Introduction
The design of hand tools has a significant influence in the development of upper limb musculoskeletal disorders. By improving the ergonomic properties of hand tools the health of users and their job satisfaction might be positively affected.Any hand tool design must consider the users’ limitations, and provide a right fit for the users. A typical example would be Tongs. In metal forming industries where workers need to use tongs to retrieve workpieces from ovens. Ideally, the tong should be able to grasp objects easily, with a minimum amount of gripping force. In reality, many people may find tongs to be awkward to use as the ability of tongs to grasp objects are generally poor.Undesirable tong design may lead to low user acceptance of tongs, which can lead to catastrophic accidents. Initially, the hand tool must be perceived to be usable, ergonomic and visually appealing in order for the users to benefit from the tools. The perception of ergonomics, usability and aesthetics will be assessed for two different tool designs, R1 ( traditional tong design) and R2 (proposed design alternative).
The existing tong design available (R1)
Proposed alternative design (R2)
Upper limb disorders and hand tool Ergonomics
A mismatch between the user perception and the actual performance of the product may be detrimental to the product’s future success and survival.An upper limb musculoskeletal disorder (ULD) is chronic in nature, and it occurs gradually over time. Several causes of ULD are; repetitive tasks, forceful exertions, vibrations, or sustained or awkward positions. ULD is the general term that is used to describe any disorder experienced in upper limbs. ULD also is used to describe the types of tissue injuries such carpal tunnel syndrome and tennis elbow. An overuse syndrome is also associated with ULD. The most effective intervention that takes place would be workplace redesign.Examples are work associated activities such as using keyboard and mouse. The term includes a group of disorders that most commonly develop in workers using excessive and repetitive motions of the head and neck extremity. The other causes of ULD are remaining in a fixed postures and poor workplace ergonomics. ULD happens when excessive and repetitive motions, coupled with high forces are exerted by the upper limbs. ULD may cause disability, to workers, resulting in loss productivity and other serious consequences. Recovery from ULD may take years, and even then complete recovery may not be possible. The most effective intervention that takes place would be workplace redesign. As the old saying goes, prevention is better than cure, therefore the design of hand tools are of paramount importance.
Method Study
As there are many types and designs of tongs in the market, it is difficult to narrow down exactly the best tong design as that will depend on the type of objects being handled, and the nature of the task itself. Therefore, instead of evaluating every single type of tong, a particular type of tong was chosen to be evaluated.R1 is used in a materials engineering lab, where round, cylindrical steel specimens ranging from 2-3 cm in diameter, and 1 cm in height are handled. Sometimes, R1 is used to handle semi circular work pieces with the same diameter and height.In the proposed design, instead of having a single tool, the proposed design has two parts, a tray and a gripper. The tray is specially designed for the gripper to securely hook the tray. In this way, instead of directly gripping the workpiece, the workpiece would be placed on the tray and the tray would then be inserted into the furnace or oven using the gripper.
The proposed design (R2) and the existing design (R1) were evaluated in terms of ergonomics and usability using a questionnaire that consisted of several questions. Participants were shown the pictures of R1 and R2 in the questionnaire. Based on the pictures, the questions were rated using a Likert type scale, ranging from 1 (least agreeable) to 6 (most agreeable). The neutral option was discarded to prevent participants from taking a neutral stance. While at the same time, the aesthetics aspect of the proposed design and the existing design were evaluated using a scale from 1 to 10, where 1 indicates least beautiful and 10 the most beautiful. The questionnaire was distributed to 50 students. The pictures of R1 and R2 were included in the questionnaire. The responses for each of the questions were then converted into agreement/disagreement percentage ratings, where responses from 1 to 3 were treated as a disagreement, and responses from 4 to 6 were treated as an agreement.
Discussion
72% of the respondents agreed that R2 will accomplish task more quickly than R1 (64%). This is also shown in the ratings for productivity, where 80% of the participants agreed that R2 will help them to increase productivity compared to R1 (66%). Productivity increase can be associated with a quick task accomplishment, and this is clearly evident in the results. The ratings for numbness and peak pressures on the hand are fairly consistent, where 64% of the respondents agreed that R1 will cause peak pressures on the hand compared to R1. The ratings for numbness did not exhibit that much difference, since perceiving numbness from pictures can be rather difficult (54% for R1 vs 50% for R2).
