset of LBP.

Methods

A systematic review has been conducted according to the guidelines of the PRISMA statement. The research was conducted in the following databases from their inception to 31st of July 2019: PubMed; CINAHL; Google Scholar; Ovid; PsycINFO; PSYNDEX; Embase; SPORTDiscus; Scientific Electronic Library Online; Cochrane Library and Web of Science. The checklists of The Joanna Briggs Institute Critical Appraisal tools were used to investigate the risk of bias of the included studies.

Results

Nineteen studies were included and the interrater agreement for full-text selection was good (K = 0.78; 0.61–0.80 IC 95%). Overall, low values of prevalence (0.7–20.2%) and incidence (0.3–22%) of LBP among runners were reported. Most reported risk factors were: running for more than 6 years; body mass index > 24; higher physical height; not performing traditional aerobics activity weekly; restricted range of motion of hip flexion; difference between leg-length; poor hamstrings and back flexibility.

Conclusions: Prevalence and incidence of LBP among runners are low compared to the others running related injuries and to general, or specific population of athletes. View the low level of incidence and prevalence of LBP, running could be interpreted as a protective factor against the onset of LBP.

Systematic review registration

PROSPERO CRD42018102001.

Exercise for the intervertebral disc: a 6-month randomised controlled trial in chronic low back pain

BACKGROUND CONTEXT

Muscle, bone and tendon respond anabolically to mechanical forces. Whether the intervertebral disc (IVD) can benefit from exercise is unclear.

PURPOSE

To examine whether exercise can beneficially affect IVD characteristics.

STUDY DESIGN/SETTING

This is a single-blinded 6-month randomised controlled trial (ACTRN12615001270505) in an exercise and physiotherapy clinic.

PATIENT SAMPLE

Forty patients with chronic non-specific low back pain (NSCLBP) are included in this study.

OUTCOME MEASURES

The primary outcome was lumbar IVD T2 time (MRI). Secondary outcomes included IVD diffusion coefficient and IVD expansion with short-duration lying.

METHODS

Twenty patients progressively loaded their lumbar IVDs (exercise) via an exercise programme involving progressive upright aerobic and resistance exercises targeting the trunk and major muscle groups and were compared to twenty patients who performed motor control training and manual therapy (control). Testing occurred at baseline, 3 months and 6 months.

RESULTS

Seventeen exercise and fifteen control patients completed the interventions. There were no group-by-time differences in T2 time of the entire IVD (exercise 94.1 ± 10.0 ms vs. control 96.5 ± 9.3 ms, p = 0.549). Exercise patients had shorter T2 time in the posterior annulus at 6 months (82.7 ± 6.8 ms vs. 85.1 ± 8.0 ms, p = 0.028). Exercise patients showed higher L5/S1 apparent diffusion coefficients and decreased IVD height at 3 months (both p ≤ 0.050). After adjustments for multiple comparisons, differences lost statistical significance. Per-protocol and intent-to-treat analyses yielded similar findings.

CONCLUSIONS

This trial found that 6 months of exercise did not benefit the IVD of people with NSCLBP. Based on this index study, future studies could investigate the effect of exercise on IVD in different populations, with different types, durations and/or intensities of exercise, and using different IVD markers. These slides can be retrieved under Electronic Supplementary Material.

Long-term running in middle-aged men and intervertebral disc health, a cross-sectional pilot study

Purpose

To measure intervertebral disc (IVD) health parameters in middle-aged long-term runners compared to matched non-physically active controls.

Methods

Seventeen males aged 44-62yr were included in the study: 9 runners with a running history of >10yr, averaging >50km/week, and eight matched non-physically active controls, the data from one participant had to be excluded. T2-relaxometry, diffusion weighted imaging, T1- and T2-weighted MR scanning, as well as T2 time mapping were performed. Morphological data relating to IVD were extrapolated.

