Effect of Temperature on the Time Course of Rigor Mortis in Ox Muscle

Abstract

SUMMARY—Changes in length and ‘extension’ during the onset of rigor mortis in cyclically loaded strips of ox sternomandibularis muscle were found to be markedly different at 1 °C from those at temperatures over the range 537°C. The delay phase of rigor mortis was longer with lower temperature within the range 1.537°C, but was shorter with lower temperature within the range 1.15°C. The onset phase was longer with lower temperature within the range 5–37°, but was shorter at 1° than at 5°C.The change in extension was completed sooner at l° than at 5° or 15°C. At 37°C, by the time the change in extension was complete, acid‐labile phosphorus had fallen to a low level, and the ultimate pH was closely approached or reached; but at 1°C, an appreciable amount of acid‐labile phosphorus still remained, and the pH was considerably above the ultimate value. The shortening at 1 °C was compared to thaw contracture.