Thesis (Ph.D.) - Cairo University - Faculty of Physical Therapy - Department of Physical Therapy for Pediatric

Background: Smartphones became part of everyone's life. Unfortunately, its excessive usage is associated with different musculoskeletal disorders through affecting upper limb muscles function .Purpose: To investigate the relation between muscle fatigue (upper trapezius, brachioradialis, flexor carpi ulnaris and abductor pollicisbrevis) and time use of smartphone in school age children. Methods: It is a one-group pretest{u2013}posttest study that was conducted on 160 healthy children of both gender aged 12 {u2013} 14 years selected randomly.The electrical activities of their right and left upper trapezius, brachioradialies, flexor carpi ulnaries and abductor pollicisbrevismuscles were recorded by Electromyography. The outcomes were assessed in six phases; 1st phase (pretest without using smartphone) and 2nd, 3rd, 4th, 5th and 6th phases (at 10, 15, 20, 25and 30) minutes respectively with using smartphone Results:The results showed that the muscles of upper trapezius and brachioradialis either right or left which are big muscles showed the maximum reduction in the electrical muscle activity after 15 minutes from starting the use of smart phone (p=0.0001). On the other hand, the muscles of abductor pollicisbrevis and flexor carpi ulnaris either right or left which are small muscles showed the maximum reduction in the electrical muscle activity after 10 minutes from starting the use of smart phone (p=0.0001). Conclusion: Reduction in muscle activity is an adverse effect fromexcessive smartphone usage; optimal usage time should be established to guide its use, especially among children.

Issued also as CD