Results

Compared to controls on average, runners had 20% greater IVD height (p = 0.002) and seven percentage points greater IVD-vertebral body height ratio (p = 0.001). No significant differences were observed between groups for mean(SD) IVD hydration status, as indicated by similar T2-times (runners: 94.4(11.1)ms, controls: 88.6(23.6)ms), or apparent diffusion coefficients (runners: 249.0(175.2)mm²/s, controls: 202.3(149.5)mm²/s). Average Pfirrmann score for the L5-S1 IVD was 2.2(0.7) for runners and 3.3(1.0) for controls (p = 0.026), average scores for all lumbar levels (L2-S1) were 1.9(0.2) and 2.5(0.7), respectively (p = 0.036). Anterior annulus T2-time and overall average lumbar level Pfirrmann grades were strongly correlated (r = 0.787, p = 0.021 and r = -0.704, p = 0.034, respectively) with greater distances run per week. Average lumbar level Pfirrmann grades were also strongly correlated (r = -0.823, p = 0.006) to total years of running.

Conclusion

Middle-aged long-term endurance runners exhibit less age-related decline in their lumbar IVDs. In addition, the measures of IVD morphology appeared to be better in those who had been running for a greater number of years, as well as in those who ran a greater distance per week.

Microfluidic Disc-on-a-Chip Device for Mouse Intervertebral Disc-Pitching a Next-Generation Research Platform To Study Disc Degeneration

Low back pain is the most common cause of disability worldwide, and intervertebral disc degeneration is a major cause of low back pain. Unfortunately, discogenic low back pain is often treated with symptomatic relief interventions, as no disease-modifying medications are yet available. Both to-be-deciphered disc biology/pathology and inadequate in vitro research platform are major hurdles limiting drug discovery progress for disc degeneration. Here, we developed a microfluidic disc-on-a-chip device tailored for mouse disc organ as an in vitro research platform. We hypothesize that continuous nutrients empowered by a microfluidic device would improve biological performance of cultured mouse discs compared to those in static condition. This device permitted continuous media flow to mimic in vivo disc microenvironment. Intriguingly, mouse discs cultured on the microfluidic device exhibited much higher cell viability, better preserved structure integrity and anabolic-catabolic metabolism in both nucleus pulposus and annulus fibrosus, for up to 21 days compared to those in static culture. This first "disc-on-a-chip" device lays groundwork for future preclinical studies in a relative long-term organ culture given the chronic nature of intervertebral disc degeneration. In addition, this platform is readily transformable into a streamlined in vitro research platform to recapitulate physiological and pathophysiological microenvironment to accelerate disc research.

Assessment of the ergonomic risk from saddle and conventional seats in dentistry: A systematic review and meta-analysis

Objective

This study aimed to verify whether the saddle seat provides lower ergonomic risk than conventional seats in dentistry.

Methods

This review followed the PRISMA statement and a protocol was created and registered in PROSPERO (CRD42017074918). Six electronic databases were searched as primary study sources. The "grey literature" was included to prevent selection and publication biases. The risk of bias among the studies included was assessed with the Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews. Meta-analysis was performed to estimate the effect of seat type on the ergonomic risk score in dentistry. The heterogeneity among studies was assessed using I² statistics.

Results

The search resulted in 3147 records, from which two were considered eligible for this review. Both studies were conducted with a total of 150 second-year dental students who were starting their laboratory activities using phantom heads. Saddle seats were associated with a significantly lower ergonomic risk than conventional seats [right side (mean difference = -3.18; 95% CI = -4.96, -1.40; p < 0.001) and left side (mean difference = -3.12; 95% CI = -4.56, -1.68; p < 0.001)], indicating posture improvement.

Conclusion

The two eligible studies for this review provide moderate evidence that saddle seats provided lower ergonomic risk than conventional seats in the examined population of dental students.

Variations of handheld loads increase the range of motion of the lumbar spine without compromising local dynamic stability during walking

BACKGROUND

Walking is often considered a beneficial management strategy for certain populations of low back pain patients. However, little is known about how simple challenges that people often encounter, such as carrying loads in the hands, affect the low back during walking.

