Sex and height appear to influence how people flex their neck when viewing handheld devices, according to a new study.

With increased phone and tablet ownership in the US comes increased levels of neck flexion compared to desktop or laptop computer use.

According to the findings published in the journal Clinical Anatomy, the researchers at the University of Arkansas looked at neck and jaw postures when using handheld electronic devices.

The research found that women and shorter individuals bend their necks differently than men and taller individuals; this could be related to the higher incidence of neck and jaw pain experienced by women.

Some evidence shows that using these devices, such as cellphones or tablets, in certain postures may influence both the neck and jaw, eventually causing the development of pain in both.

For the study, researchers asked 22 participants (10 female and 12 male) to hold and use electronic devices in five different postures while an X-ray was taken.

These postures ranged from a neutral position of sitting straight up to a fully reclined position, as if the participant were leaning back in a chair.