Complex sentence: Low self-efficacy to the affected side can hinder them from using their paretic hand, which may deteriorate brain reorganization (experience-dependent neuroplasticity) and long-term motor recovery.
Split into simpler sentences: Low self-efficacy to the affected side can hinder them from using their paretic hand. The decrease of using the paretic hand may deteriorate brain reorganization (experience-dependent neuroplasticity) and long-term motor recovery.