RESEARCH QUESTION

How do variations in hand loading affect arm swing, lumbar spine range of motion (ROM), and lumbar spine local dynamic stability (LDS) during walking?

METHODS

Sixteen young healthy participants (8 female) performed nine treadmill walking trials, each at 1.25 m/s for 3 consecutive minutes. Conditions manipulated the magnitude of hand loads (unloaded, low, high) and location of hand loads (directly in hands, in bags). Kinematic markers were used to measure sagittal plane arm swing, 3D lumbar spine ROM, and lumbar spine LDS during each trial.

RESULTS

Arm swing was significantly (p < 0.001) reduced as load increased directly in the hands; however, when held in bags load magnitude had no effect. Further, arm swing was significantly (p < 0.0001) lower when loads were held in bags. Lumbar flexion/extension ROM was greatest with the low load compared to both unloaded (p = 0.012) and high load (p = 0.0717) conditions, and was also greater (p < 0.0001) with loads held directly in the hands compared to loads in bags. Despite these changes in lumbar spine ROM, lumbar spine LDS was not significantly affected by any of the variations in hand loading.

SIGNIFICANCE

The greater lumbar spine cyclic motion, elicited by low hand loads held directly in the hands during walking, may be beneficial to the health of the low back. No changes in lumbar LDS were found, thereby suggesting that the small, likely beneficial, increases in lumbar spine ROM are well controlled by the motor control system and do not create an increased risk of injury.

Prevalence of Back Pain in Sports: A Systematic Review of the Literature

Background

Back pain is a frequent health problem in the general population. The epidemiology of back pain in the general population is well researched, but detailed data on the prevalence and risk factors of back pain in athletes are rare.

Objective

The primary objective was to review articles about back pain in athletes to provide an overview of its prevalence in different sports and compare its prevalence among various types of sports and the general population.

Data Sources

A comprehensive search of articles published through May 2015 was conducted. Two independent reviewers searched six databases from inception (PubMed^®, Embase, MEDLINE^®, Cochrane Library, PsycINFO and PSYNDEX), using specifically developed search strategies, for relevant epidemiological research on back pain in 14- to 40-year-old athletes of Olympic disciplines. The reviewers independently evaluated the methodological quality of reviewed articles meeting the inclusion criteria to identify potential sources of bias. Relevant data were extracted from each study.

Results

Forty-three articles were judged to meet the inclusion criteria and were included in the assessment of methodological quality. Of these, 25 were assessed to be of high quality. Lifetime prevalence and point prevalence were the most commonly researched episodes and the lower back was the most common localization of pain. In the high-quality studies, lifetime prevalence of low back pain in athletes was 1–94%, (highest prevalence in rowing and cross-country skiing), and point prevalence of low back pain was 18–65% (lowest prevalence in basketball and highest prevalence in rowing).

Conclusion

The methodological heterogeneity of the included studies showed a wide range of prevalence rates and did not enable a detailed comparison of data among different sports, within one discipline, or versus the general population. Based on the results of this review, however, it seems obvious that back pain requires further study in some sports.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-016-0645-3) contains supplementary material, which is available to authorized users.

Macrophage polarization contributes to local inflammation and structural change in the multifidus muscle after intervertebral disc injury

PURPOSE

Intervertebral disk (IVD) lesion and its subsequent degeneration have a profound effect on the multifidus muscle. The subacute/early chronic phase of multifidus remodeling after IVD lesion has been proposed to be regulated by inflammatory processes. The balance between pro-inflammatory (M1) and anti-inflammatory (M2) macrophages plays an important role in maintaining tissue integrity after injury. The localization, polarization of macrophage subtypes and their mediation of the pro-inflammatory cytokine tumor necrosis factor (TNF) are unknown in paraspinal muscles during IVD degeneration. A sheep model of IVD degeneration was used to investigate the role of macrophages and TNF in the structural alterations that occur within the multifidus muscle.

