Assessment of the Effect of Smartphone Usage on the Range of Motion and Fatigability of the Joints and Muscles of the Thumb Among Users: A Cross-Sectional Study in Central India.

Introduction The ability of adaptation is unique to humankind. Technology advances have introduced many appliances that increasingly are smaller in size and handheld. These devices on prolonged usage affect the thumb joint complex, and this study was therefore designed to assess any changes in the movement of the thumb joint complex and fatigability secondary to the increasing usage of smartphones in different orientations in the Central Indian population. Materials and methods An analytical cross-sectional study was performed to assess changes in the ranges of motion (ROM) of the thumb joint complex with a sample size of 137 selected nonrandomly and categorized on the basis of the orientation of smartphone usage by physical goniometer and a standardized questionnaire to assess fatigability. Results Most movements of the thumb joint complex corresponded to the existing standard values. The study found significant changes in the movement of passive flexion of the left metacarpophalangeal (MCP) joint and borderline significant modifications in the active extension of the left interphalangeal (IP) joint, passive extension of the left interphalangeal joint, and passive flexion of the left carpometacarpal (CMC) joint among the groups of participants. The Borg CR10 value of fatigue was "one," indicative of no excessive fatigue after smartphone usage. Conclusion There are no significant changes in the ranges of motion of the joint complex of the thumb in mobile phone users over a period of time. The orientations and the increased duration of usage also did not cause any fatigue in the muscles of the thumb.