Correlation Between Forearm Positions Across Elbow Joint and Ulnar Nerve Conduction Velocity Among Mobile Hand-Held Users

Abstract

Background: Mobile hand-held devices usage are on the rise in everybody's life that can be associated with physical health related problems, such as pain and numbness in the elbow and wrist and exposes forearm and hand to intense stresses at certain positions that may lead to peripheral nerve disorders. Purpose: To study correlation between forearm positions across elbow joint and ulnar nerve conduction velocity among mobile-hand held devices users. Design of the study: One shot case study. Subjects: Fifty healthy subjects from both genders, their age ranged from 20 to 40 years old. All subjects had body mass index between 18.5 and 24.9 Kg/m2. Method: Electromyography was used for measuring ulnar nerve conduction velocity across elbow joint at different angles (0 o extension, 45 o , 90 o and 120 o flexion) with different forearm positions (supination and pronation). Result: Multivariate Analysis of Variance revealed that there was a statistical significant difference in mean values of ulnar nerve conduction velocity at different angles of elbow flexion with forearm supination and pronation (P=0.001). There was a statistical significant difference in mean values of ulnar nerve conduction velocity between forearm pronation and supination at the different angles of elbow flexion (P=0.001). Conclusion: Usage of mobile hand held devices with forearm pronated and flexed elbow can decrease the motor conduction velocity of ulnar nerve more than other positions. As well as the best position for elbow joint during using mobile hand held devices is 0°-45° elbow flexion with elbow supinated.