biomechanics equilibrium (SAC 1)

Question 1

stability and balance

Answer 1

• stability is the resistance to the disruption of equilibrium
• balance is the ability to control equilibrium
  (increased stability = increased balance)
  e.g wrestlers, increased base of support
  decreased stability = decreased balance
  e.g swimmers, small diving block

Question 2

factors effecting equilibrium: friction

Answer 2

• increased friction = increased stability
  e.g surfer and wax

Question 2

factors effecting equilibrium: base of support

Answer 2

• base of support is the area bound by the outside edges of body parts in contact with the surface
  larger base of support = greater stability

Question 3

factors effecting equilibrium: body mass

Answer 3

• if all forces are equal the body with the greatest mass will be most stable
  (greater mass = greater force required to move it)

Question 3

factors effecting equilibrium: centre of gravity

Answer 3

• point at which it’s weight is balanced, regardless of the position of the body
  (higher C.O.G = decreased stability)
  (lower C.O.G = increased balance and stability)
  e.g flexing hips, bending knees, flex ankles = lower C.O.G

Question 4

line of gravity

Answer 4

• direction at which gravity acts through the body
• L.O.G through B.O.S = increased stability
• L.O.G outside B.O.S = decreased stability
  (L.O.G OUTSIDE CAN BE AN ADVANTAGE)
  e.g sprinting of starting block means the runner is unstable an can accelerate faster
  e.g adding a spin in discus adds increased angular velocity and more momentum/force helping to throw further