[Vibration syndrome among forestry workers. Subjective symptoms and diagnostic norm]

Three hundred fourteen male forestry workers using vibrating tools were analyzed to evaluate the relationship among 11 items of the special examinations for the diagnosis of vibration syndrome and the relationship between the items and 13 subjective symptoms. The following results were obtained: Age of the workers had the strongest relationship to the grip strength. However, it showed less strong relationship with other items, such as the threshold of pain sense and that of vibration sense, and the degree of Raynaud's phenomenon (number of fingers affected). Working time in years with vibrating tools showed statistically significant correlations with the threshold of pain sense, that of vibratory sense, and with the degree of Raynaud's phenomenon. The threshold of pain sense, that of vibratory sense, and the degree of Raynaud's phenomenon correlated with each other but not with the skin temperature nor the recovery time of blood flow in the finger nail-beds. The rise of pain threshold exhibited the strongest association with the subjective symptoms. Vibratory sense threshold at 250 Hz also showed similar association with the latter. The skin temperature and the recovery time of blood flow had no association with any complaints except for gastric disorders. The grip strength, only when extremely lowered, was associated with the rise of ratio of complaints, i.e. percentage of the number of workers who complain among all the workers. The age was associated in general with the decreased ratio of complaints except for muscle weakness in arms and forgetfulness.