This article was published in the Auburn University Sports Medicine Program Newsletter, Summer Issue (pp 1-2) 1998.
The Importance of Including Gait Analysis in the Training Regimen.
Robert L. Gillette, DVM, MSE
Sports Medicine Veterinary Services
Motion is the one common component of all athletic competition. Motion is a result of nerves stimulating muscle to move bone. Abnormal motion occurs when this chain of events is disrupted. Locomotion of an animal is described as its gait. The walk, trot, and gallop are three forms of gait. Gait analysis is used to assess the movement of each of the individual joints and how this movement affects locomotion.The canine athlete can present uncommon challenges to the general practitioner. If the pet owner is only interested in companionship, minimal stress will be put upon the body. As the athletic demands of the owner increase there is a proportional increase in the physical demands placed upon the animal’s body. These increased demands placed upon the animal introduce a higher risk of injury.There are four conditions that can impede performance: 1) pain, 2) fatigue, 3) depressed psychology (drive), and 4) impaired health status. In general most canine athletes are healthy, but their health status should be checked at least once a year. In healthy dogs their drive to perform is both inherited and/or acquired through a good training program. A good training program will maintain the conditioning level of the dog at a level that should eliminate the effects of fatigue. Pain is the most common cause of performance impairment and should be analyzed first. Minor pain that does not induce a lameness can show symptoms similar to the problems seen with fatigue or drive. Major pain will inhibit performance.
The canine structure is divided into segments when analyzing motion. The axial vertebral column is made up of many joints and is divided into anatomical segments. The cranial segment is the head, followed caudally by the neck (cervical), thoracic, abdominal (lumbo-sacral), and tail. The appendicular segments are the front legs and the back legs. These are subdivided into smaller segments by the leg joints: shoulder, elbow, carpus, hip, stifle, tarsus & phalanges. Locomotion as a whole is a result of the individual movements of these segments.
Dogs and horses have the ability to minimize pain by altering movement in such a way that the abnormality may be unnoticeable. This ability allows subclinical pain to go unnoticed by the trainers, and handlers. Computer-assisted videographic (CAV) gait analysis can be used to assess to what extent minor pain has an effect on the musculoskeletal system as a whole. In a normal trot the movements of the body are symmetrical. This means that the movements of one side of the body mirror the movements of the other side (Figure 1a). A minor “sprain” of the right carpus not only creates an alteration in the movement of the right carpus but also the left hip and left tarsus (Figure 1b). The back, or axial skeleton, is also affected, since it is the frame through which this alteration is transferred. This can initiate two problems in the athletic or working animal, one biomechanical and the other psychological. First, due to the high activity level of the athletic animal, this alteration caused by the primary injury can lead to secondary and tertiary pain or injuries in the back or other limbs. Secondly, it can create a loss in psychological drive. The dog might begin to associate pain with its workouts.
Trainers and handlers should include lameness examinations in their training and conditioning programs. A lameness examination includes visual gait analysis and physical palpation. Visual gait evaluation can be done once a week or once every two weeks, this allows for early lameness detection. If a gait alteration is detected, the dog should be referred to a veterinarian for a physical examination and definitive diagnosis. Rehabilitation time is relative to the level of injury and the chronicity of the injury. The longer a lameness goes undetected the longer it takes to recover from the body’s adaptations.
Subjective gait analysis is the most common diagnostic tool to assess lameness. It starts by observing the animal while it is at rest, looking for conformational abnormalities or abnormal stances. For example, does the dog seem to hold one leg up or put most of its body weight on a particular leg. After these observations are noted the animal is analyzed while moving. The trot is the best gait to use for analysis, it gives the best picture of abnormal gait. If one of the segments is impaired the gait will be out of balance. The patient is observed moving in a straight line toward and then moving away from the evaluator. Next the dog should be assessed moving in a straight line from the right side and then the left side. Then it should be observed moving in a circle, once clockwise then counter-clockwise.
Most gait abnormalities can be detected with subjective gait analysis. A dog with a lesion causing severe sharp constant pain will carry the limb and keep the weight off it when lying down. A dull aching pain will produce a limp during the gait analysis. A lesion that produces a small pain that occurs in certain phases of locomotion allows the dog to adjust their gait for relief. This altered gait can lead to subsequent orthopedic problems.
Pain is an important performance inhibitor. When compared to the active dog, subclinical pain of the companion pet does not greatly affect the musculoskeletal system. Usually anti-inflammatory therapy is sufficient. In the physically active or competitive animal any pain or lameness should be addressed as soon as possible before these problems affect performance. Gait analysis and physical examination are two useful diagnostic tools for the trainers and veterinarians working with the animal athlete.