Biomechanics

Question 1

Class I lever

Answer 1

fulcrum between effort and load, atlantooccipital joint, effort and load in opposite directions

Question 2

Class II lever

Answer 2

load is between effort and fulcrum, calf contraction at the ankle, overall load and effort in the same direction

Question 3

Class III lever

Answer 3

(most common) the effort between load and fulcrum, elbow joint, effort and load in the same direction

Question 4

Synarthroses

Answer 4

Immovable, skull sutures - fibrous joints

Question 5

Amphiarthroses

Answer 5

Slightly moveable, vertebrae and discs - cartilaginous joints

Question 6

Diarthroses

Answer 6

freely moveable, knee and shoulder - synovial joints

Question 7

Ball and socket

Answer 7

shoulder (movement in all directions)

Question 8

Hinge joint

Answer 8

elbow (opens and closes along one plane)

Question 9

Condyloid joint

Answer 9

fingers (MCP) , TMJ (everything but rotation)

Question 10

Pivot joint

Answer 10

rotation around the elbow (ulna and radius) (rotary, one bone that can swivel in a ring formed from a second bone)

Question 11

Gliding joint

Answer 11

carpal rows (plane joint)

Question 12

Saddle joint

Answer 12

thumb - CMC joint (move back and forth and side to side)

Question 13

AC joint

Answer 13

inferior rotation during first aspect of abduction

Question 14

SC joint

Answer 14

anterior rotation and anterior translation (horizontal abduction); posterior rotation and translation (horizontal adduction)

Question 15

SI joint nutation and counter-nutation

Answer 15

lumbar extension= SI joint nutates; as lumbar flexes, SI joint counter-nutates and moves posteriorly

Question 16

Coupled cervical motions

Answer 16

lateral flexion coupled with vertebral body rotation to the same side (LLR=LR), except at C0-1 and C1-2 where it contralaterally rotates (these two segments don’t have vertebral bodies)

Question 17

Lumbar coupled motions

Answer 17

if extended vertebral bodies rotate to the opposite side of lateral bending (LLR= RR); if flexed vertebral bodies rotate towards the same side of lateral bending (LLR=LR)

Question 18

Thoracic coupled motions

Answer 18

Same as Lx

Question 19

Gait cycle stance phase

Answer 19

heel strike, loading response, mid-stance, terminal stance, pre-swing

Question 20

Gait cycle swing phase

Answer 20

initial swing (toe-off), mid-swing (foot clearance), terminal swing

Question 21

Heel strike foot position

Answer 21

supinated position, strong rigidity in arches

Question 22

Mid-stance foot position

Answer 22

pronation, shock absorber

Question 23

Terminal stance foot position

Answer 23

supination, more rigid again

Question 24

Swing phase position

Answer 24

toe off, maximal hip extension, swing phase allow bringing through

Question 25

Thoracic facet orientation

Answer 25

coronal

Question 26

Lumbar facet orientation

Answer 26

sagittal

Question 27

Shoulder abduction/adduction

Answer 27

for the first 90 degrees of shoulder abduction, there is an inferior rotation of the AC joint
from 90-180, there is superior translation of the clavicle in addition to inferior rotation/tipping of the scapula

Question 28

Shoulder horizontal abduction

Answer 28

when the shoulder is horizontally abducted there is posterior rotation of the SC joint in addition to anterior translation of the joint

Question 29

Shoulder horizontal adduction

Answer 29

when the shoulder is horizontally adducted there is anterior rotation of the SC joint in addition to posterior translation of the joint

Question 30

what type of joint is the first CMC

Answer 30

saddle

Question 31

what type of joint is MCP

Answer 31

condyloid

Question 32

where is the most rotation in the c-spine

Answer 32

C1-C2

Question 33

where is the most flexion in the c-spine

Answer 33

C0-C1

Question 34

15 year old had apophysis of ileum fused, how much longer till full fusion

Answer 34

2-3 years, fully fused by 16 years of age

Question 35

shoulder at 90, arm at 90 what plane are you testing external rotators in

Answer 35

sagittal

Question 36

gymnast rolling forward, what plane of motion is this in

Answer 36

sagittal

Question 37

abductors/adductors are tested in what plane

Answer 37

frontal/coronal

Question 38

weak leg abduction, what plane of motion

Answer 38

coronal/frontal