BHK Biomechanics 3

Question 1

The concept of 'base of support' is critical to stability. Stability increases when:

Accepted Answer

Center of mass falls inside a wider base of support

Answer

Stability is maximized when the center of mass is low and its vertical projection (line of gravity) falls well within a wide base of support.

Question 2

Impulse in biomechanics is defined as:

Accepted Answer

Force multiplied by time (F × Δt)

Answer

Impulse = Force × time and equals the change in linear momentum of the body, linking force application duration to motion change.

Question 3

Electromyography (EMG) in biomechanics is used primarily to:

Accepted Answer

Record the electrical activity of muscles to infer activation timing and relative intensity

Answer

EMG detects motor unit action potentials, providing information about when muscles are active and their relative recruitment level.

Question 4

In lifting biomechanics, the risk of low back injury is most influenced by:

Accepted Answer

The horizontal distance of the load from the body's center of mass

Answer

Horizontal load distance dramatically increases the moment arm at the lumbar spine, exponentially raising compressive and shear forces on discs.

Question 5

The term 'elastic strain energy' in tendon biomechanics refers to:

Accepted Answer

Energy stored in a stretched tendon that can be released upon recoil

Answer

Tendons store elastic strain energy when stretched (like a spring) and release it during shortening, improving locomotion efficiency.

BHK - Bachelor of Kinesiology Practice Test