INGENIEUR
respectively . The left brachioradialis muscles recorded higher MVC reduction with 54 % and 48 % on the . right region , respectively .
The LBD risk results for the two groups were compared using the factors described by Marrs et al . ( 1993 ) which are lift rate , maximum sagittal position , maximum lateral velocity , and average twisting velocity . The maximum moments are shown in Figures 8 to 10 . A comparison of the spine motion analysis for traditional and mechanical apparatus is presented in Figure 11 . The comparison of an individual ’ s average probability of LBD risk using traditional and mechanical apparatus is shown in Figure 12 .
In comparison , the overall LBD risk for traditional harvesting was observed to be around 52 % ( Figure 13 ) with the maximum average twisting velocity 25 %, maximum moment 61 %, maximum sagittal flexion 98 %, and maximum lateral velocity 89 %. For the mechanical apparatus operation , the overall LBD risk observed was around 21 % with the maximum average twisting velocity 1 %, maximum moment 39 %, maximum sagittal flexion 55 %, and maximum lateral velocity 8 %.
Most individual average LBD risks were substantially and statistically significantly lower while operating the mechanical apparatus compared with the traditional harvester with the lowest average LBD risk at 15 % ( Figure 10 ).
Intervention of mechanical apparatus The results of this study showed that the mechanical apparatus is an effective tool in reducing LBD risks during cockle harvesting . By comparing the muscle activity results and spine motion results , in overall , the mechanical harvester reduced the LBD risk by 60 %, from 52 % to 21 % LBD risk ( Figure 13 ). Referring to LBD risk outlined by Marras et al . ( 2000 ), the LBD risk level at or below 30 % corresponds to the classification of industrial jobs as only “ low risk ” of LBD . Hence , the likelihood of having LBDs in using the mechanical apparatus is greatly reduced compared with traditional harvesting methods .
The results of this study were consistent with the findings reported by Kucera et al . ( 2009 ), who showed the association between LBP interruption on fishing work . The findings also showed some correlation with the findings of Mirka et al . ( 2011 ), who studied the ergonomic interventions for commercial crab fishermen using the LBD risk and muscle activity assessment . Both of the studies mentioned the ergonomics risk factors that correspondingly reduce the workers capability and productivity . The researchers also highlighted the need to develop interventions to reduce exposure to these risk factors in the aquaculture sector due to work tasks in the industry which require strength , endurance and co-ordination . These tasks expose fishermen to many of the recognised risk factors for the development of work-related musculoskeletal disorders ( Mirka et al . 2011 ).
CONCLUSION
The results showed that the implementation of interventions with the mechanical apparatus significantly reduces the probability of LBD risks compared with traditional tools . The analysis of muscle activity demonstrated significant reductions in the required muscle region and forces necessary to perform and complete the tasks . This assessment also demonstrated the effectiveness of a new ergonomic mechanical cockles harvesting tool for the reduction of the exposure to risk factors for musculoskeletal disorders amongst respondents at Sungai Sanglang , Pontian .
REFERENCE
Mirka G . A , Ning X ., Jin S ., Haddad O ., and Kucera K . L . ( 2011 ). Ergonomic interventions for commercial crab fishermen , International Journal of Industrial Ergonomics , 41 : 481-487 ( DOI : 10.1016 / j . ergon . 2011.03.006 )
Kucera K . L , Loomis D ., Lipscomb H . J ., Marshall S . W . Mirka G . A . and Daniels J . ( 2009 ). Ergonomic risk factors for low back pain in North Carolina crab pot and gill net commercial fishermen , American Journal of Industrial Medicine , 52 ( 4 ): 311-321 ( DOI : 10.1002 / ajim . 20676 )
Marras W . S ( 2000 ). Occupational low back disorder causation and control . Ergonomics , 43 ( 7 ): 880-902 ( DOI : 10.1080 / 001401300409080 )
Rosmaria , A . D ., Abu Bakar , T ., Mohd Lazim , M . S . and Saberi , M . ( 2018 ). Issues and Challenges of Cockle Production . FRI Newsletter . Vol . 21 : 17
34 VOL 84 OCTOBER-DECEMBER 2020