Joints

Types of Joints-classified by structure or function

Cartilaginous joint-body of one bone connects to thebody of another by means of cartilage-slight movement is possible-intervertebral discs-hard outer ring with soft core

Fibrous joint-bound tightly together by connective tissue-allow no movement-joints between interlocking bones of the skull

Synovial joint-allow the most movement-bony surfaces are separated by lubricating fluid (synovia)-joined by ligaments-tough bands of elastic tissue that enclose the ends of articulating bones and form the capsule containing the synovial membrane

The Characteristics of a Synovial Joint

Bone

Blood vessels

Nerve

Synovial membrane

Joint cavity (filled with synovial fluid)

Fibrous capsule

Joint capsule

Bursa

Tendon sheath

Tendon

Articular cartilage-located on the ends of bones that comein contact-protects the ends of bone-allows for a smooth contact surface -shock absorber

Fibrous layer

Membranous layer Periosteum

Synovial Membrane-allows certain nutrients to pass through

Fibrous capsule-keep synovial fluid from leaking

Bursa-small, flattened fluid filled sacs found at friction points between tendons, ligaments and bones

Ligament-Intrinsic-thick bands of fibrous connective tissue that help thicken and reinforce joint capsule-Extrinsic-separate from joint capsule, attach bones together

Types of Synovial Joints

• There are three basic types of synovial joints: • unilateral (rotation only about one axis)

• biaxial joints (movement about two perpendicular axes)

• multiaxial joints (movement about all three perpendicular axes)

Types of Synovial Joints

Ball-and-socket joint-movement around 3 axis- multiaxial joints

Hinge joint- unilateral -convex portion of one bone fits into concave portion of another-movement in one plane

Saddle joint- biaxial joints-movement in 2 planes

Gliding jointunilateral-connects flat or slightly curved bones

Pivot joint- unilateral -rotation in one plane

Ellipsoid jointbiaxial joints-movement in 2 planes

Tissue Properties Tendons:

Composed of collagen (bundles of white, fibrous protein)

Attach muscle to bone

Greater stretching range

Dynamic stabilizer Vascular

Ligaments: Tough bands of white, fibrous tissue

Attach bone to bone

Less rigid than bones Allow certain amount of stretch, but do not have same stretch as tendons

Tear when reach threshold

Static stabilizers of joint Avascular-no blood supply

Strengthen with proper training/conditioning

Common Sport Injuries

Strains, pulls, and tears

Terms used to describe injuries to all joint tissue types Sprains-tendons and ligaments

Pulls and strains-muscles

First, second and third degree

Tendinitis

Inflammation of a tendon caused by irritation due to prolonged or abnormal use

Rest, cold/heat therapy, cast, splint or anti-inflammatories

Dislocations

Bone displaced from its original location

Often in finger joints

Damage to joint capsule and ligaments Symptoms

Joint look awkward or deformed

Joint is painful when touched or moved

Joint is not usable

Tendinitis

Bursa

Common Sport Injuries

Separations

Fibrous ligaments that bind the bones tear and separate

Ex. Acromioclavicular and Sternoclavicular

Cartilage

Torn cartilage

Avascular-long time to heal

Shin splints

Tearing of the interosseous membrane or the periosteum

Result of overuse without adequate rest

Occurs on medial or lateral side of tibia (shaft)

Risk factors include training surface or regimen, changes in frequency, duration or intensity or old/worn out footware

Proper Treatment of an Injury

S.H.A.R.P – signs of injury P.I.E.R. Principle

Swelling: instantly or over time Pressure: tensor wrap

Heat: increased temperature in the

areaIce: placed on affected area

Altered: tissue will not function

properlyElevate: to reduce swelling

Red: in colour Restrict: tensors, slings, or crutches

Painful: to touch or move

The Shoulder Joint

Clavicle

Coracoclavicular ligament

Coracoid process

Scapula

Acromioclavicular ligament

Acromion

Coracoacromial ligament

Glenohumeral ligaments and joint capsule

Tendon of biceps brachii (long head)

