According to the sources provided, reduced flexibility is not a common side effect of Lipitor (atorvastatin).

The first source, Drug Patent Watch [1], provides information about the patent status of Lipitor but does not list reduced flexibility as a side effect.

The second source, a study published in the National Center for Biotechnology Information [2], discusses the possible side effects of statins, including Lipitor, but does not mention reduced flexibility as a common side effect. The study notes that muscle-related side effects, such as myopathy and myalgia, can occur in some patients taking statins. However, these side effects typically manifest as muscle pain or weakness, rather than reduced flexibility.

The third source, an article from Harvard Health Publishing [3], provides information on managing muscle pain caused by statins. The article notes that muscle pain and weakness are the most common side effects of statins, but again, does not mention reduced flexibility as a common side effect.

In conclusion, while Lipitor and other statins can cause muscle-related side effects, reduced flexibility does not appear to be a common side effect of Lipitor. Patients who experience muscle pain or weakness while taking Lipitor should speak with their healthcare provider to determine the best course of action.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463373/
[3] https://www.health.harvard.edu/pain/managing-statin-muscle-pain