Complex sentence: Anna's concern and anger grow when Kim receives a phone call from Martin at the hospital; during the conversation, Kim abruptly regains the use of her legs, only to lose mobility again when the connection is broken.
Split into simpler sentences: Anna's concern and anger grow when Kim receives a phone call from Martin at the hospital. During the conversation, Kim abruptly regains the use of her legs, only to lose mobility again when the connection is broken.