Puppet Warp (Edit>Puppet Warp) is a really useful tool to bend and distort shapes, especially for bending and moving limbs. It works by adding points, known as pins. These pins are then repositioned to move the underlying pixels. To get a realistic warp, you usually need to move several points at the same time. To select multiple points, click a point, and then hold down the Shift key as you click additional points. Each point you click will be added to the selection. Selected pins have a blue dot in the middle of them. Now you can easily move one of the pins, and all of the selected ones will move together.
This tip previously published in Colin Smith’s Photoshop Tips column, in the March, 2020 issue of Photoshop User magazine.