Humerus

The Shoulder Joint

Intrinsic unstable

Instability versatility Adduction/abduction

Flexion/extension

Elevation/depression

Protraction/retraction

Medial/Lateral rotation

Circumduction

Ball and socket-humerus and scapula

The Shoulder Joint

Ball and socket Humerus and Scapula-directly

Humeral head articulates with glenoid fossa of scapula

Held in place by ligaments

Clavicle-indirectly

Shoulder Joint Injuries

Biceps tendinitis

Caused by overuse of the biceps brachii muscle

Pain to proximal end of bicep

Shoulder separation

Tearing of the acromioclavicular ligament

Result of falls directly on shoulder

Shoulder dislocation

Occurs when the humerus “pops out” of the glenoid fossa

Result of hit or fall resulting in tear to the glenohumeral ligaments and joint capsule

Rotator cuff tears

An injury to one of the rotator cuff tendons

Difficulty laterally/medially rotating as well as abduction

Shoulder separation

The Knee Joint

• Articulation between femur and tibia• Femur does not come into contact with fibula

• Modified hinge• Flexion and extension

• Modified ellipsoid joint• Ability to slightly rotate medially and laterally

The Knee Joint – Anterior

Patella

Medial (Tibial) collateral ligament

Patellar ligament

Tibial tuberosity

Tibia

Quadriceps tendon

Fibula

The Knee Joint Anterior (deep)

Femur

Lateral (Fibular) collateral ligament removed

Medial (Tibial) collateral ligamentremoved

Lateral Meniscus

Tibial Tuberosity

Fibula

Lateral Condyle Medial Condyle

Medial Meniscus

Tibia

Posterior cruciate ligament

Anterior cruciate ligament

The Knee Joint• Articulating cartitilage at distal end of femur

• Meniscus on proximal end of each tibial condyle

• Cruciate Ligaments• ACL

• PCL

• Collateral Ligaments• MCL

• LCL

• Muscles stabilize the knee• Anterior side-quadriceps

• Posterior-gastrocnemius

The Knee Joint – Posterior

Femur

Adductor magnus tendon

Medial head of gastrocnemius tendon

Semimembranosus tendon

Medial (Tibial) collateral ligament

Lateral (Fibular) collateral ligament

Fibular head

Lateral head of gastrocnemius tendon

Oblique popliteal ligament

Fibula

Tibia

The Knee Joint – Posterior (deep)

Anterior cruciate ligament

Popliteal tendon

Lateral meniscus

Lateral (Fibular) collateral ligament

Medial (Tibial) collateralligament

Medial meniscus

Posterior cruciate

Femur

Fibula

Tibia

Posterior meniscofemoral ligament

Knee Joint Injuries

Knee ligament tearsBlows to lateral side of knee

Severity of blow determines degree of tear

Knee damage will happen to the medial side

Tear order Joint capsule

MCL, medial meniscus, ACL

Q-angle may contribute to the predisposition

of ACL tears

Knee Joint Injuries

Osgood-Schlatter syndrome Result of a condition known as osteochondritis-disease

of ossification centers

Standard explanation is growing pains for children

Affects the epiphyseal plate of the tibial tuberosity that has been overloaded or overused

Stress on patellar tendon or ligament causes plate to become inflamed-swelling and discomfort

Does not affect growth of the child

More common in males

PIER

Osgood-Schlatter syndrome

Knee Joint Injuries

Patellofemoral Syndrome (PFS) Gradual onset of anterior knee pain/pain around the patella

More common in adolscents, young adults and women

Aggravated by sports

Result of increased or misdirected force between kneecap and femur

Overuse, overload or misuse

PIER

The Ankle Joint – Medial View

Tibia

Medial malleolus

Calcaneal (Achilles) tendon

Long plantar ligament

Deltoid ligament

The Ankle Joint

• Modified hinge joint

• Distal ends of tibia, fibula resting on the talus

• Responsible for plantar flexion and dorsiflexion

The Ankle Joint – Lateral View

Tibia

Fibula

Posterior tibiofibular ligament

Lateral malleolus

Anterior tibiofibular ligament

Anterior talofibular ligament

Calcaneus

Posterior talofibular ligament

Anterior talofibular ligament

Ankle Joint Injuries

Inversion sprains

Ankle is weakest when plantar flexed

“twisted ankle” or “rolling”

Low or high

PIER

Eversion sprains

Occurs to the deltoid ligament Attaches the medial malleolus to 3 bones of

the foot.

