The association between hand arm vibration syndrome and vibrotactile perception threshold among shipyard workers

A cross sectional study was done among 47 hand-held vibrating tools workers with the objective of obtaining the current prevalence of hand-arm vibration syndrome (HAVS) and the association with vibrotactile perception threshold (VPT) and sensory threshold in a tropical environment. Questionnaire was administered in determining reported related symptoms of HAVS, Pallesthesiometer (EMSON-MAT, Poland) was used in obtaining the sensory threshold of index and little finger. Measurement was done at 31.5 Hz and 125 Hz. Results indicate 49% of the shipyard workers were manifesting HAVS symptoms. Most were exposed to the equally high intensity level of HAVS due to continuous use of vibrating hand-held tools. The VPT values were significantly higher for both fingers and both frequencies compared to the normal healthy population. No significant association was found between the reported HAVS and the level of VPT and (Monofilament) among the workers. As a conclusion, the prevalence of HAVS was high but lower compared to those working in an extreme cold environment. In addition, a higher mean of VPT value and Sensory threshold was observed compared to the normal healthy population

Comparison of diagnostic method of evaluating vibration induced sensorineural impairment among shipyard's grinders

The objectives of this study are to investigate diagnostic value of two different tests amongst tests highly recommended and used for diagnosis of HAVS of the sensorineural component; Semmes Weinstein Monofilament (SWM) and Purdue Pegboard (PP) tests using vibrotactile perception threshold (VPT) test as standard objective quantitative test. For the method, a total of 176 grinders as vibration exposed respondent of a shipyard's fabrication participated in this study. Questionnaire and vibration exposures data were collected for all respondents where 67 respondents further performed the three quantitative sensorineural testing. The result showed that mean acceleration magnitude of grinding tools used were 4.9 ms-2, exceeding recommendation by European Commission. Both cut-off point methods of mean plus two times standard deviation (mean + 2sd) and z-score (at 75th percentile) show significant difference among healthy and HAVS (p < 0.001). Correlation between SWM with VPT and PP with VPT was weak. However, results suggests progressive pathological damage to sensorineural component of the digits starts with fast-adapting II (FA II) mechanoreceptors indicated with significant correlation primarily at 125 Hz. Analyses of sensitivity and specificity found that monofilament at 0.16g force best discriminate HAVS from healthy. In the other hand, Purdue Pegboard test shows best diagnostic value of indicating HAVS at minimum insert of 16 pin and 14 pin respectively for dominant and non-dominant hand. Both Semmes Weinstein Monofilament and Purdue Pegboard tests has limited diagnostic value to be used as screening tools for early detection of HAVS

The characteristics of vibrotactile perception threshold among shipyard workers in a tropical environment

The objectives of this study are to determine the prevalence of hand-arm vibration syndrome (HAVS) and the characteristics of the vibrotactile perception threshold (VPT) among users of hand-held vibrating tools working in a tropical environment. A cross sectional study was done among 47 shipyard workers using instruments and a questionnaire to determine HAVS related symptoms. The vibration acceleration magnitude was determined using a Human Vibration Meter (Maestro). A P8 Pallesthesiometer (EMSON-MAT, Poland) was used to determine the VPT of index and little finger at frequencies of 31.5 Hz and 125 Hz. The mean reference threshold shift was determined from the reference threshold shift derived from the VPT value. The results show a moderate prevalence of HAVS (49%) among the shipyard workers. They were exposed to the same high intensity level of HAVS (mean = 4.19 ± 1.94 m/s2) from the use of vibrating hand-held tools. The VPT values were found to be higher for both fingers and both frequencies (index, 31.5 Hz = 110.91 ± 7.36 dB, 125 Hz = 117.0 ± 10.25 dB; little, 31.5 Hz = 110.70 ± 6.75 dB, 125 Hz = 117.71 ± 10.25 dB) compared to the normal healthy population with a mean threshold shift of between 9.20 to 10.61 decibels. The frequency of 31.5 Hz had a higher percentage of positive mean reference threshold shift (index finger=93.6%, little finger=100%) compared to 125 Hz (index finger=85.1%, little finger=78.7%). In conclusion, the prevalence of HAVS was lower than those working in a cold environment; however, all workers had a higher mean VPT value compared to the normal population with all those reported as having HAVS showing a positive mean reference threshold shift of VPT value