3 Flashcards
1
Q
Meyerhold’s theory
A
N=A1+A2
actor = moving/material + thinking /organizing of material
2
Q
Static work
what is it and what kind of contraction
A
no mechanical work performed
posture/joint position maintain
isometric contraction - muscle tension is equal to external load with muscle length constant
3
Q
Dynamic work
A
mechanical work performed
posture/joint position changes
Concentric contraction - muscle tension is at least equal too external load with muscle shortening
Eccentric contraction - muscle tension is equal to external load with muscle lengthening (equal to/less than)
4
Q
Concentric and eccentric contraction make (2)
A
Isokinetic contraction - constant joint velocity (variable load) that requires maximum force
using a dynomometer which changes the load depending on how much you put in (maximum voluntary contraction
Isoinertial contraction - constant resistance (variable velocity) for submaximal muscle force production
5
Q
tendons
connect?
made of?
A
connect muscles to bones
fibrous tissue entwine with periosteum (outer bone) - extension of fascia
Periosteum - tendon - surface fascia of muscle
6
Q
Fascia
A
fibrous connective tissue that surrounds and seperates individual muscles
7
Q
Fasiculus
A
bundle of muscle fibres
8
Q
Muscle fibre
A
single complete full length muscle cell of multiple nuclei and motor end plates
9
Q
Myofibril
A
delicate strand that makes one muscle fibre.
has contractile elements and striations
10
Q
sarcoplasm
A
cytoplasm in muscle
11
Q
sarcomere
A
repeated section in myofibril between z lines
12
Q
sarcolemma
A
cell membrane
13
Q
i band (2)
A
only actin
bysected by z line
14
Q
When the muscle is relaxed
A
open space
15
Q
when the muscle is contracted
A
loss of center space
16
Q
thick bands
A
myosin - h zone
17
Q
thin bands
A
actin
18
Q
a band
A
both myosin and actin
19
Q
how does cross bridge from
A
troponin pulls tropomyosin off the actin
20
Q
z line (3)
A
anchor point for actin filaments
connection point for sarcomere packages
define limit of sarcomere
21
Q
M line
A
centre f myosin filaments
22
Q
motor nerve
A
multiple motor axons to the same area
23
Q
motor unit
A
single motor axon and all the muslce fibre it innervates
24
Q
motor endplate
A
junction between axon and sarcolemma (terminal nerve branches)
25
Huxley's sliding filament theory - 11 steps
1. ap travels in on motor axon
2. ap createds end plate potential
3. epp depolarize sarcolemma
4. depolarization of sarcolemma opens transverse tubules
5. ca release
6 ca bind to troponin on actin filament
7. troponin and tropomyosin change shape, receptor sites exposed
8. actin receptor binds with myosin apt cross bridge
9. actin activates atp, adp and phosphate removed, energy released
10. energy release causes power stroke of cross-bridge, thin over thick
11. new ATP binds to cross bridge, breaking actin myosin bond
IF NOT - no breaking bond and RIGOR MORTIS
26
last four steps of the sliding filament theory will repeat as long as
Ca is in system (muscle activation)
27
3 Biomechanical spinoffs of the sliding filament theory
force length relationship
length tension relationship
positional insufficiency
28
force length relationship
| 3 scenarios
sarcomere length and difficulty of contraction
small - centre space already used up
medium - space and lots of cross bridge
large - lots of space but not enough crossbridging so no force production
29
Length tension relationship
| 3
active tension and passive tension - total tension
right around resting length is when tension is produced by sliding filament theory.
