IMU and EMG Flashcards
Kinematics
describing motion
speed, acceleration, joint angels
kinetics
decribing forces
force, moments
IMU definition
Inertial measurement unit
IMU sensors
Accelerometer
Gyroscope
Magnetometer
Accelerometer function
linear acceleartion
movement and tilt
gyroscope function
angular velocity
rotational movement
magnetometer function
earths magnetic field
fixed coordinate system
sensor fusion
combining different sensors to improve accuracy and stability, reduces noise and drift
outcome parameters IMU
joint angels
segment orientation
velocity
acceleration
Advantages IMU
mobile
cheap
quick setup
raw data allows for custom sensor fusion
disadvantages IMU
sampling frequency (too much vs too little data)
requires software
sensitive to noise and drift
no calibrated floor, no absolute position
ecological validity
how much does the setup represent a natural complex real-world scenario
EMG definition
Electromyography
All or none principle
threshold need to be reached to create muscle contraction
size principle
small fibers (type I) are recruited before large fibers (type II)
EMG signal
summe of superimposed MUAPs
MUAP definition
motor unit action potential
amplitude EMG
estimate of muscle contraction level
Frequency EMG
related to fatigue
considerations EMG
tissue characteristics
intermuscular cross-talk
electrode movement
electrical noise
limitations EMG
interindividual comparison is hard
repeated measurement are hard
comparing different muscle