Other ratings given by the participants indicated their preference for R2 design. The statements 'easy to operate tool' and 'easy to perform handling task‖ were rated slightly different from each other, although the meaning of the question is quite similar. For the statement ' easy to operate tool', R1 was rated at 82% vs 84% for R2, in which the difference was very slight (2%). Whereas, in the statement 'easy to perform handling task' a rating of 66% was given for R1, and 78% for R2. Perhaps, in the statement 'easy to operate tool' was more ambiguous in its meaning, so the rating difference was small compared to 'easy to perform handling task', which indicated a bigger difference in the ratings. Questions concerning grip force supply and force transmission yielded a similar pattern; R2 is favored more by the participants, where 70% of the participants believed that R2 would require less gripping force compared to R1 design (58%). This is due to the fact that R2 has special hooks at the end that can be inserted into the sides of the tray allowing for a more secure grip compared to R1, where the grip force required for handling R1 would depend on the type of object being handled.
The weak correlation between product aesthetics and the perception of ergonomics may be explained by the difficulty in perceiving ergonomic features. Ergonomic features are hard to perceive, for example grip force requirement and handle length. These two features can only be measured by physically touching and holding the tool itself. However, their understanding of product aesthetics does not need any further clarification. Consumers do know what a visually appealing product is by just looking at the product. On the other hand, there is no complete theory or model that can accurately predict how consumers come to perceive a product to be visually appealing or vice-versa.
Conclusion
Design have effects on .... but it can affect the productivity. Also design should be user friendly so that people working with that equipment will not get irritated. The study has shed some light into the relationship between perceived ergonomic, usability and product aesthetics. As there has yet to be an established connection between perceived ergonomics, usability and product aesthetics, buying decisions may be purely driven by aesthetics considerations, thus this may lead to usability and ergonomic problems in the future for consumers. Products that are deemed to be ergonomic and usable, has to convey that impression to the potential users. As there are a certain percentage of consumers purchasing products online, the products will have to convey the impressions of good ergonomics, usability, and aesthetics.
Reference
"The Influence of Different Hand Tool Designs on the Perception of Aesthetics,
Ergonomics and Usability"
By
M. S. Syed Mohamed
International Journal of Business and Social Science
Vol. 3 No. 3; February 2012
The design of hand tools has a significant influence in the development of upper limb musculoskeletal disorders. By improving the ergonomic properties of hand tools the health of users and their job satisfaction might be positively affected.Any hand tool design must consider the users’ limitations, and provide a right fit for the users. A typical example would be Tongs. In metal forming industries where workers need to use tongs to retrieve workpieces from ovens. Ideally, the tong should be able to grasp objects easily, with a minimum amount of gripping force. In reality, many people may find tongs to be awkward to use as the ability of tongs to grasp objects are generally poor.Undesirable tong design may lead to low user acceptance of tongs, which can lead to catastrophic accidents. Initially, the hand tool must be perceived to be usable, ergonomic and visually appealing in order for the users to benefit from the tools. The perception of ergonomics, usability and aesthetics will be assessed for two different tool designs, R1 ( traditional tong design) and R2 (proposed design alternative).
Upper limb disorders and hand tool Ergonomics
A mismatch between the user perception and the actual performance of the product may be detrimental to the product’s future success and survival.An upper limb musculoskeletal disorder (ULD) is chronic in nature, and it occurs gradually over time. Several causes of ULD are; repetitive tasks, forceful exertions, vibrations, or sustained or awkward positions. ULD is the general term that is used to describe any disorder experienced in upper limbs. ULD also is used to describe the types of tissue injuries such carpal tunnel syndrome and tennis elbow. An overuse syndrome is also associated with ULD. The most effective intervention that takes place would be workplace redesign.Examples are work associated activities such as using keyboard and mouse. The term includes a group of disorders that most commonly develop in workers using excessive and repetitive motions of the head and neck extremity. The other causes of ULD are remaining in a fixed postures and poor workplace ergonomics. ULD happens when excessive and repetitive motions, coupled with high forces are exerted by the upper limbs. ULD may cause disability, to workers, resulting in loss productivity and other serious consequences. Recovery from ULD may take years, and even then complete recovery may not be possible. The most effective intervention that takes place would be workplace redesign. As the old saying goes, prevention is better than cure, therefore the design of hand tools are of paramount importance.
