Front Matter

38 Canine Sports Medicine and Rehabilitation

The typical kinematic analysis system uses
colored, retroreflective, or light‐emitting diode
(LED) markers that identify specific anatomic
landmarks on the dog that are associated with
the limb or joint under study (Figure 2.17). The
movements of these markers when the dog is
gaited are followed by a series of cameras (min-
imum of three) that place the markers in space
relative to a control 3‐D standard. The locations
of the markers over time are then used to create
a 2‐D or 3‐D model of how the dog moves,
with  accurate calculations of bone and joint
excursion.
Kinematic parameters include displace-
ments, angular velocities, and range of motion.
Displacement is the distance recorded when a
marker changes position. Angular velocity is
the speed at which this change occurs. Range of
motion is calculated from the displacement at a
specific joint.
An example of a 2‐D kinematic measurement
is shown in Figure  2.18, which shows carpal
range of motion (ROM) during the trot (Gillette
& Angle, 2008). In contrast, 3‐D kinematic data
generate three graphs for every anatomic structure.
For example, the angles of excursion of the hip
joint in a trotting dog are shown in the sagittal
(flexion‐extension), transverse (internal‐external
rotation), and frontal (abduction‐adduction)
planes, as in Figure 2.19 (Fu et al., 2010).
A major limitation of data from kinematic
analysis systems is the tremendous breed varia-
tion in the structure of dogs, as well as variation
between individual dogs of the same breed,
such as in the amount of pelvic limb angulation
(Bertram et al., 2000). This significantly limits
comparisons between studies. In addition,

there is some uncertainty as to whether healthy

dogs truly have right and left symmetry

(Gillette & Zebas, 1999; Colborne et al., 2011).

Further, there can be limitations with respect to

the accurate placement of markers, and the

potential for skin movement can add signifi-

cant error to measurements. Several techniques

have been proposed to mitigate or correct for

skin movement in humans and horses (van

Weeren et al., 1992; Sha et al., 2004; Guo et al., 2005).

It remains to be seen how these might apply to

dogs with their generally more mobile skin.

Several other kinematic systems are under

development, including radiostereometric

analysis, dynamic magnetic resonance imag-

ing, dynamic computed tomography, acceler-

ometer systems, and electromagnetic motion

tracking (Gillette & Angle, 2008). The next

decade should provide the canine sports medi-

cine/rehabilitation professional with many

advanced tools for gait analysis.

There are now systems that will analyze and

integrate methodologies using 3‐D kinematic

(motion) analysis (i.e., which includes analysis

of the third coordinate axis), kinetic (forces)

analysis, and electromyography simultane-

ously in one system (Ritter et al., 2001; Gillette &

Angle, 2008).

Temporospatial gait analysis

Pressure‐sensing walkways have been vali-

dated to analyze gait characteristics in dogs

and to aid in diagnosing orthopedic, muscular,

and neurological disorders that affect gait.

Studies have established protocols for the col-

lection of data using these systems and have

0.45

Joint X, 2-D Angles

0.400.350.300.250.200.150.100.050

240

220

200

180

160

Degrees

140

120

100

80

60

40

0.50 0.55

Time (s)

Figure 2.18 Two‐dimensional (2‐D) kinematic analysis of carpal range of motion during the trot. Source: Adapted from
Gillette & Angle, 2008.