Stepping through Science Flashcards
1
Q
The gait cycle overview
A
- Consists of stance and swing phase
- two double support phases and two single support phases
2
Q
Stride vs step
A
- Stride is heel strike to same foot heel strike
- step is heel strike to opposite heel strike
3
Q
Stance Subphase
A
- Loading Response: Initial contact to opposite toe off
- Midstance: opposite toe-off to heel raise
- Terminal stance: heal raise to opposite initial contact
- Pre-swing: Opposite initial contact to toe-off
4
Q
Swing subphases
A
- Initial swing: toe-off to feet adjacent
- Mid-swing: feet adjacent to tibia vertical
- Terminal swing: tibia vertical to initial contact
5
Q
Gait and healthy aging
A
Reductions in
- muscle mass and strength
- motor unit function and number
- endurance (higher metabolic cost)
Changes in the nervous system
- Slow, more variable and asymmetric gait
- Sensory declines (vision and proprioception, spatial awareness)
6
Q
Spatial temporal parameters and their change in age
A
- Stride length
- Step height
- Cadence
- Speed
- Base of support
- All decrease except BoS widens
7
Q
Sensor based measuring tools
A
- Force Plates
- Inertia measurement units
8
Q
Camera based measurement tools
A
- Marker-based motion capture
- Marker-less motion capture
9
Q
Force Plates
A
- Sensorized boards (piezoelectric - convert electrical signal to force or strain gauge - deformation based)
- Operate based on newtons 3rd law: equal and opposite reaction
- Used to measure GRF
10
Q
GRF through the gait cycle
A
- Heel Strike: small backwards
- Loading: large backwards
- Midstance: medium up
- Push-off: large forward
- Toe-off: small forward
11
Q
IMUs
A
- Main circuit board
- 3 sensors (accelerometer, gyroscope, magnetometer)
- 3 dimension axis for each sensor (9 total)
- Operate off Newton’s 1st law (inertia)
- Utilize sensor fusion - combining multiple sensors to get whole picture, allows calculation of joint angles
12
Q
Marker(-less) motion capture
A
- Utilizes many cameras - require calibration (create point of reference) and may require markers
- Cameras help see video to match data with movements
- Clothing can interfere with data collection
- Software compiles data, digitizes the points in space, estimates joint angles/forces
13
Q
What is knee osteoarthritis
A
- Non-curable, degenerative joint disease impacting 4 million Canadians
- Most commonly affects medial compartment (takes 60-80% of load)
- Associated with aging abnormal joint loading - injury, obesity
14
Q
Joint changes in knee OA
A
- Osteophyte formation (bone spurs)
- Degenerating cartilage
- Inflammation surrounding tissues (bursa or meniscus)
- Irritated or damaged articulating surfaces
15
Q
Knee Flexion Angle
A
- Knee absorbs impact through slight flexion
- Knee begins to extend during stance phase
- Nearing toe-off, knee flexes closer to toe-off
- Flexion continues through mid-swing
- knee extension in preparation for heel strike
16
Q
Knee flexion angle in knee OA
A
- Decrease in overall knee flexion
- Stiff knee gait
- total knee arthroplasty can improve knee flexion
17
Q
Knee Adduction Movement
A
- force applied to medial side off knee through adduction
- Prozy measure for knee loading
- Increases in KAM indicate: disease progression, increased pain, decreased function
18
Q
Foot progression angle
A
- Measured relative to the direction of travel (calcaneus to 2nd metatarsal)
- Gait modification for FPA is easy, effective and can be done out of clinic
19
Q
KAM plot in relation to FAP
A
- KAM higher when toe out during early stance phase
- KAM higher when toe in during late stance phase
20
Q
MOCAP and foot progression angle
A
- markers on 1st metatarsal, 5th metatarsal, calcaneus
- midpoint between 1st and 5th used to find direction of foot
- several steps taken to determine direction of travel
- direction of travel compared to direction of foot on average to determine foot progression angle