increasing passive tension is produced by muscle elasticity, lose active tension but capitalize for muslce for contraction - tensile properties for muscles
30
positional insufficiency
position gives not max force production
31
muscle vector components (3)
rotary, stabilizing, dislocating components
32
Relationship between A1 and A2
(motor commands and efferent copy feeds proprioceptive info (visual and vestibular also) to thinking
33
granulation to cartilage to bone
strength (weight bearing) goes up
stiffness goes up
ultimate strain (how much it takes before it breaks) goes down - different things in place to do different things
34
Modelling of bone
process of bone development from immature to mature
| osteoblast from new bone
35
remodelling of bone
process of bone repair and maintenance
osteoblast forms new bone
osteoclast resorb old bone and repurpose Ca
36
what turns osteoblast on
load of material/ stress
37
what turns osteoclast on
not stressed bone
38
wolff's law
1892 - modelling/remodelling of bone is influenced by mechanical stressed
39
anisotropy of bone
stress vs strain
points and regions
at different orientations you have different yielding points
stress as pressure on material to cause deformity and strain as change of change
elastic region to yield point to plastic region to ultimate strain
40
plastic region
change in material property for permanent alteration and deformation
41
long bone and stress
lots but the final bit is ultimate
42
loading that fractures bones
combination of bending, torsion and compression
43
3 point bending fracture
boot top fracture
top of leg falling forward, ski boot stationary but going forward, resistance at boot top which creates a torsion
beyond yield point reactive force at ground and top of long bone, counter force in the middle
44
torsion
| 3
rotating opposite ends at opposite directions
can be horizontal, vertical, or shear forces that make spiral or torsional fractures
tension is along the plane of shear (instantaneous) high speed torsion can be drastic
45
4 steps of recovery of a bone fracture
blood escapes from ruptures blood vessels and form a hematoma
spongy bone forms near developing blood vessels, fibrocartilage forms in more distant regions
fibrocartilage replaced by boney callus
osteoclasts remove excess bony tissue/making new bone structure much like original
46
How to develop spongy bone in a gap
workable gap to develop spongy bone
perturbations will stop the advancement
too small and it will never heal because new material is never loaded - load transferred from side to side and therefore resorbed therefore you dont get a boney callus
47
young vs old bone
compact vs spongy
48
normal and immobilized bone vs load
normal bone can take more before bone integrity is compromised, and immobilized can take less because you lose bone strength by not loading it
49
narrow dynamic compression plate
organize the gap activity
changes load distribution of bone
shared force between plate and bone - rigid plate + surface of endosteal reabsorption = increased cortical porosity because osteoclast thinks we do not need as much material
50
possible solution to plate
bio dissociate plate
51
epileptic patients and bone recovery (3)
decreased bone content because antiepileptics cause vit D deficiency
seizures can disrupt bone remodelling
tonic muscle contractions cause irregular loading
52
does highly loaded bone mean accelerated loading/ roboust development?
G.A ilizarov came up with the idea of external fixation with horizontal wire through leg (compressed unions with movable rods) - loads bony callous - actively immobilized - pulls it apart so callus doesnt get resorbed
53
what promotes osteoblast activity
Increased calcium and loading for bone deposition
54
Total hip replacement started in _______ by _______________
1950 by Charnley
55
Parallel advances between total joint replacement and gait analysis
hip - charnley movements - sutherland
knee - gunston Forces - Inman
Gait analysis enabled joint placement by providing functional assessment design/redesign criteria
56
unassembled total hip
hip implant, femoral head, polythylene liner, acetabular shell
57
Why do they need lots of revision surgeries?
wear at the bearing surface (plastic cup)
| loosening of metallic femoral head
58
Risks of total hip replacement in younger patients
fracture of femoral stem
lifetime loosening of fixation
a lot needs second injuries
59
most stress on the hip replacement
stress on bottom of femoral implant and femoral head and this causes the osteoclast to resorb bony tissue and the bone thins
implant takes more of the loading of the medial aspect often resorbs due to unloading
60
pros and cons if the hip replacement is thinner (4)
more elastic, better load transfer, easier to fracture, smaller surface for weight bearing
61
pros and cons if the hip replacement is thicker (4)
less elastic
little load transfer
resistant to fractures
larger surfaces for weight bearing
62
improved design of the hip replacement
better load transfer
fins limit rotation and promote bony growth
better biological behaviour
63
solving the THR design conundrum - clinical biomechanics
moments and counter moments overload tissues at pivot point
| force plates to assess loading on the ground
64
Solving the THR design conundrum - experimental biomechanics
Gluteus maximus/abductor distance is small
strain gauges fro medial and lateral side of loading/biological loading of real femur to keep bone healthy
65
total force = 0 at the hip how?
