Forensic Medicine General e94321e3 In rigor mois muscle : A Stiffens B Shoens C Stiffens and shoens D Stiffens and lengthens High-Yield Explanation C i.e. Stiffens & shoen In rigor mois, muscle shoen (contracted) & stiffensQ, and the reaction changes from alkaline to distinctly acidic d/t local formation of lactic acid.