摘要
Muscleactionsaretypicallydividedinto3categories：concentric,isometric,andeccentric.Anactivemusclethatisshorteningandproducespositivemechanicalworkissaidtoworkconcentrically;anactivemusclethatisnotchangingitslength,andthusdoesnotproducenetwork,issaidtoworkisometrically;andanactivemusclethatiselongatedbyexternalforces,andthusabsorbswork,orproducesnegativework,issaidtoworkeccentrically．1
出版日期
2018年03月13日（中国期刊网平台首次上网日期，不代表论文的发表时间）