METHODS

Anterolateral lesions were induced at L3-4 IVD in sheep. Multifidus muscle tissue at L4 was harvested 3 and 6 months after lesion and used for immunofluorescence assays to examine total macrophage number, macrophage polarization between M1 and M2, and to assess the localization of TNF expression in muscle, adipose and connective tissues from injured and naïve control animals.

RESULTS

A greater proportion of M1 macrophages is present in muscle at both 3 and 6 months after IVD lesion, and adipose tissue at 6 months. Total number of macrophages is unchanged. At 6 months, expression of TNF is increased in adipose and connective tissue and the proportion of TNF expressed by M1 macrophages is increased.

CONCLUSIONS

These data support the proposal that macrophages and TNF (pro-inflammatory cytokine) play an active role in the subacute/early chronic phase of remodeling in muscle, adipose and connective tissues of the multifidus during IVD degeneration. This presents a novel target for treatment. These slides can be retrieved under Electronic Supplementary Material.

Intervertebral disc status is associated with vertebral marrow adipose tissue and muscular endurance

PURPOSE

Low back pain is a major public health issue. Identifying factors associated with better intervertebral disc (IVD) characteristics gives insight into IVD metabolism and highlights intervention targets for improvement of IVD health. This cross-sectional study investigates whether IVD T2-relaxation time on magnetic resonance imaging (MRI) is associated with vertebral fat fraction (VFF; to quantify marrow adipose tissue), trunk muscle cross-sectional area (CSA), muscle function and physical activity (PA).

METHODS

Seventy-nine healthy subjects (35 males, 44 females) without history of spinal disease were included. Lumbar IVDs T2-relaxation time, lumbar VFF and CSA of multifidus, erector spinae, quadratus lumborum, and psoas muscles were quantified via MRI. Isometric trunk flexion and extension endurance times as well as habitual PA levels and exposure to occupational spine risk factors were documented. Pearson-partial correlations adjusted for anthropometric differences by controlling for vertebral body height.

RESULTS

Higher IVD T2-time correlated with: (a) lower VFF (r = - 0.27, p < 0.05), (b) greater trunk extensor muscle endurance (r = 0.37, p < 0.01), and (c) greater trunk flexor muscle endurance (r = 0.30, p < 0.01) but not with muscle CSA. Lower VFF also correlated with greater extensor muscle endurance (r = - 0.26, p < 0.05) and habitual PA (MET-mins per week) (r = - 0.24, p < 0.05).

CONCLUSION

This is the first study to show that better IVD hydration is associated with lower VFF and that greater physical activity is associated with favourable levels of vertebral marrow adipose tissue in young healthy individuals. Reduced vertebral marrow adipose tissue may specifically improve IVD hydration via improved nutrient supply. These slides can be retrieved under Electronic Supplementary Material.

Spinal Health during Unloading and Reloading Associated with Spaceflight

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus, may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical.

Hydroxylated Fullerene: A Stellar Nanomedicine to Treat Lumbar Radiculopathy via Antagonizing TNF-α-Induced Ion Channel Activation, Calcium Signaling, and Neuropeptide Production

