[Parameters for determining the time of death from post-mortem muscle contraction--precision of assessing time of death]

The objectified muscular contraction on excitation with rectangular impulses of 1 sec duration and definite current intensity is in its postmortem course characterised by: 1. Change of the shape of muscular contraction (time-course of muscular contraction) from a two peak to a one peak shape 2. postmortem decrease of the maximum force of muscular contraction on definite current intensity 3. increase of the relaxation time of muscular contraction. On an random sample of fifty bodies decrease of the maximum force and increase of the relaxation time as criteria for extrapolating the time since death were investigated. The extrapolation was performed on the basis of the regression between ln of the maximum force and time using the mean values for slope and intercept and the regression between ln of the relaxation time and the ln of the time since death respectively using the mean values for slope and intercept too. On fifty bodies the calculated 95%--limits of confidence are +/- 2.85 h (decrease of the maximum force) and +/- 2.7 h (increase of relaxation time) up to 13 hpm. The calculated 95% limits of confidence were examined on an independent random sample of 20 bodies and proved to be reliable.