What is the only cytoskeletal fiber not associated with any movement?

The only cytoskeletal fiber not primarily associated with movement is the intermediate filament. These filaments provide structural support and stability to cells, helping to maintain their shape and integrity. Unlike microtubules and actin filaments, which are involved in cellular motility and transport, intermediate filaments are more focused on providing resilience against mechanical stress. Examples include keratin and vimentin, which play crucial roles in cell structure.