Lectures 6-11 Flashcards
Tendon/Ligament Composition
Tenocytes (fibroblasts in ligaments) (20%)
Extracellular Matrix (80%)
What is the Extracellular Matrix made of in tendons/ligaments
Elastin (2%)
Proteoglycan (2%)
Collagen (33%)
Water (55-75%)
Why is crimp important in tendons?
Allows for the straightening during tensile loading
What is the ratio of elastin to collagen in a ligament?
What ligament doesn’t have this ratio?
2:1
Ligamentum Flavum
What are the 3 differences between ligaments and tendons?
- Collagen fibres are not parallel
- The outer connective tissue layer is called an epiligament
- Multidirectional tensile force
What force are ligaments and tendons strongest in?
Tension
What are two viscoelasticity tests?
Stress relaxation test
Creep deformation test
What causes tensile strength and stiffness to decline?
Collagen plateau
What do steroid do to ligaments and tendons
Negatively impact them due to inhibition of collagen synthesis
Is a sprain a ligament or tendon injury?
Ligament injury
Is a strain a ligament or tendon injury?
Tendon Injury
What is a grade I ligament/tendon injury?
Micro failure to collagen fibres
some pain, no joint instability
What is a grade II ligament/tendon injury?
Partial rupture
Severe pain and some joint instability
What is a grade III ligament/tendon injury?
Total rupture has occurred
Severe pain and joint completely unstable
What is the percentage of vascularisation of tendons and ligaments
1-2%
Normal ROM of hip flexion
120 degrees
Normal ROM of hip abduction
120 degrees
Normal ROM of hip internal/external rotation
20 degrees
Why does ROM decrease with age?
Changes in motor control
Loss of motor unit
Decreases in fast twitch muscle fibres
What is the centre edge angle (angle of Wiberg)?
35 degrees
What is the acetabular anteversion angle?
20 degrees
What is the angle of inclination?
125 degrees
What is the torsion angle?
15 degrees
What affects the mobility and stability of the hip?
Coverage of Acetabulum (angle of Wiberg and Acetabular Anteversion angle)
Alignment of Femur (Torsion angle and angle of inclination
What bone externally rotates in the screw home mechanism to add stability in full knee extension?
Tibia
In walking gait, what are the two phases? Define them
Stance (65%) - Heel Strike to Toe Off
Swing (35%) - Toe Off to Heel Strike
In walking gait, what are the 8 actions
- Heel strike
- Foot flat
- Heel rise
- Push-off
- Toe-off
- Acceleration
- Toe Clearance
- Deceleration
What is the difference between stride and step length?
Stride length is the length from when an event occurs on one side, to when it reoccurs on the same side (right heel strike –> right strike off)
Step length is the length from when an event occurs on one side to when it reoccurs on the opposite side (right strike off –> left strike off)
What is the role of the subtalar job during gait?
Shock absorbs
What are the phases in running gait?
Stance (40%)
Float (15%)
Swing (30%)
Float (15%)
Movements during pronation of the foot (e.g plantar flexion, abduction, inversion)
Dorsiflexion, Abduction, Eversion
Movements during supination of the foot (e.g plantar flexion, abduction, inversion)
Plantarflexion, Adduction, Inversion
What happens to the Plantar Fascia when toes are hyperextended
It shortens causing the arch of foot to rise
Distribution of loads under the foot during stance
Heel (60%)
Midfoot (8%)
Forefoot (28%)
Toes (4%)
Role of Nucleus Pulposus
Provides the intervertebral disc elasticity and compressibility
How does the Nucleus Pulposus get nutrients?
Diffusion (no direct blood supply)
What covers the Annulus Fibrosus?
Fibrocartilage
Under compression, how much pressure can the Nucleus Pulposus and Annulus Fibrosus withstand?
Nucleus Pulposus - 1.5 times external load
Annulus Fibrosus - 0.5 times external load
Compare male and female motions of the spine
Males: more ROM in flexion/extension
Females: more ROM in lateral flexion
Where is the line of gravity in the body while standing
passes anteriorly to the centre of the fourth lumbar vertebrae
How does the body maintain balance?
The line of gravity through the body creates a forward bending moment in the spine. The body then maintains balance by increasing core and spinal muscle activity
What is sway?
Horizontal movement of the COG
What is the sacral angle of the pelvis?
30 degrees
How do you minimise pressure on the spine while sitting?
Lumbar support and leaning back
What motions increase the load on the spine?
Bending forward or sitting
If two objects are the same weight but vary in size, which one will create a greater load on the spine?
bigger size = greater load
What type of fibre are found in motor neurons
Muscle Fibres
What type of fibre are found in sensory neurons
Skin Fibres
Muscle Fibres
Tendon Fibres
Joint Fibres
What type of neuron is commonly found in the posterior root of the nerve
Sensory
What type of neuron is commonly found in the anterior root of the nerve
Motor
What are peripheral nerves made up of?
Nerves
Connective Tissue
Blood Vessels
What is the role of the myelin sheath in nerves
Increases the speed of conduction
Insulates and maintain the axon
What is the Epineurium
Protects fascicles from external trauma
Maintains oxygen supply
What is the Perineurium
Sheath surrounds each fascicle
Great mechanical strength
Specific biochemical barrier
What is the Endoneurium
Protects nerve fibres
Composed of fibroblasts and collagen
Are peripheral nerves vascularised
Yes
In what direction do blood vessels run across the perineurium
Obliquely
What is the order of the layers of connective tissue (outside to inside)
- Epineurium
- Perineurium
- Endoneurium
Where does the spinal cord end in adults?
L1
What vertebrae and areas of the body are affected by Brachial Plexus Palsy
C5-C6
Shoulders, Bicep, Brachioradialis
What is Sciatica?
A nerve compression injury
Degenerative disk puts pressure on the piriformis, causing pain in the back of the leg
What is Endomorphy
Lean <———-> Fat
What is Mesomorphy
Slender <———–> Muscular
What is Ectomorphy
Heavy <———–> Light
