KIN 2504 Chapter : Kin 2504
15 Mar 2019
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Myofibrils (strands that make up muscle fiber) are made up of actin and myosin. Slow- twitch: contract slowly over long period of time, require oxygen for contraction. Fast- twitch: contract quickly and forcefully, but they fatigue quickly. Isotonic: characterized by consistent by muscle tension as contraction proceed, results in the movement of a body part: concentric- involves overall muscle shortening, contraction (bicep, eccentric- lengthening of a muscle (tricep) Isometric: characterized by consistent muscle length throughout contraction with no visible movement of body parts (holding your arm straight out in front) Isokinetic: consistent contraction speed within a moving body part (machine required) Motor unit- nerve and muscle fibers which contract. Atrophy- decrease of muscle cross section area and results in a decrease of strength. Weight machines- good for people who want to isolate a muscle. Free weights- more advanced approach to weight training because of the range of motion, promote use of postural and stabilizer muscles.
