Consequences of ortho effect on resonance Consider any carboxylic acid with any group at ortho position. According to ortho effect, the resonance of the $\ce{C=O}$  with the ring is inhibited.

Is this resonance entirely lost? Or some little amount still exists?

Can resonance be present when the participating orbitals are not in the same plane?
If they are off the plane due to steric effect,  then resonance wouldn't occur, hence the (-)R effect of - COOH group vanishes and hence "generally" acidity of the respective acid increases.