Pott’s Fracture

A force on the medial side of ankle causing the deltoid ligament to rip off the tip of the medial malleolus; and a break of the fibula

Inversion sprain

The Three Energy Nutrients-Macronutrients Carbohydrates

4.1 calories per gram

Proteins

4.3 calories per gram

Fats 9.3 calories per gram

Bioenergetic Conversion Taking the food we eat and converting it

into fats, carbs and protein

Allows our bodies to function and carry out physical activity

The Chemistry of Energy Production

• Energy in the human body is derived from the breakdown of complex nutrients like carbohydrates, fats, and proteins.

• The end result of this breakdown is production of the adenosine triphosphate (ATP) molecule.

• ATP provides energy necessary for body functions

Carbohydrates

Fats

Proteins

ATP

Muscular Work

Digesting Food

Thermoregulation

Breakdown of Energy currency Biochemical processes

The Role of Carbohydrates

Carbohydrates are the most abundant organic substances in nature, and they

are essential for human and animal life.

Come from foods that originate from plants and grain

Veggies, fruits, breads and pastas

Formed by green plants by photosynthesis

Reactants-water and carbon dioxide

Products-oxygen and glucose

Glucose

Primary carb used/assimilated by humans

Stored as glycogen in human body (liver and skeletal muscle)

Glycogen is broken down and carried through blood and used as an

energy source

MetabolismHighly complex

Process in which energy is supplied throughout the body

Energy rich materials are assimilated through the body-energy renewal

Adenosine Triphosphate (ATP)-final form of free energy

Adenosine triphosphate (ATP)

Made in the mitochondrion

Captures chemical energy from food breakdown

Fuel various cell processes

Resynthesized in two ways

Aerobically

Anaerobically

ATP ADP + P + ENERGY

Two Energy Systems

Anaerobic System

Without the use of oxygen (O2)

None of its metabolic activity will involve O2

Utilizes chemicals and enzymes

Occurs in the muscle fibre

Occurs quickly

Required for powerful but short-lived physical actions

Aerobic System

In the presence of oxygen (O2)

All of its metabolic activity will involve O2

Occurs in the mitochondria

Involves many enzymes and several sub-pathways

Leads to the complete breakdown of glucose

Three Metabolic Pathways

ATP-PC System

(anaerobic alactic)

Glycolysis

(anaerobic lactic)

Cellular respiration

(aerobic)

PC + ADP ATP + CREATINE

ATP-PC System

ATP-PC System (anaerobic alactic)

First of two anaerobic energy pathways

Relies on the action of stored ATP and phosphocreatine

Yields enough ATP for 10–15 seconds of energy-short and powerful burts

Use stored ATP

Synthesize ATP

Provides highest rate of ATP synthesis

Limited amount PC Needs to be regenerated using ATP

during recovery time

No by-product No lactic acid produced (alactic)

Glycolysis Glycolysis (anaerobic lactic)

Second anaerobic energy pathway

Provides additional 1–3 minutes in high-level performance

Ideal back-up because glucose is plentiful

First sequence in complete breakdown of glucose

Partially breaks down glucose

Involves 11 separate biochemical reactions

Uses glucose and glycogen to make ATP

Transfer energy from glucose and rejoins phosphate and ADP

Yields twice as much ATP

By product is lactic acid (LA)

C6H12O6 + 2ADP + 2Pi 2C3H6O3 + 2ATP + 2H2O

(Glucose) (Lactate)

Pyruvate and Lactic Acid

• Aerobic condition• Oxygen available• Beginning of the third

energy system (aerobic system)

• Leads to complete breakdown of glucose and synthesis of large amounts of ATP

• Anaerobic condition• No oxygen available• Intense exercise or high

altitudes• Pyruvate is converted

into lactic acid• Build-up of lactic acid

hampers the break-down of glucose and decreases ability of muscles to contract

• Exhaustion or painful muscle agony begins

The main product of glycolysis is pyruvate!

