Influencing Factors Of Work-related Musculoskeletal Disorders And Emg Characteristics Of Climbing Work Among Operation And Maintenance Personnel Of Power Supply Enterprises

Objectives To investigate the prevalence and influencing factors of work-related musculoskeletal disorders(WMSDs)among operation and maintenance personnel of power supply enterprises through occupational epidemiological survey.Further screen high-risk positions,combine with the simulation of working condition in the laboratory,detect the changing conditions of the EMG signals of workers and to further explore the adverse ergonomics and mechanism of action.In order to provide scientific basis for the occupational health management,the prevention and control of the WMSDs and the improvement of ergonomics in the working environment of power supply enterprise.Methods1.A total of 1343 operation and maintenance personnel from 10 power supply enterprises were selected as research subjects using the stratified cluster sampling method.A revised Musculoskeletal Disorders Questionnaire was used to investigate the prevalence and adverse ergonomic factors of WMSDs.The x~ 2 test and multivariate logistic regression model were used to explore the influencing factors of WMSDs among operation and maintenance personnel.2.The high-risk positions were screened out based on the results of the previous epidemiological survey.The most severe musculoskeletal injury was of the most typical work of climbing pylons among operation and maintenance personnel in the power transmission position.The 10 male were selected as volunteers to simulate the typical working work of climbing pylons.In this study,the spacing of foot nails of pylons was designed as 30 cm,40cm and 50 cm,and the climbing height was designed as 20 m,40m and 60 m.The Biovision surface electromyography was used to collect surface EMG signals.The Borg,s Rating of Perceived Exertion(Borg,s RPE)was used to evaluate subjective fatigue.The Borg subjective fatigue of subjects were evaluated when climbing height of20 m,40m and 60 m,and surface EMG signals were collected throughout the climbing process.The time interval between the two experiments at least 24 hours.The one-way ANOVA and the LSD test were used to compare the differences of sueface EMG signals.The simple linear regression and the jointed EMG amplitude and spectrum(JASA)analysis were used to evaluate muscle fatigue.Results1.The basic situation among operation and maintenance personnel of power supply enterprise: A total of 1433 subjects were investigated,1343 valid questionnaires were recovered and effective recovery rate was 93.72% in this study.There were 1158 males(86.22%)and 185 females(13.78%).The average length of service was 11.00(5.00,21.00)years,and the average age was 39.42±9.89 years.2.The prevalence of WMSDs among operation and maintenance personnel of power supply enterprise: The total prevalence of WMSDs in this survey was 81.5%.The prevalence of WMSDs in 9 parts of the body which ranged from high to low were neck(66.0%),waist(56.1%),shoulder(54.1%),back(41.3%),knee(37.2%),wrist(26.7%),ankle foot(21.9%),elbow(16.6%)and hip(15.3%).3.The influencing factors of WMSD among operation and maintenance personnel of power supply enterprise:(1)Risk factors of neck WMSDs: often or very often sitting in a long time(OR=1.949),sometimes working in uncomfortable body position(OR=1.689),often or very often working in uncomfortable body position(OR=2.373),keeping the neck slightly forward in a long time(OR=1.303),keeping the knee bent in a long time(OR=1.583),doing the same work every day(OR=1.713)and the departmentor or team staff shortages(OR=1.563);physical exercise(OR=0.635)was its protective factor.(2)Risk factors of waist WMSDs: age(OR values of 30-years,40-years and 50-years were1.546,1.523 and 1.512,respectively),often or very often working in uncomfortable body position(OR=1.668),keeping the neck slightly forward in a long time(OR=1.310),keeping the neck back in a long time(OR=1.509),keeping the ankle/foot in unnatural bent in a long time(OR=1.761),moving or lifting weights frequently(OR=1.553),the head doing the same movement multiple times within one minute(OR=1.852),the lower limbs and ankles doing the same movement multiple times within one minute(OR=1.651),sometimes slip soles or fall(OR=1.460)and the departmentor or team staff shortages(OR=2.583);physical exercise(OR=0.593)was its protective factor.