Method Study
As there are many types and designs of tongs in the market, it is difficult to narrow down exactly the best tong design as that will depend on the type of objects being handled, and the nature of the task itself. Therefore, instead of evaluating every single type of tong, a particular type of tong was chosen to be evaluated.R1 is used in a materials engineering lab, where round, cylindrical steel specimens ranging from 2-3 cm in diameter, and 1 cm in height are handled. Sometimes, R1 is used to handle semi circular work pieces with the same diameter and height.In the proposed design, instead of having a single tool, the proposed design has two parts, a tray and a gripper. The tray is specially designed for the gripper to securely hook the tray. In this way, instead of directly gripping the workpiece, the workpiece would be placed on the tray and the tray would then be inserted into the furnace or oven using the gripper.
The proposed design (R2) and the existing design (R1) were evaluated in terms of ergonomics and usability using a questionnaire that consisted of several questions. Participants were shown the pictures of R1 and R2 in the questionnaire. Based on the pictures, the questions were rated using a Likert type scale, ranging from 1 (least agreeable) to 6 (most agreeable). The neutral option was discarded to prevent participants from taking a neutral stance. While at the same time, the aesthetics aspect of the proposed design and the existing design were evaluated using a scale from 1 to 10, where 1 indicates least beautiful and 10 the most beautiful. The questionnaire was distributed to 50 students. The pictures of R1 and R2 were included in the questionnaire. The responses for each of the questions were then converted into agreement/disagreement percentage ratings, where responses from 1 to 3 were treated as a disagreement, and responses from 4 to 6 were treated as an agreement.
Discussion
72% of the respondents agreed that R2 will accomplish task more quickly than R1 (64%). This is also shown in the ratings for productivity, where 80% of the participants agreed that R2 will help them to increase productivity compared to R1 (66%). Productivity increase can be associated with a quick task accomplishment, and this is clearly evident in the results. The ratings for numbness and peak pressures on the hand are fairly consistent, where 64% of the respondents agreed that R1 will cause peak pressures on the hand compared to R1. The ratings for numbness did not exhibit that much difference, since perceiving numbness from pictures can be rather difficult (54% for R1 vs 50% for R2).
Other ratings given by the participants indicated their preference for R2 design. The statements 'easy to operate tool' and 'easy to perform handling task‖ were rated slightly different from each other, although the meaning of the question is quite similar. For the statement ' easy to operate tool', R1 was rated at 82% vs 84% for R2, in which the difference was very slight (2%). Whereas, in the statement 'easy to perform handling task' a rating of 66% was given for R1, and 78% for R2. Perhaps, in the statement 'easy to operate tool' was more ambiguous in its meaning, so the rating difference was small compared to 'easy to perform handling task', which indicated a bigger difference in the ratings. Questions concerning grip force supply and force transmission yielded a similar pattern; R2 is favored more by the participants, where 70% of the participants believed that R2 would require less gripping force compared to R1 design (58%). This is due to the fact that R2 has special hooks at the end that can be inserted into the sides of the tray allowing for a more secure grip compared to R1, where the grip force required for handling R1 would depend on the type of object being handled.
The weak correlation between product aesthetics and the perception of ergonomics may be explained by the difficulty in perceiving ergonomic features. Ergonomic features are hard to perceive, for example grip force requirement and handle length. These two features can only be measured by physically touching and holding the tool itself. However, their understanding of product aesthetics does not need any further clarification. Consumers do know what a visually appealing product is by just looking at the product. On the other hand, there is no complete theory or model that can accurately predict how consumers come to perceive a product to be visually appealing or vice-versa.
Conclusion
Design have effects on .... but it can affect the productivity. Also design should be user friendly so that people working with that equipment will not get irritated. The study has shed some light into the relationship between perceived ergonomic, usability and product aesthetics. As there has yet to be an established connection between perceived ergonomics, usability and product aesthetics, buying decisions may be purely driven by aesthetics considerations, thus this may lead to usability and ergonomic problems in the future for consumers. Products that are deemed to be ergonomic and usable, has to convey that impression to the potential users. As there are a certain percentage of consumers purchasing products online, the products will have to convey the impressions of good ergonomics, usability, and aesthetics.
Reference
"The Influence of Different Hand Tool Designs on the Perception of Aesthetics,
Ergonomics and Usability"
By
M. S. Syed Mohamed
International Journal of Business and Social Science
Vol. 3 No. 3; February 2012
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