PTS4 triathletes have coordination affected at a low-level on one side, at a high degree in one arm, or the absence of limbs.
In the swim all have a reduction of power. In the cycle PTS4’s tend to either have good power but reduced control or vice-versa. In the run all compensate for imbalance and asymmetry.
Those with two good arms lose the advantage the have in the swim when changing prosthetics in transition.