Injuries caused by vibrations are a common problem that can emerge from daily exposure when using handheld power tools like grass trimmers. These are often permanent and can’t be cured. Rotations caused by the motor create vibrations where unbalance of the trimmer line can create high amplitudes of vibrations. This report studies how these vibrations affect the trimmer and what solutions that can dampen them with the help of material and mechanical design. By using experimental tests and theoretical evidence it is possible to show how vibrations emerge. These tests proved to be useful when concepts and prototypes were created.