Analisis Perbaikan Postur Kerja dengan Cornell Musculoskeletal Discomfort Questionnaires (CMDQ) dan Metode Rapid Entire Body Assesment (REBA) Beban Fisik Pekerja Konstruksi (Studi Kasus: Pembangunan Jembatan Mlowo, Cs Nguter Sukoharjo)

Proyek konstruksi memiliki tekanan bagi para pekerja, sehingga memicu kelelahan, penyakit akibat kerja, sehingga menurunkan produktivitas. Pekerja melakukan penanganan material yang tidak tepat menggunakan Manual Material Handling, menyebabkan pekerja mengalami nyeri pada bagian tubuh. Otot para pekerja menerima beban statis terus-menerus dalam jangka waktu lama berpotensi mengakibatkan gangguan muskuloskeletal. Tujuan penelitian untuk menganalisis postur kerja para pekerja proyek konstruksi pembangunan Jembatan Mlowo, Cs Nguter Sukoharjo. Penelitian ini menggunakan metode penelitian eksperimental di lokasi proyek, kemudian dianalisis menggunakan kuesioner CMDQ dan metode REBA. Terdapat 7 aktivitas yang dianalisis dalam penelitian ini, sebab memiliki tingkat risiko tinggi dan dilakukan berulang, antara lain aktivitas penulangan, pemindahan baja tulangan, pengecoran (menahan bak penuang cor), pemasangan bagesting, pengecoran (mengalirkan cor), pemindahan girder, dan pemindahan las listrik. Hasil penelitian menunjukkan bahwa semua aktivitas memerlukan proses perbaikan. Berdasarkan kuesioner CMDQ, bagian tubuh yang sering dirasakan nyeri oleh pekerja adalah lengan atas. Penilaian dengan REBA, penulangan skor 7 (perlu perbaikan), pemindahan baja tulangan skor 10 (harus segara perbaikan), pengecoran (menahan bak) skor 11 (saat ini dilakukan perbaikan), pemasangan bagesting skor 7 (perlu perbaikan), mengalirkan pengecoran skor 9 (segera perbaikan), pemindahan girder skor 12 (perbaikan saat ini), dan pemindahan las listrik skor 10 (segera perbaikan).

Penentuan Beban dan Tinggi Rak yang Optimal terhadap Kebutuhan Energi Pekerja pada Area Penyimpanan di Mini Market X

Aktivitas Manual Material Handling (MMH) merupakan aktivitas yang memerlukan energi lebih besar dibandingkan aktivitas lainnya di gudang penyimpanan. Penelitian ini dilakukan untuk menganalisis pengaruh tinggi rak, dan bobot barang terhadap kebutuhan energi para pekerja pada aktivitas MMH. Penelitian dilakukan dengan menggunakan desain eksperimen untuk mengetahui respon dua faktor terhadap kebutuhan energi pekerja melalui denyut jantung. Faktor bobot barang memiliki dua jenis, yaitu 5 kg dan 10 kg sedangkan faktor tinggi rak adalah 76 cm dan 126 cm. Responden dari penelitian ini adalah empat pekerja laki-laki dalam rentang usia 18-25 tahun, sehingga rancangan dasar yang digunakan adalah Rancangan Acak Lengkap (RAL). Hasil uji ANOVA menunjukkan bahwa kedua faktor memiliki pengaruh terhadap kebutuhan energi antara faktor bobot barang terhadap kebutuhan energi. Hasil perhitungan konsumsi energi menunjukkan bahwa energi yang dibutuhkan pekerja untuk melakukan aktivitas MMH pada penelitian ini masih termasuk dalam kriteria beban kerja ringan.

A questionnaire-based musculoskeletal disorder assessment for aircraft maintenance technicians

