Final answer:
Changes in the base of support affect balance and stability. Standing up, moving to a staggered stance, and lifting one foot off the ground are all examples of changes to the base of support. Thus, 'All of the above' is the correct answer to the question.
Step-by-step explanation:
The term 'base of support' refers to the area beneath an individual or object that includes every point of contact that the individual or object makes with the supporting surface. Changes in the base of support can affect balance and stability. Looking at the options provided, standing up from a chair, moving to a staggered stance from a standing position, and lifting one foot off the ground from a standing position all reflect changes in the base of support.
- (a) When a person stands up from a seated position, they change their base of support from the chair's surface area to their feet.
- (b) Moving to a staggered stance from a standing position alters the base of support by modifying the arrangement of the feet and hence the ground area supporting the body.
- (c) Lifting one foot off the ground definitely changes the base of support since the body is then supported by just one foot rather than two.
Therefore, all of these actions involve a change in base of support, making the correct answer (d) All of the above.