Differences in Myoelectric Activity of the Lumbar Muscles between Recurrent and Chronic Low Back Pain : a cross-sectional study

Background: Altered lower back muscle activity is proposed as a contributing factor to the reoccurrence and chronicity of low back pain (LBP). This study compared lumbar muscle activity during trunk extension in patients with continuous chronic LBP (CLBP), non-continuous CLBP, recurrent LBP (RLBP) and healthy subjects. Methods: In 75 subjects (16 continuous CLBP, 15 non-continuous CLBP, 23 RLBP, 21 healthy controls), surface electromyographic (EMG) activity of the lumbar erector spinae (ES), multifidus (MF), latissimus dorsi (LD) and gluteus maximus (GM) was recorded during the concentric, holding and eccentric phase of a modified Biering Sorenson exercise. Results: Continuous CLBP patients showed higher EMG activity in the ES and MF muscles compared to healthy controls in the concentric (p = 0.011; p = 0.009 respectively) and the holding phase (p = 0.015; p = 0.013). Higher EMG activity was observed in continuous CLBP compared to RLBP in the ES and MF muscles in the holding phase (p = 0.035; p = 0.037), and in the MF in the concentric phase (p = 0.046), but not in the ES (p = 0.062). No differences in muscle activity were established in either the concentric, holding, and eccentric phase for the LD and GM muscles. No differences were found between non-continuous CLBP and the other groups. Conclusions: An enhanced muscle activity of the lumbar muscles during the concentric and holding phase was observed during trunk extension in patients with continuous CLBP compared to patients with RLBP and healthy subjects. No differences between groups are present in the GM and LD muscles during concentric and holding phases and for and muscle in the eccentric phase

HTLV-1 clonality during chronic infection and BLV clonality during primary infection

peer reviewedaudience: researcherHTLV-1 clonality during chronic infection and BLV clonality during primary infection Nicolas A Gillet1,2*, Carol Hlela1, Tine Verdonck3, Eduardo Gotuzzo3, Daniel Clark3, Sabrina Rodriguez2, Nirav Malani4, Anat Melamed1, Niall Gormley5, Richard Carter5, David Bentley5, Charles Berry6, Frederic D Bushman4, Graham P Taylor7, Luc Willems2, Charles R M Bangham1 1Department of Immunology, Wright-Fleming Institute, Imperial College London, London, W2 1PG, UK. 2Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) of University of Liège (ULg), Liège, 4000, Belgium. 3Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. 4Department of Microbiology, University of Pennsylvania School of Medicine, Pennsylvania, Philadelphia, PA, 19104, USA. 5Illumina, Chesterford Research Park, Essex, Little Chesterford, CB10 1XL, UK. 6University of California, California, La Jolla San Diego, CA, 92093-0901, USA. 7Department of Genitourinary Medicine and Communicable Diseases, Wright-Fleming Institute, Imperial College London, London, W2 1PG, UK. HTLV-1 persists by driving clonal proliferation of infected T-lymphocytes. A high proviral load predisposes to the inflammatory and malignant diseases associated with HTLV-1. Yet the reasons for the remarkable variation within and between individuals in the abundance of HTLV-1-infected clones remain unknown. We demonstrate that negative selection dominates during chronic infection, favouring establishment of proviruses integrated in transcriptionally silenced DNA: this selection is significantly stronger in asymptomatic carriers. We postulated that this selection occurred mainly during the primary infection. We are testing this hypothesis in an animal model by studying the BLV clonality during the primary infection in cows. By measuring the proviral load, the anti-BLV immune response and the BLV clonality we aim to quantify the impact of the immune response on the rate of infectious spread and on the selection of proviruses inserted in a particular genomic environment. Co-infection with Strongyloides stercoralis or Staphylococcus appears to be another risk factor for the development of HTLV-1 associated diseases. We observed that HTLV-1 clonality is altered by co-infection with these pathogens with an increase of both the number and the abundance of the infected T-cell clones. The genomic characteristics of the proviral integration sites in the most abundant clones differ significantly between co-infected individuals and those with HTLV-1 alone, implying the existence of different selection forces in co-infected patients. The rate of appearance of new clones in patients co-infected with Strongyloides stercoralis is higher than in patients with HTLV-1 alone. By comparing skin lesions and blood samples from patients with Infective Dermatitis associated with HTLV-1 (IDH), we observed a significant proportion of distinct infected clones between the two compartments. The skin lesions seem to be a site for HTLV-1 infectious spread

Relationship between the foot progression angle and eversion and exercise-related lower leg pain

Background In clinical practice, out-toeing is often linked with an increased eversion and an increased medial pressure distribution. However, in the literature, there is little evidence for this relationship. On the other hand, as an increased eversion and an increased medial pressure distribution have been detected as risk factors for exercise-related lower leg pain (ERLLP) [1, 2], and if the foot progression angle is related to these parameters, the occurrence of ERLLP could be due to an increased foot progression angle. The purpose of this study was therefore 1) to investigate the relationship between the foot progression angle and the amount of eversion and the medio-lateral pressure distribution and 2) to check if the foot progression angle is a risk factor for ERLLP. Materials and methods 3D gait kinematics combined with plantar pressure profiles were collected from 400 healthy physical education students. After this evaluation, all sports injuries were registered by a sports physician during 3 years. Relationship between foot progression angle and the amount of eversion and the medio-lateral pressure distribution were tested with Pearson correlation. Cox regression analysis was used to investigate the effect of the foot progression angle on the development of ERLLP. Results Forty-six subjects developed ERLLP and 29 of them developed bilateral symptoms thus giving 75 symptomatic lower legs. Bilateral lower legs of 167 subjects who developed no injuries in the lower extremities served as controls. Pearson correlation showed no significant correlation between the foot progression angle and the eversion excursion (R=.121) and the medio-lateral pressure distribution (R=.116). Cox regression analysis showed no significant differences for the foot progression angle between the injured and uninjured subjects. Conclusions The findings of this study suggest that the foot progression angle is not a risk factor for ERLLP as the foot progression angle is not related to the amount of eversion and the medio-lateral pressure distribution

