Front Matter

512 Canine Sports Medicine and Rehabilitation

have been determined for many of the periph-
eral nerves (Brown & Zaki, 1979; Cuddon, 2002).
Data acquired from the motor nerve conduction
study can be compared with normal values or
with values on the nonaffected limb. Decreased
velocities are indicative of pathology affecting
the nerve being tested.

Thermography

Thermal imaging can identify soft tissue
changes involved in subtle performance and
gait abnormalities, and may be used to monitor
rehabilitation progress or to evaluate training
stressors before they create injury. Thermography
provides a mechanism to capture radiant energy
in a clinical setting (Kaplan, 2007; Ring et  al.,
2004). Interpretation and standardization crite-
ria for the use of thermal imaging have been
published (Ring & Ammer, 2012). Current
human applications include orthopedic trauma
and disease identification (Spalding et al., 2008;

Varju et  al., 2004), identification of tissue

ischemia (Kulis et al., 2012), response to physical

therapy (Cohen & Lee, 2007; Barker et al., 2012),

fitness evaluation and identification of soft

tissue stress in sports medicine (Ferreira et  al.,

2008; Castro, 2010; Hildebrandt et  al., 2010),

infectious disease management (Hidalgo, 2010;

Hewlett et al., 2011), and breast cancer detection

and surgical management (Brioschi et  al., 2010;

Wishart et al., 2010; Wang et al., 2011).

Initial use of thermal imaging to detect soft

tissue trauma in horses (Purohit & McCoy,

1980; Turner et al., 1986; Turner, 1991) expanded

into uses for pregnancy assessment (Bowers

et  al., 2009), conditioning (Turner, 2006), lesion

localization and characterization in neurology

(Neimann, 2010), and hoof vascularity (Van

hoogmoed & Snyder, 2002). Canine thermal

imaging research continues to increase with

studies evaluating the use of thermography to

identify issues in hips, stifles, elbows, and disc

disease (Loughin & Marino, 2007; Infernuso,

2010; Henneman, 2011a; Marino, 2011;

Table 20.1 Electromyogram potentials and their characteristic oscilloscope wave form and sound of the produced
action potential associated with normal and abnormal motor unit responses. Source: Adapted from Brown & Zaki
(1979) and Chrisman et al. (1972).

Electromyogram potentials Oscilloscope reading Auditory signal Indicates

Insertion Sharp spike in electrical

activity; stops abruptly

Sharp, crisp sound;

stops abruptly

Normal response to insertion

of the electrode

Minimal contraction

potential

Bi‐ or triphasic action

potential; various

amplitude

Popping sound

with each action

potential

Mild normal muscle

contraction, incomplete

relaxation

Maximal contraction

potential

Bi‐ or triphasic action

potentials

Popping sound

with each action

potential

Significant normal muscle

contraction, voluntary

withdrawal of the limb

Polyphasic potentials 4+ phase to action

potential

Rattling, rasping Pathology affects motor unit so

that summation cannot occur

Positive waves Primary phase of action

potential is downward

Dull thud Associated with denervation

or disease of muscle;

neuropathies and myopathies

Fibrillation Biphasic, low amplitude Frying eggs Severe disease of motor unit

Myopathic potentials Increased number of

action potentials for

strength of contraction;

amplitude and duration

are all reduced

Recruitment of additional

motor units to compensate for

myopathy

Neuropathic potentials Fewer action potentials

during contraction

Motorboat Loss of motor units firing in

neuropathy