1. Joint Mechanics & Joint Injuries

2.  Joints are the points at which bones connect
 Joints are the points at which bones connect.  Vitally important because they play a critical role in human movement  Are also points of great stress and can be a common source of injury.  The articular system is a term that refers to the joints and the surrounding tissues that make connections, and therefore movement, possible. Joint’s are classified according to their structure (what they are made of) or their function ( the type and extent of movement they permit).  The structural classification recognizes three main types of joints: 1. Fibrous Joints (immovable joint) aka- synarthrosis Cartilaginous Joints (slightly movable joint aka- amphiarthrosis 3. Synovial Joints (freely movable joint aka- diarthrosis
The Different Types of Human Joints:

3. Types of Joints
Fibrous joint
Cartilaginous joint
Synovial joint

4. Fibrous Joint
Bound tightly together by connective tissue- allow no movement
These joints can be found between the interlocking bones of the skull
Also known as “Sutures”
What happens to these joints after birth?
Become immobile- fuse together
Fibrous joint

5. Fibrous Joint

6. Cartilaginous Joints (Fibrocartilaginous Joints)
The body of one bone connects to the body of another by means of cartilage
Allow for slight movement, but typically lack large ROM
The intervertebral discs 23
Hard elastic outer ring, with a soft core permitting some movement while at the same time providing protection against severe jolts
What is the purpose of having discs when jumping?
Discs=shock absorbers… stable for up and down movements, not very stable for blows to the side
Cartilaginous joint

7. Cartilaginous Joints (Fibrocartilaginous Joints)
Discs=shock absorbers… stable for up and down movements, not very stable for blows to the side

8. Synovial Joints These joints allow the most movement
Characterized by capsules surrounding the articulating surfaces and the lubricating synovial fluid within those synovial cavities
Knee, shoulder, ankle
Synovial joint

9. Types of Synovial Joints
Joints allow the bones coming together to form the joint to move relative to one another in various ways and to various extents
Synovial joints are the only joints that allow significant movement and for this reason we are interested in synovial joints as they are important in our understanding of human movement
Distinguished by the kind of movement the joint permits- 6 types…

10. Types of Synovial Joints
Gliding joint
Ball-and-socket
joint
Hinge joint
Pivot joint
Ellipsoid joint
Saddle joint

11. Types of Synovial Joints
Ball-and-socket (spheroidal) joints:
most manoeuvrable of joints- allows for; forward, backward, and circular movement. (tri-axial)
“ball” at one bone fits into the “socket” of another, allowing movement around 3 axes
Hip- femur rests in the acetabulum of the pevis
Shoulder- humerus rests in the glenoid cavity

12. Types of Synovial Joints Cont…
2. Gliding (or plane or arthrodia)Joints:
Connects flat or slightly curved bone surfaces that glide against one another
Joints in the foot between the tarsals and the hand among the carpals

13. Types of Synovial Joints Cont…
3. Hinge (ginglymust) Joints:
Have a convex portion of one bone fitting into a concave portion of another
Allow movement in ONE plane (uni-axial)
Joints between the bones of the fingers (phalanges) and between the ulna (inner bone of forearm) and the humerus (upper arm)

14. Types of Synovial Joints Cont…
4. Pivot (or trochoid) Joints:
allows rotation in one pane (uni-axial)- a rounded point of one bone fits into a groove of another
Atlas- axis first two cervical vertebra- allow rotation of the head- no-yes

15. Types of Synovial Joints Cont…
5. Saddle Joints:
Like ellipsoid joints, allow movement in two planes(bi-axial) i.e. flexion-extension, abduction-adduction, but do not allow for rotation like your ball-and-socket joint
Example- carpo-metacarpal articulation of the thumb

16. Types of Synovial Joints Cont…
6. Ellipsoid Joints:
Allows movement in two planes(bi-axial)
Wrist, second metacarpal and first phalanx of the second finger

17. Task Read page 70 of the text and take notes on;
The characteristics of synovial joints
Complete the workbook exercise 4.3 on the knee joint.

18. Synovial Joint Structure
Bone
WORKBOOK EXERCISE 4.3
Blood vessels
Nerve
Joint cavity (filled with synovial fluid)
Joint capsule
Synovial membrane
Fibrous capsule
Articular cartilage
Bursa
Articulating cartilage
Joint capsule
Synovial membrane
Fibrous capsule
Joint cavity
Bursa
Tendon sheath
Membranous layer
Tendon
Periosteum
Fibrous layer
Label
Label & Define!