(3)Risk factors of shoulder WMSDs: female(OR=1.627),age(OR values of 30-years,40-years and 50-years were 1.668,1.843 and 2.312,respectively),length of service(OR values of 10-years and 20-years were 1.576 and 1.628,respectively),smoking(OR=1.344),often or very often sitting in a long time(OR=1.718),sometimes working in uncomfortable body position(OR=1.555),often or very often working in uncomfortable body position(OR=1.995),keeping the neck slightly forward in a long time(OR=1.557),keeping the elbow bent in a long time(OR=1.404),arm often raised above shoulder(OR=1.572),posture discomfort so that not with gusto(OR=1.611),the departmentor or team staff shortages(OR=1.837);physical exercise(OR=0.708)was its protective factor.(4)Risk factors of back WMSDs: sometimes working in uncomfortable body position(OR=1.398),often or very often working in uncomfortable body position(OR=2.201),keeping the neck slightly forward in a long time(OR=1.504),keeping the elbow bent in a long time(OR=1.343),doing the same work every day(OR=1.413)and the departmentor or team staff shortages(OR=1.446);physical exercise(OR=0.607)and taking turns with colleagues in work(OR=0.741)were its protective factor.(5)Risk factors of knee WMSDs: age(OR values of 30-years,40-years and 50-years were 1.727,2.036 and 2.905,respectively),overweight(24≤BMI<28)(OR=1.513),obesity(BMI≥28)(OR=1.617),sometimes working in uncomfortable body position(OR=1.699),often or very often working in uncomfortable body position(OR=1.772),keeping the neck back in a long time(OR=1.762),frequently repeated bent the knee(OR=2.035),the knee doing the same movement multiple times within one minute(OR=1.572),sometimes slip soles or fall(OR=1.650)and the departmentor or team staff shortages(OR=2.142).(6)Risk factors of wrist WMSDs: often or very often working in uncomfortable body position(OR=1.638),arm often raised above shoulder(OR=1.663),keeping the ankle/foot in unnatural bent in a long time(OR=1.957),frequently repeated bent the knee(OR=1.555),the upper arm/finger doing the same movement multiple times within one minute(OR=1.542),the head doing the same movement multiple times within one minute(OR=1.415),doing the same work every day(OR=1.583),the departmentor or team staff shortages(OR=1.575)and need for shifts(OR=1.373).(7)Risk factors of ankle foot WMSDs: length of service(OR values of 10-years and 20-years were 1.437 and 1.722,respectively),overweight(24≤BMI<28)(OR=1.920),obesity(BMI≥28)(OR=2.837),often or very often working in uncomfortable body position(OR=1.820),keeping the ankle/foot in unnatural bent in a long time(OR=1.975),the head doing the same movement multiple times within one minute(OR=1.487),doing the same work every day(OR=1.657)and the departmentor or team staff shortages(OR=1.915);physical exercise(OR=0.679)was its protective factor.(8)Risk factors of elbow WMSDs: age(OR values of 40-years and 50-years were 3.216 and 6.162,respectively),length of service(OR value of 10-years was 2.014),often or very often working in uncomfortable body position(OR=2.224),keeping the neck largely forward in a long time(OR=1.688),keeping the ankle/foot in unnatural bent in a long time(OR=2.104)and need for shifts(OR=1.430).(9)Risk factors of hip WMSDs: age(OR value of 50-years was 2.109),sometimes working in uncomfortable body position(OR=1.573),often or very often working in uncomfortable body position(OR=2.369),keeping the back slightly bent in a long time(OR=1.529),keeping the back largely bent in a long time(OR=1.806),keeping the neck largely forward in a long time(OR=1.535),arm often raised above shoulder(OR=2.150),keeping the ankle/foot in unnatural bent in a long time(OR=1.721),sometimes slip soles or fall(OR=1.760),doing the same work every day(OR=1.644)and work tasks change with the seasons(OR=1.494).4.The basic situation among subjects: A total of 10 male volunteers were recruited in this study.The average age was 24.60±1.35 years,the average height was 176.61±6.01 cm,the average weight was72.65±11.44 kg and the average BMI was 23.23±3.18 kg/m2.5.The subjective fatigue among subjects:(1)The spacing of foot nails of pylons was 30 cm,the Borg scale scores of climbing 20 m,40m and 60 m were 11.70±1.57,14.80±1.55 and 17.50±1.84,respectively.The subjects climb height higher,and the level of subjective fatigue higher(P<0.05).