Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2008
Forfattere
Klaus Mittenzwei Ivar GaaslandSammendrag
Det er ikke registrert sammendrag
Forfattere
Agnar Hegrenes Gudbrand Lien Ole Jakob Bergfjord Ola Flaten Ragnar Tveterås Leif Jarle AsheimSammendrag
Det er ikke registrert sammendrag
Redaktører
Lars Johan RustadSammendrag
Det er ikke registrert sammendrag
Forfattere
Geir Wæhler GustavsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Geir Wæhler GustavsenSammendrag
Det er ikke registrert sammendrag
Redaktører
Ivar PettersenSammendrag
Det er ikke registrert sammendrag
Redaktører
Heidi KnutsenSammendrag
Det er ikke registrert sammendrag
Redaktører
Lars Johan RustadSammendrag
Det er ikke registrert sammendrag
Forfattere
Tove Maria Østensvik Kaj Bo Veiersted Emmanuel Cuchet Petter Nilsen Jan Johansson Hanse Caisa Carlzon Jørgen WinkelSammendrag
The present cross-sectional study was performed to analyze potential risk factors for upper extremity disorders in two groups of forest machine operators driving harvesting vehicles and performing equal tasks in France (n=18) and Norway (n=19). This comparative design implied similar work tasks, but potentially different external work demands. Previous studies have suggested higher levels of neck and shoulder complaints among Norwegian operators compared to those of the French. This may be related to different external work demands and/or individual motor performance. Surface electromyography (EMG) of the right upper trapezius (RUT) and extensor digitorum (RED) muscles were measured continuously during 1 working day (7.5–8 h per operator) and video of body postures was recorded inside the cabin (1 h per operator). A questionnaire on external work demand factors and psychosocial stressors was used together with the collection of symptom data. A physical examination was performed on all workers. Borg's CR-10 scale of intensity of discomfort/pain was rated four times throughout the test day. The French operators reported less complaint (p<0.01) in the right neck compared to their Norwegian colleagues. Furthermore, the French had on average two to three times longer lunch breaks during 5 work days, less continuous hand intensive use of the control lever with more frequent short breaks during the test day compared to the Norwegian operators. However, the average static load level on the RUT muscle for the whole working day was significantly higher among the French (0.7% EMGmax) in comparison with the Norwegian operators (0.3% EMGmax). No difference was found in number of periods with sustained low-level muscle activity neither in the RUT nor the RED muscle. In conclusion, our results support that the higher prevalence of discomfort/pain among the Norwegian forest machine operators may be related to organizational factors.
Forfattere
Tove Maria Østensvik Petter Nilsen Kaj Bo VeierstedSammendrag
The goal of this cross-sectional study was to investigate the impact of different physical work station designs, expressed in two different brands of forest vehicles, on the muscle activity patterns in the neck and upper extremities among the vehicle operators. Surface electromyography (sEMG) was continuously recorded bilaterally on the trapezius (TM) and the extensor digitorum muscles (EDM) during one working day among operators driving Timberjack and Valmet vehicles, either as harvesters (n = 7 and 6, respectively) or forwarders (n = 9 and 9, respectively). Both the construction of the crane in relation to the chassis and the design of the control levers vary between the Tim-berjack and Valmet vehicles, which demand different ergonomic performance by the operators. The operators mostly handle control levers in the harvesters or forwarders, the latter with a more varied work load, in a fixed, seated working posture in the cabin for long hours with little rest. The sustained low- level muscle activity was quantified by periods with muscle activity above 0.5 percent EMGmax into 10 predetermined duration intervals from 1.6 to 5 s up to above 20 min (SULMA periods). These SULMA periods were analyzed both for number in the different intervals and cumulated periods above the predefined values. Amplitude and frequency parameters were analyzed and the number and total duration of muscle rest periods were calculated. The operators driving Valmet harvesters had a significantly higher number of long cumulated SULMA periods above 10 min in the left TM, and showed a higher level of static muscle activity and less total duration of muscle rest in TM bilaterally. The operators driving Timberjack forwarders had a significantly higher number of SULMA periods between 10 and 20 min in the right TM. No difference was found between the operators in the EDM activity pattern. The results of our study showed that operators driving Valmet harvesters had more sustained low-level activity in the neck than those driving Timberjack, including a higher number of long cumulated SULMA periods, higher static level, and less muscle rest. Despite a small sample, the results in muscle activity pattern raise the question of needs for improvements of the forest vehicle workstation design.