Purpose Aircraft maintenance technician (AMT) is the most critical profession in the aircraft maintenance system. The tasks of a licensed AMT require expertise and involve repetitive physical tasks such as tightening or loosening aircraft parts, carrying or removing parts during long working hours under time pressure and day/night shifts. This study aims to attract attention to the difficult working conditions of AMTs and identify the body parts that are at risk of musculoskeletal disorder (MSD). Design/methodology/approach A questionnaire is developed by the authors to gather demographic information, use of hand tools, equipment, use of fall protection, manual material handling (lifting, pushing, pulling), load weight, environmental factors, and MSD discomfort level perceptions. The questionnaire is applied to 150 AMTs during six months period, and the obtained data are analyzed by sequential ordinal logistic regression (OLR) models. Findings The ORL results confirm that the use of equipment (lift platform, scissors lift), safety belt attached to the platform, manual material handling, environmental factors (humidity, vibration and illumination) and resting periods have a significant effect on MSD risks. On the contrary, age, experience level, use of small hand tools, temperature and noise are not identified as statistically significant. Originality/value The study is original for it considers the working conditions and perceived discomfort levels of AMTs. A questionnaire is introduced to assess the consequences of the use of tools, equipment, fall protection equipment, environmental conditions and work organization on various body parts (neck, shoulder, elbow, back, lower back, wrist-hand, hip, knee, and ankle-feet), and strain level is identified. The study contributes to the theoretical aircraft maintenance literature and managers in practice.

Analisis Penanganan Postur Kerja Manual Material Galon Menggunakan Metode Rapid Entire Body Assessment

CV Tirta Mineral merupakan perusahaan distributor air mineral cara memindahkan galon masih menggunakan tenaga manual atau biasa disebut manual material handling (MMH). Postur tubuh pada saat bekerja yang kurang tepat berpotensi mengakibatkan terjadinya cedera otot atau cedera sistem muskuloskeletal yang disebut Musculoskeletal Disorders (MSDs). Penelitian ini untuk mengetahui gangguan postur tubuh yang terjadi pada pekerja maka dipergunakan metode REBA (Rapid Entire Body Assessment). Metode ini digunakan untuk mengukur aktivitas pekerjaan yang bersifat manual. Pengukuran dilakukan terhadap pekerja yang melakukan proses pengangkatan galon air mineral di salah satu perusahaan UMKM di daerah Cileungsi. Hasil penelitian ini menunjukan bahwa postur kerja yang analisis mempunyai level resiko yang tinggi, yaitu skor 8 sampai 10, nilai tersebut sangat beresiko menyebabkan cedera yang berarti perlu adanya perbaikan segera. Perbaikan yang dilakukan berupa usulan alat bantu bagi pekerja berupa troli, diharapkan dengan troli tersebut mampu menghindari resiko terjadinya cedera serta memperbaiki postur kerja.

Sex-Dependent Estimation of Spinal Loads During Static Manual Material Handling Activities—Combined in vivo and in silico Analyses

Manual material handling (MMH) is considered as one of the main contributors to low back pain. While males traditionally perform MMH tasks, recently the number of females who undertake these physically-demanding activities is also increasing. To evaluate the risk of mechanical injuries, the majority of previous studies have estimated spinal forces using different modeling approaches that mostly focus on male individuals. Notable sex-dependent differences have, however, been reported in torso muscle strength and anatomy, segmental mass distribution, as well as lifting strategy during MMH. Therefore, this study aimed to use sex-specific models to estimate lumbar spinal and muscle forces during static MHH tasks in 10 healthy males and 10 females. Motion-capture, surface electromyographic from select trunk muscles, and ground reaction force data were simultaneously collected while subjects performed twelve symmetric and asymmetric static lifting (10 kg) tasks. AnyBody Modeling System was used to develop base-models (subject-specific segmental length, muscle architecture, and kinematics data) for both sexes. For females, female-specific models were also developed by taking into account for the female’s muscle physiological cross-sectional areas, segmental mass distributions, and body fat percentage. Males showed higher absolute L5-S1 compressive and shear loads as compared to both female base-models (25.3% compressive and 14% shear) and female-specific models (41% compressive and 23.6% shear). When the predicted spine loads were normalized to subjects’ body weight, however, female base-models showed larger loads (9% compressive and 16.2% shear on average), and female-specific models showed 2.4% smaller and 9.4% larger loads than males. Females showed larger forces in oblique abdominal muscles during both symmetric and asymmetric lifting tasks, while males had larger back extensor muscle forces during symmetric lifting tasks. A stronger correlation between measured and predicted muscle activities was found in females than males. Results indicate that female-specific characteristics affect the predicted spinal loads and must be considered in musculoskeletal models. Neglecting sex-specific parameters in these models could lead to the overestimation of spinal loads in females.

Do overweight/obesity and low levels of leisure-time vigorous physical activity moderate the effect of occupational physical activity on self-rated health of construction workers?

