Deck 2: The Mechanics of Movement

Question 1

Which of the following factors is key to preserving dynamic trunk stability?

A) A neutral pelvis
B) Decreased or reduced lumbar lordosis
C) Extension of the hips
D) Flexion of the spine

Answer 1

A

Question 2

Which statement regarding levers in movement is true?

A) An axis of movement and a single source of force are required to establish a lever.
B) For a basic lever, usually there are two external or two internal forces.
C) In the human body, levers usually involve a single force and axis of motion.
D) Levers are utilized in the body when an external force is countered or controlled by muscle force.

Answer 2

D

Question 3

You are preparing to transfer a patient who just had bilateral knee replacements from the bed to the bedside chair. The patient is much taller than you are, and you want to make sure that the transfer is safe for you and the patient. As you face the patient, you determine that blocking both knees is not required. Which of the following positions is the best way to position your feet?

A) Place your feet about 10 in. apart and staggered.
B) Place your feet about 20 in. apart and side by side.
C) Place your feet about 30 in. apart and staggered.
D) Place your feet about 40 in. apart and side by side.

Answer 3

C

Question 4

Match the following terms to their definitions.
A. Pulling that tries to stretch or lengthen tissue
B. The amount of force across a given area
C. The force applied to a given area
D. Twisting force about a structure's axis
E. Two opposite direction forces, parallel to contacting surfaces
Stress

Question 5

The concept of momentum is derived from Newton's Second Law of Motion. In which of the following scenarios is momentum most likely to be an element that needs to be controlled?

A) A patient is bridging in the bed to scoot to the right.
B) A patient is rolling from his back to his right side.
C) A patient is transferring from the floor to standing using a chair for support.
D) A patient is walking with crutches and a full leg cast.

Question 6

Which of the following is an example of an internal force commonly used when assisting patients with movement?

A) Ankle weights
B) Friction
C) Gravity
D) Muscular tension

Question 7

Your patient just had surgery on her right knee to repair an injury she sustained while playing volleyball. The physician has ordered "open chain" exercises. Which of the following activities would be most appropriate for this patient?
A) Mini-wall squats with the right foot up on a step
B) Sitting on the mat and straightening the right knee
C) Knee flexion and extension with resistance tubing while standing on the tubing
D) Supine bridging with both legs
A) Mini-wall squats with the right foot up on a step

A) Pulling that tries to stretch or lengthen tissue
B) Sitting on the mat and straightening the right knee
B) The amount of force across a given area
C) Knee flexion and extension with resistance tubing while standing on the tubing

Question 8

Which of the following is the best definition of center of mass?

A) The balance point of an object
B) The direction of movement when weight is added
C) The point directly behind the gravity pull
D) The push or pull that modifies movement

Question 9

Which of the following force-couple applications is less than optimal for patients to use when preparing to transition from sitting to standing?

A) Leaning forward and pulling up with both arms supported on the walker
B) Leaning forward and using the hip and thigh muscles to achieve liftoff
C) Pushing the upper trunk into the back of the chair while sliding the pelvis forward
D) Shifting from side to side to walk the hips forward to the front of the chair

Question 10

To understand the fundamental principles of movement, it is most important to know which of the following?

A) The amount of ground reaction force in Newtons
B) The direction of force application
C) The distance between the center of mass and the BoS
D) The exact measure of inertia to be overcome

Question 11

Match the following terms to their definitions.
A. Pulling that tries to stretch or lengthen tissue
B. The amount of force across a given area
C. The force applied to a given area
D. Twisting force about a structure's axis
E. Two opposite direction forces, parallel to contacting surfaces
Shear

Question 12

When considering how the concept of center of mass affects your patient's movement, which of the following statements is true?

A) Center of pull is another term for center of mass.
B) Each body part, such as a leg or an arm, has its own center of mass.
C) The whole body has a center of mass that cannot be localized.
D) When weight is added to body, the center of mass moves away from the added weight.

Question 13

Your patient has been in bed for the past 7 days with a case of acute pneumonia. You are going to help her stand for the first time since she became sick. Which of the following muscle actions will be needed for the patient to successfully stand?

A) The back extensor muscles must be able to counteract inertia.
B) The hip extensor muscles must be able to control the LoG.
C) The knee extensor muscles must be able to counteract gravity.
D) The knee flexor muscles must be able to control the CoM.

Question 14

The primary reason we are interested in biomechanics as physical therapists is that

A) understanding biomechanics will ensure that we do not sustain common injuries affecting the lower back.
B) we need to be able to explain moment and lever arms to our patients.
C) we need to know how to move twice our own body weight safely.
D) we need to be able to apply biomechanical principles to assist patients safely and efficiently.

Question 15

Match the following terms to their definitions.
A. Pulling that tries to stretch or lengthen tissue
B. The amount of force across a given area
C. The force applied to a given area
D. Twisting force about a structure's axis
E. Two opposite direction forces, parallel to contacting surfaces
Tension/tensile forces

Question 16

Which of the following statements regarding vectors and representation of movement forces is true?

A) For internal forces, the tail of the arrow lies at the muscle attachment on the moving lever of the muscle exerting the force.
B) Gravity is only depicted as a vertical arrow with the tail of the arrow originating behind a point at about S2.
C) Muscle contraction force is depicted with an arrow pointing opposite the combined effect of the muscle fibers.
D) The arrow on the vector is straight and points in the direction away from force exertion.

Question 17

Which of the following would be most effective in promoting stability during patient-care activities?

A) Increase the distance of the center of mass above the BoS.
B) Minimize the BoS
C) Position the LoG posterior to the BoS.
D) Position the LoG near the center of the BoS.

Question 18

If your patient has developed muscle atrophy while on a ventilator in the ICU, what is the most likely the cause?

A) The appropriate amount of load applied to the tissues
B) Too little load applied to the tissues
C) Too much load applied to the tissues
D) Repeated rapid load to the tissues

Question 19

Match the following terms to their definitions.
A. Pulling that tries to stretch or lengthen tissue
B. The amount of force across a given area
C. The force applied to a given area
D. Twisting force about a structure's axis
E. Two opposite direction forces, parallel to contacting surfaces
Torsion

Question 20

Match the following terms to their definitions.
A. Pulling that tries to stretch or lengthen tissue
B. The amount of force across a given area
C. The force applied to a given area
D. Twisting force about a structure's axis
E. Two opposite direction forces, parallel to contacting surfaces
Pressure