Center of Gravity and Stability – MCQs

1. The center of gravity (COG) of the human body is defined as:
(A) The point where body weight is equally balanced in all directions
(B) The point of maximum muscle force
(C) The midpoint of the spinal cord
(D) The center of the chest cavity

2. In an adult standing upright, the COG is located approximately:
(A) At the level of the second sacral vertebra (S2)
(B) At the thoracic spine
(C) At the cervical spine
(D) At the lumbar vertebra L5

3. Stability of the body increases when:
(A) Base of support is wide
(B) Center of gravity is high
(C) Line of gravity falls outside the base
(D) Body mass decreases

4. Which factor reduces stability?
(A) Narrow base of support
(B) Low center of gravity
(C) Greater body weight
(D) Line of gravity inside base

5. The line of gravity should fall:
(A) Within the base of support for stability
(B) Outside the base of support for stability
(C) At the highest point of the body
(D) Parallel to the spine always

6. Stability is directly proportional to:
(A) Size of base of support
(B) Shortness of body
(C) Distance from the ground
(D) Narrowness of stance

7. Lowering the center of gravity makes a person:
(A) More stable
(B) Less stable
(C) Equally stable
(D) Completely unstable

8. A tightrope walker extends arms to:
(A) Increase base of support
(B) Decrease body weight
(C) Raise center of gravity
(D) Shorten line of gravity

9. The broader the base of support:
(A) The greater the stability
(B) The lower the stability
(C) The less the balance
(D) The weaker the posture

10. Which posture is most stable?
(A) Squatting position
(B) Standing upright
(C) Standing on tiptoes
(D) Balancing on one foot

11. The line of gravity is an imaginary line:
(A) Passing vertically through the center of gravity
(B) Passing horizontally across the body
(C) Passing diagonally across the spine
(D) Passing only through the feet

12. Stability decreases when:
(A) Center of gravity is raised
(B) Base of support is widened
(C) Weight increases
(D) Line of gravity is central

13. Which of the following enhances stability in sports?
(A) Bending knees and lowering COG
(B) Standing tall on tiptoes
(C) Keeping legs close together
(D) Shifting COG outside base

14. Static stability refers to:
(A) Maintaining balance while stationary
(B) Maintaining balance while moving
(C) Changing posture rapidly
(D) Controlling acceleration

15. Dynamic stability refers to:
(A) Maintaining balance while in motion
(B) Standing still
(C) Reducing body weight
(D) Restricting movement

16. An acrobat balances on one hand by keeping:
(A) Line of gravity inside the base (hand)
(B) COG outside the hand
(C) Base of support very wide
(D) Center of gravity raised high

17. Elderly people are prone to falls due to:
(A) Higher COG and reduced stability
(B) Lower COG
(C) Wide base of support
(D) Increased balance reactions

18. Which sport uses low COG for stability?
(A) Wrestling
(B) Gymnastics
(C) Swimming
(D) Running

19. The relationship between balance and COG is that:
(A) Lower COG increases balance
(B) Higher COG increases balance
(C) COG position does not matter
(D) Stability is independent of COG

20. A person carrying a heavy load should:
(A) Lean forward to keep COG within base
(B) Lean backward
(C) Stand upright without leaning
(D) Shift COG outside base

21. High-heeled shoes reduce stability because:
(A) They raise the center of gravity
(B) They widen the base
(C) They lower body mass
(D) They increase line of gravity length

22. Balance can be maintained when:
(A) Line of gravity falls within base of support
(B) Line of gravity falls outside base of support
(C) Base of support is very narrow
(D) Center of gravity is raised high

23. Gymnasts spread arms and legs while landing to:
(A) Increase stability by widening base of support
(B) Decrease stability
(C) Raise center of gravity
(D) Reduce weight

24. An object is said to be in equilibrium when:
(A) Line of gravity passes through base of support
(B) Line of gravity is outside base
(C) Center of gravity is highest
(D) Base of support is narrow

