Stres Ergonomik

1. Stres Ergonomik Tekanan Ergonomik Fisik dan Mental

2. Definisi = llmu yang mempelajari hubungan manusia dan lingkungan kerjanya untuk mencapai keseimbangan dalam efisiensi, kesehatan dan kesejahteraan = disiplin ilmu yang ditujukan untuk membantu pekerja bekerja secara produktif, dalam taraf ekonomi yang dapat diterima oleh pengusaha/pemberi kerja, dan pada saat yang sama juga memberikan kesejahteraan faali dan emosional yang tinggi pada pekerja Disiplin ilmu yang terkait: ilmu rekayasa, fisika, biologi, sosial dan perilaku TUJUAN ERGONOMI: Mencegah tekanan kerja, kelelahan, ketidakpedulian terhadap kerja, produktivitas rendah, labor turn over rate yang tinggi

3. Ilmu-ilmu terkait ergonomik • Engineering sciences: mechanics • Physical sciences: physical energy stresses • Biological sciences: anatomy, physiology  biomechanics • Social and behavioral sciences: anthropology, (industrial) psychology, (industrial) sociology  engineering psychology

4. Aplikasi dalam industri • Orientasi desain dan produksi: • Human factors in engineering • Industrial design • Industrial engineering • Orientasi kesehatan/keselamatan: • Industrial hygiene • Safety engineering • Occupational medicine

5. Ergonomi berhubungan dengan: • Anatomi, fisiologi memberikan informasi mengenai struktur dan fungsi tubuh • Anthropometry memberikan informasi mengenai ukuran tubuh • Psikologi, mempelajari fungsi dari otak dan sistem syaraf • Higiene industri, mendefiniskan kondisi pekerjaan yang membuktikan adanya bahaya terhadap tubuh • Ilmu fisika dan teknik lainnya yang mendukung

6. Ahli ergonomi harus menguasai: • Anatomi-fisiologi tubuh  misal: efisiensi angkat junjung, telunjuk untuk menunjuk/extension, dari lain untuk operation • System muskulo-skeletal  keseimbangan beban pada otot • System neuro-muskuler  kecepatan rekasi/gerak kerja, kelellahan • System sensori-neural  display, bentuk, diskriminasi permukaan alat • Pancaindera  display visual, auditory, taktual • System kardio-vaskuler: kelelahan • Biokimia: energi untuk kerja, beban kerja • Gizi, kesehatan: fitness • Dasar desain peralatan industri: handtools, antropometri • Layout ruang kerja • Penempatan peralatan

7. Jenis pekerjaan terbagi: • KERJA STATIK: - Sering dilupakan - ada otot yang lelah - postur tubuh perlu diperhatikan - lengkung/bungkuk menyebabkan lelah karena beban pada satu bagian tubuh, supply oksigen kurang, buangan terakumulasi, otot akan lelah - sebaiknya kerja bergantian statis dan dinamis • KERJA DINAMIK - Membawa, mengangkat - perlu diperhatikan sandaran lengan yang empuk - posisi yang tidak alami perlu dihindari - karena perbedaan antropometri  alat harus disesuaikan

8. Sumber Kelelahan • Orang yang lelah  mudah mengalami kecelakaan/cacat dan sakit • Variabel pekerja: usia, jenis kelamin, ukuran antropometri • Lelah = perasaan yang subyektif Lelah = penurunan efisiensi kerja fisik dan ketahanan kerja • Sumber kelelahan: - kelelahan umum - beban fisik dan mental berat - kelelahan mental dan lama - kelelahan visual - lingkungan: suhu, bising, - kelelahan syaraf iluminasi, cuaca, suasana - kerja yang monoton kerja - sakit badaniah, gizi, kebiasaan makan - aktor kejiwaan: tanggung jawab, konflik, risau

