Mechanical performance, level of continuous contraction and muscle pain symptoms in home care personnel

Abstract

The interrelationships between reported complaints, clinical status, mechanical performance and EMG pattern of the shoulder flexors and the knee extensors, respectively, during maximum dynamic contractions were investigated. A group of 97 randomly selected women employed in the home care service participated. Those who reported complaints had more clinical findings, such as reduced mobility, tender points and muscle tightness, than non-complainers. The level of muscle activity during the passive part of the contraction cycle was significantly higher in the shoulder flexors than in the knee extensors. Subjects without reported complaints who had been employed for more than ten years had a significantly lower activity level in the shoulder muscles than subjects without complaints who had been employed for a shorter time. We suggest that a high muscle tension level between contractions might precede muscle pain. A cluster analysis including sociodemographic, clinical and physiological variables revealed different subgroups, which points to the need to investigate the work situation in a multivariate way.