Long term use of mobile phones is not only "brain drain", but also "hand drain". Finnish and German researchers have recently developed an artificial intelligence (AI) model that can simulate the musculoskeletal system load when people use smartphones, and analyze how to operate phones more efficiently. Aalto University in Finland recently released a press release stating that researchers from the university and Leipzig University in Germany have developed an AI model called "Log2Motion". This model is based on smartphone touch recording and human motion research data, which can simulate the motion trajectory of people using mobile phones, and evaluate the speed, accuracy, and load on the musculoskeletal system of related actions. The simulation results show that some operations are indeed more "laborious", such as swiping up and down, clicking on smaller icons, and interface elements in the corners of the screen, which often require more effort. Researchers believe that this model provides a new perspective for the study of smartphone usage and interface design. Developers can discover less user-friendly designs earlier, optimize interface layout, reduce user workload, and develop more ergonomic and comfortable human-computer interaction methods. This model is also expected to provide reference for accessible design, such as helping to analyze tremors, muscle weakness, or obstacles that users wearing prosthetics may encounter when operating mobile phones. (New Society)