Locomotion Flashcards
Why is the analysis of locomotion important?
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
What are the pros and cons of the two ways in which locomotion can be measured and which do vets use mostly?
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
What are gaits?
Specific patterns of footfall during locomotion. These change with speed and have characterised sequences.
What is a stride and how is it different to a gait?
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
What are the 4 gaits?
Walk, Trot, Canter, Gallop
What are the properties associated with walk?
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
What are the properties associated with trot?
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
What are the properties associated with canter?
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
What are the properties associated with gallop?
Four-beat, asymmetric, lead with inside/lead leg around a turn, moment of suspension
What is the moment of suspension?
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)
What are the 3 types of gallop and how many moments of suspension do they have?
Transverse = 1 (LH RH LF RF *)
Rotary = 2 (RH LH * LF RF *)
Counter-rotary = 2, just opposite of rotary
What species use transverse gallops?
Dogs at low speed
Horses (odd-toed ungulates*)
Cattle (large even-toed ungulates)
*mammals with hooves
What species uses rotary gallop?
Cats
Dogs at high speed
Gazelle, antelope (small uneven-toed ungulates)
Running rodents
Horses during disunited canter
What species uses counter-rotary gallop?
Greyhounds on the track as it’s anti-clockwise
Why do animals change gait?
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
What are the two main neurological impacts on limb coordinatin?
Sensation ie. Vision, Nociceptors (pain), Mechanoreceptors (touch)
Motor response to stimuli ie. Nervous system; voluntary and involuntary, Brainstem, Cerebellum (balance)
What are the two ways in which horses are adapted for high-speed locomotion?
Equine Species Adaptation
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.
What adaptations allow energy conservation during locomotion?
Equine Species Adaptation
- Whiplash effect on limbs
- Long tendons to transfer load, absorb shock and store energy
- Stable joints to limit range of movement (require more support)
Why do horses have a rigid spine/sacroiliac junction?
Equine Species Adaptation
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.
How are dogs adapted for high-speed locomotion?
Canine Species Adaptation
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
What are the clinical consequences in the equine adaptation to high-speed locomotion?
Equine Species Adaptation
Fractures and tendon strain
Low soft tissue covering distal limb so poor wound and fracture healing and prone to joint injuries and arthritis
