Chapter 7: Lesson 5 Flashcards
Force
An influence applied by one object to another, which results in an acceleration or deceleration of the second object.
Length-tension relationship
The resting length of a muscle and the tension the muscle can produce at this resting length.
Resting length
The length of a muscle when it is not actively contracting or being stretched.
Actin
The thin, stringlike, myofilament that acts along with myosin to produce muscular contraction.
Myosin
The thick myofilament that acts along with actin to produce muscular contraction.
Sarcomere
The structural unit of a myofibril composed of actin and myosin filaments between two Z-lines.
Muscle balance
When all muscles surrounding a joint have optimal length-tension relationships, allowing the joint to rest in a neutral position.
Altered length-tension relationship
When a muscle’s resting length is too short or too long, reducing the amount of force it can produce.
Reciprocal inhibition
When an agonist receives a signal to contract, its functional antagonist also receives an inhibitory signal allowing it to lengthen.
Altered reciprocal inhibition
Occurs when an overactive agonist muscle decreases the neural drive to its functional antagonist.
Muscle imbalance
When muscles on each side of a joint have altered length-tension relationships.
Neutral position
The optimal resting position of a joint that allows it to function efficiently through its entire normal range of motion.
Stretch Shortening Cycle
Loading of a muscle eccentrically to prepare it for a rapid concentric contraction.
Series elastic component
Springlike noncontractile component of muscle and tendon that stores elastic energy.
Amortization phase
The transition from eccentric loading to concentric unloading during the stretch-shortening cycle.