The Aerobic System

Aerobic system (cellular respiration)

Third energy system

Glycolysis Same as anerobic lactic

Pyruvate is converted to Acetyl Co-A

Krebs cycle or Citric Acid Cycle

8 reactions

Synthesize compounds that can store “high-energy” electrons

Electron transport chain Electrons pass down the chain resulting in the production of large amounts of ATP

Uses glucose, glycogen, fats (exercise longer than 20 minutes), and protein (starvation) to make ATP

After 90 seconds of activity

Endurance type activity Sustain activity for very long time

Complete breakdown of glucose

C6H12O6 + 6O2 + 36ADP + 36Pi 6CO2 + 36ATP + 6H2O

Energy Pathways

Interaction of Energy System

• Rest• Small amounts of energy are needed

• Supplied almost exclusively by aerobic metabolism

• Beginning of exercise• Slight energy demand

• Continue with aerobic

• Immediate and high demand• ATP-PC system until either the aerobic system catches up or

anaerobic glycolysis kicks in• Proves that warm-up is necessary

Interaction of Energy System

• Steady state exercise• Supply of oxygen had met the demand

• Aerobic pathway-oxidative complete breakdown of glucose

• Strenuous exercise• Energy demand is rapid and expected for extended period

of time

• Anaerobic pathway is the main producer of ATP if oxygen demand cannot be met

• Production of lactic acid results in muscle fatigue or failure

Lactic Acid• Blood Lactate (Anaerobic) Threshold

• Point (exercise intensity) at which blood lactate levels increase abruptly beyond resting level

• Production is greater than removal

• Exercising below the LT allows any lactate produced by the muscles to be removed without building up

• Point where aerobic system cannot supply enough ATP for the body’s needs forcing anaerobic system to increase their contribution

• Lower the threshold indicates oxidative energy system are not working well or are being over-taxed

• Untrained athletes have a lower threshold

Lactic Acid-Cori Cycle

Energy Sources for Different Sports

Energy from Fats and Protein Aerobic system (cellular

respiration)

Third energy system

Glycolysis

Krebs cycle

Electron transport chain

Uses glucose, glycogen, fats, and protein to make ATP

Lasts 120 seconds and beyond

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Energy from Fats

• Contain large quantities of stored energy• Twice as much as carbs and protein (slide 2)

• Primary type in muscle cells and adipose tissue-fatty acid

• Stored as triglycerides

• Lipolysis• Breakdown of TG to produce fatty acids

• Available as an energy source

Energy from Fats

• Fatty acids enter the energy system at the KREB CYCLE

• First need to be converted to acetyl-CoA through beta-oxidation

• Similar to pyruvate from glycolysis

• Drive the production ATP in the ETC

• Fat balance• Amount necessary as energy source and excessive

amounts leading to unhealthy body

Energy from Protein

• Energy equal to carb and half that of fat (slide 2)

• No protein reserves in the body• All part of existing body tissue or actively engaged in

metabolic activity

• Comprised of 20 amino acids• Nine essential

• Must be in a.a form to be used as energy

• Endurance activity or glycogen stores are low-energy back-up

Slow-Twitch and Fast-Twitch Muscles

Slow-twitch muscle fibres:

Most active during: long-distance running, swimming, and cycling

Red or dark in colour

Generate and relax tension slowly; able to maintain a lower level of tension for long durations

Low levels of myosin ATPase and glycolytic enzymes (anerobic)

High levels of oxidative enzymes (aerobic)

Most active during long-distance swimming, running and cycling

Fast-twitch muscle fibres:

Ideal for: short sprints, powerlifting, and explosive jumping

Pale in colour

Ability to tense and relax quickly; generate large amounts of tension with low endurance levels

Two to three times faster than slow twitch fibres

High levels of myosin ATPase and glycolytic enzymes

Ideal for fast, powerful contraction needed for sprinting, power lifting or jumping

Importance of Myoglobin-dependency of muscles fibres on oxygen

• Difference in muscle fibre types is due the extent at which a particular muscle relies on oxygen

• Myoglobin• Oxygen storage unit that delivers oxygen to working muscles

• Ability to sustain long-term activity is related to a muscle use of aerobic processes

Importance of Myoglobin-dependency of muscles fibres on oxygen

• Slow-twitch, red muscle fibres• High in myoglobin

• Ideal for endurance activity

• Fast-twitch fibres• Low in myoglobin

• Adapted for shorter bursts of energy

Three Fibre Types

Type I or Slow-Oxidative (SO)