Current nonsurgical treatments of discogenic lumbar radiculopathy are neither effective nor safe. Our prior studies have suggested that hydroxylated fullerene (fullerol) nanomaterial could attenuate proinflammatory cytokine tumor necrosis factor alpha (TNF-α)-induced neuroinflammation and oxidative stress in mouse dorsal root ganglia (DRG) and primary neurons. Here, we aim to investigate the analgesic effect of fullerol in a clinically relevant lumbar radiculopathy mouse model and to understand its underlying molecular mechanism in mouse DRGs and neurons. Surprisingly, single and local application of fullerol solution (1 μM, 10 μL) was sufficient to alleviate ipsilateral paw pain sensation in mice up to 2 weeks postsurgery. In addition, microCT data suggested fullerol potentially promoted disc height recovery following injury-induced disc herniation. Alcian blue/picrosirius red staining also suggested that fullerol promoted regeneration of extracellular matrix proteins visualized by the presence of abundant newly formed collagen and proteoglycan in herniated discs. For in vitro DRG culture, fullerol attenuated TNF-α-elicited expression of transient receptor potential cation channel subfamily V member 1 (TRPV-1) and neuropeptides release (substance P and calcitonin gene-related peptide). In addition, fullerol suppressed TNF-α-stimulated increase in intracellular Ca²⁺ concentrations in primary neurons. Moreover, Western blot analysis in DRG revealed that fullerol's beneficial effects against TNF-α might be mediated through protein kinase B (AKT) and extracellular protein-regulated kinase (ERK) pathways. These TNF-α antagonizing and analgesic effects indicated therapeutic potential of fullerol in treating lumbar radiculopathy, providing solid preclinical evidence toward further translational studies.

Back pain in elite sports: A cross-sectional study on 1114 athletes

OBJECTIVES

To establish the prevalence of back pain in German elite athletes; examine the influence of age, sex, sports discipline and training volume; and compare elite athletes with a physically active control group.

METHODS

A standardized and validated online back pain questionnaire was sent by the German Olympic Sports Confederation to approximately 4,000 German national and international elite athletes, and a control group of 253 physically active but non-elite sports students.

RESULTS

We received responses from 1,114 elite athletes (46.5% male and 53.1% female, mean age 20.9 years ± 4.8 years, mean height 176.5 ± 11.5 cm, mean weight 71.0 ± 10.3 kg) and 166 physically active sports students (74.7% male and 24.1 female, mean age 21.2 ± 2.0 years, mean height 180.0 ± 8.0 cm, mean weight 74.0 ± 14.5 kg). In elite athletes, the lifetime prevalence of back pain was 88.5%, the 12-month prevalence was 81.1%, the 3-month prevalence was 68.3% and the point prevalence was 49.0%, compared with 80.7%, 69.9%, 59.0% and 42.8%, respectively in the control group. The lifetime, 12-month and 3-month prevalences in elite athletes were significantly higher than in the control group. Regarding the individual sports disciplines, the prevalence of back pain was significantly higher in elite rowers, dancers, fencers, gymnasts, track and field athletes, figure skaters and marksmen, and those who play underwater rugby, water polo, basketball, hockey and ice hockey compared with the control group. The prevalence of back pain was significantly lower in elite triathletes.

CONCLUSIONS

Back pain is a common complaint in German elite athletes. Low back pain seems to be a problem in both elite athletes and physically active controls. A high training volume in elite athletes and a low training volume in physically active individuals might increase prevalence rates. Our findings indicate the necessity for specific prevention programs, especially in high-risk sports. Further research should investigate the optimal dose-effect relationship of sporting activity for the general population to prevent back pain.

Curcumin alleviates lumbar radiculopathy by reducing neuroinflammation, oxidative stress and nociceptive factors

