Wrist twisting strength of four year olds: Product packaging implications

Rohles, Frederick H.; Laviana, Joseph E.; Moldrup, Kelli L.

doi:10.1037/e574162012-024

Cited by 3 publications

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“…(Rohles et al, 1984) demonstrated torque obtained by clockwise and counterclockwise rotation was not significantly different.) The lids were given to the subjects in a different random order each day.…”

Section: Introductionmentioning

confidence: 92%

Knurls on Push and Turn Lids

Cranmer

Konz

1990

Proceedings of the Human Factors Society Annual Meeting

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This study investigated the effects of knurling on exertable torque on a "childprooff1 prescription lids; that is, where a llpush and turn" action is required. Twelve lids with the same height (12.7 mm) were used. knurling designs were evaluated for two lid diameters (32 mm and 54 mm): smooth lid, a lid with two levers, and lids with 7-8 knurls/cm, 4 knurls/cm, 2 knurls/cm and 1 knurl/cm. pushed and turned the 12 lids in a clockwise direction against a torque meter. The effects of gender, size, knurl design, and the interaction of gender and size were significant. females. Subjects exerted 200% more torque on the 54 mm lids than the 32 mm lids. The interaction of size and gender showed that increasing lid diameter was more advantageous for males than females. levers provided 54% more torque than the smooth lid for the 32 mm lid but only 21% more for the 54 mm lid. than the smooth lid. SixThe 35 male and 13 female subjects Males exerted 42% more torque thanThe lid with twoThe knurl designs gave 4-15% more torque INTRODUCTION

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Section: Introductionmentioning

confidence: 92%

Knurls on Push and Turn Lids

Cranmer

Konz

1990

Proceedings of the Human Factors Society Annual Meeting

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“…It is interesting to see from Peebles and Norris 35 that a mean value for opening torque exerted by male children under the age of 5 years (sample = 7) on a 45mm diameter lid is 0.81 (SD = 0.48), whereas Rohles et al 36 give a value of 0.8 Nm for the torque exerted by 4-year old children on a 35mm diameter screw top which is used on child-resistant bottles 37 . The 5 th percentile female value for the torque as given by the present study is 1.32 Nm, which is greater than that can be generated by male children under the age of 5 years.…”

Section: Wrist Twisting Strength Comparisonmentioning

confidence: 99%

Pinch grip, power grip and wrist twisting strengths of healthy older adults

Nayak

Queiroga²

2004

Gerontechnology

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Objectives of this cross-sectional study were to collect data on handgrip and wrist twisting strengths of healthy older adults and to arrive at regression equations that estimate pinch and power grip strengths of communitydwelling older adults in the United Kingdom. Methods. The study sample comprised 65 males and 85 females within the age range of 55 to 85 years. A strain-gauge hand-held dynamometer was used to measure various pinch and power grip strengths. A torque meter was used to measure wrist twisting strength. Results. The correlation between pinch grip and power grip strengths was high (r>0.65) resulting in a linear regression equation. A multiple regression equation was developed, with power grip strength as the dependent variable and age, hand area, and mid arm circumference as predictor variables. Conclusion. Knowing a relationship between pinch grip and power grip strengths, and an equation to calculate the power grip strength, designers of food packaging can estimate pinch strengths of healthy older individuals living in the community. A torque value of 1.3 Newton-metre, as calculated in this paper, can be recommended as a removal torque for opening child-resistant bottle tops.

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Jar Lids: Effect of Diameter, Gripping Materials and Knurling

Nagashima

Konz

1986

Proceedings of the Human Factors Society Annual Meeting

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In Exp. 1 , 10 female subjects each twisted six jar lids vs a torque meter with a bare hand, rubber gripper and a cotton cloth. The torques of 3.17 Nm f o r the 48 mm dia, 5.02 for the 67 mm dia, and 6.04 for the 86 mm dia lids differed significantly. Torques of 4.04 f o r the cotton cloth in the hand, 4.85 for the bare hand and 5.36 for the rubber gripper also varied significantly. The 4.66 Nm for non-knurled was not significantly different from the 4.84 for knurled.Exp. 2 replicated Exp. 1 with 5 of the 6 lids for 29 visitors to a University Open House. The results were compatible with Experiment 1. Torque exertable on a lid can be predicted well from grip strength, lid radius and the gripping material (rubber, bare hand o r cloth).

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Wrist twisting strength of four year olds: Product packaging implications

Cited by 3 publications

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Knurls on Push and Turn Lids

Knurls on Push and Turn Lids

Pinch grip, power grip and wrist twisting strengths of healthy older adults

Jar Lids: Effect of Diameter, Gripping Materials and Knurling

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