TOPIC 30A. Statics of the forelimbs in horses, the phases of the step on the distal end of the forelimb

Question 1

What are statics

Answer 1

describe the maintenance of equilibrium in state of rest/motion

Question 2

statics of forelimb

Answer 2

main supporters of trunk (55%)
elastic spring like apparatus
shock absorber system

Question 3

Proximal buffers

Answer 3

1. biceps tendons and lacertus fibrosus
2. triceps long head
3. m ext carpi radial
4. m flex carpi ulnaris

Question 4

distal supports

Answer 4

1. sesamoid ligaments
2. SDF and DDF tendons (check ligs)
3. M interosseus medius (Tractus Apposticus)

Question 5

what ability in eq aid in standing w/o tiring

Answer 5

passive stay apparatus (locking ability)

Question 6

name the most important suspensory muscle of the trunk

Answer 6

m serratus ventralis (pars cervicis and pars thoracis)

Question 7

how is the shoulder joint prevented from collapsing

Answer 7

collateral ligaments medial and lateral - m infraspinati and m subscapularis

Question 8

what structure plays major role in preventing shoulder joint from buckliing

Answer 8

lacertus fibrosus - from biceps to radial carpal extensor

Question 9

How is the elbow prevented from buckling forward

Answer 9

m triceps and SDF

Question 10

How is overextension of the carpal joint prevented

Answer 10

palmar liggs,
carpal liggs,
accessory bone,
interosseus and SDF + DDF

Question 11

what locks the fetlock joint

Answer 11

sesamoidal liggs, suspensory liggs,

Question 12

what protects the pastern joint from hyperextension

Answer 12

has a weak palmar lig - so SDF and DDF help

Question 13

what protects the coffin joint from hyperextension

Answer 13

navicular bone and liggs (same as fetlock - sesamoidal and suspensory)

Question 14

List the elements of the passive stay apparatus of EQ in FL

Answer 14

1. lacertus fibrosus
2. m. interosseous medius + tractus appositus
3. supf. + deep dig. flexor with lig. accessorium
   (proximal, distal check ligaments)
4. suspensory apparatus (fetlock) (sesamoid and suspensory ligaments
5. m serratus ventralis

Question 15

variation in phases of step in FL

Answer 15

varies only in intensity and rhythm - never in order.

Question 16

Thoracic and pelvic limbs 4 phases of movement

Answer 16

1. lift
2. swing
3. support
4. thrust

Question 17

the hanging limb stage includes

Answer 17

the lift and swing phases

Question 18

the supporting limb stages

Answer 18

support and thrust phase

Question 19

one lift phase to the next is the

Answer 19

step

Question 20

the distance covered between the two phases is

Answer 20

the step-length

Question 21

types of walk

Answer 21

quick, normal, slow/shortened

Question 22

step length of the walk

Answer 22

1.3 - 1.8m

Question 23

speed of walk

Answer 23

6-7 km/hr

Question 24

which limb moves first

Answer 24

HL moves before ipsilateral FL (same side)

RH RF LH LF

Question 25

head movements during walk

Answer 25

lowered during swing

lifted during support

Question 26

what happens in shortened walk

Answer 26

swing phase is shortened - hoof brought to ground quicker, can walk backwards but requires more energy

Question 27

what is the stance phase

Answer 27

time the limb is in contact with the ground

Question 28

what is the swing phase

Answer 28

time limb is not in contact with the ground

Question 29

what is the FL support limb

Answer 29

the one supporting the trunk while being propelled forwards by HL

Question 30

how is the thoracic limb raised off the ground

Answer 30

by shoulder girdle muscles and flexion of joints by all flexor muscles

Question 31

in the swing phase, what protracts the limb

Answer 31

brachiocephalic, omo and trap

Question 32

at end of swing phase what extends the joints again

Answer 32

triceps, ext carpi radialis and distal extensors

Question 33

what does the biceps extend

Answer 33

the shoulder and carpus via lacertus fibrosus

Question 34

what joint gets hyperextended

Answer 34

fetlock

Question 35

what happens before the limb is lifted again

Answer 35

the SDF and suspensory lig relax,

DDF and accessory lig tense - so that coffin flexes once foot is lifted again