Leg Sensor

i have a doubt.. i am making a leg exoskeleton. what sensor should i use in the joint so that after that it reads an angle and tells my motor to start?

Flex sensor, encoder, pot. Just from the top of my head. There may be more options.

Which one works best depends on the required accuracy, speed, possible construction methods, etc.

nihal1812:
i am making a leg exoskeleton. what sensor should i use in the joint

Which joint? My real leg has many... measuring 3d angles in a hip, for instance, very different from a knee.