25. A standing person is more stable when:
(A) Feet are wide apart
(B) Feet close together
(C) Standing on one leg
(D) Standing on toes

26. The stability of an object depends on:
(A) Height of COG, base of support, and line of gravity
(B) Color of the object
(C) Shape of muscles
(D) Weight only

27. Moving COG closer to ground improves:
(A) Stability
(B) Instability
(C) Motion only
(D) Acceleration only

28. Which of the following reduces stability in walking?
(A) Faster speed and narrower base
(B) Wide stance
(C) Low COG
(D) Strong posture

29. When a person is standing on a bus that suddenly stops, they fall forward because:
(A) Line of gravity shifts outside base
(B) COG lowers
(C) Base of support widens
(D) Stability increases

30. The wider the base of support in martial arts:
(A) The greater the stability
(B) The lesser the stability
(C) The weaker the posture
(D) The higher the COG

31. Stability in standing is least when:
(A) Feet together, arms overhead
(B) Squatting
(C) Feet apart and knees bent
(D) Sitting down

32. In biomechanics, balance is the ability to:
(A) Maintain COG within base of support
(B) Keep spine erect only
(C) Keep limbs still
(D) Reduce body mass

33. Why does a wider base increase stability?
(A) It allows the line of gravity to fall within the base over a greater area
(B) It lowers the center of gravity
(C) It increases body weight
(D) It reduces height

34. A standing soldier at attention has:
(A) Less stability compared to wide stance
(B) More stability
(C) Maximum stability
(D) Dynamic stability

35. Balance reactions help in:
(A) Restoring COG within base of support
(B) Raising the COG
(C) Reducing body mass
(D) Widening base only

36. Stability is influenced by body mass because:
(A) Heavier objects require more force to topple
(B) Lighter objects are more stable
(C) Weight does not affect stability
(D) Heavier objects always fall quickly

37. Line of gravity must pass:
(A) Through the base of support for stability
(B) Outside the base for stability
(C) Above the head
(D) At the hands

38. A pyramid shape is stable because:
(A) Low COG and wide base
(B) Narrow base and high COG
(C) Heavy top
(D) Line of gravity outside base

39. Which factor is NOT directly related to stability?
(A) Shape of the nose
(B) Base of support
(C) Line of gravity
(D) Center of gravity

40. Children are less stable because:
(A) Higher relative COG
(B) Wider base
(C) Heavier weight
(D) Larger bones

41. An athlete starts low at the beginning of a race to:
(A) Lower COG and increase stability before moving
(B) Raise COG for speed
(C) Reduce base of support
(D) Eliminate stability

42. The plank position has reduced stability because:
(A) Narrow base of support and high COG
(B) Wide base and low COG
(C) Base and COG aligned
(D) Greater weight

43. A person on crutches widens stability by:
(A) Enlarging base of support
(B) Raising center of gravity
(C) Narrowing line of gravity
(D) Reducing body weight

44. Lower limb prostheses must consider:
(A) Proper COG alignment
(B) Color of prosthesis
(C) Shoe size
(D) None of these

45. Gymnasts balance on beams by:
(A) Keeping COG over the narrow base
(B) Raising COG above shoulders
(C) Increasing weight
(D) Shortening arms

46. Stability is best described as:
(A) Resistance to disturbance of equilibrium
(B) Inability to move
(C) Flexibility of joints
(D) Decrease in posture

47. An inverted cone is unstable because:
(A) High COG and narrow base
(B) Wide base and low COG
(C) Heavy bottom
(D) Low weight

48. In rehabilitation, balance training focuses on:
(A) Controlling COG within dynamic bases of support
(B) Increasing weight
(C) Lowering height only
(D) Widening feet permanently

49. Which factor contributes to stability in sitting?
(A) Wide base (buttocks and thighs) and low COG
(B) Narrow base
(C) Raised arms overhead
(D) Standing posture

50. The study of COG and stability is important in physiotherapy for:
(A) Balance training and fall prevention
(B) Digestion improvement
(C) Vision correction
(D) Breathing exercises