Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Muscles
Biomechanics Test 2
| Question | Answer |
|---|---|
| Trigger Point | Areas in muscle that are hot spots for nerve pain, areas of high tension along the nerve. |
| Musculotendinous Unit (Mechanical perspective) | The contractile component (muscle fiber) runs parallel to the parallel elastic component (membranes) and connect to the series elastic component (tendons) |
| Behavioral Properties of Musculotendinous unit | Extensibility; ability to be stretched or increase in length (applies to ALL soft tissue sxs) Elasticity; ability to return to normal resting length following a stretch. |
| Two components of elasticity | Parallel Elastic Component, Series Elastic Component |
| Stretch-Shortening Cycle | eccentric contraction (as muscle is actively stretched) followed immediately by concentric contraction. |
| Irritability | Ability to respond to a stimulus. |
| Parallel Elastic Component | Passive elasticity derived from the muscle membranes (muscle fibers) |
| Series Elastic Component | Passive elasticity derived from the tendons when a tensed muscle is stretched. (More explosive athletes have stiffer tendons) |
| Ability to Develop Tension | The contractile component of a muscle function. |
| Components of Muscle FIber | Sarcolemma (plasma membrane) filled with sarcoplasm (cytoplasm) |
| Muscle Fiber Length | Some muscle fibers can run the entire length of the muscle and others are shorter. |
| Muscle Fiber Growth | Fibers grow in length and diameter from birth to adulthood. |
| How can muscle fiber diameter be increased | Through resistance training |
| Basic sxl unit of muscle fiber | sarcomere; A bands Dark with myosin surrounded by actin |
| Motor Unit | Single motor neuron and all of the fibers it innervates; functional unit of neuromuscular system. |
| Fast twitch vs Slow Twitch | Fast Twitch muscle fibers reach peak tension and relax more quickly than slow twitch. Peak tension is greater for fast twitch. |
| Two organizations of muscle fibers | Pennate: short fibers attach to one or more tendons within the muscle (gastrocs) Parallel: fibers roughly parallel to longitudinal axis of muscle. |
| Angle of pennation | Increases as tension in the muscle fibers increases, allowing the muscles to withstand larger loads |
| Motor Unit Recruitment | Slow twitch muscles recruited first, increased duration, speed, or force causes increased recruitment of fast twitch muscles with progressively higher thresholds. |
| 3 types of contractions | Concentric: Shortening, Eccentric: Lengthening, Isometric: no change in length. |
| Agonist | acts to cause a movement |
| Antagonist | acts to slow or stop a movement |
| Stabelizer | acts to stabilize a body part against some other force |
| Neutralizer | counteracts an undesired movement caused by the agonist |
| Two disadvantages of muscles that cross two joints | active insufficiency (failure to produce force when slack) and passive insufficiency (decreased range of motion at joint when fully stretched) |
| Example active insufficiency | difficulty to forming a fist when wrist is flexed (failure to produce force when slack) |
| Example of passive insufficiency | decreased range of motion when fingers are extended (decreased rom at joint when muscle is fully stretched) |
| Force, velocity relationship | as force load decreases, velocity increases. When force is negligible, muscle contracts with maximum velocity. |
| Isometric Maximum | When force has increased to the point where velocity slows to 0. |
| electromechanical delay | delay between arrival of stimulus and contraction of muscle (milliseconds) |
| Measurement of muscular strength | Torque; the amount of torque, or force that has a tendency to rotate and object, a muscle group can generate at a given joint. |
| Where is the component of the muscle that produces torque attached | perpendicular to the attached bone at the joint. |
| Factors that influence muscle strength | Muscle Cross sectional area (# of myofibrils and training state of myofibrils), Moment arms of muscle (attachment distance and angle) |
| How to calculate muscle strength | Muscle Torque (Tm) = Muscle Force (Fm) X Muscle moment arm; distance from the joint center (D) |
| When is mechanical advantage at biceps brachii maximized | when the joint angle is at 90, all the muscle force is going to the rotation of the forearm at the joint |
| Muscular Power (3 definitions) | 1) product of muscular force and velocity of muscle shortening 2) Rate at which torque is generated at a joint. 3) the product of net torque and angular velocity at a joint |
| Muscular endurance | Ability of a muscle to produce tension over time |
| Affects of Muscle tempurature | neuromuscular function speed increases, higher maximum isometric load, higher maximum velocity. |
Created by:
hannahprt