At approximately 110-120% of its resting length, a sarcomere:
exerts its greatest tension because at this length the greatest number of myosin can connect with actin filaments.
Match the classification of muscle contraction at the single fiber/motor unit level (first letter) with corresponding intact human classification (second letter
E - A; B - C; D - F
The most likely site and cause of muscular fatigue are:
within the contractile mechanism primarily because of metabolic factors.
The most probable cause for immediate (during and right after) localized soreness of a muscle is:
increase in metabolites (i.e. lactic acid)
The most probable cause(s) for delayed (24 to 48 hrs) muscle soreness is:
rupture/tear of connective tissue and muscle fiber spasm
Which is most likely to cause muscle soreness?
negative workout where a spotter assists with the lifting phase but not the lowering phase.
The influence of muscle fiber type on the force-velocity curve relationship shows that:
the peak torque (force x lever arm or movement arm distance) generated by a muscle decreases with increasing velocities of movement regardless of the fiber type distribution.
Nautilus equipment
compensates for variations in muscular force at different joint angles by changing the lever arm such that the muscle exerts near maximal force over the full range of motion.
What contractions develops the greatest force?
eccentric dynamic
An individual was tested with the following results:
Angle pull (E) 40 80 120 160 200
Pounds pulled (max lb.) 40 60 90 65 60
What is the greatest amount of weight that can be lifted (isotonically, concentrically) over the full range of motion for this ind
40
What is not a cause of age-related decline in strength?
decrease in the amount of stored ATP
____________ are used to measure static strength.
Dynamometers
What is not a reason to assess muscular strength, endurance, and power that a muscle is capable of generating?
to determine the amount of functional LBM in a person with a chronic muscular disease
What is an example of relative muscular strength?
1 push-up
What is an example of a test for relative muscular power?
Vertical jump
The integrated model which explains delayed onset muscle soreness (DOMS) says that DOMS is related to an accumulation of which of the following:
calcium
The probable explanation for the difference in energy cost between positive and negative work is:
engthening involves less cycling of the cross-bridges and hence less energy.
What would cause an increase in force production?
Recruiting more motor units
Recruiting larger motor units
Recruiting motor units at a faster rate
Compared muscle strength to women, men:
Men have greater muscle strength
Decreased muscle strength that occurs with advanced age is the result of:
decreased muscle mass
Consider the situation of throwing a ball. The fastest arm and shoulder contractions could be achieved when throwing
tennis ball
Asking a subject to perform as many push-ups as they can with good form would test the subject's ___.
muscular endurance
Muscle tension
force developed when a contracting muscle acts on an object.
Load
Force exerted on the muscle
Contraction
Tension-producing process of the contractile elements within muscle.
Torque
The capability of a force to produce rotation of a limb around a joint.
Isotonic Contraction
A muscle fiber contraction in which the tension generated by the muscle fiber is constant through the range of motion.
Dynamic contraction
A muscle contraction in which the force exerted varies as the muscle shortens to accomodate change in muscle length and/or joint angle throughout the range of motion while moving a constant external load.
Concentric Contraction
A dynamic muscle contraction that produces tension during shortening.
Eccentric Contraction
A dynamic muscle contraction that produces tension (force) while lengthening.
Isokinetic contraction
A muscle fiber contraction in which the velocity of the contraction is kept constant.
Isokinematic Contraction
A muscle contraction in which the rate of limb displacement or joint rotation is held constant with the use of specialized equipment.
Static Contraction
A muscle contraction that produces an increase in muscle tension but does not cause meaningful limb displacement or joint displacement and therefore does not result in movement of the skeleton.
Delayed-onset muscle soreness (DOMS)
is a condition characterized by muscle tenderness, pain on palpitation, and mechanical stiffness that appears approximently 8 hours after exercise, increase and peaks over the next 24-48 hours, and usually subsides within 96 hours.
Strength
The ability of a muscle or muscle group to exert maximal force against a resistance in a single repetition.
Muscular Endurance
The ability of a muscle or muscle group to repeatedly exert force against a resistance.
Power
The amount of work done per unit of time; the product of force and velocity; the ability to exert force quickly.
Electromyography (EMG)
The measurement of the neural or electrical activity that brings about muscle contractions.