An ablation catheter includes an electrode assembly having a plurality of longitudinally spaced sets of spines, which include a distal set of spines each having a distal end connected to a spine distal junction and a proximal end connected to a first joint, and a proximal set of spines each having a proximal end connected to the distal end of the catheter body and a distal end connected to the first joint or a second joint. The spines include electrodes. Zero or more additional sets of spines are connected between the distal set and proximal set, such that neighboring sets of spines are connected by a joint. Each joint is flexible to permit bending along the longitudinal axis. The electrode assembly is movable between a collapsed arrangement and an expanded arrangement with the intermediate segments of the spines in the expanded arrangement moving outwardly with respect to the collapsed arrangement.
