A comfort evaluation tool for sitting postures: the case of Library chairs

According to ergonomic researches regarding a good sitting posture, the chair, the desk and the objects on the desk, have to be aligned in a certain way to ensure to users a natural curve of the back in order to prevent musculoskeletal disorders. A brief observation among the main Scientific Technology Library inside the University campus showed that students used to complain about neck and lumbar pain, especially after a study day. Thus, a sitting posture comfort analysis had been performed on chairs inside the library. A long-time sitting posture during the daily study activity had been simulated with fifteen volunteer students performing 1-hour tests (divided into four tasks of 15 minutes each). Subjective perceptions had been gathered through questionnaires rating on a 5-point Likert scale both the expected comfort at the beginning of the experiment, and the Localized Postural Comfort at the end of each task. Moreover, just before the end of each task, postural angles had been detected by photographic acquisition and processed by Kinovea®; in addition, CAMan® software had been used to calculate the (dis)comfort indexes by detected postural angles. Finally, subjective and objective data had been statistically processed and compared. Results showed the lumbar area as the most suffering area (lower perceived comfort) while perceived (dis)comfort was independent on participants and tasks, but dependent on the time.