Experimental study of the level of manual performance disability caused by exposure to hand-arm vibration among automobile casting workers

Abstract

Background: Exposure to hand-arm vibration is one of the most common physical harmful factors. The purpose of this study was Experimental study of the level of manual performance disability caused by exposure to hand-arm vibration among automobile casting workers. Methods: This study was performed on 53 casting workers as case group and 28 controls as control group. The measurement of the vibration of the worker's arms and hands was carried out in accordance with the ISO 5349 standard. The level of manual performance disability was evaluated using skeletal-muscular, sensory-neural and vascular tests. Also, a questionnaire was used for the level of disability of the arm, shoulder and hand DASH. Data were analyzed using SPSS16. Results: The 8-hour vibration exposure was 8.33 m / s 2 (4.49), which exceeded the permissible level. Skill and dexterity, fingers and grip strength of the dominant hand in the case group were decreased by 4%, 13.3% and 11%, respectively (P<0.05). The regeneration time of the dominant hand in the case group was 41.2% higher than the control group (P<0.05). Sensory-neurological complications increased in the case group compared to the control group, however, it was not statistically significant. The DASH score in the case group was 10.7 (13.4) and the control group was 4.1 (5.1). Conclusion: Hand-arm manual performance disability in workers exposed to vibration decreased from 4% to 14%, which confirmed the DASH score. In addition, workers showed a higher level of vascular complications compared with sensory-neurological complications.

Effect of the level of manual performance disability caused by exposure to vibration among sailors working on sailing speed vessels

“…Equation 1 indicates the vibration acceleration result in which, a hwy , a hwx , and a hwz show effective acceleration in each axis. The following equation indicates 8-hour vibration acceleration in which T represents the total time of exposure (hr) and T 0 shows the considered limited time (8 hr) [ 1 ]. …”

“…The questionnaire was adopted from the Institute of Sound and Vibration Research (ISVR) at the University of Southampton, UK, and the Occupational Medicine and Rehabilitation Institute at the University of Trieste, Italy to examine complications of exposure to hand and arm vibration [ 1 ]. This questionnaire included personal information, job records, exposure to vibration, vibration complications (arterial, neurosensory, and musculoskeletal), and medical records of the worker.…”

“…According to the validity and reliability of this questionnaire in Iran, the Content Validity Ratio (CVR) and Content Validity Index (CVI) of the DASH questionnaire were 0.74 and 0.90, respectively. Cronbach’s alpha coefficient of this questionnaire was estimated to be 0.75 [ 1 ].…”

“…Purdue Pegboard A32020 Model with a reliability interval of 0.76-0.89 was used to measure skill and dexterity [ 1 ]. Purdue Pegboard has some holes used by the person to place the metal pieces and washers in respective holes.…”

“…The vibration occurs when the body is exposed to a vibrating surface [ 1 ]. The hand and arm are the most common areas exposed to such vibrating surfaces [ 2 ].…”