-gluteus maximus - bodyweight +fsupportof hip
66
longer femur
more loading
67
safe phases of gait
pre initiation
Double limb support?
post termination
68
3 componenets of gait
bones - stable multisegment structure
muscles - energy transfer system
sensory motor closed loop control system
69
power if paradox
exercise's promise for rural and urban canadians living with pd
70
historical research with pd
deficit and what neurological foundation makes them exist?
retrospective
theoretical
important but inaccessible to patients
71
PD
chronic and progressive motor (resting tremor, stiffness and rigidity, slowness of movement, gait and balance problem as legs do not move with will, 70% fall every year) and non-motor (apatheric, depressed) disorder because of the lack of dopamine in basal ganglia
72
New research with pd
persistent skills and what that indicates of their neuromechanical potential - accessible and important as it capitalizes applied theory perspective
biopsychosocial benefits and overcome biopsychsocial barriers
73
paradoxical kinesias
surprised movements that use tricks to powerful rehab, so they're enjoyable and functional therapeutic exercises and ADL
can be aroused from negative or positive emotional arousal
74
Why is there low levels of PA support
low levels of support due to lack of experience/comfort of health care professionals, more than 90% had little or no info about the benefits of PA
75
age of PD
10% is younger than 50 years
| doesnt just happen to old people and doesnt make you old
76
Why isolation and stress of PD patients
three years between symptoms and diagnosis of PD with GPs and and neurologists and limited support
77
muscle activation increases
after activity
78
sensorimotor enhancement could be from
```
(cues to move)
- sound
- visual
- proprioception
- smell
which activates neurological networks underneath
```
79
phase 1 of experiments
preliminary and feasibility
80
phase 2 of experiments
futuristic - intervention such as skating training and technical
81
2 experimental studies
motion tracking skates
| music and walking dual task
82
to increase balance one could (4)
bigger base of support, lower centre of mass, further into perturbation so CoM has bigger distance to travel
internal resistance
83
centre of pressure
at the bottom between ground and body
84
6 components to balance
```
bones
muscles
sensorimotor system
proprioceptive
visual
vestibular
```
85
mean elliptical sway area
measure of magnitude of balance, decrease in older adults after fitball training
86
peak plate velocity
measure of rate of balance. decrease in older adults after fitball training
87
to isolate a component
take different components away
- blind/manipulate vision
- manipulate proprioception
- presence of sound
88
PD patient balance with only vision
2 central points of balance - mediolateral
89
What and persistant skills bring psychosocial advantages
supported in community health and rec settings
90
osteoperosis
large holes/gaps in bone matrix
| think cortical bones with thin trabeculae
91
osteoarthritis
```
worn cartilage
rough weight bearing surface
narrow joint space
denatured bone at bone cartilage interface
damage along weight bearing surface
```
92
metal stem of hip replacement
weight bearing against plastic cup which is glued to the socket and the stem is hammered into the long bone
93
Gunsten knee replacement
metal stem bearing against plastic cup
stem into distal bone
cup glued to proximal long bone
94
acetabular shell of total hip replacement
low friction
| screw holds it in place
95
second generation of acetabular shell
with more cement
96
elastic mismatch
rigid stem but biological and flexible femur
97
increased calcium
increased osteoblast activity and bone deposition
98
stress shielding
implant takes more of the loading along medial aspect
99
2 components to maintaining balance
projection of center of mass and correction afterwards
