Only $35.99/year

Exercise Physiology part 1

Terms in this set (46)

Series elastic elements: Force transmission to bone via tendon
Contraction types:
1. Concentric: muscle shortens when it contracts and does work (muscle tension>=load). (Lifting weight) Shortening of sarcomeres
-force developed by the cross-bridges exceeds the external load, and the sarcomeres shorten
-muscle performs positive work (force × distance) and produces power (work/time)
-peak power acheived at relatively moderate loads and velocities
Ex: Picking up a coffee, winning at arm wrestling

2.Isometric: length of muscle does not change, but amount of tension increases. Shortening of sarcomeres with no change to external length of muscle. external length of a muscle (or muscle fiber) is held constant, the sarcomeres shorten at the expense of stretching the series elastic elements.
-external length held constant, sarcomeres shorten, series elastic elements stretch
Ex: Holding your coffee, start of arm wrestle

3.Eccentric: Isotonic contractions in which tension is maintained in a muscle but opposing resistance is great enough to cause muscle to increase in length. Lengthening of sarcomeres (while generating force) and increasing joint angle
-force developed by the cross-bridges is less than the imposed load, and the sarcomeres lengthen, muscle performs negative work, thus providing a brake to decelerate the applied force being applied, and absorbs power. Less active tension, more passive tension and thusly total tension
Ex: Attempting to hold your coffee cup while someone pours lead into the cup, losing at arm wrestling

-Incorporate size principle + rate coding: IE picking up a tissue box full of lead
-Parallel elastic elements - extracellular matrix, connective tissue