title: Mobile input device type, texting style and screen size influence upper extremity and trapezius muscle activity, and cervical posture while texting.
abstract: This study aimed to determine the effects of input device type, texting style, and screen size on upper extremity and trapezius muscle activity and cervical posture during a short texting task in college students. Users of a physical keypad produced greater thumb, finger flexor, and wrist extensor muscle activity than when texting with a touch screen device of similar dimensions. Texting on either device produced greater wrist extensor muscle activity when texting with 1 hand/thumb compared with both hands/thumbs. As touch screen size increased, more participants held the device on their lap, and chose to use both thumbs less. There was also a trend for greater finger flexor, wrist extensor, and trapezius muscle activity as touch screen size increased, and for greater cervical flexion, although mean differences for cervical flexion were small. Future research can help inform whether the ergonomic stressors observed during texting are associated with musculoskeletal disorder risk.
authors.affiliation: School of Health Related Professions, Rutgers, The State University of New Jersey, 40 E. Laurel Road, Stratford, NJ, USA. Electronic address: kietrydm@shrp.rutgers.edu.
authors.forename: David M
authors.initials: DM
authors.lastname: Kietrys
authors.affiliation: Occupational Therapy Assistant Program, Harcum College, 750 Montgomery Ave., Bryn Mawr, PA, USA; Department of Rehabilitation Sciences, Temple University, 3307 N. Broad St., Philadelphia, PA 19140, USA. Electronic address: mgerg@harcum.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gerg
authors.affiliation: Department of Occupational Medicine, Epidemiology, and Prevention, Hofstra North Shore-LIJ School of Medicine, 175 Community Drive, Great Neck, NY 11021, USA. Electronic address: Jdropkin@NSHS.edu.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dropkin
authors.affiliation: Centre for Musculoskeletal Research, University of Gävle, 801 76 Gävle, Sweden; Department of Public Health, Temple University, 3307 N. Broad St., Philadelphia, PA 19140, USA(1). Electronic address: Judith.Gold@hig.se.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Gold
mesh_terms: D000293:Adolescent; D000328:Adult; D001132:Arm / Q000502:physiology*; D004576:Electromyography; D006804:Ergonomics; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009333:Neck / Q000502:physiology; D011187:Posture / Q000502:physiology*; D000068997:Smartphone / Q000295:instrumentation* / Q000592:standards; D064171:Superficial Back Muscles / Q000502:physiology*; D060145:Text Messaging; D055815:Young Adult
keywords: Ergonomic exposure; SMS (short message service); Text messaging