ift distance to precisely simulate real donning/doffing situations. Interestingly, there are no cases showing significant correlation between electrode shift distance and changes in the online performance (not shown here).

3.4. Results for the subject with congenital deficiency {#sec023}
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The offline inter- and intra-position performance of the subject with congenital deficiency is presented in [Fig 10](#pone.0186318.g010){ref-type="fig"}, where the red, green and blue bars indicate the offline performance obtained from respective three test positions for the corresponding four training positions (P1, P2, P3, and Com), respectively. The fundamental trend shown in the able-bodied subjects' result ([Fig 5](#pone.0186318.g005){ref-type="fig"}) is similarly observed in [Fig 10](#pone.0186318.g010){ref-type="fig"}, in that the original offline performance attained from the same training and test position is relatively high, but that is not retained for all other arm positions.

![Offline intra- and inter-position performance of the subject with congenital deficiency.\
The red, green and blue bards show the R^2^ values estimated from three test arm positions (P1, P2, and P3), respectively, for the four training positions (P1, P2, P3, and Com). The fundamental trend shown in the able-bodied subjects' result ([Fig 5](#pone.0186318.g005){ref-type="fig"}) is similarly observed, in that intra-position R^2^ values are generally higher than inter-position ones. Compared to the offline result of the intact-limb subjects ([Fig 5](#pone.0186318.g005){ref-type="fig"}), there are two distinct points: 1) P2 test position performs good for all training positions and 2) P3 test position is more severely influenced by the training position (see the performance of P3 test position at P2 and 'Com' training positions).](pone.0186318.g010){#pone.0186318.g010}

[Fig 11(a)](#pone.0186318.g011){ref-type="fig"} shows the online control performance of the subject with congenital upper-li