19. Characteristics of Synovial Joints:
Articulating Cartilage Located at the ends of bones that come in contact with one another- protects the ends of bone and allows for smooth contact surface for the bone to move- act as a shock absorber
Joint Capsule Fibrous structure that consists of the synovial membrane and fibrous capsule.
Synovial Membrane- allows certain nutrients to pass through
Fibrous Capsule- keeps synovia fluid from leaking
3. Joint Cavity Located between the two bony articulating surfaces- filled with synovial fluid- acts as a lubricant for the joint- lubricant is essential in reducing friction and providing nutrients for the articulating cartilage
4. Bursae small, flattened fluid sacs found at friction points between tendons, ligaments, and bones
5. Intrinsic Ligaments Thick bands of fibrous connective tissue that helps thicken and reinforce the joint capsule
6. Extrinsic Ligaments Help reinforce the joint by attaching bones together

20. Wear and Tear on Joints
Continuous, heavy use of the joints over many years can result in wear and tear on the articular cartilage at the ends of bones, leading to the erosion of the surfaces of bones at the articulations where bones come together.
This process is known as osteoarthritis, is common for older individuals and athletes or anyone active
Results in joint pain and stiffness and restricted mobility
Osteoarthritis- commonly occurs in the larger weight-bearing synovial joints i.e. hips, knees- but can affect hands, feet, and even spine
Is a degenerative disease- is irreversible- results in decreased effectiveness of articular cartilage both as shock absorber and lubricated surface
Treatment= pain medication- joint replacement

21. Wear and Tear on Joints cont…
Because of heavy continual use sheer strength of the forces that are generated at joints, they are a common site for injuries.
Most sport related injuries included; twisted ankle, sprained wrist, overextended elbow, damaged knee ligaments, or bursitis- inflammation of the fluid sacs (bursae) at the friction points between tendons, ligaments, and bones.
How do we decrease injuries?
Warming up properly prior to exercise, by exercising correctly and stretching during recovery.

22. Joint-Related Injuries:
Joints allow movement and make our skeleton flexible
Without them, we would not be able to move our bodies.
Because of the wear and tear joint-related injuries can occur
3 Types of Cartilage”
Hyaline Cartilage
Occurs at the ends of long bones as well as in the ear, fetal skeleton, nose, larynx, trachea and bronchi
Weakest and most common type of cartilage in the body
Fibrocartilage
Found in disks between vertebrae, pubic symphysis, skull
Strongest cartilage in the body
Elastic (yellow) Cartilage
Flexible, interlacing, branching fibres
Found in epiglottis and external ears
Cartilage Damage
Cartilage= connective tissue found at the end of bones and free-moving joints
Is avascular- nutritional needs of cartilage are NOT met through the blood- no blood vessels
Cartilage damage or injuries- “torn cartilage”- is common in the knee because of sports that need vigorous lateral movement and when contact is common i.e. basketball, football
Arthroscopy- surgical procedure- small incisions made so that small fibre optic camera devices can assess the extent of the damage

23. Tissue Properties Tendons:
Composed of collagen (bundles of white, fibrous protein)
Attach muscle to bone, dynamic stabilizer of joints
Vascular (has a blood supply)
Strains occur in muscle and tendons
Ligaments:
Tough bands of white, fibrous tissue
Attach bone to bone(one or more bones together), static stabilizer of joints
Avascular (no blood supply) (Cartilage is avascular as well)
When they reach their threshold, will stretch minimally, but usually will tear.
Sprains occur when a ligament is overstreched

24. Tissue Properties Strains, sprains, and tears
Are terms used to describe all joint injuries- this will usually include: tendons, ligaments, and muscles
Injury Severity- strain(muscle/tendons) and sprain(ligaments) grading classified by degrees:
1st Degree Sprain: mild injury, a few days of recovery- treated easily since only a few ligament fibres are stretched- minimal swelling and some pain
2nd Degree: result of partially torn ligament fibres, result in bruising, swelling and pain more considerable- require diagnosis by doctor + treatment
3rd Degree: entire ligament is completely or nearly completely torn- severe, require a diagnosis by doctor + may require surgery(ligament back to bone), 6-12 months for full recovery

25. Common Sport Injuries Strains, pulls, and tears Tendinitis
Terms used to describe injuries to all joint tissue types (1st to 3rd degree)
Tendinitis
Inflammation of a tendon
Dislocations
Bone displaced from its original location
Separations
Fibrous ligaments that bind the bones tear and separate
Cartilage
Torn cartilage
Shin splints
Tearing of the interosseous membrane or the periosteum on medial and lateral side of tibia- shin bone.
Tendinitis

