With the expansion of technology-based applications, daily phone use has increased significantly. According to a 2020 study, phone use habits among young adults aged 18-34 increased by 38.1%, and the time spent on the phone exceeding one hour increased by 68%. Currently, there is no clear definition of smartphone "addiction" or smartphone use, but like other types of addiction, it refers to the effort to control smartphone habits that cause problems or distress in daily life. Recent studies have reported a correlation between excessive screen use and individuals' mental and physical health. Excessive use of phones and video games causes many negative effects, including attention deficit, inability to enjoy life, hyperactivity, depression, anxiety, pain, and functional loss.

Video games are a type of game played through an audiovisual device and can be story-based. While many video games improve players' critical thinking, strategic planning, and problem-solving skills, they can also cause musculoskeletal problems due to the long hours spent at the desk and the repetitive movements involved.

The human spine is a kinematic chain with all joints interconnected; this means that changes in other body parts, such as the increased head tilt while texting on a smartphone, can have significant effects on the entire spine. A 2023 study showed an increase in spinal curvature, particularly in the cervical region, as smartphone use time increased. A study in Korea linked smartphone use to increased pain in the neck, wrists, hands, shoulders, and back. Another significant problem for smartphone users and video game players is "text neck," which occurs from prolonged screen time. This causes tension in the cervical spine, leading to neck pain and stiffness.

Smartphone addiction leads to hand-related problems, primarily hand and wrist pain. Furthermore, excessive use of smartphones, game controllers, and joysticks can lead to repetitive strain injuries such as carpal tunnel syndrome. Prolonged phone use, repetitive movements, and uncomfortable hand positions during use cause inflammation of the muscles and tendons in the hands and wrists, leading to swelling, pain, and loss of function in these joints. Video games are played using devices such as computers, consoles, handheld computers, and smartphones. The continuous, repetitive, and uninterrupted movements performed while using these devices can lead to musculoskeletal disorders, particularly in the upper extremities. Prolonged playing of these games results in musculoskeletal problems such as carpal tunnel syndrome and tendinitis. Extensive studies have shown that individuals' pain and symptoms worsen after prolonged gaming sessions. However, to date, there has been no study comparing smartphone addicts and video game players.

The aim of this research is to compare individuals with smartphone addiction, those who play video games for extended periods, and those without these habits in terms of pain, posture, and upper extremity function.

Inclusion Criteria:

• Being between 18-45 years old
• Volunteering to participate in the study

Exclusion Criteria:

• Individuals who have undergone major surgery or trauma related to the musculoskeletal system, primarily the upper extremities and trunk
• Individuals with neurological diseases
• Individuals with active rheumatic diseases
• Individuals with systemic diseases (diabetes, hypothyroidism, infection, malignancy, etc.)
• Individuals with serious psychological problems (scoring 30 or higher on the BDE)
• Individuals with contraindications to the assessment methods (acute inflammations, viral and bacterial infections, infectious diseases, fever, deep vein thrombosis, active malignant disease, aneurysms)
• Obesity (BMI ≥ 30 kg/m2)

The study will include 60 individuals: 20 with smartphone addiction (Group 1), 20 with digital game addiction (Group 2), and 20 without addiction (Group 3).