Generate energy slowly

Fatigue-resistant

Depend on aerobic processes

Type IIA or Fast-Oxidative Glycolytic (FOG)

Intermediate-type muscle fibres

Allow for high-speed energy release

Allow for glycolytic capacity

Type IIB of Fast-Glycolytic (FG)

Store glycogen and high levels of enzymes

Allow for quick contraction without the need for oxygen

Research indicates that type IIB fibres can become type IIA with aerobic endurance training

Characteristics of Different Muscle Fibre Types

Distribution of Muscle Fibre Types

• Muscle fibre makeup generally determine function and vice versa

• Tonic Muscles• Assist body with maintaining posture or stability

• Standing, walking and throwing

• High % of Type I fibre• Slow-twitch with little ability for explosiveness

• Considerable endurance

• Example: Soleus• Dorsiflexes the foot and ensures body posture

Distribution of Muscle Fibre Types

• Phasic Muscles• High % of Type IIA and IIB

• Example: bicep

• Muscle biopsy is the only way to determine the % of muscle fibre type

Approximate Distribution of Muscle Fibre Types for Different Sports

Training Energy systems

Anaerobic Alactic (ATP-PC)

• All training for this system should be powerful (100% intensity) and short (6-12s).

• The recovery time for this system should be minimal (15s-120s).

ATP-PC Examples

• Running – 10 repetitions of 30m sprints with 30s recovery

• Strength Training – 4 repetitions of 90% maximum load with 30s recovery

• Swim – 8 repetitions of 25m sprints with 30s recovery

Effects of training on Anaerobic Alactic system:

• 20-40% increase of creatine phosphate stores• increase of ATP stores

• increase in creatine kinase function

Anaerobic lactic (Glycolysis)

• Training for this system should be fairly powerful (70-95% intensity) and a longer timeframe than immediate alactic training (12s-3 min.).

• The recovery time for this system is also longer (45s-180s).

Examples

• Running – 5 repetitions of 300m sprints with 60s recovery

• Strength Training – 10 repetitions of 70% maximum load with 60s recovery

• Swim – 5 repetitions of 200m sprints with 60s recovery

Why does lactic acid inhibit muscle contraction?• An increase in lactic acid causes a release of hydrogen ions, which

inhibit calcium from binding to tropomysosin, so actin binding sites are still blocked.

•

Why does lactic acid inhibit muscle contraction?• The hydrogen ions cause the muscles to become acidic. The acidity

slows the breakdown of glucose, and aggravates nerve endings.

• The pain and irritation reaches the central nervous system and is the reason why some athletes feel disoriented or nauseous after exercise.

• Do not confuse this with exhaustion.

When does this occur?

• Inhibited muscle contraction occurs when anaerobic threshold is reached. Anaerobic Threshold (AT) is the point at which the lactic acid is accumulating in the blood stream.

• The production of lactic acid is too great for the removal of the lactic acid via the Cori cycle to keep up.

• When this point is reached, the release of hydrogen ions will cause the acidity in the muscle. Trained athletes have a higher AT (at 80-90% of max. effort) while untrained athletes have a lower AT (~55% of max. effort).

Effects of training on short term lactic acid system:

• Enables oxygen system to be utilized sooner to limit lactic acid production

• Increases lactic acid removal from muscles

• Increases speed of conversion of lactic acid into glucose

Aerobic (Cellular Respiration)

• Training for this system should be low to moderate intensity (40-70% intensity) and have a long timeframe (3 min.- 180 min.).

• The recovery time for this system is the longest (90s – 12 hours).

Examples:

• Running – 5k run or 30 minute continuous run

• Strength Training – Circuit training at a low intensity

• Swim – 1500m swim or 30 minute continuous swim

Effects of training on aerobic system:

• Increase in vascularization (# of blood vessels) within muscles. (Angiogenesis)

Effects of training on aerobic system:

• Increases size and number of mitochondria in muscle.

Effects of training on aerobic system:

• Increases enzyme activity involved in aerobic system.

• Use of fats rather than glycogen for energy.