Centre of mass & Stability

What is centre of mass?

point at which a body is balanced in all direction

Application of centre of mass to fosbury flop?

Approach - J curve, jump over backwards
Take off - lift arms and knees, CoM is high
Flight - CoM moves outside body under bar, jumper rotates about CoM

What is stability?

ability of a body to resist motion and remain at rest

Factors that affect stability

height of CoM
mass of body
base of support
line of gravity
points of contact

What is the effect of the height of centre of mass?

lower centre of mass, the more stable

What is the effect of the mass of the body?

the greater the mass, greater inertia, so greater stability

What is the effect of the base of support?

wider base of support, greater stability

What is the effect of line of gravity?

if line of gravity is in base of support, it increases stability

What is the effect of points of contact?

more points of contact means better stability

Why might performers want to minimise stability?

reduce movement time
increase speed
change direction
rotation
increase range of motion

What can happen to a centre of mass?

-can be manipulated by body position
-can move outside body to act as a point of rotation