It means your tree is trying to become a shrub. Not uncommon. Cut them off as close to the trunk as possible. Some apple & crabapples just do this. You will likely have to cut off the suckers once or twice a growing season.

To add to Bob's words, most fruit trees do not grow on their own roots, but are grafted onto the roots of another tree. When you see shoots coming from near ground level this means the tree is sending shoots from the root stock and you do not want this as the root stock isn't a good tree for harvesting from. The root stock was chosen for disease resistance, cold hardiness and other factors, not culinary or ornamental value.