Measurement of Lumbar Multifidus Asymmetry in Amateur Cricket Pace Bowlers using Real-Time Ultrasound

International Journal of Exercise Science 11(3): 875-885, 2018. Objectives: To determine if lumbar multifidus asymmetry existed between the fifth lumbar (L5) and 1stsacral (S1) spinal level in a group of amateur cricket pace bowlers and a healthy non-cricketing group of males, and to determine if there were significant differences between groups in lumbar multifidus asymmetry at rest, on contraction, or during activation. Design: A prospective single blinded cross-sectional study. Methods: Forty healthy participants were recruited to two groups: an amateur cricket pace bowling group (n=20) and a non-cricketing group (n=20). Bilateral real-time ultrasound imaging of lumbar multifidus was conducted at the L5/S1 level in a resting and contracted state. Muscle thickness was measured and percentage activation was calculated. A force probe device was used to standardise force, inclination and roll of the ultrasound probe during real-time ultrasound imaging. Results: There was evidence of asymmetry in both groups, but differences between dominant and non-dominant sided lumbar multifidus thickness were non-significant. Between group comparisons of lumbar multifidus asymmetry indicated no significant difference for rest or activation. However, the cricket group had a significantly greater asymmetry of lumbar multifidus when contracted compared to controls (p=0.04). Conclusions: The results indicate that amateur cricket pace bowlers had significantly greater contracted lumbar multifidus asymmetry than non-cricketers. The resting lumbar multifidus asymmetries demonstrated previously in elite pace bowlers were not found in this population. Future research should investigate lumbar multifidus asymmetry in amateur pace bowlers in relation to lower back injury, and make comparisons between amateur and elite cricket pace bowlers

Variability in detection of SARS-CoV-2-specific antibody responses following mild infection: a prospective multicentre cross-sectional study, London, United Kingdom, 17 April to 17 July 2020.

IntroductionImmunoassays targeting different SARS-CoV-2-specific antibodies are employed for seroprevalence studies. The degree of variability between immunoassays targeting anti-nucleocapsid (anti-NP; the majority) vs the potentially neutralising anti-spike antibodies (including anti-receptor-binding domain; anti-RBD), particularly in mild or asymptomatic disease, remains unclear.AimsWe aimed to explore variability in anti-NP and anti-RBD antibody detectability following mild symptomatic or asymptomatic SARS-CoV-2 infection and analyse antibody response for correlation with symptomatology.MethodsA multicentre prospective cross-sectional study was undertaken (April-July 2020). Paired serum samples were tested for anti-NP and anti-RBD IgG antibodies and reactivity expressed as binding ratios (BR). Multivariate linear regression was performed analysing age, sex, time since onset, symptomatology, anti-NP and anti-RBD antibody BR.ResultsWe included 906 adults. Antibody results (793/906; 87.5%; 95% confidence interval: 85.2-89.6) and BR strongly correlated (ρ = 0.75). PCR-confirmed cases were more frequently identified by anti-RBD (129/130) than anti-NP (123/130). Anti-RBD testing identified 83 of 325 (25.5%) cases otherwise reported as negative for anti-NP. Anti-NP presence (+1.75/unit increase; p < 0.001), fever (≥ 38°C; +1.81; p < 0.001) or anosmia (+1.91; p < 0.001) were significantly associated with increased anti-RBD BR. Age (p = 0.85), sex (p = 0.28) and cough (p = 0.35) were not. When time since symptom onset was considered, we did not observe a significant change in anti-RBD BR (p = 0.95) but did note decreasing anti-NP BR (p < 0.001).ConclusionSARS-CoV-2 anti-RBD IgG showed significant correlation with anti-NP IgG for absolute seroconversion and BR. Higher BR were seen in symptomatic individuals, particularly those with fever. Inter-assay variability (12.5%) was evident and raises considerations for optimising seroprevalence testing strategies/studies