Page 55 - Canine Lameness

2.4 ­Making the he oe our Mk M M oohe k i 27

2.3.4 Other Methods of Kinematic Analysis
The methods discussed previously are the most common methods used in clinical patients.
However, there are other less common methods used mainly in a research setting that do not
require markers to be placed on the skin of clinical patients:

Radiographic and advanced imaging methods (such as fluoroscopy, computerized tomogra-
phy [CT], and magnetic resonance imaging [MRI]) have been used (mostly in a research setting)
to evaluate kinematics. Some of these methods increase the radiation exposure to patients as
well as personnel. The equipment needed for these methods is not widely available in most clini-
cal practices and is not clinically applicable at this time.
Body‐mounted inertial sensors, called inertial measurement units (IMUs), are used in human
laboratories and have gained interest for use in veterinary patients (Duerr et al. 2016). This
method relies on the attachment of IMUs, which contain accelerometers and gyroscopes, to
provide information on 3D motion. However, attachment of these small devices to the body has
proven difficult in small animal patients and therefore their clinical usefulness at this time is
uncertain.

2.3.5 Kinematic Variables
Although many variables are recorded in veterinary kinematics related to joint motion, the most
commonly evaluated are (Figure 2.3) as follows:
Average Joint Angle – The average or mean joint angle during movement.
Maximum Joint Angle (MAX) – The maximum (e.g. largest) joint angle during movement.
Minimum Joint Angle (MIN) – The minimum (e.g. smallest) joint angle during movement.
Joint Range of Motion (ROM) – The total range of joint motion during movement calculated by
subtracting the minimum joint angle from the maximum.
Percentage of Gait Cycle – Kinematics can evaluate the entire gait cycle and therefore the stance
phase and swing phase are often reported as a percentage of the total gait cycle.
Note: kinematic variables can be reported and evaluated as single point values (e.g. minimum or
maximum joint angle) or as a complete gait waveform.

2.4 Making the Best of Your Gait Data Collection

Clinicians can take important steps to make the best of the gait collection process. Most of these
steps help reduce error in a patient’s gait data by limiting factors that contribute to data variability.
Some factors are difficult to minimize, such as the small trial‐to‐trial or day‐to‐day variations, as
well as the effect of skin motion artifact on kinematic analysis (Torres 2018). However, other fac-
tors discussed below are easier to address.

2.4.1 Habituation
This is the process of acclimating clinical patients to the gait collection process and environment.
Clinicians should allow their patients a period of adjustment in the gait collection area prior to
collecting data. However, the ideal length of time needed for this is not established and may vary
between animals. In most cases, several minutes or more is recommended.