9. Gejala kelelahan • Kaku dan canggung dalam gerak • Ingin berbaring, susah berpikir • Lelah bicara • Menjadi gugup • Tidak dapat konsentrasi • Sukar memberi perhatian • Cenderung lupa • Kurang percaya diri • Cemas • Koordinasi gerak menurun • Kaku di bahu • Nyeri punggung • Perhatianturun • Reaksilamban • Sulitberpikir • Kemauanmenurun • Motivasikerjaturun • Kurangefisiendikerjafisik/mental • Beratdikepala, lelahseluruhbadan • Kaki terasaberat • Menguap • Pikirankacau • Mengantuk • Beratmata

10. Mencegah kelelahan kerja • Aspek postur tubuh: keserasian tubuh dengan alat kerja, volume kerja • Aspek rekayasa • Aspek lain: motivasi kerja, aturan istirahat, suasana yang menyenangkan, perbaiki kesejahteraan termasuk gaji, gizi.

11. Hubungan manusia dengan mesin • Ada perbedaan sistem manusia dan mesin. • Manusia menerima dan memproses informasi kemudian bertindak • Task stresses, tekanan pada tugas pekerjaan • Yang paling utama adalah fisiologi dan psikologi, pekerjaan harus sesuai dengan umur, jenis kelamin, bentuk tubuh pekerja. • Pekerjaan terlalu mudah membosankan, terlalu berat akan sakit. • Tugas Industrial Hygienist adalah mencari keseimbangannya.

13. Kemampuan manusia vs mesin (1)

14. Kemampuan manusia vs mesin (2)

15. Biomekanik • Biomekanika = Mekanika biologi organisme • Biomekanika merupakan alat yang dapat mencegah beban kerja • Mempelajari fungsi dan struktur bagian tubuh serta efeknya tekanan/beban internal/eksternal terhadapnya. • Beban berat yang kumulatif dapat menyebabkan kelainan fisik. • Dirasakan sebagai gejala pertama sakit: sesuatu yang tidak comfortable • Bila tidak diperhatikan dapat menyebabkan kecelakaan di kemudian hari

16. Contoh Biomekanika • Tangan dan lengan bawah kerja tangan dilaksanakan oleh otot yang melekat pada tulang ulna dan radius  memperhatikan garis fleksi tangan dan lengan bawah Contoh: memegang obeng, gegep, dll. • Tungkai bawah Beberapa titik lemah: • Daerah belakang lutut • Bagian bawah dan belakang tungkai atas • Lengkung bawah kaki • Jangan menekan bagian ini Contoh: posisi duduk, bila tidak sesuai akan menyebabkan kesemutan

17. Tungkai bawah • Kursi terlalu dalam akan menekan lutut • Kursi terlalu tinggi akan menekan bagian bawah belakang tungkai atas • Sandaran kaki, bila sepatu empuk, lekuk kaki akan tertekan • Timbul kesemutan • Pedal kaki yang terlalu dekat/jauh akan menyebabkan sudut normal terlampaui

18. Head height • Allow adequate space for the tallest possible worker. • Position displays at or below eye level because people naturally look slightly downward. Shoulder height • Control panels should be placed between shoulder and waist height. • Avoid placing above shoulder height objects or controls that are used often. Arm reach • Place items within the shortest arm reach to avoid over-stretching while reaching up or outward. • Position items needed for work so that the tallest worker does not need to bend while reaching down. • Keep frequently used materials and tools close to and in front of the body. Elbow height • Adjust work surface height so that it is at or below elbow height for most job tasks. Hand height • Make sure that items that have to be lifted are kept between hand and shoulder height. Leg length • Adjust chair height according to leg length and the height of the work surface. • Allow space so that legs can be outstretched, with enough space for long legs. • Provide an adjustable footrest so that legs are not dangling and to help the worker change body position. Hand size • Hand grips should fit the hands. Small hand grips are needed for small hands, larger grips for bigger hands. • Allow enough work space for the largest hands. Body size • Allow enough space at the workstation for the largest worker.

