(03) 5333 4639

5 Ripon Street North, Ballarat

(03) 5303 0458

501a Wiltshire Lane, Delacombe


    Mobile Phones - A Real Pain in the Neck

    Billions of people are using mobile phone devices - essentially in poor posture. This study assesses the forces incrementally seen by the cervical spine as the head is tilted forward, into worsening posture.


    Assessment of Stresses in the Cervical Spine Caused by Posture and Position of the Head




    Billions of people are using mobile phone devices - essentially in poor posture. This study assesses the forces incrementally seen by the cervical spine as the head is tilted forward, into worsening posture.


    A model of the cervical spine was created with realistic values. Calculations were made and then forces extracted in newtons and then converted into pounds/kg. We made the calculations using neck + head, which gave an average weight of 60 newtons (6kg or 13.2 pounds). The center of mass was located 16cm above C7 or 15cm from the top of the skull.


    The weight on the spine dramatically increases when flexing the head forward at varying degrees. An adult head weighs 4.5 – 5.5kg in the neutral position. As the head tilts forward the forces seen by the neck surges to 12.3kg at 15o, 18kg at 30o, 22kg at 45o and 27kg at 60o. At 90o the model prediction was not reliable.



    15 °


    45 °

    60 °


      Force To Cervical Spine  

    4.5 – 5.5kg 





    Not Measurable


    As far as we are aware, and after a review of the National Library of Medicine publications, there is no other study available to assess the stresses about the neck when incrementally moving the head forward.

    The muscles, tendons, and ligaments dampen the stresses seen by the cervical spine. For our assessments, the calculations of the stresses seen by the neck are for the neck and muscles, including ligaments and tendons.

    Good posture is defined as ears aligned with the shoulders and the shoulder blades, retracted. In proper alignment, spinal stress is diminished. It is the most efficient position for the spine.

    Amy Cuddy and associates1-3 showed that:

    • High-power posture posers experienced elevations in testosterone, increases in serotonin, decreases in cortisol, and increased feelings of power and tolerance for risk taking
    • Low-power posture posers exhibited the opposite pattern.

    Poor posture occurs with the head in a tilted forward position and the shoulders drooping forward in a rounded position.4,5

    Loss of the natural curve of the cervical spine leads to incrementally increased stresses about the cervical spine. These stresses may lead to early wear, tear, degeneration, and possibly surgeries.

    People6 spend an average of 2 - 4 hours a day with their heads tilted over reading and texting on their smart phones and devices.  Cumulatively this is 700 - 1400 hours a year of excess stresses seen about the cervical spine. It is possible that a high school student may spend an extra 5,000 hours in poor posture.

    While it is nearly impossible to avoid the technologies that cause these issues, individuals should make an effort to look at their phones with a neutral spine and to avoid spending hours each day hunched over.

    Cervical spine surgeons need to pay attention to the alignment and therefore to the stresses about the spine when performing anterior discectomies and fusion - Misalignment of a reconstructed segment into kyphosis (reversed neck curve) will lead to a biomechanical disadvantage and more than likely will affect breakdown of the adjacent segment.


    1. Cuddy A. Power Poser - Game Changers TIME content.time.com/.../ 0,28804, 2091589_ 2092033_2109441,00 .html.
    2. Huang L1, Galinsky AD, Gruenfeld DH, et al. Powerful postures versus powerful roles: which is the proximate correlate of thought and behavior? Psychol Sci 2011;22(1):95–102.
    3. Carney DR1, Cuddy AJ, Yap AJ. Power posing: brief nonverbal displays affect neuroen- docrine levels and risk tolerance. Psychol Sci. 2010 Oct;21(10):1363–8.
    4. Walsh J1, Eccleston C2, Keogh E2. Pain communication through body posture: The development and validation of a stimulus set. Pain. 2014 Aug 26. pii: S0304- 3959(14)00378–9. doi: 10.1016/j.pain.2014. 08.019.
    5. Data Pew Research Center http://www.org/ 2013/09/19/ cell-phone- activities-2013/.
    6. Harvard Editorial Board: How to soothe a sore neck. The essentials are icing and heat, gentle therapeutic exercise, and good posture. Harv Mens Health Watch 2014;18(11):5.

    PostureWorks A: 5 Ripon Street North, Ballarat, Victoria 3350         T: (03) 5333 4639

                       A: 501a Wiltshire Lane, Delacombe, Victoria 3350      T: (03) 5303 0458

    PostureWorks © 2018 Website Designed and Created by The Ad Group