Using deformers as mentioned above is a pretty good way to go about doing this, but it could soon become allot more work than necessary. Playing with and fine tuning the deformers, to exactly replicate the shape and flow of the poles in and 3 axises. Could soon become a tedious pain!!!

What i would do is create a CV curve to outline the profile of a Bar stool pole, and then create a Nurbs circle and extrude it along the curve.

It would take about 10-15 minutes to complete the hole stool!

Though the stool in your image is not very complex at all, and would be no paint to model with deformers. as it's built up by basic straight and rounded shapes.