19. Mengangkat-junjung Mengangkat-junjungbendaberatdapatmenyebabkanterjadinyakecelakaan Perlumemperhatikan: - Variabelkerja: lokasi, ukuranobyek, ketinggiandaridanketempatjunjung, frekuensikerja, beratobyek, posisikerja - Variabelmanusia: usia, jeniskelamin, pelatihan, fitness, ukurantubuh - variabellingkungan: temperatur, kelembaban, kontaminandiudara • Mengangkatbersama-sama Semeratamungkin, janganterlalubanyakorangsehinggamengganggu, sebaiknyasamatinggi, bergerakbersama-sama-komando, setiaporangpadaposisidanpegangan yang benar

20. Basic ergonomic principles It is generally most effective to examine work conditions on a case-by-case basis when applying ergonomic principles to solve or prevent problems. Sometimes even minor ergonomic changes in the design of equipment, workstations or job tasks can make significant improvements in worker comfort, health, safety and productivity. The following are a few examples of ergonomic changes which, if implemented, can result in significant improvements: • For assembly jobs, material should be placed in a position such that the worker's strongest muscles do most of the work. • For detailed work which involves close inspection of the materials, the workbench should be lower than for work which is heavy. • Hand tools that cause discomfort or injury should be modified or replaced. Workers are often the best source of ideas on ways to improve a tool to make using it more comfortable. For example, pliers can be either straight or bent, depending on the need. • A task should not require workers to stay in awkward positions, such as reaching, bending, or hunching over for long periods of time. • Workers need to be trained in proper lifting techniques. A well designed job should minimize how far and how often workers have to lift. • Standing work should be minimized, since it is often less tiring to do a job sitting than standing. • Job assignments should be rotated to minimize the amount of time a worker spends doing a highly repetitive task, since repetitive work requires using the same muscles again and again and is usually very boring. • Workers and equipment should be positioned so that workers can perform their jobs with their upper arms at their sides and with their wrists straight.

21. If the workstation is properly designed, the worker should be able to maintain a correct and comfortable body posture. This is important because an uncomfortable work posture can cause a variety of problems, such as: • back injury; • development or aggravation of RSIs; • circulatory problems in the legs. The main causes of these problems are: • poorly designed seating; • standing for long periods; • reaching too far; • inadequate lighting forcing the worker to get too close to the work. • The following are some basic ergonomic principles for workstation design. A general rule of thumb is to consider body size information, such as height, when choosing and adjusting workstations. Above all, workstations must be adjusted so that the worker is comfortable.

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43. Interactions between man and such traditional environmental elements including all tools and equipment pertaining to the work place. • The modern concept: man is to be considered the monitoring link of a man-machine environment system.

44. Management is interested in the behavior and physical operating characteristics of man to the extent that they affect the economic and productive outputs from such system. • A system is an orderly arrangement of components which are interrelated and which act and interact to perform some task or function in a particular environment.

45. It is essential to recognize that a failure of malfunction of any component can affect the other components and thus degrade performance. • The environment is an important consideration in a system. Most components (man, tools) in a system will perform their task properly only under a given set of conditions. • A component that works well at normal temperatures may malfunction or fail if placed in a system near another component that generates high heat.

46. To achieve maximum efficiency, a man-machine system must be designed as a whole, with man being complementary to the machine and the machine being complementary to the abilities of man. • Consideration should be given to the general physical and mental demands of the task, so as not to overload the operator.

47. Ergonomics includes the physiological and psychological stresses of the task. • The task should not require excessive mental and muscular effort. • The job should not be so easy that boredom and inattention lead to unnecessary errors and accidents.

48. These ergonomic stresses can impair the health and efficiency of the worker just as significantly as the other more common environmental stresses. • Most men can work for short periods under overloaded conditions, such as when there are high production demands; however, when such an overload reaches some undefinable point, man may completely breakdown.

49. The task of the design engineer and safety professional is to find the happy blend between “easy” and difficult” jobs. • With very low levels of physiological and psychological stress, performance is also low; as stress increases, however, performance also increases—to a point. • The task is to design jobs that will be centered around optimum performance.

50. Often, the man’s contribution to a system is to provide a countermeasure in the event of system malfunction or component failure. • To do this he must know that a failure has occurred and what to do about it.