Intro to Normal Gait Flashcards
What makes up the kinetics of gait?
Center of Mass, Ground Reaction Forces, Joint Moments/Torques, Center of Pressure
What makes up normal gait energetics?
Work, Energy, Power
What is the Center of Mass?
Point where all mass of body is assumed to be concentrated
What is the Ground Reaction Force?
Force exerted by the ground on a body in contact with it
What are the three components of the GRF?
Vertical, Anterior/Posterior, Medial/Lateral
What are the internal forces of movement?
Active - muscles, ligaments, working against gravity // Passive - non-contractile tissues
What are the external forces of movement?
Gravity, external weights
To understand forces of movement, you also need to understand what 3 things?
Magnitude of the torque, Direction of the force, and Point of Application (insertion of working muscle to fight the force)
What is internal torque created by?
muscles and soft tissues
What is external torque created by?
GRFs
How do you define torque?
The direction of it (CW/CCW), and axis/point of rotation
How to determine the direction of a torque?
based on joint position in relation to the GRF
What are sagittal plane forces?
flexion - extension
what are frontal plane forces?
abduction - adduction / valgus - varus / inversion - eversion
what are transverse plane forces?
rotational torque
Movements for open-chain knee flexion?
free limb, tibia on femoral
movements for closed-chain knee flexion?
fixed limb, femoral on tibia
What is Center of Pressure? (CoP)
point of application of GRF vector / not a point of greatest force/pressure
What are the 3 systems of balance input?
vision, vestibular, and somatosensory
What are the requirements of balance applied to gait?
Postural Orientation and Postural Equilibrium
What does Postural Orientation involve?
active alignment of trunk and head with respect to gravity, support surfaces, visual surroundings, and any internal references
What does Postural Equilibrium involve?
coordinating movement strategies to stabilize the CoM during self-initiated and externally triggered disturbances of stability
How does Visual Input contribute to gait?
visual flow cues help us determine our speed of locomotion, influence alignment of body with reference to gravity and environment
How does Vestibular Input contribute to gait?
otolith organs detect angle of head with respect to rotation, stability of head in sagittal plane, vertical reference for control of trunk in space
