Humans have engaged in endurance running for millions of years, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or ...wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.
Anti‐spike antibody testing has emerged as a powerful tool to assess SARS‐CoV‐2 vaccine response in solid organ transplant (SOT) recipients, many of whom remain at risk for COVID‐19 despite ...vaccination. Neither the US Food and Drug Administration nor major transplant societies recommend testing antibody responses after vaccination, or its general incorporation into COVID‐19 risk stratification. Notably, in December 2021, the American Society of Transplantation recognized anti‐spike seronegativity as a consideration for use of monoclonal antibody pre‐exposure prophylaxis. In this viewpoint, we narrate the evolving rationale for anti‐spike antibody testing and ultimately recommend that all SOT recipients be tested for anti‐spike antibody after vaccination. This result should then be used to personalize efforts to improve protection versus COVID‐19 for the most vulnerable, such as additional vaccination strategies and consideration of passive immunoprophylaxis.
Anti‐spike antibody testing of solid organ transplant recipients after vaccination is a useful marker to assess vulnerability to COVID‐19. Fishman and Alter comments on page 1291
Objective
To evaluate disease flare and postvaccination reactions (reactogenicity) in patients with rheumatic and musculoskeletal diseases (RMDs) following 2‐dose SARS–CoV‐2 messenger RNA (mRNA) ...vaccination.
Methods
RMD patients (n = 1,377) who received 2‐dose SARS–CoV‐2 mRNA vaccination between December 16, 2020 and April 15, 2021 completed questionnaires detailing local and systemic reactions experienced within 7 days of each vaccine dose (dose 1 and dose 2), and 1 month after dose 2, detailing any flares of RMD. Associations between demographic/clinical characteristics and flares requiring treatment were evaluated using modified Poisson regression.
Results
Among the patients, 11% reported flares requiring treatment; there were no reports of severe flares. Flares were associated with prior SARS–CoV‐2 infection (incidence rate ratio IRR 2.09, P = 0.02), flares in the 6 months preceding vaccination (IRR 2.36, P < 0.001), and the use of combination immunomodulatory therapy (IRR 1.95, P < 0.001). The most frequently reported local and systemic reactions included injection site pain (87% after dose 1, 86% after dose 2) and fatigue (60% after dose 1, 80% after dose 2). Reactogenicity increased after dose 2, particularly for systemic reactions. No allergic reactions or SARS–CoV‐2 diagnoses were reported.
Conclusion
Flares of underlying RMD following SARS–CoV‐2 vaccination were uncommon. There were no reports of severe flares. Local and systemic reactions typically did not interfere with daily activity. These early safety data can help address vaccine hesitancy in RMD patients.
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