Effect of Problematic Smartphone Use

Primary outcomes

1. Smartphone Addiction Scale Short Form

   Time frame: Baseline

   It is a 10-item scale to assess problematic smartphone use. Each item in the scale is scored between 1 (strongly disagree) and 6 (strongly agree). The total score ranges from 10-60, with higher scores indicating an increased risk of smartphone addiction. The cut-off score of the scale was reported as 33 for women and 31 for men.

2. Upper Extremity Functions-Quick Disabilities of Arm, Shoulder & Hand (Quick DASH)

   Time frame: Baseline

   In the 11-question scale, difficulties encountered during activities of daily living (carrying shopping bags, opening jars, using a knife to cut food, etc.) due to problems in the shoulder, elbow and hand regions are scored from 1 (no difficulty) to 5 (no difficulty at all). A higher total score indicates an increased level of functional limitation in the upper limb.

3. Upper Extremity Functions-Reaction Time

   Time frame: Baseline

   The upper extremity reaction time will be assessed using the BlazePod Trainer (Blazepod Trainer Device, Play Coyotta Ltd, Tel Aviv, Israel). Participants will be asked to hit 5 LEDs on a table as quickly as possible using only one hand while in a seated position. The LEDs will be arranged in an arc on the table within the participant's reach without disturbing their seated posture. The right and left hands will be evaluated separately. The number of LEDs hit in 30 seconds, the unit hit time (ms), and the number of missed LEDs (those that automatically hit after a 5-second waiting period) will be recorded through the BlazePod app installed on the researchers' phones.

4. Upper Extremity Functions-Grip Strength

   Time frame: Baseline

   A calibrated digital Jamar dynamometer (Performance Health, Warrenville, IL) will be used for grip strength. Participants will be instructed to squeeze the dynamometer as hard as possible while sitting in an upright position as recommended by the American Society of Hand Therapists, with arms at their sides, elbows flexed 90° and forearms in a neutral position. For hand grip strength, 3 measurements will be made with one minute intervals between each measurement and the average value will be recorded.

5. Cognitive Functions-Stroop Test ÇAPA Form

   Time frame: Baseline

   It is used to assess executive functions such as attention, information processing speed and response inhibition. The Stroop Test ÇAPA Form consists of a total of 60 items. In the first part, there are small rectangles (0.5 x 1 cm) with colors such as yellow, blue and red. In the second part, there are color names written in different colors. The test is administered in 3 stages. In the first part (Stroop A), the person is asked to name the colors in the boxes from left to right. If a color blindness is detected, the test can be terminated. In the second part (Stroop B), the person is asked to read quickly the color names written in different colors (yellow, red, green). In the third part (Stroop C), participants are asked to say the colors of the words (blue, green, yellow) without reading the color names. In all three parts, the time is timed and recorded with a stopwatch.

6. Cognitive Functions-Trail Making Test

   Time frame: Baseline

   It is used to assess cognitive functions such as working memory, complex attention and cognitive flexibility. It requires visual scanning and hand-eye coordination. The Trail Making Test consists of 25 circles with numbers distributed on paper and has 2 sections (IST A-B). Section A contains numbers numbered between 1 and 25, and during the test, individuals are asked to connect the circles by drawing lines consecutively and in the correct order. In part B, the circles contain both numbers and letters. Participants are asked to quickly connect the circles in consecutive order in accordance with the order of numbers and letters (1-A, 2-B, 3-C, etc.) by drawing a line without lifting the pencil from the paper. The time to complete each trace is recorded in seconds (s), A and B.

7. Cognitive Functions-Cognitive Failures Questionnaire

   Time frame: Baseline

   Errors in perception, memory and motor functions in daily life are assessed with 25 questions. Each question is scored from 0 (never) to 4 (very often). The total score ranges from 0-100, with a higher score indicating an increased level of cognitive error.