Three-dimensional kinematic gait analysis of Doberman Pinschers with and without cervical spondylomyelopathy

Extraction of canine gait characteristics using a mobile gait analysis system based on inertial measurement units

This study aims to investigate two simple algorithms for extracting gait features from an inertial measurement unit (IMU) based canine gait analysis system. The first algorithm was developed to determine the hip/shoulder extension/flexion range of motion. The second algorithm automatically determines the stance and swing phase per leg. To investigate the accuracy of the algorithms, two dogs were walked on a treadmill and measured simultaneously with an IMU system, an optical tracking system and two cameras. The range of motion estimation was compared to the optical tracking systems, with a total of 280 steps recorded. To test the stance and swing phase detection, a total of 63 steps were manually annotated in the video recordings and compared with the output of the algorithm. The IMU's-based estimation of the range of motion showed an average deviation of 1.4° to 5.6° from the optical reference, while the average deviation in the detection of the beginning and end of the stance and swing phases ranged from -0.01 to 0.09 s. This study shows that even simple algorithms can extract relevant information from inertial measurements that are comparable to results from more complex approaches. However, additional studies including a wider subject pool need to be conducted to investigate the significance of the presented findings.

Development of a detailed canine gait analysis method for evaluating harnesses: A pilot study

Dog harnesses are becoming more popular, with their large variety stemming from the idea that different dogs and scenarios require different types of harnesses. While their benefits over collars are self-explanatory, there is a lack of research on their effect on gait, and even the existing studies examine only a limited set of parameters. The goal of present study was to establish a method capable of quantifying canine gait in detail. Based on 3D motion capture, the developed method allows for the examination of 18 joint angles and 35 spatio-temporal parameters throughout multiple gait cycles, and can be used to analyze canine movement in detail in any kind of scenario (e.g. comparing healthy and lame dogs, or measuring the effect of training). The method is presented through the measurement of how different harnesses affect walking kinematics compared to free (unleashed) movements. Four dogs with varying body sizes and breeds and multiple types of harnesses were included. Marker data was filtered using a zero-lag 6th order Butterworth-filter with a cutoff frequency of 20 Hz. The normality of the spatio-temporal and joint range of motion parameters was tested using the Anderson-Darling test (p = 0.05), with most parameters passing in 60+% of test cases. Swing time and range of motion of the sagittal aspect of spinal angle at T1 vertebrae failed more regularly, both resulting from the measurement setup rather than the actual parameters being not normally distributed. Two-sample Kolmogorov-Smirnov tests (p = 0.05) were used to compare each parameter’s distribution between cases, showing that most parameters are significantly altered by the harnesses in about 2/3rd of the cases. Based on the results, there’s no absolute superior harness, however, it is possible to select the best fit for a specific dog and application, justifying their large variety.

The effect of a traditional and a stick gang-line on the body position of working sled dogs

This study aimed to investigate the effect of two different gang-lines on the pulling angle of sled dogs. It was hypothesised that dogs would run with a straighter angle of pull (in relation to the main-line) in stick gang-lines (STICK) than they would do in traditional gang-lines (TRAD). Eight sled dogs, divided into two teams, ran a 3.1 km trail twice in both types of gang-lines, pulling a quadbike on dry ground. Each dog remained in its team in the same position (side of gang line, and forward or back in the line) for both runs, using both types of lines in randomised order between the runs. Markers were placed on the dogs and on the main lines, and the runs were recorded by a video camera. The dogs’ angle of pull measured from the video recordings was compared between the two conditions. Thirteen positional measurements for each dog during each run were taken. The dogs were used to running in TRAD and were not acclimatised to STICK. Data was analysed using Wilcoxon and Spearmans rho tests. Data regarding individual dogs (n=13), teams (n=52), dogs’ placements in teams (n=4), and gang-line related pulling angles (n=104) was analysed. Overall, the position of the dogs was straighter when pulling in STICK, than when pulling in TRAD, with a median of 19° (inter quartile range (IQR) 24.75°) and 32° (IQR 25.75°), respectively (P<0.001). Between the two teams, there was no significant difference in pulling positions when running in STICK (P=0.543), but there was in TRAD (P<0.001). In individual assessment, six of the eight dogs ran in a straighter position (P=0.003 to 0.046) in STICK. Dogs running in the front of both teams pulled significantly straighter when in STICK (21°; IQR 23.75) than in TRAD (median 39°; IQR 18; P<0.001).

