Serum creatine kinase relationship to postural constraints in manual work

Serum creatine kinase (CK) variations during work and subjective assessments of postural discomfort were analysed in 30 workers assigned to three different tasks in a rolling mill. After four days of work, serum CK levels were significantly increased above control levels. No difference was found between the tasks studied. Inter-individual variability in CK response was large: a marked CK increase was only seen in 21 workers, while 5 workers showed a marked CK decrease. The postural discomfort sensations increased with work in each group, with their location in the body being related to the characteristics of each task or workplace. No relationship was found between the postural discomfort scores and CK changes. Results showed that determination of an individual baseline CK level was difficult to achieve in an occupational setting. It is concluded that CK variations cannot reliably be used in the field for detection of individuals exposed to excessive postural constraints. Their use as a screening tool in groups of workers assigned to similar tasks deserves further study.