Technique, muscle activity and kinematic differences in young adults texting on mobile phones

Abstract

The aim of this study was to investigate whether there are differences in technique between young adults with and without musculoskeletal symptoms when using a mobile phone for texting and whether there are differences in muscle activity and kinematics between different texting techniques. A total of 56 young adults performed a standardised texting task on a mobile phone. Their texting techniques were registered using an observation protocol. The muscular activity in six muscles in the right forearm/hand and both shoulders were registered by surface electromyography and the thumb abduction/adduction and flexion/extension were registered using a biaxial electrogoniometer. Differences in texting techniques were found between the symptomatic and the asymptomatic group, with a higher proportion of sitting with back support and forearm support and with a neutral head position in the asymptomatic group. Differences in muscle activity and kinematics were also found between different texting techniques. The differences in texting technique between symptomatic and asymptomatic subjects cannot be explained by them having symptoms but may be a possible contribution to their symptoms.

Statement of Relevance: There has been a dramatically increased use of mobile phones for texting especially among young people during the last years. A better understanding of the physical exposure associated with the intensive use is important in order to prevent the development of musculoskeletal disorders and decreased work ability related to this use.

Keywords:

• electrogoniometer
• electromyography
• mobile phone
• posture
• thumb movements

Acknowledgements

The study was financially supported by the Swedish Council of Working Life Research and AFA Försäkring, Stockholm. The authors would like to thank Ulrika Wedberg, Christina Ahlstrand, Linda Åhlström, Jesper Eriksson and Björn Torén for all their work during the data collection and Angelika Fors for the input of all data.