Style: J of occupational medicine and toxicology vibration induced injuries in hands in long-term vibration exposed workers.

INTRODUCTION

Long-term vibration exposure may cause neurophysiological disturbances such as numbness and tingling, reduced grip strength and difficulties in handling small objects. The dominant hand will usually have a higher vibration exposure than the non-dominant hand, which may cause more severe neurological symptoms and signs in the dominant hand.

METHODS

The study is based on 47 (36 males and 11 females) vibration exposed workers, all former patients from the department of Occupational and Environmental medicine, Gothenburg university. The comparison group consisted of 18 randomly selected subjects from the general population of Gothenburg. All participants completed several questionnaires and had a standardized medical examination. Thereafter, neurophysiological tests such as the determination of vibration and thermal perception thresholds were performed, as well as muscle strength tests in hands and fingers.

RESULTS

The temperature perception thresholds (TPTs) and the vibration perception thresholds (VPTs) did not differ significantly between the dominant and non-dominant hand in vibration exposed workers. The referents showed a significantly better performance ( ≤ 0.02 and  ≤ 0.034, respectively) than the workers for both TPTs and VPTs, indicating a negative effect on the Aß, as well as on the Aδ and C-fibers among the exposed workers.The Purdue Pegboard test showed a significantly better performance in the dominant vs non-dominant hand in both workers ( = 0.001) and referents ( = 0.033). The referents showed a better performance than the workers in both hands ( < 0.001). The Baseline handgrip, the Pinch grip and 3-Chuck grip tests did not differ significantly between the dominant and non-dominant hand in neither workers nor referents.

CONCLUSIONS

In this study, minor differences between the dominant and non-dominant hand were noted for the Purdue Pegboard test in both workers and referents. Despite a probably higher vibration exposure in the dominant hand (mostly the right hand), however, quite similar test results were noted for VPTs, TPTs, Baseline handgrip, Pinch grip and 3-Chuck grip when comparing the dominant and non-dominant hand in the vibration exposed workers. In case of lack of time and financial obstacles, neurological tests in solely the dominant hand, will probably satisfactory reflect the conditions in the non-dominant hand.