Lecture 2 Flashcards
What is gait analysis used for?
To determine why people walk the way they do and then help make improvements to their cycle
(e.g. sports performance, surgical planning, prothesis design, rehabilitaion)
What is a key paramter that can change the typical/normal gait cycle of a patient?
Walking speed
What are the requirements for capturing movement?
Camera calibration
A coordinate system for the lab
Reflective markers
What is the name of the kinematic model that is normally used?
Conventional gait model (CGM)
(…or Newington, or Davis, or VCM, or PiG, or…)
What is the joint in relation to rigid segments?
The joint serves as a connection between 2 rigid segments
What are the anatomical planes?
Frontal (shoulder to shoulder)
Sagittal (Front to back)
Transversal/Axial (top to bottom)
How are the coordinate systems traditionally arranged?
Origin - at the anatomical centre of adjacent joints
Z-axis = Up is positive
Y-axis = left is positive (medial -lateral directions)
X-axis = Posterior-anterior (positive is forward)
What are the top and bottom of the femur?
The femoral head is the ball at the hip joint centre (HJC)
The base is at the knee joint centre (KJC)
Origin is at the KJC
What is extension?
The lengthening of a muscle
What is flexion?
The shortening of a muscle
Which joint centre does the foot rotate around?
The ankle joint centre (AJC)
Which direction is foot dorsiflexion and which direction is foot plantarflexion
Dorsiflexion is when the foot lifts up (this is the positive direction)
Plantarflexion is when the foot points down (this is the negative direction)
[Remember: PLANTING of the foot requires the foot being in contact with the ground]
What do the colours of the lines in a kinematic graph indicate?
Red line = left side
blue line = right side
What is the pattern observed in normal hip kinematics?
2 phases in the sagittal plane (flexion to extension, then extension to flexion)
What is the pattern observed in normal pelvic kinematics?
Pelvic tilt should be very stable in the sagittal plane and should be minimally in the anterior direction
What is the pattern observed in normal knee kinematics?
3 phases in the sagittal plane
(3rd phase is a more dramatic bend that comes from the knee bending to help the foot clear the ground)
What is the pattern observed in normal ankle and foot kinematics?
4 phases in the sagittal plane
- plantar (heel touches the ground and foot PLANTARFLEXION moves the sole to the surface)
- The tibia moves forward making the foot experiance dorsiflexion
- Foot and tibia both move forward in preparation for pushoff (plantar)
- Push off occurs and the foot experiences dorsiflexion to move the foot into a position to clear the ground in swing)
What is the main source of error in kinematic measurments?
Marker placement
