Ther Ex for Rehab Flashcards
Rehab…
prevents atrophy
restores strength, endurance, power
One muscle fiber is made up of many ______
myofibrils
One myofibril is made of ______ which lie in series with ________
sarcomeres; myofibrils
Myosin fibers are…
thicker
During contraction…
actin and myosin slide over one another
Z line
end of actin filaments
I band
action only that straddles the Z line
A band
runs length of myosin filament
H zone
only myosin filament w/ no overlap of actin
M line
very center of myosin in the H band
Sliding Filament Theory
myosin cross bridges flex- pull actin filaments toward the center of sarcomere
H zone becomes smaller and Z lines move toward center
Sarcomere length changes b/c actin and myosin fils slide over each other
Regulation of muscle contraction
the nervous system exerts control over motor activity by way of the motor unit
Ration of muscle fibers to motor units
the bigger the muscle the more units you have
Cross sectional area
muscles that are larger in cross-sectional area have larger numbers of sarcomeres in series
Angle of pennation
muscles with more pennation have greater cross sectional areas
strength
the maximal force that a muscle can develop in a single contraction
Functional strength is…
the ability of the neuromuscular system to produce, relax, and control forces during functional activities, in a smooth, coordinated manner
Power
Force x Distance/ Time
Endurance
the ability to perform low intensity, repetitive or sustain activites over a prolonged time
Isometric contractions
muscle contracting but holding at an angle
Isotonic contractions
Concentric
Eccentric
Length tension relationship
a muscles ability to generate tension depends on the position
- Peak force production is at or near mid range
- 90 degrees should be strongest; sometimes 45 is
Active insuffiencency
muscle is too short to generate tension
Passive insuffiencency
muscle is too long to generate force
