I really liked this line from an article about hand strength, how much it matters to have strong hands.  We were born with incredibly strong hands, but over time instead of making them even stronger, their relative strength starts to decline.  At least in modern times, almost everything you touch on a daily basis is lighter than its predecessor.  

Louis Robinson, a surgeon at a children’s hospital in England, tested some 60 infants—many within an hour of birth—by having them hang from a suspended “walking stick.” With only two exceptions, according to one report, the infants were able to hang on, sustaining “the weight of their body for at least ten seconds.” Many could do it for upward of a minute.  In a later-published photograph, Robinson swapped out the bar for a tree branch, to bring home his whole point: Our “arboreal ancestry.”

By developing the whole hand on the sphere, to me it seems like it can stretch the fingers out, makes each one strong in its own way.  The hand remembers how to be strong, but you have to practice, a lot.

I really like using these myself, both the overhand grip and the underhand grip.  Hold it in each hand for a minute and feel the work getting done.

I made a few of these, if you would like a set please contact [email protected]

Thanks