Originally Posted by
John Hanley
You can go insane naming all the subtlety different types of grip, but they're all basically variations of thumb and finger flexion.
You should train the thumb and finger flexors the same way you train other non-stabilizer muscle group...through a full range of motion. Static holds? No, that's isometric. Farmer's walks? Nope. Isometric.
Isometric training largely optimizes your existing muscle cross sectional area for a specific purpose.
Training via resistance though the largest effective range of motion is how you grow muscle.
Grippers do this ^