This is the harbor freight hydraulic log splitter.
If you could connect the ends of a pair of pedals to the lever arms with a set of drive rods, you could easily power this thing.
Loading and unloading would require stopping or a helper.
I might start with typical geared bike.
I would elevate the rear wheel, remove the tire and using cast
concrete, add weight to it.
Then I would use an inverted front fork to hold a tricycle wheel.
The drive rods would connect to the trike pedals, the trike would connect to the bike via a pulley belt.
The lack of a way to engage or disengage the flywheel from the work is a sever flaw.
It occurs to me that a pedal powered air pump might allow for us to store air pressure to use with a pneumatic ram, making it easier for one person to split wood.
Pedal, build up air pressure, split wood.
Other air tools could also benefit.
Now to find a manual air pump that can build sufficient psi to power a pnumatic ram...