The Effects of Smartphone Addiction on Pinch Strength, Muscle Stiffness, and Hand/Wrist Function in Young Adults

The Effects of Smartphone Addiction on Pinch Strength, Muscle Stiffness, and Hand and Wrist Function in Young Adults: A Cross-Sectional Study

Smartphones have become an indispensable part of daily life, and their increasing use has raised concerns about various health effects, including musculoskeletal symptoms. Repetitive movements of the thumb and hand muscles can lead to issues such as tendinosis, myofascial pain syndrome, and a decrease in pinch strength. Studies have shown that musculoskeletal symptoms related to smartphone use are common among young adults and university students. Additionally, an increase in device size may place greater strain on the wrist and finger muscles. Repetitive movements can cause stiffness changes in the thumb muscles, and the relationship between these changes and pinch strength is considered an important research topic. In this study, we aimed to investigate the effects of smartphone addiction on pinch strength, muscle stiffness, hand/wrist pain, and function in young adults.

This study was designed as a cross-sectional study. Volunteers eligible to participate were first screened based on the results of the Smartphone Addiction Scale-Short Version (SAS-SV), and they were divided into two groups as Smartphone Addiction and Non-Smartphone Addiction, with a cutoff score of 31 for males and 33 for females. Subsequently, the determination of dominant hand was performed. All assessments were conducted on the participants' dominant extremity. The assessments were carried out in the following order: Patient-Rated Wrist/Hand Evaluation Questionnaire (PRWHE), the Finkelstein test, muscle stiffness measurement, and finally, pinch strength assessment, as it was considered to potentially cause fatigue. All assessments were conducted by expert physiotherapists within a total duration of 30 minutes, and participants were not followed up afterward, nor recieved any intervention.

Inclusion Criteria:

• Willing to participate in the study
• Have been using a smartphone for more than one year
• Aged between 18 and 25 years
• Send 25 or more text messages or emails per day
• Spend more than 2 hours browsing the internet and/or play games for more than one hour a day

Exclusion Criteria:

• Having radiating/radicular pain in the upper extremity
• Having neck pain
• Congenital deformities in the upper extremity and neck
• A history of diagnosed neurological, rheumatic, musculoskeletal, or cardiovascular diseases
• Having previously undergone surgery on the neck and/or upper extremity
• Having been diagnosed with De Quervain's disease or tendinopathy in the hand/hand wrist muscles before