What would happen if the flexors of your forearm were functional but not the antagonistic extensors?

It won't be able to move. What action would occur if both the flexors and extensors contracted simultaneously.

Plants take energy from the sunlight with the of chlorophyll so the plant starts the food chain. then an herbivore eats the plant and gets its energy.then a carnivore or a human eats the herbivore and gets its energy. : )