Effect of Handedness on Electromyographic Activity of Hand Muscles and Nerve Conduction Velocity During Use Mobil Phone in School Age Children
NCT Number: NCT06497179
Status: ACTIVE_NOT_RECRUITING
Study Type: OBSERVATIONAL
Conditions: Lateralization of the Brain Hemispheres
Sponsor: MTI University
Sex: ALL
Age: CHILD
Enrollment: 70
Study Design: Observational Model: |Time Perspective: p
Start Date: 2024-07-10
Completion Date: 2024-09-10
Locations: faculty of pysical therapy, MTI university, Cairo, Egypt

Summary:
Asymmetries in both physiology and anatomy at different levels of the central nervous system, which controls the upper extremities, are well-established. These asymmetries, related to handedness, are evident in the motor cortex and corticospinal tract. Moreover, variances have been identified in peripheral nervous pathways, including elevated sensory detection thresholds and increased conduction velocities in the motor nerve of the dominant arm.

Apart from disparities in the nervous system, differences also arise in the muscles. Prolonged preferential utilization of muscles on the dominant side of the body may lead to alterations in muscle fiber composition, characterized by a higher predominance of slow-twitch type I fibers.

Modern technology plays a key role in daily human life. This involves keeping pace with rapid changes in the field of communication technology. In this context, smartphones have become an essential part of life, not only in matters related to communication, but also as essential social accessories. As a result of this social involvement in communication technology, young children have become avid smartphones users. Holding a phone in hand needs support from fingers, flexion of hand and wrist, so holding the phone in same position for long periods can cause huge amount of stress on the structures present in the hand. This stress can cause injuries and damages in longer periods.

To address this objective, we will examine muscle synergies on the dominant sides in right-handed and left-handed participants while performing upper limb motor tasks. To accomplish this, we will conduct the following: Comparative analysis of motor and sensory nerve conduction velocities (radial, median, and ulnar) in right-handed and left-handed individuals during smartphone use. Comparison of hand muscle activation between right-handed and left-handed individuals during smartphone use.

Primary Outcome Measures: Nerve Conduction Velocity, Nerves Assessed: Ulnar, median, and radial Phases: Phase 1: Pre-test without smartphone use. Phase 2: After 10 minutes of smartphone use. Consistency: Testing and laboratory environments will be kept constant. The same physiotherapist and neurophysiologist administered all tests. Measurements will be taken while participants used their dominant hand to operate the smartphone., one day|maximum voluntary isometric contraction (MVIC), Muscle Activation Assessment for Flexor carpi ulnaris (FCU), extensor carpi radialis (ECR), abductor pollicis longus (APL), and first dorsal interosseous muscle. Positioning: Participants will sit on a chair with feet on the ground. Coupling gel will be applied to electrodes, straps will be used to prevent movement and wires will be kept loose. EMG machine functionality will be checked prior to use. MVIC measures and evaluates muscle strength and normalizes EMG data. Procedure: Explained to parents beforehand, with measurements will take on the same day. Peak force and target muscle force will be analyzed for MVIC. Data Analysis: Average Rectified EMG (ARV) will be used to measure muscle activity, as it is less variable compared to peak EMG variables. Changes in EMG signal indicating muscle fatigue included increased mean absolute value, amplitude, duration of muscle action potential, and a shift to lower frequencies., one day