Exam 3

What factors affect muscular strength?

-Distance between muscle attachments to bone & joint center. Angle - of the muscle s attachments to the bone.

What are the three factors that affect muscle force?

-Force velocity, Length - tension, Electromechanical Delay

What factors contribute to flexibility?

-Intervening bony or muscle tissue or fat at the end of the ROM -Tightness/laxity in the muscle and collagenous tissue crossing a joint -Muscle fatigue

arthritis

-Joint inflammation, pain/swelling i. Rheumatoid arthritis- Most painful; immune system attacks healthy tissues ii. Osteoarthritis- "Degenerative joint disease"

Condyloid- (freely movable)

-Oval/ellipsoidal + concave; flex/ext/add/abd/circEx: 2nd-5th metacarophalangeal joints

Ball and socket- (freely movable)

-Spheroidal Convex+concave; 3 planes mvmtEx: hip and shoulder joints

Symphysis-slightly moveable

-a place where two bones are closely joined, either forming an immovable joint (as between the pubic bones in the center of the pelvis) or completely fused -hyaline cartilage connects and allows little movement.

Synarthrosis (immovable joints)

-an immovably fixed joint between bones connected by fibrous tissue (for example, the sutures of the skull).-allows no movement under normal conditions. -(SYN = Together) (arthron) = joint

Syndesmosis

-bones connected by ligaments -- is the type of fibrous joint found between parallel bones. The gap between the bones may be wide and filled with a fibrous interosseous membrane, or it may narrow with ligaments spanning between the bones. ex) tibia and fibula are joined together by connective tissue

sprain

Twisting of bones, stretch/tear tendons/ligaments

motor unit

a nerve or a neuron that specifically communicates with our motor or development skeletal system. -Considered the fictional unit of the neuromuscular system

articular cartilage

a protective layer of dense white connective tissue covering the articulating bone surfaces-It spreads loads over a wide area, thereby reducing contact stress (Resists compression-It provides a protective lubrication that minimizes friction and mechanical wear at the joint (Allows movement)

Proprioceptive neuromuscular facilitation (PNF)

is a group of stretching procedures involving alternating contraction and relaxation of the muscles being stretched

Slow twitch fiber

muscle fibers that contract at a slow rate and have very good endurance-rely on aerobic respiration to fuel muscle contractions and are ideal for long term endurance

concentric

muscle shortening under tension that produces a torque larger than the resistance torque at a joint.

Isometric

no change-the opposing toque at the joint crossed by the muscle is equal to the torque produced by the muscle (with no zero net torque present)

synchondrosis joint

-is a type of cartilaginous joint where hyaline cartilage completely joins together two bones. Synchondroses are different than symphyses (secondary cartilaginous joints) which are formed of fibrocartilage.

Active stretching

-produced by active development of tension in the antagonist (opposite) muscles ADVANTAGES: -Strengthening opposite muscle you're stretching as you're having to hold the weight DISADVANTAGES: Without it, the muscles shorten and become tight. Then, when you call on the muscles for activity, they are weak and unable to extend all the way. That puts you at risk for joint pain, strains, and muscle damage.

joint stability

(Ability of a joint to resist abnormal displacement of the articulating bones, or joint displacement)

muscle fibril (myofibril)

(also known as a muscle fibril) is a basic rod-like unit of a muscle cell. Muscles are composed of tubular cells called myocytes, known as muscle fibres in striated muscle, and these cells in turn contain many chains of myofibrils.

Gliding

- (freely movable)-Nearly flat; nonaxial gliding ex: intercarpal/intertarsal joints

hinge

- (freely movable)Convex+concave; planar hinge-like motion ex: ulnohumeral (elbow & knee)

What factors contribute to joint stability?

- A closely reciprocating match of the articulating bone surfaces (stability is maximal when joints are in the close-packed position) · Ex: close-packed = hip more stable loose-packed = shoulder, less stable · A strong array of ligaments and muscle tendons crossing the joint · Absence of muscle fatigue

Discuss the relationship between joint stability and joint flexibility... discuss the importance of stability and mobility for these differing sports: gymnastics, football, swimming.

- Flexibility is defined as the ability of soft tissues (which include muscles, tendons and ligaments) to lengthen correctly, which allows a joint to move through its optimal ROM. Stability is the ability of the surrounding soft tissue to support a joint through that ROM.

Goniometer

- a device that measures an angle or permits rotation of an object to a definite position. The art and science of measuring the joint ranges in each plane of the joint are called goniometry.

Diarthroses (Freely moveable)

- a form of articulation that permits maximal motion, as the knee joint. -Joints allowing full movement include many bone articulations in the upper and lower limbs. Examples of these include the elbow, shoulder, and ankle -(Di = "through joint")

Amphiarthrosis (slightly moveable)

- a joint that has limited mobility. An example of this type of joint is the cartilaginous joint that unites the bodies of adjacent vertebrae. ... Another example of an amphiarthrosis is the pubic symphysis of the pelvis. -(Amphi = both)

What are the four common types of muscle injuries?

1. Strains 2. Contusions 3. Cramps 4. Delayed on-set muscle soreness

Explain why athletes' joints are often taped before the athletes participate in an activity. What are some possible advantages and disadvantages of taping?

