Effect of the presence or absence of upper limb support on posture when a smartphone user is in a seated position under ambient light conditions

• Published in: International journal of industrial ergonomics Vol. 80; p. 103050
• Main Authors: Merbah, Johan, Jacquier-Bret, Julien, Gorce, Philippe
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2020; Elsevier BV; Elsevier
• Subjects: Browsing; Engineering Sciences; Ergonomic recommendation; Injury prevention; Kinematics; Musculoskeletal disorders; Posture; Public transportation; Sitting position; Smartphone interaction; Smartphones; Studies; Support effect; Variance analysis; Work environment; Musculoskeletal disorders; Support effect; Smartphone interaction; Ergonomic recommendation
• ISSN: 0169-8141; 1872-8219
• DOI: 10.1016/j.ergon.2020.103050

Home, public transport, work, the number of environmental positions constraining the use of smartphones is significant. How can the presence of an upper limb support influence the sitting posture of smartphone users under fixed illumination and brightness? 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. 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. 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. •Quantification of the axial skeleton joint's orientations.•Quantification of Upper Limb joint angles.•The presence of a support allows a straightening of the neck.•Ergonomic recommendations based on Rapid Upper Limb assessment (RULA).