Honors Theses

Date of Award

Spring 5-9-2020

Document Type

Undergraduate Thesis



First Advisor

Carol Britson

Second Advisor

Gregg Roman

Third Advisor

Colin Jackson

Relational Format



Reports in the media by celebrities have sparked an interest in a phenomenon being called “selfie-wrist,” in which smartphone users develop symptoms traditionally associated with carpal tunnel syndrome (CTS). There has been no research to date which investigates the claims of “selfie wrist.” The primary aim of this study was to address the validity of “selfie wrist” claims. The secondary aim of this study was to further investigate the effects of texting on musculoskeletal health, taking into account the differences between texting one-handed versus two-handed, and the effect of using a grip device while texting.

The experiment consisted of an intake survey component, a selfie-taking component, and a texting component. Subjects who, for various reasons, were unable to participate in the in-person experiment completed an online alternate survey. The surveys assessed smartphone usage habits. Photos of the flexion angles of the thumb, wrist, and elbow were taken of participating subjects during flexion without holding a smartphone, during selfie-taking and group selfie-taking for each joint. Surface electromyography was used to assess the muscle activity of the trapezius, flexor carpi ulnaris, flexor carpi radialis (FCR), and abductor pollicis longus muscles during texting tasks performed one-handed, two-handed, and with and without a grip device. Joint angle data and muscle activity data were analyzed with a two-way analysis of variance, with the two factors being joint and number of hands used during texting, and grip device in use and number of hands used during texting, respectively.

A significant increase was found only in the elbow joint angle during selfie-taking and group selfie-taking. The significant increase that occurred in the elbow joint was expected since the baseline data reflected flexion of the elbow, and the performance of selfie-taking results in extension. These results indicate that a detrimental angle of flexion was not achieved with any selfie-taking task, and that “selfie wrist” is not a real phenomenon. Further research is needed to determine the potential effects of selfie-taking when viewed as a repetitive strain injury. All muscles except for the FCR showed a significant increase in muscular output during texting one-handed as compared to two-handed. There was no significant difference found in the use of a grip device during texting one-handed nor two-handed. The results of this study indicate that neither texting nor selfie-taking result in the development of musculoskeletal disorders.



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