Chalk 的迷思

2007-10-27, 18:53

使用碳酸鎂粉(一般稱為Chalk), 已經是攀岩者不可或缺的工具.

但是這一篇學術研究的文章, 結果甚是有趣. Chalk 的使用反而會減少手部和把手點之間的摩擦力.

我是無意間看到這篇研究, 基於著作權及智慧財產權規定, 我不能post在這邊,

有興趣的人可以去找這篇文章:

Li, F.-X.,Margetts, S., & Fowler, I. (2001). Use of 'chalk' in rock climbing:Sin qua non or myth? Journal of Sports Sciences. 19 (6). 427-432.

或許有很多新創意的台灣攀岩者能發展出比Chalk更有效的產品喔!

在澳洲手指韌帶斷掉即將要開刀的人留

2007-10-28, 00:59

下載pdf檔(第二個連結可下載檔案): http://scholar.google.com/scholar?hl...47720762522570

Titre du document / Document title

Use of 'chalk' in rock climbing: sine qua non or myth?Auteur(s) / Author(s)

LI F.-X.⁽¹⁾ ; MARGETTS S.⁽¹⁾ ; FOWLER I.⁽¹⁾ ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾Perception Action Laboratory, School of Sport and Exercise Sciences, The University of Birmingham, Edgbaston, Birmingham BIS 2TT, ROYAUME-UNI
Résumé / Abstract

Magnesium carbonate, or'chalk', is used by rock climbers to dry their hands to increase the coefficient of friction, thereby improving the grip of the holds. To date, no scientific research supports this practice; indeed, some evidence suggests that magnesium carbonate could decrease the coefficient of friction. Fifteen participants were asked to apply a force with the tip of their fingers to hold a flattened rock (normal force), while a tangential force pulled the rock away. The coefficient of friction - that is, the ratio between the tangential force (pulling the rock) and the normal force (applied by the participants) - was calculated. Coating (chalk vs no chalk), dampness (water vs no water) and rock (sandstone, granite and slate) were manipulated. The results showed that chalk decreased the coefficient of friction. Sandstone was found to be less slippery than granite and slate. Finally, water had no significant effect on the coefficient of friction. The counter-intuitive effect of chalk appears to be caused by two independent factors. First, magnesium carbonate dries the skin, decreasing its compliance and hence reducing the coefficient of friction. Secondly, magnesium carbonate creates a slippery granular layer. We conclude that, to improve the coefficient of friction in rock climbing, an effort should be made to remove all particles of chalk; alternative methods for drying the fingers are preferable.Revue / Journal Title

Journal of sports sciences (J. sports sci.) ISSN 0264-0414 Source / Source

2001, vol. 19, n^o6, pp. 427-432 (24 ref.)Langue / Language

Anglais
Editeur / Publisher

Taylor and Francis , London, ROYAUME-UNI (1983) (Revue)
Mots-clés anglais / English Keywords

Rock climbing ; Mountaineering ; Force ; Finger ; Friction coefficient ; Magnesite ; Magnesium Carbonates ; Human ; Sport ; Hand ; Lower limb ; Mots-clés français / French Keywords

Escalade ; Alpinisme ; Force ; Doigt ; Coefficient frottement ; Magnésite ; Magnésium Carbonate ; Homme ; Sport ; Main ; Membre inférieur ; Mots-clés espagnols / Spanish Keywords

Escalada ; Alpinismo ; Fuerza ; Dedo ; Coeficiente roce ; Magnesita ; Magnesio Carbonato ; Hombre ; Deporte ; Mano ; Miembro inferior ; Localisation / Location

INIST-CNRS, Cote INIST : 20279, 35400009541997.0050

2007-10-27, 18:53	#1
pyw 中度攀言者註冊日期: 2003-11 文章: 116	Chalk 的迷思使用碳酸鎂粉(一般稱為Chalk), 已經是攀岩者不可或缺的工具. 但是這一篇學術研究的文章, 結果甚是有趣. Chalk 的使用反而會減少手部和把手點之間的摩擦力. 我是無意間看到這篇研究, 基於著作權及智慧財產權規定, 我不能post在這邊, 有興趣的人可以去找這篇文章: Li, F.-X.,Margetts, S., & Fowler, I. (2001). Use of 'chalk' in rock climbing:Sin qua non or myth? Journal of Sports Sciences. 19 (6). 427-432. 或許有很多新創意的台灣攀岩者能發展出比Chalk更有效的產品喔! 在澳洲手指韌帶斷掉即將要開刀的人留 __________________ 王伯宇

2007-10-28, 00:59	#2
kevin 論壇管理員註冊日期: 2001-11 文章: 1042 部落格文章: 1	下載pdf檔(第二個連結可下載檔案): http://scholar.google.com/scholar?hl...47720762522570 Titre du document / Document title Use of 'chalk' in rock climbing: sine qua non or myth?Auteur(s) / Author(s) LI F.-X.⁽¹⁾ ; MARGETTS S.⁽¹⁾ ; FOWLER I.⁽¹⁾ ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s) ⁽¹⁾Perception Action Laboratory, School of Sport and Exercise Sciences, The University of Birmingham, Edgbaston, Birmingham BIS 2TT, ROYAUME-UNI Résumé / Abstract Magnesium carbonate, or'chalk', is used by rock climbers to dry their hands to increase the coefficient of friction, thereby improving the grip of the holds. To date, no scientific research supports this practice; indeed, some evidence suggests that magnesium carbonate could decrease the coefficient of friction. Fifteen participants were asked to apply a force with the tip of their fingers to hold a flattened rock (normal force), while a tangential force pulled the rock away. The coefficient of friction - that is, the ratio between the tangential force (pulling the rock) and the normal force (applied by the participants) - was calculated. Coating (chalk vs no chalk), dampness (water vs no water) and rock (sandstone, granite and slate) were manipulated. The results showed that chalk decreased the coefficient of friction. Sandstone was found to be less slippery than granite and slate. Finally, water had no significant effect on the coefficient of friction. The counter-intuitive effect of chalk appears to be caused by two independent factors. First, magnesium carbonate dries the skin, decreasing its compliance and hence reducing the coefficient of friction. Secondly, magnesium carbonate creates a slippery granular layer. We conclude that, to improve the coefficient of friction in rock climbing, an effort should be made to remove all particles of chalk; alternative methods for drying the fingers are preferable.Revue / Journal Title Journal of sports sciences (J. sports sci.) ISSN 0264-0414 Source / Source 2001, vol. 19, n^o6, pp. 427-432 (24 ref.)Langue / Language Anglais Editeur / Publisher Taylor and Francis , London, ROYAUME-UNI (1983) (Revue) Mots-clés anglais / English Keywords Rock climbing ; Mountaineering ; Force ; Finger ; Friction coefficient ; Magnesite ; Magnesium Carbonates ; Human ; Sport ; Hand ; Lower limb ; Mots-clés français / French Keywords Escalade ; Alpinisme ; Force ; Doigt ; Coefficient frottement ; Magnésite ; Magnésium Carbonate ; Homme ; Sport ; Main ; Membre inférieur ; Mots-clés espagnols / Spanish Keywords Escalada ; Alpinismo ; Fuerza ; Dedo ; Coeficiente roce ; Magnesita ; Magnesio Carbonato ; Hombre ; Deporte ; Mano ; Miembro inferior ; Localisation / Location INIST-CNRS, Cote INIST : 20279, 35400009541997.0050 __________________ 台灣攀岩資料庫

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