Selecting using the keyboard
                                          

To finely adjust the selection: 
1. Move to the start or the end of the selection.
2. Hold down the shift key.
3. Click Step Forward or Step Backward.
					— or — use Left Arrow or Right Arrow.

         The end point of the selection changes.

To select the current frame only: 
1. Hold down the shift key and the option key.
2. Click Step Forward or Step Backward.
					— or — use Left Arrow or Right Arrow.

         The current frame becomes selected.