Impact of (long) COVID on athletes' performance : a prospective study in elite football players

Objectives To investigate possible persistent performance deficits after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in elite athletes. Methods A prospective cohort study in three Belgian professional male football teams was performed during the 2020 - 2021 season. Participants were submitted to strength, jump, and sprint tests and an aerobic performance test (the Yo-Yo Intermittent Recovery test (YYIR)). These tests were repeated at fixed time intervals throughout the season. Assessment of SARS-CoV-2 infection was performed by a polymerase chain reaction (PCR) test before each official game. Results Of the 84 included participants, 22 were infected with SARS-CoV-2 during follow-up. At the first testing after infection (52.0 +/- 11.2 days after positive PCR testing) significantly higher percentages of maximal heart rate (%HRmax) were seen - within the isolated group of infected players- during (p = .006) and after the YYIR (2 min after, p = .013), compared to pre-infection data. This increase in %HRmax was resolved at the second YYIR testing after infection (127.6 +/- 33.1 days after positive PCR testing). Additionally, when comparing the first test after infection in formerly infected to non-infected athletes, significantly higher %HRmax were found during (p < .001) and after the YYIR test (p < .001),No significant deficits were found for the jump, muscular strength or sprint tests. Conclusion Aerobic performance seems compromised even weeks after infection. Simultaneously, anaerobic performance seemed to be spared. Because of the potential detrimental effects on the immune system, caution might be advised with high-intensity exposure until aerobic performance is restored. KEY MESSAGES Elite football players' aerobic performance seems to be affected for weeks after they return to sports after a SARS-CoV-2 infection. Similarly, anaerobic performance tests showed no discernible changes between both before and after SARS-CoV-2 infections. Regular YYIR testing is recommended to monitor aerobic performance after SARS-CoV-2 infection

Association between SARS-COV-2 infection and muscle strain injury occurrence in elite male football players : a prospective study of 29 weeks including three teams from the Belgian professional football league

Objectives The aim of this study was to investigate the association between SARS-CoV-2 infection and muscle strain injury in elite athletes. Methods A prospective cohort study in three Belgian professional male football teams was performed during the first half of the 2020-2021 season (June 2020-January 2021). Injury data were collected using established surveillance methods. Assessment of SARS-CoV-2 infection was performed by a PCR test before each official game. Results Of the 84 included participants, 22 were infected with SARS-CoV-2 and 14 players developed a muscle strain during the follow-up period. Cox's proportional hazards regression analyses demonstrated a significant association between SARS-CoV-2 infection and the development of muscle strain (HR 5.1; 95% CI 1.1 to 23.1; p=0.037), indicating an increased risk of developing muscle strains following SARS-CoV-2 infection. All athletes who sustained a muscle strain after infection were injured within the first month (15.71 +/- 11.74 days) after sports resumption and completed a longer time in quarantine (14.57 +/- 6.50 days) compared with the infected players who did not develop a muscle strain (11.18 +/- 5.25days). Conclusion This study reported a five times higher risk of developing a muscle strain after a SARS-CoV-2 infection in elite male football players. Although this association should be examined further, it is possible that short-term detraining effects due to quarantine, and potentially pathological effects of the SARS-CoV-2 infection are associated with a higher risk of muscle strain injury

Azithromycin during Acute COPD Exacerbations Requiring Hospitalization (BACE): a Multicentre, Randomized, Double-blind, Placebo-controlled Trial.

RATIONALE: Azithromycin prevents acute exacerbations of chronic obstructive pulmonary disease (AECOPDs); however, its value in the treatment of an AECOPD requiring hospitalization remains to be defined. OBJECTIVES: We investigated whether a 3-month intervention with low-dose azithromycin could decrease treatment failure (TF) when initiated at hospital admission and added to standard care. METHODS: In an investigator-initiated, multicenter, randomized, double-blind, placebo-controlled trial, patients who had been hospitalized for an AECOPD and had a smoking history of ≥10 pack-years and one or more exacerbations in the previous year were randomized (1:1) within 48 hours of hospital admission to azithromycin or placebo. The study drug (500 mg/d for 3 d) was administered on top of a standardized acute treatment of systemic corticosteroids and antibiotics, and subsequently continued for 3 months (250 mg/2 d). The patients were followed for 6 months thereafter. Time-to-first-event analyses evaluated the TF rate within 3 months as a novel primary endpoint in the intention-to-treat population, with TF defined as the composite of treatment intensification with systemic corticosteroids and/or antibiotics, a step-up in hospital care or readmission for respiratory reasons, or all-cause mortality. MEASUREMENTS AND MAIN RESULTS: A total of 301 patients were randomized to azithromycin (n = 147) or placebo (n = 154). The TF rate within 3 months was 49% in the azithromycin group and 60% in the placebo group (hazard ratio, 0.73; 95% confidence interval, 0.53-1.01; P = 0.0526). Treatment intensification, step-up in hospital care, and mortality rates within 3 months were 47% versus 60% (P = 0.0272), 13% versus 28% (P = 0.0024), and 2% versus 4% (P = 0.5075) in the azithromycin and placebo groups, respectively. Clinical benefits were lost 6 months after withdrawal. CONCLUSIONS: Three months of azithromycin for an infectious AECOPD requiring hospitalization may significantly reduce TF during the highest-risk period. Prolonged treatment seems to be necessary to maintain clinical benefits