11

Effects of different kinds of Effects of different kinds of arch support materials for arch support materials for

prolonged standingprolonged standing

Reporter : Chao-Yi ZhengReporter : Chao-Yi Zheng

Adviser : Sai-wei YangAdviser : Sai-wei Yang

Date: 2007/06/06Date: 2007/06/06

22

GuidelineGuideline

IntroductionIntroductionMotivation and purposeMotivation and purposeMaterial and methodMaterial and methodFlow chartFlow chart referencesreferences

33

introductionintroduction

Many occupations, such as assembly workers, require standing in one area for long periods of time.

Service trade workers in Taiwan had increased 54,000 since 1999 to 2002.

Standing time7.5 time, walking time3 time

44

fatigue and body discomfort

Interference with the venous return from thInterference with the venous return from the lower limbs to the heart, resulting in e lower limbs to the heart, resulting in tissutissue hypoxiae hypoxia

Interference with the venous return from thInterference with the venous return from the lower limbs to the heart, resulting in e lower limbs to the heart, resulting in oedoedemaema

Intervertebral disc stress from Intervertebral disc stress from excessive loexcessive lordosisrdosis

Stretching of ligamentsStretching of ligamentsMessing K, Kilbom A, Appl Ergon(2001)Messing K, Kilbom A, Appl Ergon(2001)

55

Shoe insolesShoe insoles

Shoe insoles are effective by decreasing sShoe insoles are effective by decreasing subjective pain and discomfort felt by the wubjective pain and discomfort felt by the worker in his natural work setting.orker in his natural work setting.

Shoe insoles are made from viscoelastic Shoe insoles are made from viscoelastic material have the best long-term ability to material have the best long-term ability to maintain a cushioning property.maintain a cushioning property.

(Pratt, 1990)(Pratt, 1990)

66

the arch support can reduce muscle fatigue in the calf and disperse arch pressure Chiu and Wang, Appl Ergon(2007)

The insole with maximal support to the foot have effect in decreasing low back pain. S.Shabat et al, Eur Spine J(2005)

The best shoe parameter combination conThe best shoe parameter combination consists in the EVA insole hardness is 36.8 sists in the EVA insole hardness is 36.8 Hsieh and Wu, 1998Hsieh and Wu, 1998

77

motivationmotivation

Insole with arch support can decrease Insole with arch support can decrease fatigue and body discomfort, but the best fatigue and body discomfort, but the best property for arch material is not clear.property for arch material is not clear.

88

purposepurpose

Compare the effects of Compare the effects of cork arch insolecork arch insole, , EVA arch insoleEVA arch insole, and , and rubber archrubber arch insole insole on prolonged standing workers’ on prolonged standing workers’ perceptions of discomfort and fatigueperceptions of discomfort and fatigue, , posture stabilityposture stability, , objective muscle fatigueobjective muscle fatigue

99

Material and method Material and method

Subject sSubject sExperimental conditionsExperimental conditionsquestionnaire questionnaire InstrumentsInstrumentsprocedureprocedure

1010

subjectssubjects

30 semiconductor workers30 semiconductor workers Inclusion criteriaInclusion criteria

Standing more than 4 hours in the workStanding more than 4 hours in the workWith no history of lower-extremity or back With no history of lower-extremity or back

problemsproblems

1111

Experimental conditionExperimental condition

Insole with arch made of corkInsole with arch made of cork insole with arch made of EVAinsole with arch made of EVA insole with arch made of rubberinsole with arch made of rubberShoe: workers they wore originally shoesShoe: workers they wore originally shoes

1212

instrumentsinstruments

objectiveobjectiveEMG( anterior tibialis m., gastrocnemius EMG( anterior tibialis m., gastrocnemius

m., erector spinae m.)m., erector spinae m.)Rs scan (COP of tandom gait with eye cloRs scan (COP of tandom gait with eye clo

se)se)

SubjectiveSubjectivequestionnairequestionnaire

1313

EMGEMG

anterior tibialis m., gastrocnemius m., erector spianterior tibialis m., gastrocnemius m., erector spinae m.nae m.

75% maximum voluntary contraction75% maximum voluntary contraction keep 5 s keep 5 secec

Record EMG signal in 75% maximum voluntary Record EMG signal in 75% maximum voluntary contractioncontraction

Kim J Y, Stuart-Buttle C, and Marras W S. , Appl Ergon(1994)

1414

questionnairequestionnaire

General fatigueGeneral fatigue Leg fatigueLeg fatigue Upper-back discomfortUpper-back discomfort Lower-back discomfortLower-back discomfort Knee discomfortKnee discomfort Lower-leg discomfortLower-leg discomfort Ankle discomfortAnkle discomfort Foot discomfortFoot discomfort

King PM. Appl Ergon(2002)King PM. Appl Ergon(2002)

1515

Basic data collection

Before work data collection

After work Data collection

Cork arch

EVA arch rubber arch

Statistics analysis

Work conditions

1616

procedureprocedure

Before workBefore work After workAfter work

questionnairequestionnaire questionnairequestionnaire

EMGEMG EMGEMG

COPCOP COPCOP

1717

Three standing conditions, each condition Three standing conditions, each condition for a weekfor a week

Take experiments on Monday, WednesdaTake experiments on Monday, Wednesday, and Friday before and after worky, and Friday before and after work

1818

referencesreferences Kim J Y, Stuart-Buttle C, and Marras W S. The effects of Kim J Y, Stuart-Buttle C, and Marras W S. The effects of

mats on back and leg fatigue. Applied Ergonomics 1994, mats on back and leg fatigue. Applied Ergonomics 1994, 25(1) 29-34.25(1) 29-34.

King PM. A comparison of the effects of floor mats and shKing PM. A comparison of the effects of floor mats and shoe in-soles on standing fatigue. Applied Ergonomics 2002 oe in-soles on standing fatigue. Applied Ergonomics 2002 Sep;33(5):477-84. Sep;33(5):477-84.

Zander JE, King PM, Ezenwa BN. Influence of flooring coZander JE, King PM, Ezenwa BN. Influence of flooring conditions on lower leg volume following prolonged standing.nditions on lower leg volume following prolonged standing. International Journal of Industrial Ergonomics 34(2004)27 International Journal of Industrial Ergonomics 34(2004)279-288.9-288.

Messing K, Kilbom A. Standing and very slow walking: fooMessing K, Kilbom A. Standing and very slow walking: foot pain-pressure threshold subjective pain experience and t pain-pressure threshold subjective pain experience and work activity. Applied Ergonomics 32(2001), 81-90.work activity. Applied Ergonomics 32(2001), 81-90.

Cham R. and Redfern M.S.Cham R. and Redfern M.S. Effect of Flooring on Standing Effect of Flooring on Standing Comfort and Fatigue. Human Factor 43(3), 381-391.Comfort and Fatigue. Human Factor 43(3), 381-391.

1919

Thank you for your attentionThank you for your attention