Description
Anatomical Kinesiology: HES 207
The Musculature:
∙ Fibers Continued:
Fiber Architecture
o Strap
o Fusiform
o Triangular
o Pennate
∙ Fiber Arrangements
LOA = Line of Action (pull)
o Goes in same direction as fiber
o Needs to offset from joint center
o Creates a moment arm We also discuss several other topics like How have humans evolved as part of the natural world, how have environmental changes affected human development?
Angle of Attachment
∙ Muscle Contractions
Concentric: Shortening occurs
o muscle contracts with greater force than resistance and shortens If you want to learn more check out How does the criminal justice system respond to crime?
Don't forget about the age old question of What does the thermodynamic variable mean?
Eccentric: Lengthening occurs
o muscle contracts with less resistance force less than resistance and lengthens
Isometric: No change in length
o muscle contracts but does not change length
Isotonic: Same force (tension)
Isokinetic: Same Speed
Passive:
o Lengthening
o Shortening
o When muscles on one side of a joint are active, the other side is passive
∙ Muscles Play Different Roles
We also discuss several other topics like Where is the genetic material contained in the nucleus?
Agonist: Prime Mover
Antagonist: Opposes the action of agonist Don't forget about the age old question of What is the meaning of population ecology?
Synergist: Perform or help agonist perform same motion Stabilizer: Prevents movement at a joint other than where motion is wanted
Neutralizer: Eliminates the undesired effect at joint of desired movement
∙ Muscle Force
Max Force (along line of action)
o Physiological Cross-Sectional Area (PCSA)
Larger cross-sectional area = more sarcomeres =
more muscle fibers
Perpendicular to muscle fibers If you want to learn more check out What is anton van leeuwenhoek's contribution to cell theory?
Accounts for all of the fibers
o Pennation Angle
Disadvantage: Limited distance of muscle travel
Force Modifiers
o Length (relative to resting length)
o Velocity of Shortening/ Lengthening
o Activation Level
o Others
Factors that Influence Force
o Temperature: Hot is better because the muscle and
tendons are more elastic
o Recent stretch history: Sarcomeres at optimal length
o Fatigue: Force production might go down, if lactate and hydrogen ion production is faster than the body can buffer causes that “burn”