Purpose To investigate the combined effects of occupational physical activity (OPA) and either overweight/obesity or low levels of leisure-time vigorous physical activity (LTVPA) on self-rated health. Methods A longitudinal study was performed among 29,987 construction workers with complete data on 2 Workers’ Health Surveillance Programs during 2010–2018. Self-reported OPA involved strenuous work postures and manual material handling. Low level of LTVPA was defined as self-reported vigorous activity for less than three times per week lasting at least 20 min per session. Overweight and obesity were based on Body Mass Index (BMI) (25.0 ≤ BMI < 30.0 kg/m2 and BMI ≥ 30.0 kg/m2, respectively) using measured body height and weight. Self-rated health was measured using a single item question. Logistic regression analysis was used to investigate the associations between the separate risk factors at baseline and self-rated health at follow-up. The combined effects of demanding OPA and either overweight/obesity or low level of LTVPA on self-rated health were analyzed using the relative excess risk due to interaction (RERI). Results Mean follow-up duration was 31.7 (SD = 14.9) months. Construction workers with strenuous work postures (OR 1.35 95% CI 1.25–1.46), manual material handling (OR 1.29 95% CI 1.19–1.40), obesity (OR 1.31 95% CI 1.17–1.47) and low LTVPA (OR 1.13 95% CI 1.01–1.25) were more likely to report poor self-rated health at follow-up. No statistically significant interaction effects were found for OPA and obesity or low LTVPA. Conclusions OPA, obesity and low level of LTVPA were separate risk factors for poor self-rated health, but did not appear to have a synergistic effect.

Formulating and Deploying Strength Amplification Controllers for Lower-Body Walking Exoskeletons

Augmenting the physical strength of a human operator during unpredictable human-directed (volitional) movements is a relevant capability for several proposed exoskeleton applications, including mobility augmentation, manual material handling, and tool operation. Unlike controllers and augmentation systems designed for repetitive tasks (e.g., walking), we approach physical strength augmentation by a task-agnostic method of force amplification—using force/torque sensors at the human–machine interface to estimate the human task force, and then amplifying it with the exoskeleton. We deploy an amplification controller that is integrated into a complete whole-body control framework for controlling exoskeletons that includes human-led foot transitions, inequality constraints, and a computationally efficient prioritization. A powered lower-body exoskeleton is used to demonstrate behavior of the control framework in a lab environment. This exoskeleton can assist the operator in lifting an unknown backpack payload while remaining fully backdrivable.

Postural Analysis on Manual Pine Resin Collecting Work: Lifting Index and L5/S1 Compression-Shear Forces

Even though pine oleoresin harvesting is labor-intensive forestry work involving manual material handling (especially lifting) and is massively carried out in Indonesia, there is a lack of ergonomics studies on manual pine oleoresin harvesting. This study focused on lifting-related postures in pine oleoresin harvesting. A Three Dimension Static Strength Prediction Program Version 7.1.0 was used to identify the injury risk on the lower back (lumbosacral joint, L5/S1) using biomechanical criteria (compression and shear forces) at extreme postures. Recommended Weight Limit (RWL) and Lifting Index (LI) were calculated for a comprehensive analysis. The exceeding compression and shear forces indicated that the L5/S1 injury risk on oleoresin collecting work (part of oleoresin harvesting) is high. The psychophysical analysis confirmed the findings, as several main postures in this work were categorized as intense manual lifting due to the excessive score of LI. A significant reduction in the L5/S1 compression and shear forces were shown at a simulation using a proposed load threshold (using the calculated RWL). Keywords: biomechanics, ergonomics, forestry work, manual lifting, oleoresin harvesting

Examining human perception of weight during loaded standing and walking

While the psychophysics of weight perception may help assess the effort needed in manual material handling tasks, the perception of weight is subjective and not necessarily accurate. The purpose of this study was to examine weight perception during standing and walking. Participants (n=10) performed a series of weight comparison trials against a reference load while holding loads (standing) or carrying loads (walking). Polynomial logistic regression models were built to examine the effects of walking, box weight ratio, and reference weight level on the probability of detecting a weight difference. The results showed that weight ratio and reference weight level had statistically significant effects on the detection probability while walking did not have a significant effect. Findings from this study can help inform the design of subjective evaluation of job demands involving motion, and it can be further extended to the gradual increase in load of strengthening tasks in therapeutic exercises.