Chapter 4 Biomechanics

The water content of bone makes up approximately what percentage of the total bone weight?

25% - 30%

After age 60, what percentage of fractures are osteoporosis related?

90%

Which of the following is a possible symptom of osteoporosis? A. vertebral crush fractures B. reduced body height C. dowager's hump D. all of the above

D. all the above

A fracture caused by a tendon or ligament pulling a small chip of bone away from the rest of the bone is called what?

Avulsion fracture

The "female athlete triad" can result in which of the following? A. stress fractures B. irreversible bone loss C. death D. both A and B E. all of the above

E. all of the above

Which of the following is true regarding epiphyseal plate injuries? A. These injuries can terminate longitudinal bone growth. B. These injuries can result from acute trauma. C. These injuries can result from repetitive loading of a low magnitude. D. both A and B E. all of the above

E. all of the above

Which of the following is/are part of the "female athlete triad"? A. osteoporosis B. disordered eating C. cessation of menses D. both A and B E. all of the above

E. all of the above

Which of the following statements is/are true regarding bone growth? A. When bone remodeling occurs, bone mass may stay the same. B. When bone remodeling occurs, bone mass may decrease. C. When bone modeling occurs, bone mass increases. D. both A and B E. all of the above

E. all of the above

Which of the following is known as the longitudinal "growth center" of a bone?

Epiphysis

What is the most common symptom of osteoporosis?

Back pain derived from vertebral fractures

Specialized bone cells that build new bone tissue are called what?

Osteoblasts

Reduced bone mass and density without the presence of a fracture defines what?

Osteopenia

Which of the following is an example of a flat bone?

Scapula

Which of the following terms is used to describe bone with relatively high porosity?

Trabecular

Which of the following is an irregular bone?

Vertebrae

Which of the following activities would likely produce the greatest bone mineral density?

Walking

Which of the following occurs in the absence of gravitational forces?

Bone atrophy

What happens when osteoclast activity exceeds osteoblast activity?

Bone mass decreases

Appropriate strategies to lessen the likelihood of acquiring osteoporosis include which of the following? A. adequate dietary calcium intake B. regular weight-bearing exercise C. both A and B D. none of the above

C. both A and B

In a child, severe injury to an epiphysis may result in which of the following? A. premature closure of the epiphyseal junction B. termination of bone growth C. both A and B D. none of the above

C. both A and B

Which of the following factors can predispose runners to stress fractures? A. increased training duration or intensity without allowing time for bone remodeling B. abrupt changes in running surface C. both A and B D. runners are not predisposed to stress fractures

C. both A and B

Which of the following statements is/are true regarding the strength of bone? A. Cortical bone can withstand more stress than trabecular bone. B. Trabecular bone can withstand more strain than cortical bone. C. both A and B D. none of the above

C. both A and B

Which of the following statements regarding bone growth is true? A. Longitudinal growth continues only as long as the epiphyses exist. B. Circumferential growth continues throughout most of the lifespan. C. both A and B are true D. neither A nor B is true

C. both A and B are true

Which of the following components of bone provides it with flexibility?

Collagen

Cortical bone is strongest in resisting which type of stress?

Compressive test

What happens when osteoblast activity exceeds osteoclast activity? A. bone hypertrophy B. bone modeling C. increased bone mass D. all of the above

D. all of the above

Which of the following is part of the axial skeleton? A. the skull B. the vertebrae C. the sternum D. all of the above

D. all of the above

Which of the following is/are known risk factor(s) for developing osteoporosis? A. smoking B. calcium deficiency C. excessive caffeine consumption D. all of the above

D. all of the above

Loss of bone mass has been found in which of the following? A. bed-ridden patients B. astronauts C. tennis players D. both A and B E. all of the above

D. both A and B

Undesirably low body weight in young female athletes can lead to what? A. amenorrhea B. osteoporosis C. menopause D. both A and B E. all of the above

D. both A and B

Which of the following is true regarding greenstick fractures? A. They are incomplete fractures. B. They are caused by bending or torsional loads. C. They are more common in adults than children. D. both A and B E. all of the above

D. both A and B

Which of the following is true regarding Osgood-Schlatter's disease? A. It occurs at the tibial tubercle where the patellar tendon attaches. B. It is more common in children than adults. C. It is an epiphyseal injury. D. both A and B E. All of the above

E. All of the above

Which of the following could contribute the most in preventing or prolonging osteoporosis?

Girls jumping rope before puberty

How do bones typically respond to stress?

Hypertrophy

Where is articular cartilage located?

It covers all long bone surfaces at articulations

The tarsals are examples of what type of bones?

Long bones

When a skier's body rotates in a direction opposite of the foot (held steady by the boot), what type of fracture is likely in the tibia?

Spiral

Which of the following terms is defined as deformation divided by original length?

Strain

Which type of fracture results from repeated loading of relatively low magnitude?

Stress

Which of the following is part of the appendicular skeleton?

The humerus