Impact of grinding technology on bilateral asymmetry in muscle activity of the upper limb

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F16%3A10331380" target="_blank" >RIV/00216208:11310/16:10331380 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.jas.2016.07.001" target="_blank" >http://dx.doi.org/10.1016/j.jas.2016.07.001</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jas.2016.07.001" target="_blank" >10.1016/j.jas.2016.07.001</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Impact of grinding technology on bilateral asymmetry in muscle activity of the upper limb

Popis výsledku v původním jazyce

This paper proposes and tests the idea that a major change in technology associated with the grinding of cereals may account for changes in asymmetry in the upper arms of women in the Neolithic through Iron Age across a large area of Europe. It has been observed that bilateral asymmetry in humeral strength (i.e., polar section modulus) decreased to near zero in early agricultural females, but increased again during the Iron Age. These changes in asymmetry in females have been interpreted as the direct consequence of the adoption of the saddle quern at the start of the Neolithic and its subsequent replacement by the rotary quern in the Iron Age. To test the impact of these alternative cereal grinding methods, we tested the efficiency of saddle and rotary quern grinding with 16 female volunteers and the effect of grinding on muscle activity of the upper limb with 20 female volunteers. We used electromyography to measure muscle activity in the pectoralis, deltoideus, infraspinatus and triceps muscles and adjusted muscle activity for efficiency and muscle size. Saddle quern grinding was 4.3 times less efficient than rotary quern grinding and produced a significantly higher amount of coarse- and middle-grained flour but a significantly lower amount of very fine grained flour than rotary quern grinding. Saddle quern grinding showed symmetrical muscle activity in all four studied muscles, whereas rotary quern grinding yielded consistent directional asymmetry in a majority of muscles even during bimanual rotation. Our results support the view that saddle quern grinding may have played a major role in the decrease in directional asymmetry in humeral strength in early agricultural females and that the adoption of the rotary quern during the Iron Age may have increased humeral directional asymmetry mainly because of increased asymmetrical loading and the reduced time needed for grinding in favor of other manipulative tasks.

Název v anglickém jazyce

Impact of grinding technology on bilateral asymmetry in muscle activity of the upper limb

Popis výsledku anglicky

This paper proposes and tests the idea that a major change in technology associated with the grinding of cereals may account for changes in asymmetry in the upper arms of women in the Neolithic through Iron Age across a large area of Europe. It has been observed that bilateral asymmetry in humeral strength (i.e., polar section modulus) decreased to near zero in early agricultural females, but increased again during the Iron Age. These changes in asymmetry in females have been interpreted as the direct consequence of the adoption of the saddle quern at the start of the Neolithic and its subsequent replacement by the rotary quern in the Iron Age. To test the impact of these alternative cereal grinding methods, we tested the efficiency of saddle and rotary quern grinding with 16 female volunteers and the effect of grinding on muscle activity of the upper limb with 20 female volunteers. We used electromyography to measure muscle activity in the pectoralis, deltoideus, infraspinatus and triceps muscles and adjusted muscle activity for efficiency and muscle size. Saddle quern grinding was 4.3 times less efficient than rotary quern grinding and produced a significantly higher amount of coarse- and middle-grained flour but a significantly lower amount of very fine grained flour than rotary quern grinding. Saddle quern grinding showed symmetrical muscle activity in all four studied muscles, whereas rotary quern grinding yielded consistent directional asymmetry in a majority of muscles even during bimanual rotation. Our results support the view that saddle quern grinding may have played a major role in the decrease in directional asymmetry in humeral strength in early agricultural females and that the adoption of the rotary quern during the Iron Age may have increased humeral directional asymmetry mainly because of increased asymmetrical loading and the reduced time needed for grinding in favor of other manipulative tasks.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

AC - Archeologie, antropologie, etnologie

OECD FORD obor

—

Projekt

<a href="/cs/project/GA14-22823S" target="_blank" >GA14-22823S: Lidé na sklonku Velké Moravy: bioarcheologická a tafonomická analýza nového pohřebiště u rotundy na severovýchodním předhradí Pohanska u Břeclavi</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Archaeological Science

ISSN

0305-4403

e-ISSN

—

Svazek periodika

72

Číslo periodika v rámci svazku

August

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

15

Strana od-do

142-156

Kód UT WoS článku

000382350100011

EID výsledku v databázi Scopus

—