Background: Home, public transport, work, the number of environmental positions constraining the use of smartphones is significant.Research question: How can the presence of an upper limb support influence the sitting posture of smartphone users under fixed illumination and brightness?Methods: Twelve subjects (21,6 ± 5,5 years old) performed web browsing under two environmental positions (POSITION): sitting with and without support (table). The users' postures were evaluated through relative kinematics joint angles analysis. A repeated measure analysis of variance and Tukey post-hoc tests were performed to test the effect of POSITION on posture.Results: In sitting position in front of a table, neck is less stressed (flexion < 10°) and trunk and shoulder are supported which suggests less constrains for the joints.Relevance to industry: To prevent injury or pain, the use of an upper limb support (to lean on) should be considered for people/workers who use the smartphone frequently.