Urinary excretion of calcium in workers handling sewing machines

ABSTRACT

The relationship of subjective symptoms and clinical signs of muscles and joints and calcium excretion in urine was investigated in 60 workers handling sewing machines aged 15-60 and in 30 normal control subjects aged from 15-50 with no occupational exposure to vibration. The subjective symptoms [paraesthesia, numbness, weakness of hand grip, pain in shoulder muscles, in arms, forearms, around the elbow, around wrist, in neck muscles and in back muscles] were frequent in exposed group. The prevalence of subjective symptoms increased with increase in TOT. An increase in TOT from, 5,000 hours experience to 85,000 hours experience was accompanied by a significant increase in calcium excretion in urine. This significant increase was observed between one TOT group and another except between groups 65,000 hours experience and 85,000 hours experience, where the difference was not significant. From the combined findings mentioned above, we presume that to repair alteration to bones caused by prolonged use of sewing machine, the synthesis of new bone is accelerated since it produces increase in calcium excretion. In conclusion, calcium excretion in urine, in absence of other causes of hypercalciuria, may be used as an indicator of damage to bones and joints caused by prolonged use of vibrating tools