Advantages: Athletic taping does allow for an earlier return to activity and offers protection from further injury. The functions of taping and padding are for support, control of excessive motion (flexible splint), proprioception and protection (reduced end range of motion stress). The athlete can remain active while injured. It is used to enable early return to sport/training and minimise time lost for injury. While the benefits of taping are as yet inconclusive, the benefits of an active recovery are strongly supported. Taping can decrease pain and increase joint stability. Disadvantages: Can be harmful if not performed correctly e.g. further injury, skin damage, etc. Can restrict movement and therefore performance Could increase risk of injury to other joints

Saddle- (freely movable)

Both shaped like saddles; greater ROM than condyloidEx: carpometacarpal joint at thumb

Describe the three different types of muscle contraction

Concentric- muscle shortening under tension that produces a torque larger than the resistance torque at a joint. Isometric- no change-the opposing toque at the joint crossed by the muscle is equal to the torque produced by the muscle (with no zero net torque present) Eccentric- involving lengthening -opposing joint torque exceeds that produced by tension in a muscle

Active insufficiency

Condition occurring when a TWO joint muscle cannot shorten enough to cause a full range of motion at both joints It crosses at the same time.

Sarcomere

Contractile unit of muscle & is the basic structural unit of the muscle fiber.

Dislocation

Displaced bones; have a professional relocate ASAP!

muscle fiber

Each bundle of muscle fiber is called a fasciculus and is surrounded by a layer of connective tissue called the perimysium. Within the fasciculus, each individual muscle cell, called a muscle fiber, is surrounded by connective tissue called the endomysium.

Compare/contrast fast twitch and slow twitch (as well as intermediate) muscle

Fast twitch fiber- Rely on anaerobic respiration to fuel muscle contractions and are ideal for quick contractions of short duration. Intermediate fiber- are fast twitch muscle fibers which have been converted via endurance training. Slow twitch fiber- muscle fibers that contract at a slow rate and have very good endurance-rely on aerobic respiration to fuel muscle contractions and are ideal for long term endurance

What is the difference between articular cartilage and fibrocartilage (discuss the composition, location, and purpose of each)?

Fibrocartilage provides the tough material of the intervertebral discs; the intraarticular cartilages of the knee, wrist and temporo-mandibular joints; Articular fibrocartilage- Soft discs that are between the bones providing some layer of fusion between them. Functions: •Distributing loads over joint surfaces • Improving the fit of articulations • Limiting slip between articulating bones • Protecting the joint periphery • Lubricating the joint• Absorbing shock at the joint -the articular cartilage of the temporo-mandibular joint and of the joint between the clavicle and the sternum. -Articular cartilage-a protective layer of dense white connective tissue covering the articulating bone surfaces -It spreads loads over a wide area, thereby reducing contact stress (Resists compression-It provides a protective lubrication that minimizes friction and mechanical wear at the joint (Allows movement)

Cramps

Imbalance of excitation from muscle spindle and inhibition from GTO (resulting from neuromuscular fatigue)

Bursitis

Inflammation of the bursa, limited movement / pain

Muscular strength

Is measured by the amount of torque a muscle group can generate at a joint.

Torque

Is produced by a muscle at the joint center of rotation is the product of muscle force and muscle moment arm.

Contusions

Muscle bruise; caused by compressive force (impact)

DOMS- DELAYED ON SET MUSCLE SORENESS

Muscle pain 24-72 hours post exercise.

What are the four behavioral properties of muscle?

Normal resting length, Extended, After passive recoil, and Contracted.

Strains

Overstretching muscle tissue Mild --> 2nd degree --> Full tear

Fast twitch fiber

Rely on anaerobic respiration to fuel muscle contractions and are ideal for quick contractions of short duration.

Pivot- (freely movable)

Rotation around one axis Ex: atlantoaxial joint

Articular fibrocartilage

Soft discs that are between the bones providing some layer of fusion between them. Functions: •Distributing loads over joint surfaces• Improving the fit of articulations• Limiting slip between articulating bones• Protecting the joint periphery• Lubricating the joint• Absorbing shock at the joint

Muscle is the only tissue capable of actively developing

TENSION

Muscular Endurance

The ability of muscle to exert tension over a period of time. The opposite of muscle fatigability.

Myofilaments

The contractile proteins, actin and myosin, of muscle cells

static stretching

The process of passively taking a muscle to the point of tension and holding the stretch for a minimum of 30 seconds ADVANTAGES: -Effective in increasing range of motion DISADVANTAGES: -Increased risk of injury when performed before strength or endurance training. -Decreased maximum strength when performed before strength training. -Decreased long term training effect when performed before or during strength training.

Muscular power

The product of muscular force and the velocity of muscle shortening

Length-tension

The total tension present in a stretched muscle is the sum of the Active tension provided by the muscle fibers and the passive tension provided by the tendons & muscle membranes.

myosin filaments

Thick filament of protein found in middle of skeletal muscle cells

What are the benefits of a warm up activity before competition?

Warm ups speed up the nerve & muscle to communicate.

