Gait in dogs with neurologic disease is often assessed with subjective numeric rating scales. Olby et al1 proposed a disability index with the advantage that the dog can be scored without ambulation. That system uses a numeric rating system in which the dog is assigned a number on the basis of the level of neurologic dysfunction. The index has several disadvantages, including nonlinear levels of disability represented by a linear scale, evaluator subjectivity, and low sensitivity.2,3 Subjective evaluation of patients may allow evaluator bias because it is not always possible to adequately mask an evaluator. For example, if a comparison were being made between surgical and nonsurgical management of a neurologic disorder, masking would be difficult because of preparation and wound closure. Sham surgery avoids this complication, but in clinical trials, sham surgery is difficult to justify ethically. Additionally, intra- and interobserver variation may make it difficult to distinguish between groups, collaborate with multiple locations, or compare studies.
Numeric rating systems have inherent disadvantages, including the requirement of nonparametric statistical testing if there are < 5 categories. The Olby et al1 disability index uses a 14-point numeric scoring system; however, the improvement between adjacent scores may not be equivalent. For example, to improve from a score of 4 to 5, a dog with non–weight-bearing activity in > 1 joint < 50% of the time must improve to weight bearing ≥ 50% of the time. To improve from a score of 5 to 6, the dog must become 100% weight bearing. Moving from a score of 5 to a score of 6 is more of an improvement than from a score of 4 to a score of 5. Subjective rating scales are also insensitive at detecting subtle differences between groups.2–4
Kinematic gait analysis is a sensitive, objective measure of gait. Two- or 3-D kinematic gait analysis is used to quantify neurologic dysfunction in ambulatory dogs.5,a Cameras are used to record ambulation with joints identified by use of reflective markers or digital identification. Specialized software is then used to measure characteristics such as changes in joint angles during the various phases of gait as well as angular limb velocities. Range of motion in each joint and some spatiotemporal characteristics can be measured but not ground reaction forces. Error is introduced with placement and movement of markers relative to the actual joint, and some subjectivity is inherent in the videography digitizing process.2–4
Force platform gait analysis is considered the gold standard for quantifying limb function in dogs with orthopedic disease. It is objective and far more sensitive than visual assessment of gait.6–8 Pressure walkways have been validated as an alternative to the force platform, which uses symmetry of ground reaction forces, peak vertical force, and vertical impulse.9,10 A single pressure walkway can accommodate dogs of greater size and measure consecutive footfalls, whereas force platforms of multiple sizes placed in series are necessary for dogs of different sizes and for consecutive footfalls. This can be cost prohibitive. Pressure platforms also measure spatiotemporal gait characteristics. These characteristics have not been used to assess gait in dogs with orthopedic or neurologic disease.
The spatiotemporal characteristics velocity, stance time, swing time, stride time, and stride length have been used in human and basic science research to evaluate neurologic gait disturbance.11–14 In rats, stance time, swing time, and stride time are shorter after induced spinal cord injury.15 Velocity, stride length, swing time, and stance time have been used to help evaluate physical therapy patients and measure response to treatment for neurologic disorders.11–13
We hypothesized that spatiotemporal characteristics may be used to assess gait in dogs with neurologic disease. The objective of the study reported here was to determine the spatiotemporal gait characteristics and associated covariates of clinically normal dogs and dogs with spinal cord disease.
Jeffery N. Quantitative outcome measures after spinal cord injury (abstr), in Proceedings. Annu Meet Eur Coll Vet Med 2008;539–540.
Tekscan Walkway, Tekscan Inc, Boston, Mass.
GAITrite System with GAITfour software, CIR Systems Inc, Havertown, Pa.
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Basso DM. Behavioral testing after spinal cord injury: congruities, complexities, and controversies. J Neurotrauma 2004;21:395–404.
Giglio CA, Defino HLA, da-Silva CA, et al.Behavioral and physiological methods for early quantitative assessment of spinal cord injury and prognosis in rats. Braz J Med Biol Res 2006;39:1613–1623.
Gradner G, Bockstahler B, Peham C, et al. Kinematic study of back movement in clinically sound Malinois dogs with consideration of the effect of radiographic changes in the lumbosacral junction. Vet Surg 2007;36:472–481.
Conzemius MG, Evans RB, Besancon MF, et al. Effect of surgical technique on limb function after surgery for rupture of the cranial cruciate ligament in dogs. J Am Vet Med Assoc 2005;226:232–236.
Evans R, Horstman C, Conzemius M. Accuracy and optimization of force platform gait analysis in Labradors with cranial cruciate disease evaluated at a walking gait. Vet Surg 2005;34:445–449.
Waxman AS, Robinson DA, Evans RB, et al. Relationship between objective and subjective assessment of limb function in normal dogs with an experimentally induced lameness. Vet Surg 2008;37:241–246.
Horstman CL, Conzemius MG, Evans R, et al. Assessing the efficacy of perioperative oral carprofen after cranial cruciate surgery using noninvasive, objective pressure platform gait analysis. Vet Surg 2004;33:286–292.
Besancon MF, Conzemius MG, Derrick TR, et al. Comparison of vertical forces in normal greyhounds between force platform and pressure walkway measurement systems. Vet Comp Orthop Traumatol 2003;16:153–157.
Youdas JW, Hollman JH, Aalbers MJ, et al. Agreement between walkway 2 and a stopwatch-footfall count method for measurement of temporal and spatial gait characteristics. Arch Phys Med Rehabil 2006;87:1648–1652.
Merory JR, Wittwer JE, Rowe CC, et al. Quantitative gait analysis in patients with dementia with Lewy bodies and Alzheimer's disease. Gait Posture 2007;26:414–419.
Balasubramanian CK, Bowden MG, Neptune RR, et al. Relationship between step length asymmetry and walking performance in subjects with chronic hemiparesis. Arch Phys Med Rehabil 2007;88:43–49.
Kim CM, Eng JJ. Symmetry in vertical ground reaction force is accompanied by symmetry in temporal but not distance variables of gait in persons with stroke. Gait Posture 2003;18:23–28.
McEwen ML, Springer JE. Quantification of locomotor recovery following spinal cord contusion in adult rats. J Neurotrauma 2006;23:1632–1653.
Evans R, Gordon W, Conzemius M. Effect of velocity on ground reaction forces in dogs with lameness attributable to tearing of the cranial cruciate ligament. Am J Vet Res 2003;64:1479–1481.
Deumans R, Jaken RJP, Marcus MAE, et al. The CatWalk gait analysis in assessment of both dynamic and static gait changes after adult rat sciatic nerve resection. J Neurosci Methods 2007;164:2120–2130.
Verghese J, Wang C, Holtzer R, et al. Quantitative gait dysfunction and risk of cognitive decline and dementia. J Neurol Neurosurg Psychiatry 2007;78:929–935.
Budsberg SC, Verstraete MC, Soutas-Little RW. Force plate analysis of the walking gait in healthy dogs. Am J Vet Res 1987;48:915–918.
Dusing SC, Thorpe DE. A normative sample of temporal and spatial gait characteristics in children using the GAITRite electronic walkway. Gait Posture 2007;25:135–139.
Krishnamurthy M, Verghese J. Gait characteristics in nondisabled community-residing nonagenarians. Arch Phys Med Rehabil 2006;87:541–545.
Boyd BS, Puttlitz C, Noble-Haeusslein LJ, et al.Deviations in gait pattern in experimental models of hindlimb paresis shown by a novel pressure mapping system. J Neurosci Res 2007;85:2272–2283.