Different conformations of the German shepherd dog breed affect its posture and movement

The conformation of the German shepherd dog (GSD) varies considerably within the breed. These differences may result in large variation in the movement and limb loading and undesirable consequences to their musculoskeletal health. This study aimed to investigate the relationship between conformation and biomechanical measures in 60 GSDs. Full body kinematic and kinetic measures were computed from 3D motion capture and pressure data. The dogs were divided into groups based on their back slope and curvature. Correlation analysis and statistical differences between groups showed that GSDs with a greater back slope have a greater contact area in their forelimbs and place them closer together when standing (n = 60). During trot, the dogs with sloped back showed a greater vertical force in the forelimbs and a greater mid-thoracic flexion (n = 60). Unilateral differences were found in the stifle flexion, hock flexion and hock adduction, suggesting greater movement asymmetry with an increase in the back slope (n = 30). In conclusion, several biomechanical parameters are affected by the GSD's slope of the back and not by its curvature. Further studies are required to determine whether the variation in movement, posture and conformation within the breed relates to an increased susceptibility to musculoskeletal disorders.

Review of kinematic analysis in dogs

Objective gait analysis techniques aid investigators in the study of motion. Kinematic gait analysis techniques that objectively quantitate motion are valuable tools used to understand normal and abnormal motion in domestic animals. Recent advances in video technology have made the study of motion more readily accessible. Available systems can document gait in two or three dimensions (2D or 3D, respectively). Knowledge of fundamental gait analysis concepts is critical to generating meaningful data. The objective of this report is to review principles of kinematic data collection and analyses, with a focus on differences between 2D and 3D systems.

Impact of wearing a service vest on three-dimensional truncal motion in dogs

OBJECTIVE

To develop a 3-D kinematic model to measure truncal motion in dogs and assess changes in truncal motion in dogs when wearing each of 2 service vests.

ANIMALS

5 adult mixed-breed dogs.

PROCEDURES

27 reflective markers were placed on the pelvis, trunk, and scapula of each dog. Six infrared cameras were placed around a treadmill to track the location of the markers within a calibrated space. Dogs were recorded during walking and trotting on the treadmill. Local and global coordinate systems were established, and a segmental rigid-body model of the trunk was created. Dogs were then recorded while wearing a custom vest and an adjustable vest during walking and trotting on the treadmill. Range of motion of the trunk when dogs were and were not wearing vests was compared by repeated-measures ANOVA.

RESULTS

An anatomic coordinate system was established by use of markers located at T1, T13, and the xiphoid process. Range of motion of the trunk during a gait cycle did not differ significantly regardless of the day of the test for both walking and trotting gaits. Trunk motion of dogs when walking and trotting was significantly reduced when dogs were wearing a vest, compared with trunk motion when not wearing a vest.

CONCLUSIONS AND CLINICAL RELEVANCE

A 3-D kinematic model for measuring truncal rotation was developed. Results indicated measurable differences in the gait of dogs when wearing each of the 2 service vests, compared with the gait when not wearing a vest.

Development of a Novel Gait Analysis Tool Measuring Center of Pressure for Evaluation of Canine Chronic Thoracolumbar Spinal Cord Injury

Gait evaluation after spinal cord injury (SCI) is an important component of determining functional status. Analysis of center of pressure (COP) provides a dynamic reflection of global locomotion and postural control and has been used to quantify various gait abnormalities. We hypothesized that COP variability would be greater for SCI versus normal dogs and that COP would be able to differentiate varying injury severity. Our objective was to investigate COP, COP variability, and body weight support percentage in dogs with chronic SCI. Eleven chronically non-ambulatory dogs after acute severe thoracolumbar SCI were enrolled. COP measurements in x (right-to-left, COPx) and y (craniocaudal, COPy) directions were captured while dogs walked on a pressure-sensitive treadmill with pelvic limb sling support. Root mean square values (RMS_COPx and RMS_COPy) were calculated to assess variability in COP. Body weight support percentage was measured using a load cell. Gait also was quantified using an open field scale (OFS) and treadmill-based stepping and coordination scores (SS, RI). Mean COPx, COPy, RMS_COPx, and RMS_COPy were compared between dogs with SCI and previously evaluated healthy controls. RMS measurements and support percentage were compared with standard gait scales (OFS, SS, RI). Mean COPy was more cranial and RMS_COPx and RMS_COPy were greater in SCI versus normal dogs (p < 0.001). Support percentage moderately correlated with SS (p = 0.019; R² = 0.47). COP analysis and body weight support measurements offer information about post-injury locomotion. Further development is needed before consideration as an outcome measure to complement validated gait analysis methods in dogs with SCI.

