Locomotion

Question 1

Why is the analysis of locomotion important?

Answer 1

Allows evaluation of what is normal/abnormal
You can assess gait patterns
Becomes easier to identify gait adaptations – e.g. lameness
Highlights performance and welfare indicators

Question 2

What are the pros and cons of the two ways in which locomotion can be measured and which do vets use mostly?

Answer 2

Human Observation (vets use)
P - low technical requirements, low cost
C - subjective/biased, human eye misses details, experience needed
Technical Equipment
P - objective, less bias, measurable
C - needs dedicated equipment, space, resources, personnel and has high cost

Question 3

What are gaits?

Answer 3

Specific patterns of footfall during locomotion. These change with speed and have characterised sequences.

Question 4

What is a stride and how is it different to a gait?

Answer 4

A stride takes place within a gate, it is the complete cycle of one movement* and has two phases:
The stance phase (weight bearing) and the swing phase (non-weight bearing)

*from the setting down pf foot to the next setting down of the same foot

Question 5

What are the 4 gaits?

Answer 5

Walk, Trot, Canter, Gallop

Question 6

What are the properties associated with walk?

Answer 6

Four-beat, Symmetric, Never >3 or<2 limbs bearing weight at one time, centre of gravity in a triangle between weight bearing feet

Footfall sequence : RH-RF-LH-LF

Question 7

What are the properties associated with trot?

Answer 7

Two-beat, symmetric, diagonal gait, body supported alternately by L&R diagonals, period of suspension (between successive stance phases), marked axial twisting resisted by axial system

Question 8

What are the properties associated with canter?

Answer 8

Three-beat, asymmetric, 1 moment of suspension (when forelimb leaves ground before hindlimb hits the ground), lead leg is left or right, one diagonal pair and other two limbs out of phase

Question 9

What are the properties associated with gallop?

Answer 9

Four-beat, asymmetric, lead with inside/lead leg around a turn, moment of suspension

Question 10

What is the moment of suspension?

Answer 10

Period when o feet are in contact with the ground (fast trot, canter, gallop)
Usually 1 per cycle but 2 in greyhounds and cheetahs (see image)

Question 11

What are the 3 types of gallop and how many moments of suspension do they have?

Answer 11

Transverse = 1 (LH RH LF RF *)
Rotary = 2 (RH LH * LF RF *)
Counter-rotary = 2, just opposite of rotary

Question 12

What species use transverse gallops?

Answer 12

Dogs at low speed
Horses (odd-toed ungulates*)
Cattle (large even-toed ungulates)

*mammals with hooves

Question 13

What species uses rotary gallop?

Answer 13

Cats
Dogs at high speed
Gazelle, antelope (small uneven-toed ungulates)
Running rodents
Horses during disunited canter

Question 14

What species uses counter-rotary gallop?

Answer 14

Greyhounds on the track as it’s anti-clockwise

Question 15

Why do animals change gait?

Answer 15

Physical necessity due to the pendulum effect, centrifugal force acting upwards and fraude number* = leg moving at constant velocity:gravitational force

Metabolic advantages, so animal will move at speed which is energy efficient and that matches with the respiratory rate

Mechanical advantages to reduce bone strain

*Speed at which we change gait ie. walk to run

Question 16

What are the two main neurological impacts on limb coordinatin?

Answer 16

Sensation ie. Vision, Nociceptors (pain), Mechanoreceptors (touch)

Motor response to stimuli ie. Nervous system; voluntary and involuntary, Brainstem, Cerebellum (balance)

Question 17

What are the two ways in which horses are adapted for high-speed locomotion?
Equine Species Adaptation

Answer 17

They have increased stride length thanks to an elongated distal limb, a mobile scapula and the whiplash effect - small motion upper limb = flick of lower

The mass of their limbs are minimised so that most the work during locomotion is the speed at which the limbs are moved at as less mass means less resistance to change in motion. So muscles are mostly proximal and the number of bones in the leg is decreased.

Question 18

What adaptations allow energy conservation during locomotion?
Equine Species Adaptation

Answer 18

• Whiplash effect on limbs
• Long tendons to transfer load, absorb shock and store energy
• Stable joints to limit range of movement (require more support)

Question 19

Why do horses have a rigid spine/sacroiliac junction?
Equine Species Adaptation

Answer 19

To support their large gut and body mass> To allow the transfer of energy from the hind-quarters and to minis the up-down movement of the body during locomotion which saves energy.

Question 20

How are dogs adapted for high-speed locomotion?
Canine Species Adaptation

Answer 20

They have elongated limbs, they are digitigrade* (claws assist with grip), flexible back (arch and stretch lengthens stride, no gut restriction), tail (balance assist)

*on toes

Question 21

What are the clinical consequences in the equine adaptation to high-speed locomotion?
Equine Species Adaptation

Answer 21

Fractures and tendon strain
Low soft tissue covering distal limb so poor wound and fracture healing and prone to joint injuries and arthritis