The document discusses valve float, which occurs at high engine speeds when the inertial forces on valve components become comparable to the elastic force of springs, preventing valves from closing properly. Desmodromic valve actuation, where the valves are closed mechanically rather than via springs, can prevent this issue. However, while desmodromic distribution provides benefits over conventional systems, its use has been limited mainly to racing due to the added complexity and cost for street vehicles, as performance gains have been modest in most applications.