Suspensory Stay and Reciprocal Apparatus, Hindleg locking mechanism

Question 1

What is the function of the suspensory apparatus?

Answer 1

Support the fetlock joint during the weight-bearing phase of the stride

Question 2

Main contributing causes for suspensory apparatus injuries:

Answer 2

Uneven loading of the limb during weight bearing (lunge lining),
Uneven ground
Poor foot balance
Rider balance

Question 3

It takes a _____ time to heal suspensory.

Answer 3

Long

Question 4

The structures that make up the suspensory apparatus include:

Answer 4

Suspensory ligament
2 proximal sesamoid bones
Intersesamoidean ligament
Distal sesamoidean ligament
Collateral sesamoidean ligament
Superficial digital flexor tendon
Deep digital flexor tendon

Question 5

The stay apparatus enables the horse to _____ with _____.

Answer 5

Stand for long periods of time with minimal fatigue

Question 6

The stay apparatus consists of _____, _____, and _____ that _____ and _____.

Answer 6

Muscles, ligaments and tendons that stabilize all the joints of the forelimb and the lower joints (fetlock and pastern) of the hind limb.

Question 7

_____ is needed to hold tension on these ligaments and tendons, which in turn prevent _____ and _____.

Answer 7

Minimal muscular activity needed; Prevent flexion of the joints and collapsing of the leg

Question 8

The suspensory apparatus supports the _____ and prevents it from…

Answer 8

Supports the fetlock to prevent it from collapsing and falling to the ground

Question 9

Of the stifle joint: The end of the femur consists of 2 _____ that roll their way back and forth across the articular surface of the _____.

Answer 9

2 condyles; tibia

Question 10

Of the stifle joint: There is the _____, which consists of 2 ridges that serves as a _____ system and provides a track for the _____.

Answer 10

There is the trochlea, serves as a pulley system, provudes a track for the patella

Question 11

Condyles of the stifle joint are _____, while the articular surface of the tibia is _____ and _____.

Answer 11

Condyles - round

Tibia surface is flat and horizontal

Question 12

The articular surfaces of the tibia in the stifle joint do not correspond, so there are 2 _____ inserted between the two bones. The intercondylar eminence separates the two.

Answer 12

Menisci (mandarin shaped cushions)

Question 13

The patella rests in the groove of the _____ and is located underneath the end of the _____. It slides between the _____’s ridges in response to the muscle’s movement.

Answer 13

The patella rests in the groove of the trochlea. Located underneath the end of the Quadriceps femoris muscle. Slides between the trochlea’s ridges

Question 14

When the horse is moving and the _____ is operational, the patella enables the passage of the muscle over ridges of the trochlea.

Answer 14

Quadriceps femoris muscle

Question 15

When the horse is resting, the patella is a _____ device.

Answer 15

Labor-saving

Question 16

By raising one hip, the horse can cause the _____ muscle to lift the patella into position above the _____. This _____ the hinge and _____ the limb so that it can become _____. When one hindlimb is fixed, the other can rest on its toe

Answer 16

Cause the quadriceps muscle to life the patella into position above the medial trochleal ridge
This locks the hinge and fixes the limb so that it can become self-supporting.

Question 17

The hind leg locking mechanism is unlocked by the _____ and _____.

Answer 17

Contraction of the quadriceps femoris muscle and biceps femoris

Question 18

What can occur if the hind leg locking mechanism doesn’t work properly?

Answer 18

Disease: Upward fixation of the patella

Question 19

Upward fixation of the patella is seen mostly in _____.

Answer 19

Young, immature horses ad ponies (Shetlands especially)

Question 20

What are the causes of Upward fixation of the patella?

Answer 20

Straight hindlimb conformation
Poor muscle tone
Poor condition
Hereditary factors
Trauma to the stifle

Question 21

One treatment for Upward fixation of the patella is to establish a _____ to increase level of _____ and _____ of muscle tone.

Answer 21

Establish a “conditioning program” to increase level of fitness and strength of muscle tone
Exercise tediously

Question 22

One treatment for Upward fixation of the patella is _____. (Hint: Results are unpredictable)

Answer 22

Injecting irritants (“blistering”) into and around middle patellar ligaments to thicken and shorten them.

Question 23

One treatment for Upward fixation of the patella is _____ with raised heels to help by limiting the degree of _____ of the stifle joint.

Answer 23

Corrective shoeing

Limiting the degree of extension of the stifle joint

Question 24

Surgical treatments for Upward fixation of the patella:

Answer 24

Med. Pat. Lig. desmotomy (cutting)

Med. Pat. Lig. splitting

Question 25

One treatment for Upward fixation of the patella is _____ by allowing _____ to increase the strength of the ligament. Administered weekly.

Answer 25

Hormonal therapy

Estrogen

Question 26

Recpricol apparatus: The _____ cannot move without the _____.

Answer 26

Hock cannot move without the stifle

Question 27

The _____ (corresponds with the human heel) works as a lever.

Answer 27

Calcaneus

Question 28

2 fundamental structures of the reciprocal apparatus

Answer 28

1) Peroneus tertius (in front of limb)

2) Superficial digital flexor muscle (behind limb)

Question 29

The reciprocal apparatus pulls the hock _____

Answer 29

Forward

Question 30

If the stifle flexes, the _____ closes the angle of the hock and the hock flexes.

Answer 30

Peroneus tertius

Question 31

The _____ is also connected to the mechanism. It automatically adpots the correct position for whateve the stifle and hock are about to do.

Answer 31

Fetlock joint

Question 32

The action of the _____ is to extend the stifle joint. In doing this, it automatically engages the _____.

Answer 32

Quadriceps femoris muscle

Engages the reciprocal apparatus

Question 33

The _____ contracts and extends the hock. This action is limited and influenced by the pelvis’ position.

Answer 33

Gastrocnemius

Question 34

The _____ gives rise to the Achilles’ tendon, which inserts on the calcaneus tuberosity.

Answer 34

Gastrocnemius

Question 35

If a horse ruptures it’s peroneus tertius, the leg of the horse…

Answer 35

Can only be held extended

Question 36

If a horse ruptures the gastrocnemius and superficial digital flexor tendon, the leg of the horse…

Answer 36

Can only be held in a flexed/bended position