My Brother Had A Graft For An Electrical Burn To

My brother had a graft for an electrical burn to his chest and back, also he has an exit wound to his left shoulder. He wakes up every couple of hours with tightness and pain to affective areas. First question: What causes that and is it normal? Secondly: How can it be relieved? Thirdly: It's been approximately a month since his accident, can he now stretch without harming graft and if so how much? His donor sites were his legs.