China
Africa
Explore chapters and articles related to this topic
Model for Predicting the Performance of Planetary Suit Hip Bearing Designs
Published in Vincent G. Duffy, Advances in Applied Human Modeling and Simulation, 2012
Matthew S. Cowley, Sarah Margerum, Lauren Harvill, Sudhakar Rajulu
Mobility visualizations were created to show the generally unused regions of motion that the hip bearing of the Mark III allows for. Figure 6 is an illustration of the hip mobility in the Mark III compared to unsuited hip motion. Each shape represents the possible locations of the knee joint in 3D, the blue disk-like area is the maximum allowable motion of the Mark III in the nominal condition, and the green is unsuited hip motion for common tasks (walking, kneeling, climbing, etc.). Functional hip motion is taken from published walking data (Gage, DeLuca, and Renshaw, 1995) and previous NASA functional mobility tests (England, Benson, and Rajulu, 2010). The general area of unsuited hip motion not accounted for by the Mark III hip joint is shown as the green volume not overlapped by the blue. Approximately 60% of the unsuited hip motion area would have been unreachable by someone in a Mark III suit trying to move in the exact same way. The inverse of the previous statement is also represented visually where only a fraction of the allowable mobility of the Mark III would be used to perform common tasks without compensating with other joint motion (i.e., waist and leg rotation).
Musculoskeletal Disorders
Published in Stephan Konz, Steven Johnson, Work Design, 2018
Most jobs have a relatively low incidence of musculoskeletal disorders in the lower leg, although prolonged standing (ushers), dancing, or walking (postal delivery) can be a problem (Lewis, 2006). The knee can be a problem if the worker spends a lot of time kneeling (e.g., carpet and tile workers). The workers are putting approximately 89% of their body weight on a small surface area with minimal fatty tissue. The result is bursitis of the knee.
Repetitive TasksRisk Assessment and Task Design
Published in R. S. Bridger, Introduction to Human Factors and Ergonomics, 2017
Knee disorders, including OA and bursitis, are associated with squatting and with heavy physical work (Jensen and Eenberg, 1996). The 12-month prevalence of knee problems in the Danish population was reported to be 19%. Unsurprisingly, kneeling work was associated with bursitis (housemaid's knee). Table 5.5 summarizes the main risk factors for knee disorders (see, e.g., Sandmark et al., 2000).
Effects of working posture and roof slope on activation of lower limb muscles during shingle installation
Published in Ergonomics, 2020
Amrita Dutta, Scott P. Breloff, Fei Dai, Erik W. Sinsel, Christopher M. Warren, Robert E. Carey, John Z. Wu
Awkward kneeling posture is considered as a primary risk factor for musculoskeletal disorders (MSDs) among occupations that require frequent kneeling (Xu et al. 2017). Due to the unique work condition of slanted rooftops, residential roofers spend more than 75% of their working time in crawling, squatting, stooping and kneeling postures. The cumulative effects of these awkward postures combined with repetitive motions have, in large part, led to a high incident rate of MSDs among residential roofers (Dulay, Cooper, and Dennison 2015; Wang, Dai, and Ning 2015). Awkward postures during a task can lead to less efficient force production in skeletal muscle. This decrease in muscle efficiency may result in higher muscle activation and muscle overloading compared to a neutral posture (Kaushik and Charpe 2008). Cumulative muscle overloading coupled with repetitive motions without adequate recovery time may cause MSDs due to overexertion or imbalance (Kumar 2001; Hofer et al. 2011). According to Marras and Karwowski (2003), the incident rate of knee MSDs is the highest among residential roofers in comparison to other workers in construction.
The effects of a simulated occupational kneeling exposure on squat mechanics and knee joint load during gait
Published in Ergonomics, 2018
Liana Michele Tennant, Helen Christina Chong, Stacey Marie Acker
The control of the knee during squat transitions was impaired following the kneeling exposure. Both the peak and the mean frontal plane knee motion increased following kneeling, and mean deviation remained elevated when measured again 30 min post-kneeling, which supported the hypotheses. Although not necessarily directly linked to knee osteoarthritis risk, frontal plane knee motion has been linked to increased injury risk (Hewett et al. 2005). Because some workers must perform many transitions to-and-from the ground in a single day, it is possible that negative adaptations in frontal plane knee motion following prolonged kneeling could increase the risk for meniscal tears, which have been shown to be a common injury among workers who kneel (McMillan and Nichols 2005; Reid et al. 2010; Snoeker et al. 2013). Both meniscal tears and subsequent meniscectomies are associated with an increased risk for the development of knee osteoarthritis (Cicuttini et al. 2002; Englund et al. 2009). Therefore, based on research that has shown that certain movement patterns can be risk factors for injury (Hewett et al. 2005; Pohl et al. 2008), it is possible that workers may be at greater risk of injury when the knee is in a more highly deviated posture, which could lead to the development of knee osteoarthritis. This finding supports the theory suggested by Jensen et al. (2012) that kneeling workers may be at greater risk of meniscal tears compared to workers in trades that do not require kneeling, due to in appropriate movements when transitioning to-and-from the floor.
Detection of kneeling and squatting during work using wireless triaxial accelerometers
Published in Ergonomics, 2020
Peter Fjeldstad Hendriksen, Mette Korshøj, Jørgen Skotte, Andreas Holtermann
Kneeling and squatting postures often occurs in occupations such as miners, floor layers and construction workers (Botje et al. 2010; Jensen 2005; Jensen and Eenberg 1996; Sharrard 1965). Occupational knee-straining postures, such as kneeling and squatting are well documented to increase the risk for knee pain (Miranda et al. 2002; Herquelot et al. 2014; Descatha et al. 2011), chronic knee pain (Herquelot et al. 2015), meniscal tears (Snoeker et al. 2013; Jensen, Rytter, and Bonde 2012), knee osteoarthrosis (McWilliams et al. 2011; Coggon et al. 2000), and radiologically determined knee cartilage degeneration (Jensen, Rytter, and Bonde 2012; Amin et al. 2008; Jensen et al. 2000).