Investigation of the relationship between cervical joint position sense and upper extremity performance in smartphone addicted young adults

Aim: This study aimed to investigate the relationship between cervical joint position sense and upper extremity performance in young adults addicted to smartphones. Methods: The study included 100 healthy young adults aged 18-25. Participants' levels of smartphone addiction were assessed using the Smartphone Addiction Scale-Short Form. Cervical joint position sense was evaluated through the Laser Pointer-Assisted Angle Reproduction Test, while upper extremity strength was measured using a hand dynamometer. Upper extremity endurance was assessed with the Closed Kinetic Chain Upper Extremity Stability Test, balance with the Upper Quarter Y-Balance Test, power through the Seated Medicine Ball Throw Test, and reaction time using the Nelson Visual Hand Reaction Test. Results: No significant relationship was found between cervical joint position sense and upper extremity strength, endurance, or power (p˃0.05). A weak negative correlation was observed between extension joint position sense error and the left superolateral reach score (p=0.014, r=-0.246). There was also a weak negative correlation between left lateral flexion joint position sense error and the right inferolateral reach score (p=0.003, r=-0.290), and between left lateral flexion joint position sense error and the right composite score (p=0.029, r=-0.218). Additionally, a weak negative correlation was found between left lateral flexion joint position sense error and the left inferolateral reach score (p=0.044, r=-0.202). A weak positive correlation was observed between extension joint position sense error and upper extremity reaction time (p=0.005, r=0.277), as well as between left rotation joint position sense error and upper extremity reaction time (p=0.013, r=0.248), and between left lateral flexion joint position sense error and upper extremity reaction time (p=0.012, r=0.250). Conclusion: The study found a relationship between cervical joint position sense and balance and reaction time in young adults addicted to smartphones. As cervical joint position sense error increased, balance scores significantly worsened, and reaction time significantly increased. Promoting a healthy lifestyle, limiting smartphone use, and increasing physical activity levels may be beneficial in preventing future musculoskeletal injuries and maintaining upper extremity performance in healthy young adults.