 Why don't we know where our fingers are? Joint position reproduction requires memorizing a position, then reproducing it. For JPR of a trajectory we analyze, does memory contribute to JPR, and is error correlated with movement characteristics? Memorized reproduction had 50% higher error. Memory is a major factor for JPR. Error was velocity dependent, higher for fast and slow extremes. This suggests the brain integrates velocity signals to understand position, but these same melt are both noisy and biased.