(2)The spacing of foot nails of pylons was 40 cm,the Borg scale scores of climbing 20 m,40m and 60 m were 11.90±1.45,15.30±1.49 and 17.40±1.51,respectively.The subjects climb height higher,and the level of subjective fatigue higher(P<0.05).(3)The spacing of foot nails of pylons was 50 cm,the Borg scale scores of climbing 20 m,40m and 60 m were 12.20±0.79,15.40±1.58 and17.40±1.78,respectively.The subjects climb height higher,and the level of subjective fatigue higher(P<0.05).6.The comparison of EMG indexes MVE%,MF and MPF among subjects:(1)Climbing height of 20 m,the MVE%,MF and MPF among subjects were different in 4,4 and 5 muscles between different spacing of foot nails.The MVE% of the right erector spinae,left rectus femoris and right rectus femoris were the lowest when the spacing of foot nails was 40cm(P<0.05).The MF of the left rectus femoris and right rectus femoris were the lowest when the spacing of foot nails was40cm(P<0.05).The MPF of the left rectus femoris,right rectus femoris,left gastrocnemius and right gastrocnemius were the lowest when the spacing of foot nails was 40cm(P<0.05).(2)Climbing height of 40 m,the MVE%,MF and MPF among subjects were different in 8,4 and 5muscles between different spacing of foot nails.The MVE% of the left trapezius,right trapezius,right erector spinae,left rectus femoris,right rectus femoris and left gastrocnemius were the lowest when the spacing of foot nails was 30cm(P<0.05).The MF of the right trapezius and right gastrocnemius were the lowest when the spacing of foot nails was30cm(P<0.05).The MPF of the left trapezius,left rectus femoris,left gastrocnemius and right gastrocnemius were the lowest when the spacing of foot nails was 30cm(P<0.05).(3)Climbing height of 60 m,the MVE%,MF and MPF among subjects were different in 6,6 and 6 muscles between different spacing of foot nails.The MVE% of the left rectus femoris,right rectus femoris,right gastrocnemius,left erector spinae and right erector spinae were the lowest when the spacing of foot nails was30cm(P<0.05).The MF of the left trapezius,right trapezius,left rectus femoris and right rectus femoris were the lowest when the spacing of foot nails was 30cm(P<0.05).The MPF of the left rectus femoris,right rectus femoris,left gastrocnemius and right gastrocnemius were the lowest when the spacing of foot nails was 30cm(P<0.05).7.JASA analysis of muscle fatigue among subjects:(1)Climbing height of 20 m,under the condition of 30 cm,40cm and 50 cm of the spacing of foot nails,the subjects showed 3,3 and 4 muscles of fatigue,respectively.(2)Climbing height of 40 m,under the condition of 30 cm,40cm and 50 cm of the spacing of foot nails,the subjects showed 4,5 and6 muscles of fatigue,respectively.(3)Climbing height of 60 m,under the condition of 30 cm,40cm and 50 cm of the spacing of foot nails,the subjects showed 5,7 and 7 muscles of fatigue,respectively.Conclusions1.The prevalence of WMSDs among operation and maintenance personnel of power supply enterprises is 81.5%,and the neck,waist,shoulder and back are the most commonly affected part of the body.2.The risk factors of WMSDs among operation and maintenance personnel of power supply enterprises involve individual factors,static loads,dynamic loads,physical loads,repetitive operations,ergonomic environment and labor organization;physical exercise and taking turns with colleagues in work are protective factor.3.The left rectus femoris and right rectus femoris are most seriously injured muscle group of climbing work,followed by the left gastrocnemius and right gastrocnemius.The left trapezius,right trapezius,left erector spinae and right erector spinae are slightly injured.4.The adverse ergonomic factors of climbing work include the height of climbing and the spacing of foot nails.The height of pylons is20 m,the spacing of foot nails of 30 cm or 40 cm is the most suitable.The height of pylons are 40 m and 60 m,the spacing of foot nails of 30 cm is the most suitable.It is recommended that the power supply enterprises design the spacing of the foot nails based on the different heights of the pylons.