Clinical, electrophysiological, and ultrasound evaluation for early detection of musculoskeletal hand disorders and nerve entrapment in mobile phone users

ABSTRACT Introduction: Smartphone overuse may lead to musculoskeletal manifestations, such as carpal tunnel syndrome (CTS) and arthritis of hand joints, with an increased median nerve cross-sectional area (CSA). Objective: The aim of this study is the early detection of musculoskeletal hand disorders using ultrasound techniques, and to detect nerve entrapment using clinical evaluation, ultrasound, and electrophysiological studies, in university employees younger than 35 years using mobile phones. Function is assessed using the Michigan Hand Outcomes Questionnaire (MHQ). Materials and methods: Cross-sectional controlled study included 74 smartphone users classified into two groups according to a smartphone addiction scale (SAS), into high and low smart phone users, with 35 non-smartphone users with matched age and gender as a control group. A clinical assessment of nerve entrapment symptoms was performed, and the Michigan Hand Outcomes Questionnaire (MHQ), with a total score from 0 to100, was used to assess hand function. Electrodiagnostic studies of median and ulnar nerves were used to detect early nerve entrapment. Bilateral ultrasound was performed in order to assess the median nerve CSA and involvement of thumb and small hand joints. The data collected were analyzed using the SPSS program version 20. Results: CSAs of median nerves were significantly higher in the dominant hand of high smartphone users than in low and non-smartphone users (p < 0.001). There was a significant positive correlation between CSA and SAS (r = 0.45), visual analogue scale (VAS) (r = 0.61), and duration of smartphone use (r = 0.80), with negative correlation with MHQ (r = -0.63). Significant differences in were found in the electrophysiological studies of median and ulnar nerves. The mean ultrasound score for both hands was higher in the high smartphone users compared to low smartphone users (15.08 ± 4.17 vs. 6.46 ± 1.38, p < .001). Conclusions: There is increased median nerve CSAs among high smartphone users associated with prolongation of both sensory and motor latencies and slow conduction velocities. Caution should be exercised when using mobile phones, in order to minimize the risk of developing hand musculoskeletal disorders.

Effects of smartphone overuse on hand function, pinch strength, and the median nerve.

INTRODUCTION: In this study we investigated the flexor pollicis longus (FPL) tendon and median nerve in smartphone users by ultrasonography to assess the effects of smartphone addiction on the clinical and functional status of the hands. METHODS: One hundred two students were divided into 3 groups: non-users, and high or low smartphone users. Smartphone Addiction Scale (SAS) scores and grip and pinch strengths were recorded. Pain in thumb movement and rest and hand function were evaluated on the visual analog scale (VAS) and the Duruöz Hand Index (DHI), respectively. The cross-sectional areas (CSAs) of the median nerve and the FPL tendon were calculated bilaterally using ultrasonography. RESULTS: Significantly higher median nerve CSAs were observed in the dominant hands of the high smartphone users than in the non-dominant hands (P<0.001). SAS scores correlated with VAS pain for movement and rest, DHI scores, and pinch strength (P<0.05; r=0.345, 0.272, 0.245, and 0.281, respectively). CONCLUSIONS: Smartphone overuse enlarges the median nerve, causes pain in the thumb, and decreases pinch strength and hand functions.