Variables and research indicators: - Determining the prevalence of MSDs and assessing the impact of MSDs on work and life + prevalence of MSDs in general and by anatomical site, age, gender, medical history, work characteristics + The relationship between MSDs and quality of life, anxiety, absenteeism at work - Assess knowledge, attitudes and practices about MSDs and some factors related to MSDs on nurses 7 + The percentage of correct answering about knowledge - attitudes - practices of MSDs + The relationship between MSDs and the sociological characteristics of nurses + Relationship between MSDs and nurses' career characteristics + The relationship between MSDs and the score of knowledge - attitude - practice on nurses' MSDs - Evaluate the effectiveness of interventions by health education communication and physical exercise + The percentage of MSDs in general and according to the anatomical position before and after the intervention + Percentage of people with good knowledge - attitudes - practices about MSDs before and after the intervention + Quality of life and anxiety level scores on nurses before and after the intervention 2.3.3.