26. Proper Treatment of an Injury
S.H.A.R.P
P.I.E.R. Principle
Swelling: instantly or over time
Pressure: tensor wrap, slings, cruches
Heat: increased temperature in the area
Ice: placed on affected area- first 48 hrs- every few hours
Altered: tissue will not function properly
Elevate: to reduce swelling- higher than heart- especially at night
Red: in colour
Rest: activities need to be put on hold, stop activity that causes pain, used tensors, splints, slings to help rest injured body part
Painful: to touch or move

27. Dislocations
Dislocations occurs when a bone is displaced from its joint- i.e. shoulder dislocation – humerus “pops out” of the glenoid fossa, resulting in a tear of the ligament and joint capsule.
Most common- finger joint
Don’t attempt to put back in place on your own- seek medical attention
Signs of a Dislocation:
Significant pain- inability to move the appendage from its current position
Numbness, no feeling of appendage
Square appearance of the joint area and/or visibly noticeable lack of bone in the injured joint area.

28. The Shoulder Joint – Workbook Exer.4.4
Clavicle
Acromioclavicular ligament
Coracoclavicular ligament
Acromion
Coracoacromial ligament
Coracoid process
Glenohumeral ligaments and joint capsule
Scapula
Tendon of biceps brachii (long head)
Humerus

29. Shoulder Dislocation

30. Separations:
Does not directly affect the joint itself, but rather the connecting tissue
i.e. should separation- the ligaments attaching your collarbone (clavicle) and shoulder blade (scapula) are disrupted.
When the ligaments are torn, the bones ma separate
Separations are classified from grades I-IV according to severity and the position of the injured bone
Symptoms:
Pain at the end of the bone or over the joint
Swelling and obvious lump where the joint has been disrupted
Pain on moving

31. Shoulder Joint Injuries
Biceps tendinitis
Caused by overuse of the biceps brachii muscle (back to shoulder diagram)
Shoulder separation
Tearing of the acromioclavicular ligamenthttp://
Shoulder dislocation
Occurs when the humerus “pops out” of the glenoid fossa(see next slide)
Rotator cuff tears
An injury to one of the rotator cuff tendons( teres minor, subscapularis, infraspinatus, supraspinatus)
Shoulder separation

32. The Knee Joint – Anterior- Workbook Exer. 4.4
Quadriceps tendon
Patella
Medial (Tibial) collateral ligament
Patellar ligament
Fibula
Tibial tuberosity
Tibia

33. The Knee Joint Anterior (deep)
Femur
Posterior cruciate ligament
Lateral (Fibular) collateral ligament removed
Medial (Tibial) collateral ligament removed
Lateral Condyle
Medial Condyle
Anterior cruciate ligament
Lateral Meniscus
Medial Meniscus
Tibial Tuberosity
Fibula
Tibia

34. The Knee Joint – Posterior
Femur
Adductor magnus tendon
Medial head of gastrocnemius tendon
Lateral head of gastrocnemius tendon
Semimembranosus tendon
Oblique popliteal ligament
Medial (Tibial) collateral ligament
Lateral (Fibular) collateral ligament
Fibular head
Fibula
Tibia

35. The Knee Joint – Posterior (deep)
Femur
Anterior cruciate ligament
Posterior meniscofemoral ligament
Medial meniscus
Medial (Tibial) collateral ligament
Popliteal tendon
Lateral meniscus
Posterior cruciate
Lateral (Fibular) collateral ligament
Fibula
Tibia

36. Knee Joint Injuries Knee ligament tears
Q-angle may contribute to the predisposition of ACL tears
Osgood-Schlatter syndrome
Affects the epiphyseal plate of the tibial tuberosity
Patellofemoral Syndrome (PFS)
Gradual onset of anterior knee pain/pain around the patella
Osgood-Schlatter syndrome

37. The Ankle Joint – Medial View
Tibia
Medial malleolus
Deltoid ligament
Calcaneal (Achilles) tendon
Long plantar ligament

38. The Ankle Joint – Lateral View
Tibia
Fibula
Lateral malleolus
Anterior tibiofibular ligament
Posterior tibiofibular ligament
Posterior talofibular ligament
Anterior talofibular ligament
Calcaneus
Anterior talofibular ligament

39. Ankle Joint Injuries Inversion sprains “twisted ankle”
Eversion sprains
Occurs to the deltoid ligament
Pott’s Fracture
A force on the lateral side of ankle causing the deltoid ligament to rip off the tip of the medial malleolus; and a break of the tibia
Inversion sprain

40. Reading
Pages
Joint Assignment