A method for postural critical factors checking: The case of library chairs

BACKGROUND:According to ergonomic researches regarding a good sitting posture, it is essential to ensure a natural back-curve in order to prevent musculoskeletal disorders. A brief observation among the Scientific Technology Library inside the University of Salerno showed that students used to complain about neck and lumbar pain, especially after a study day. OBJECTIVE:On the light of this background, a sitting posture comfort analysis had been performed on chairs inside the library to check the critical factors that influence the postural comfort and, consequently, the learning. METHODS:A prolonged sitting posture, that is common during the daily study activity, had been simulated with fifteen volunteer students performing 1-hour tests (divided into four 15-minutes tasks). Subjective perceptions had been gathered through questionnaires rating on a 5-point Comfort scale, both the expected comfort at the beginning of the experiment and the Localized Postural Comfort at the end of each task have been investigated. Then, postural angles had been gathered through photographic acquisition and Kinovea®. CaMAN software had been used to calculate the objective (dis)comfort indexes. Finally, subjective and objective data had been statistically processed and compared. RESULTS:Lumbar area scored the lowest perceived comfort while the perceived comfort was independent of participants and tasks, but dependent on time. CONCLUSIONS:After this comfort-driven analysis, critical factors of the chair-design were checked, and a proposal for a future re-design was hypothesized.