Objective：To investigate the lower limb skeletal muscle stiffness in healthy individuals.

Methods：Using ultrasonographic elastography, we measured the degree of stiffness of the rectus femoris and medial head of the gastrocnemius in healthy individuals and investigated the relationships between muscle stiffness and thickness, a quantitative measure of muscles, and between muscle stiffness and brightness, a qualitative measure of muscles. Furthermore, relationships between muscle stiffness and age, body weight, and body mass index (BMI) were also studied.

Results：Rectus femoris stiffness was positively correlated with muscle thickness. Rectus femoris stiffness had a weak negative correlation with muscle brightness and a weak positive correlation with body weight and BMI. Stiffness of the medial head of the gastrocnemius showed no correlation with any of the study variables. Muscle stiffness did not correlate with age in either of the muscles. No sex-related difference was found in the degree of muscle stiffness.

Conclusion：Although rectus femoris stiffness was associated with muscle thickness and brightness, these relationships were not observed for muscle stiffness of the medial head of the gastrocnemius. The data suggested that rectus femoris stiffness reflects the quantitative and qualitative states of the muscle, and the presence of such relationships may depend on the location of the muscle.

　　Introduction: Reimbursement for breathing care services was started with the revision of the nation's medical service fee system in 2010. Our hospital was not properly equipped in the light of certain standards governing facilities. Nonetheless, we started giving instructions to nurses on how to check the respirator at work. In addition to the on-the-job training, we are engaged in educational activity and information gathering. Out team comprises clinical engineers, physical therapists and registered nurses. They are all certified respiratory therapists. We hereby report our activities and refer to future problems.　　Activities: 1. Safety checks of respirators while in use. 2. Respiratory rehabilitation during hemodialysis. 3. Respirator-related workshops. 4. Review of accidents.　　Results: 1. It has become easier to discover potential problems and meet them at once. This is because our team is made up of different specialists, each used to looking at things differently. 2. Being constantly on the alert for any indication of a trouble ensures safety during breathing rehabilitation. 3. The number of accidents during 2012 decreased from 2011.　　Future: We think that since “safety management” is the center piece of our activity, our team ought to be recognized as an official organization of the hospital.