Current non-surgical treatments for lumbar radiculopathy [e.g. epidural steroids and Tumour necrosis factor-α (TNF-α) antagonists] are neither effective nor safe. As a non-toxic natural product, curcumin possesses an exceptional anti-inflammatory profile. We hypothesised that curcumin alleviates lumbar radiculopathy by attenuating neuroinflammation, oxidative stress and nociceptive factors. In a dorsal root ganglion (DRG) culture, curcumin effectively inhibited TNF-α-induced neuroinflammation, in a dose-dependent manner, as shown by mRNA and protein expression of IL-6 and COX-2. Such effects might be mediated via protein kinase B (AKT) and extracellular signal regulated kinase (ERK) pathways. Also, a similar effect in combating TNF-α-induced neuroinflammation was observed in isolated primary neurons. In addition, curcumin protected neurons from TNF-α-triggered excessive reactive oxygen species (ROS) production and cellular apoptosis and, accordingly, promoted mRNA expression of the anti-oxidative enzymes haem oxygenase-1, catalase and superoxide dismutase-2. Intriguingly, electronic von Frey test suggested that intraperitoneal injection of curcumin significantly abolished ipsilateral hyperalgesia secondary to disc herniation in mice, for up to 2 weeks post-surgery. Such in vivo pain alleviation could be attributed to the suppression, observed in DRG explant culture, of TNF-α-elicited neuropeptides, such as substance P and calcitonin gene-related peptide. Surprisingly, micro-computed tomography (μCT) data suggested that curcumin treatment could promote disc height recovery following disc herniation. Alcian blue/picrosirius red staining confirmed that systemic curcumin administration promoted regeneration of extracellular matrix proteins, visualised by presence of abundant newly-formed collagen and proteoglycan content in herniated disc. Our study provided pre-clinical evidence for expediting this natural, non-toxic pleiotropic agent to become a new and safe clinical treatment of radiculopathy.

Optimising conservative management of chronic low back pain: study protocol for a randomised controlled trial

Background

Lower back pain is a global health issue affecting approximately 80% of people at some stage in their life. The current literature suggests that any exercise is beneficial for reducing back pain. However, as pain is a subjective evaluation and physical deficits are evident in low back pain, using it as the sole outcome measure to evaluate superiority of an exercise protocol for low back pain treatment is insufficient. The overarching goal of the current clinical trial is to implement two common, conservative intervention approaches and examine their impact on deficits in chronic low back pain.

Methods/design

Forty participants, 25–45 years old with chronic (>3 months), non-specific low back pain will be recruited. Participants will be randomised to receive either motor control and manual therapy (n = 20) or general strength and conditioning (n = 20) exercise treatments for 6 months. The motor control/manual therapy group will receive twelve 30-min sessions, ten in the first 3 months (one or two per week) and two in the last 3 months. The general exercise group will attend two 1-hour sessions weekly for 3 months, and one or two a week for the following 3 months. Primary outcome measures are average lumbar spine intervertebral disc T2 relaxation time and changes in thickness of the transversus abdominis muscle on a leg lift using magnetic resonance imaging (MRI). Secondary outcomes include muscle size and fat content, vertebral body fat content, intervertebral disc morphology and water diffusion measured by MRI, body composition using dual energy X-ray absorptiometry, physical function through functional tests, changes in corticospinal excitability and cortical motor representation of the spinal muscles using transcranial magnetic stimulation and self-reported measure of pain symptoms, health and disability. Outcome measures will be conducted at baseline, at the 3-month follow-up and at 6 months at the end of intervention. Pain, depressive symptomology and emotions will be captured fortnightly by questionnaires.

Discussion

Chronic low back pain is ranked the highest disabling disorder in Australia. The findings of this study will inform clinical practice guidelines to assist with decision-making approaches where outcomes beyond pain are sought for adults with chronic low back pain.

Trial registration

Australian New Zealand Clinical Trials Registry, ACTRN12615001270505. Registered on 20 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1913-8) contains supplementary material, which is available to authorized users.

Running exercise strengthens the intervertebral disc

There is currently no evidence that the intervertebral discs (IVDs) can respond positively to exercise in humans. Some authors have argued that IVD metabolism in humans is too slow to respond anabolically to exercise within the human lifespan. Here we show that chronic running exercise in men and women is associated with better IVD composition (hydration and proteoglycan content) and with IVD hypertrophy. Via quantitative assessment of physical activity we further find that accelerations at fast walking and slow running (2 m/s), but not high-impact tasks, lower intensity walking or static positions, correlated to positive IVD characteristics. These findings represent the first evidence in humans that exercise can be beneficial for the IVD and provide support for the notion that specific exercise protocols may improve IVD material properties in the spine. We anticipate that our findings will be a starting point to better define exercise protocols and physical activity profiles for IVD anabolism in humans.