Force-Velocity

When resistance (force) is negligible, muscle contracts with maximal velocity. (low resistance, high concentration velocity) - As load increases, concentric contraction velocity slows to zero at isometric maximum (no movement) The stronger the muscle is, the greater the magnitude of maximum isometric tension.

articular capsule

a double-layered membrane that surrounds the joint

Ballistic stretching

a series of quick, bouncing-type stretches -ADVANTAGES: -Can be used as a warming up. -DISADVANTAGES: -By activating the stretch refelx (myotatic reflex) the muscles can't relax and range of motion does not increase. -The large peak tension on muscles and tendons caused by the powerful bouncing movements increase risk of injury. -Decrease in maximum strength when performed before strength training.

Tetanus

a sustained muscular contraction resulting from a rapid series of nerve impulses-Develop tension

Describe / compare active and passive insufficiency, giving an example of each

a. Active insufficiency- Condition occurring when a TWO joint muscle cannot shorten enough to cause a full range of motion at both joints It crosses at the same time. b. Passive insufficiency- inability of a two joint muscle to stretch enough to allow full range of motion at both joints at the same time.

Discuss an exercise movement and identify which muscles play which roles in the movement (Agonist, antagonist, etc.)

a. Agonist- acts to cause a movement b. Antagonist- acts to slow or stop a movement c. Stabilizer- acts to stabilize a body part against some other force d. Neutralizer- Acts to eliminate an unwanted action produced by an agonist.

Be able to differentiate the common injuries of the joints.

a. Sprain- Twisting of bones, stretch/tear tendons/ligaments b. Dislocation- Displaced bones; have a professional relocate ASAP! c. Bursitis- Inflammation of the bursa, limited movement / pain d. Arthritis- Joint inflammation, pain/swelling

Golgi tendon organs (GTO)

a. inhibit tension in muscle and initiate tension development in antagonists. Within tendons near the muscle-tendon junction in series with muscle fibers Increase in muscle tension 1) inhibit tension development in stretched muscle 2) initiate tension development in stretched muscle Promote stretch in muscle being stretched

muscle spindles

a. provoke reflex contraction in stretched muscle and inhibit tension in antagonists. - Interspersed among muscle fibers in parallel with the fibers Increase in muscle length 1) initiate rapid contraction of stretched muscle 2) inhibit tension development in antagonist muscles Inhibit stretch in muscle being stretched

Agonist

acts to cause a movement

Antagonist

acts to slow or stop a movement

Stabilizer

acts to stabilize a body part against some other force

Synovial fluid

also called synovia, is a viscous, non-Newtonian fluid found in the cavities of synovial joints. With its egg white-like consistency, the principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement.-a clear, slightly yellow liquid that provides lubrication inside the articular capsule for a free movement. fluid. The knee is an example of a synovial joint, with a ligamentous capsule, an articular cavity, and articular cartilage.

Synchondroses (cartilaginous)

bones united by hyaline cartilage -The sternocostal joints are examples of synchondroses, wherein the articulating bones are joined by a thin layer of hyaline cartilage. Also epiphyseal plates (growth plate)

I bands

contain only thin actin filaments.

A bands

contain thick, rough myosin filaments surrounded by six thin, smooth actin filaments.

eccentric

involving lengthening -opposing joint torque exceeds that produced by tension in a muscle

Electromechanical delay

delay or gap between the muscle & when the muscle gets into twitch.

Parallel fiber arrangement-

fibers are roughly parallel to the longitudinal axis of the muscle (More range of Motion) examples: sartorius, rectus abdominus, biceps brachii

Sutures

immovable joints of the skull -starts soft and flexible, then solitifies and is no longer movable. (looks like crack lines on the skull)-Function is to absorb shock

Passive insufficiency

inability of a two joint muscle to stretch enough to allow full range of motion at both joints at the same time.1

Summation

increased force of contraction by a skeletal muscle fiber when a twitch occurs before the previous twitch relaxes (added twitches)

passive stretching

produced by a force other than tension in the antagonist muscles. ADVANTAGES: Passive stretching can improve flexibility, range of motion, and mobility. It helps improve your performance while lowering your risk of injury. Its benefits extend to people who may not be able to stretch on their own. Passive stretching may also stimulate muscle growth and prevent muscle weakness DISADVANTAGES: risk that the external force is stronger than you are flexible and could potentially cause damage

pennate fiber arrangement

short fibers attach to one or more tendons within the muscle examples: tibialis posterior, rectus femoris, deltoids

associated bursae

small capsules filled with synovial fluid that cushion the structures they separate

dynamic stretching

technique in which muscles are stretched by moving joints slowly and fluidly through their range of motion in a controlled manner; also called functional stretching ADVANTAGES: -Increases Range of Motion, especially in sports-specific movements. -An effective and safe way to warm up the muscles prior to exercise. -Small acute increases in maximum strength compared to no specific warming up or other stretching methods. DISADVANTAGES: -Less effective in increasing Range of Motion than Proprioceptive Neuromuscular Facilitation.

actin filaments

thin filaments of a muscle fiber coming off Z line.

muscle

tissue composed of fibers that can contract, causing movement of an organ or part of the body