An experimental study of low-level laser therapy in rat Achilles tendon injury

The aim of this controlled animal study was to investigate the effect of low-level laser therapy (LLLT) administered 30 min after injury to the Achilles tendon. The study animals comprised 16 Sprague Dawley male rats divided in two groups. The right Achilles tendons were injured by blunt trauma using a mini guillotine, and were treated with LLLT or placebo LLLT 30 min later. The injury and LLLT procedures were then repeated 15 hours later on the same tendon. One group received active LLLT (λ = 904 nm, 60 mW mean output power, 0.158 W/cm2 for 50 s, energy 3 J) and the other group received placebo LLLT 23 hours after LLLT. Ultrasonographic images were taken to measure the thickness of the right and left Achilles tendons. Animals were then killed, and all Achilles tendons were tested for ultimate tensile strength (UTS). All analyses were performed by blinded observers. There was a significant increase in tendon thickness in the active LLLT group when compared with the placebo group (p < 0.05) and there were no significant differences between the placebo and uninjured left tendons. There were no significant differences in UTS between laser-treated, placebo-treated and uninjured tendons. Laser irradiation of the Achilles tendon at 0.158 W/cm2 for 50 s (3 J) administered within the first 30 min after blunt trauma, and repeated after 15 h, appears to lead to edema of the tendon measured 23 hours after LLLT. The guillotine blunt trauma model seems suitable for inflicting tendon injury and measuring the effects of treatment on edema by ultrasonography and UTS. More studies are needed to further refine this model

Riscos ocupacionais na legislação trabalhista brasileira: destaque para aqueles relativos à saúde e à voz do professor Occupational risks in the Brazilian labor legislation: highlight on those related to teacher's health and voice

OBJETIVO: Analisar a legislação a respeito de riscos ocupacionais, com destaque para aqueles relacionados à saúde e à voz do professor. MÉTODOS: Trata-se de pesquisa bibliográfica, de caráter qualitativo, que considerou as políticas públicas sobre Saúde e Segurança no Trabalho. As Normas Regulamentadoras foram lidas e seus conteúdos analisados e organizados por categorias, com recorte para aqueles referentes ao ambiente escolar. RESULTADOS: As 33 normas focalizam os fatores de risco, níveis de tolerância e controle para saúde e segurança no trabalho. Os agentes ambientais nocivos são múltiplos e suas especificidades, como concentração e frequência, determinam o nível de tolerância à exposição. Na escola, os riscos ambientais como ruído, poeira, temperatura e iluminação inadequadas, dentre outros, estão presentes, porém em grau leve. O tratamento acústico, de iluminação e de ventilação é indicado para controle desses riscos. Os documentos mostram situações de agravos à saúde dos trabalhadores em graus de risco muito maiores do que aqueles da docência. Não há explicitação de fatores inerentes à organização do trabalho e os cuidados com a voz limitam-se à profissão de teleoperador, o que pode servir de referência para o professor. CONCLUSÃO: A legislação trabalhista é ampla ao abarcar a diversidade de condições de trabalho e garantir a saúde dos trabalhadores. A docência apresenta riscos ocupacionais à saúde mais leves do que outras profissões; contudo, os fatores organizacionais do trabalho, assim como os distúrbios de voz, muito frequentes na docência, carecem de maior atenção da legislação no Brasil.<br>PURPOSE: To analyze the legislation regarding occupational risks, highlighting those related to teacher's health and voice. METHODS: A bibliographic search of qualitative nature regarding the public policies about Health and Security at Work was carried out. The Regulatory Standards were read and their contents analyzed and organized into categories, detaching those from the scholar environment. RESULTS: The 33 regulatory standards focus the risk factors, tolerance levels, and control for health and security at work. The harmful environmental agents are multiple and their specificities, such as concentration and frequency, determine the level of tolerance to exposition. At school, the environmental risks like noise, dust, temperature and inadequate lighting, among others, are present, however in a mild degree. The acoustic, lighting and exhaust ventilation treatments are indicated for the control of such risks. The documents show situations of worsening of the workers' health in much higher degrees of risk than those from teaching activities. There is no explicitation of factors inherent to the work organization, and the care with the voice is limited to the profession of telesales workers, which can serve as a reference to the teacher's work. CONCLUSION: Labor legislation is ample to cover the diversity of work conditions and to ensure the workers' health. Teaching presents milder occupational risks to health than other professions; nevertheless, the organizational factors of work, as well as voice disorders, very frequent in this activity, demand greater attention from Brazilian legislation