Effect of Handedness on Electromyographic Activity of Hand Muscles and Nerve Conduction Velocity During Use Mobil Phone in School Age Children

Handedness is a well-recognized behavioral phenomenon characterized by a preference for using one hand over the other. This study investigates the impact of handedness on electromyographic (EMG) activity of hand muscles and nerve conduction velocity during smartphone use. This interventional parallel study included 70 participants (35 left-handed, 35 right-handed) aged 12 - 14 years inclusion criteria: normal BMI (16.5-24 kg/m²) no regular athletic activity, Participants shared the same socioeconomic level used the same smartphone model (6.7-inch touchscreen). Exclusion criteria included: peripheral nerve injury upper extremity movement limitations history of upper extremity fractures or deformities, neurological disorders such as peripheral neuropathy due to type I diabetes mellitus. EMG activity and nerve conduction velocities (radial, median, and ulnar nerves) will be measured before and during smartphone use. Muscle activation will be assessed for the abductor pollicis longus (APL), extensor carpi radialis (ECR), flexor carpi ulnaris (FCU), and first dorsal interosseous muscles. Statistical analysis will be conducted to identify significant differences between left-handed and right-handed participants.