Relationship Between Gait Mechanics and the Speed of the Trot in the Weimaraner Dog Breed

While the size of the Weimaraner may assist in the breed performing the tasks of a sporting dog, the large size coupled with these tasks may also make the breed more susceptible to orthopedic issues. The understanding of the normal gait mechanics of the Weimaraner can be a useful tool in examining for gait abnormalities associated with these orthopedic issues, and yet, research concerning breed-specific gaits in the canine is limited. Therefore, study objectives were to define the normal Weimaraner trotting kinematics and determine the influence of speed on these parameters. Markers were attached to palpation points on the limbs and head of American Kennel Club registered Weimaraners. Dogs were tracked while performing a slow (1.2-1.7 m/s) and fast (1.9-2.3 m/s) trotting speed. Frame-by-frame analysis was performed. Paw ground contact and lift-off was documented and marker displacement was tracked. At both speeds, the trot had a diagonal footfall sequence with diagonal limb pairing alternating between diagonal bipedal support and suspension. The faster speed was achieved with significant increases in stride length and displacements of the head, withers, and fore and hind paws (P < .05). Range of motion of the elbow and hip significantly increased as the dog transitioned from a slow to fast speed (P < .05). Through gait analysis, the Weimaraner trot was defined as a 2-beat diagonal rhythm gait with suspension. Speed did not change these characteristics, but did influence stride length and linear and angular displacements, and thus, should be a consideration in clinical examination.

Three-Dimensional Kinematic Motion Analysis of Shivers in Horses: A Pilot Study

Our aim was to assess three-dimensional kinematic motion analysis as an objective diagnostic tool for the characterization of the movement disorder of Shivers in horses. Kinematic parameters were measured in three horses with Shivers and were compared with a control group of four normal horses. Multiple parameter differences were found in the horses with Shivers at the walk, during backing, and when asked to pick up their hindlimbs. Most significant changes were a wider hindlimb stance of 0.39 ± 0.15 m and increased abduction angle of 48.7 ± 7.52° and hoof elevation (0.77 ± 0.08 m left and 0.94 ± 0.11 m right) when the horses were asked to pick up their hindlimbs. Control horses could back easily in a straight line and with symmetrical hoof separation and could maintain their center of weight when picking up their hindlimbs. In contrast, the horses with Shivers had difficulty backing straight, were slower, with a shorter stride and asymmetric hoof separation. They could not maintain their center of balance when picking up their hindlimbs. The findings of this pilot study advance the understanding of the movement disorder of Shivers and could be used as outcome measures to evaluate treatment modalities.

Kinetic and kinematic follow-up gait analysis in Doberman Pinschers with cervical spondylomyelopathy treated medically and surgically

Background

The efficacy of treatment of dogs with cervical spondylomyelopathy (CSM) is commonly based on the owner's and clinician's perception of the gait, which is highly subjective and suffers from observer bias.

Hypothesis/Objectives

To compare selected kinetic and kinematic parameters before and after treatments and to correlate the findings of gait analysis to clinical outcome.

Animals

Eight Doberman Pinschers with CSM confirmed by magnetic resonsance imaging.

Methods

Patients were prospectively studied and treated with either medical management (n = 5) or surgery (n = 3). Force plate analysis and 3‐D kinematic motion capture were performed at initial presentation and approximately 8 weeks later. Force plate parameters evaluated included peak vertical force (PVF). Kinematic parameters measured included number of pelvic limb strides, stifle flexion and extension, maximum and minimum thoracic limb distance, truncal sway, and thoracic limb stride duration.

Results

Kinematic analysis showed that deviation of the spine to the right (truncal sway) was significantly smaller (P < .001) and the degree of right stifle flexion was significantly larger (P = .029) after treatment. Force plate analysis indicated that PVF was significantly different after treatment (P = .049) and the difference of the PVF also was significantly larger (P = .027). However, no correlation was found with either method of gait analysis and clinical recovery.

Conclusions and Clinical Importance

Kinetic and kinematic gait analysis were able to detect differences in dogs with CSM before and after treatment. A correlation of gait analysis to clinical improvement could not be determined.

Cavalier King Charles Spaniels with Chiari-like malformation and Syringomyelia have increased variability of spatio-temporal gait characteristics

BACKGROUND

Chiari-like malformation in the Cavalier King Charles Spaniel is a herniation of the cerebellum and brainstem into or through the foramen magnum. This condition predisposes to Syringomyelia; fluid filled syrinxes within the spinal cord. The resulting pathology in spinal cord and cerebellum create neuropathic pain and changes in gait. This study aims to quantify the changes in gait for Cavalier King Charles Spaniel with Chiari-like malformation and Syringomyelia.

