Biomechanics

The rise in passive tension of a muscle usually begins:

• after activation

• before activation

• in shortenend positions

• in the midrange of motion

• at the end range of motion

With upward motion positive, what is the linear velocity of a person's center of mass in the countermovement of a vertical jump?

• positive

• zero

• negative

• not enough information to answer

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

A person flexing their shoulder with a positive angular velocity will likely have what acceleration near the end range of motion?

• zero

• negative

• positive

• not enough to answer

In a sit-to-stand movement, the trunk extends from a 45 degree position up to vertical (0 degrees) in 0.5 seconds. What is the average angular velocity (in deg/sec) of trunk rotation?

• -90

• -45

• 0

• 45

• 90

The peak force acting on the feet in landing can be decreased by:

• decreasing momentum

• decreasing time of landing

• increasing impulse

• increasing time of landing

• making leg joints more stiff

Tags

NGSS.HS-PS2-3

Lifting heavy objects close to the body is important to protect the lower back because:

• the moment arm for the weight of the object decreases

• the arms are used more

• the torque created by gravity increases

• the back muscles angle of pull is improved

• it equalizes forces on both sides of the body

A 180 lb diver stands at the edge of a diving board 5 feet from the support under the board. Ignoring the mass of the board, what is the size of the gravitational torque created by the diver's body?

• 0

• 28

• 36

• 92

• 900

An exercise leader selected bent-leg (small knee flexion) calf muscle group stretches over straight-leg stretches because:

• this increases the passive torque in the calf muscles

• this focuses more stress on the gastrocnemius

• this increases stress in the knee joint capsule

• this focuses more stress on the soleus

• not enough information to answer

The activation of different motor units in a muscle is called

• depolarization

• rate coding

• firing rate

• recruitment

• inhibition

In biomechanics, what is the primary function of tendons?

• To connect muscles to bones

• To connect bones to bones

• To provide cushioning between bones

• To produce red blood cells