Front Matter

36 Canine Sports Medicine and Rehabilitation

recommended that gait analysis be performed
with the patient wearing a collar with a loose
leash attached as harnesses and other external
apparatuses have been reported to affect gait
(Carr & Zink, 2016). Finally, it is important to
have the handler on the same side of the dog
each time data are recorded as handler side has
also been shown to affect gait characteristics
(Keebaugh et al., 2015).

Kinetic systems

Kinetic systems measure forces in three dimen-
sions: vertical, craniocaudal, and mediolateral.
These systems generally are ground‐based, with
the traditional system based on force plates,
which measure forces (Box  2.1) by incorporat-
ing strain gauges as sensing elements or
quartz crystals to generate piezoelectric signals.
The measured forces are often presented graph-

ically, with the peak forces as the maximum

forces generated in the described phase of

gait, represented by the force–time curve. The

impulse is then represented as the area under

the force–time curve.

Peak vertical force (PVF) is the single largest

force during the stance phase and represents

only a single data point on the force–time curve.

Vertical impulse (VI) can be derived by calcu-

lating the area under the vertical force curve

using time. PVF and VI are the two most

commonly used indices to detect lameness. In

general, a lame dog has a lower PVF and VI in

the affected limb (Nunamaker & Blauner, 1985;

Gillette & Angle, 2008; Gordon‐Evans, 2012).

While braking, propulsion, and mediolateral

forces may be useful in evaluating mechanisms

of locomotion, they are not used commonly

for  diagnostic purposes or to assess outcome

(Gillette & Angle, 2008).

A typical report from a force plate is seen in

Figure  2.16, which shows the forces produced

by the thoracic limb (first peak) and the pelvic

limb (second peak) in each of the three dimen-

sions. Force plate measurements are the most

widely used quantitative gait application in

veterinary medicine to date (Voss et al., 2007).

Thus, force plate analysis is currently viewed as

the gold standard for quantification of gait

characteristics by objective gait analysis.

Limitations of kinetic systems include the

potential for habituation of dogs to the system,

Table 2.3 Comparison of commonly used objective canine gait analysis systems

Advantages Disadvantages

Kinematic gait

analysis

Collects positions, velocities, acceleration/

deceleration, and angles of various anatomic

structures in space

Can be performed in 2‐D or 3‐D

Skin movement affects marker

placement

Difficult to establish consistent

positioning with breed variation

Technically challenging to operate

Kinetic gait

analysis

Measures forces in three dimensions

Very well studied

Most widely used quantitative gait application

Only collects a single reading per

single pass

Technically challenging to operate

Size restrictions can apply

Temporospatial

gait analysis

Provides multiple readings from a single pass

Determines stride and step length

Provides information on limb placement

User‐friendly software

Portable

No size restrictions

Can only measure total ground reac-

tion force

Box 2.1 Types of ground reaction forces

● Peak vertical force

● Vertical impulse

● Rising and falling slope

● Braking force

● Braking impulse

● Propulsive force

● Propulsive impulse

● Mediolateral force