METHODS

We compared Cavalier King Charles Spaniel with Chiari-like malformation with (n = 9) and without (n = 8) Syringomyelia to Border Terriers (n = 8). Two video cameras and manual tracking was used to quantify gait parameters.

RESULTS AND CONCLUSIONS

We found a significant increase in coefficient of variation for the spatio-temporal characteristics and ipsilateral distance between paws and a wider base of support in the thoracic limbs but not in the pelvic limbs for Cavalier King Charles Spaniels compared with the border terrier.

An EMG-driven biomechanical model of the canine cervical spine

Due to the frequency of cervical spine injuries in canines, the purpose of this effort was to develop an EMG-driven dynamic model of the canine cervical spine to assess a biomechanical understanding that enables one to investigate the risk of neck disorders. A canine subject was recruited in this investigation in order to collect subject specific data. Reflective markers and a motion capture system were used for kinematic measurement; surface electrodes were used to record electromyography signals, and with the aid of force plate kinetics were recorded. A 3D model of the canine subject was reconstructed from an MRI dataset. Muscles lines of action were defined through a new technique with the aid of 3D white light scanner. The model performed well with a 0.73 weighted R² value in all three planes. The weighted average absolute error of the predicted moment was less than 10% of the external moment. The proposed model is a canine specific forward-dynamics model that precisely tracks the canine subject head and neck motion, calculates the muscle force generated from the twelve major moment producing muscles, and estimates resulting loads on specific spinal tissues.

Kinetic and kinematic gait analysis in the pelvic limbs of normal and post-hemilaminectomy Dachshunds

OBJECTIVE

To compare pelvic limb kinetic and kinematic gait parameters between Dachshunds six months following hemilaminectomy for treatment of thoracolumbar disc extrusion (post-hemilaminectomy; PHL) and Dachshunds without history and clinical evidence of spinal cord disease (control; CON).

METHODS

The CON (n = 8) and PHL (n = 6) Dachshunds were recruited for objective gait evaluation. Kinetic data collected included peak vertical force (PVF), stance phase duration and swing phase duration. Kinematic data collected included tarsal, stifle and hip range of motion (ROM) during stance and swing phases of the trot, tail ROM, and horizontal and vertical components of pelvis ROM.

RESULTS

No significant differences were identified between tarsal, stifle, hip, and tail ROM between CON and PHL Dachshunds. Although PVF was not significantly different between CON and PHL Dachshunds, PVF varied on average by 14% between the pelvic limbs in PHL Dachshunds (p <0.01). Horizontal and vertical components of pelvic ROM were on average 51% and 36% greater in PHL Dachshunds compared to CON Dachshunds (p = 0.04 and p = 0.02 respectively).

CLINICAL SIGNIFICANCE

Six months after decompressive hemilaminectomy, Dachshunds have abnormal pelvic motion and asymmetric pelvic limb weight bearing. Pelvic sway (ROM) may be a more sensitive indicator of myelopathy than pelvic limb joint ROM and may serve as a useful objective tool to characterize response to treatment in patients with spinal cord disease.

A preliminary evaluation of the reliability of a modified functional scoring system for assessing neurologic function in ambulatory thoracolumbar myelopathy dogs

BACKGROUND

The objective of this study was to develop and assess the reliability of a modified scoring system for evaluating the function of the two pelvic limbs separately, in ambulatory thoracolumbar myelopathy dogs. A previously established neurologic score scale for dogs with T3-L3 lesions was modified in order to provide a separate score for each pelvic limb.

RESULTS

Seventeen ambulatory dogs with thoracolumbar myelopathies were evaluated. Using the new scale, two observers independently performed 22 observational gait analyses (OGAs) in ten dogs without videotape. Another 18 OGAs were performed in seven dogs by watching videotapes of them ambulating. There was poor agreement (concordance correlation coefficient, 0.87) between the two observers for all 40 OGAs. When stratified, the agreement was moderate (concordance correlation coefficient, 0.90) in the OGAs without videotaping and poor (concordance correlation coefficient, 0.80) for the OGAs based on videotapes. For the decision regarding which pelvic limb was more severely affected, a fair agreement (kappa value, 0.30) between the two observers was noted. Without videotape there was only slight agreement (kappa value, 0.05), but with videotape there was moderate agreement (kappa value, 0.56).

CONCLUSIONS

The modified scoring system in this study provides moderate reliability in assessing the functional neurologic status of each pelvic limb, by OGA without videotape, in canine T3-L3 patients. Further development of this scoring system is required. However, imperfect agreement when visually quantifying neurological deficits is not unexpected.