Kinetic and temporospatial gait parameters in a heterogeneous group of dogs.

BACKGROUND: A prime concern of the gait analysis in a heterogeneous group of dogs is the potential influence of factors such as individual body size, body mass, type of gait, and velocity. Thus, this study aimed to evaluate in a heterogeneous group of dogs a possible correlation of the stride frequency with kinetic and temporospatial variables, as well as the percentage of body weight distribution (%BWD), and compare symmetry index (SI) between trotting and walking dogs. Twenty-nine clinically healthy dogs moving in a controlled velocity were used. The dogs were organized into two groups based on duty factor. Group 1 comprised 15 walking dogs, aged from 9 months to 8 years and weighing about 22.3 kg. Group 2 had 14 trotting dogs, aged from 1 to 6 years and weighing about 6.5 kg. The kinetic data and temporospatial parameters were obtained using a pressure-sensing walkway. The velocity was 0.9-1.1 m/s. The peak vertical force (PVF), vertical impulse (VI), gait cycle time, stance time, swing time, stride length, and percentages of body weight distribution among the four limbs were determined. For each variable, the SIs were calculated. Pearson's coefficient was used to evaluate correlation between stride frequency and other variables, initially in each group and after including all animals. RESULTS: Except for the %BWD (approximately 60% for the forelimbs and 40% for the hind limbs), all other parameters differed between groups. Considering each Group individually a strong correlation was observed for most of the temporospatial parameters, but no significant correlation occurred between stride frequency and PVF, and stride frequency and %BWD. However, including all dogs a strong correlation was observed in all temporospatial parameters, and moderate correlation between stride frequency and VI, and weak correlation between stride frequency and PVF. There was no correlation between stride frequency and %BWD. Groups 1 and 2 did not differ statistically in SIs. CONCLUSIONS: In a heterogeneous group of dogs conducted at a controlled velocity, the %BWD and most of SIs presented low variability. However, %BWD seems to be the most accurate, since factors such as the magnitude of the variables may influence the SIs inducing wrong interpretation. Based on results obtained from correlations, the standardization of stride frequency could be an alternative to minimize the variability of temporospatial parameters.

Kinematic analysis of forelimb and hind limb joints in clinically healthy sheep.

BACKGROUND: Variations associated with sex, age, velocity, breed and body geometry should be considered in the determination of kinematic parameters for a gait considered normal. Therefore, this study aimed to evaluate kinematic patterns of forelimbs and hind limbs in clinically normal sheep from two different age groups walking at a constant velocity. The hypothesis was that the age may influence sagittal plane kinematic patterns. Fourteen clinically healthy female sheep were divided into Group 1--seven animals aged from 8 to 12 months, and Group 2--seven animals aged above 5 years. Before starting data collection, the sheep were trained to be conducted for walking in a pre-determined space at constant velocity. A minimum of 5 valid trials were obtained from the right and left sides of each sheep. Data were analyzed by use of a motion-analysis program. Flexion and extension joint angles (maximum, minimum, displacement), and angular velocity (maximum, minimum) were determined for the shoulder, elbow, carpal, hip, stifle, and tarsal joints. RESULTS: Within each group, no significant differences were observed between the right and left limbs in all kinematic variables. Significant differences were observed in the following kinematic parameters between G1 and G2: minimum angle (G1 < G2), angular displacement (G1 > G2), maximum angular velocity (G1 > G2), minimum angular velocity (G1 > G2) of the carpus; angular displacement (G1 > G2), minimum angular velocity (G1 > G2) of the shoulder; minimum angle (G1 > G2), angular displacement (G1 < G2) of the tarsus; maximum angular velocity (G1 < G2) of the stifle; maximum angular velocity G1 > G2 of the hip. The lengths of both forelimbs and hind limbs differed between groups (G1 < G2). The Froude number differed between groups for forelimbs and hind limbs. CONCLUSIONS: In conclusion, sheep of two different ages walking at a constant velocity present, within the same group, similar kinematic data between sides, and exhibit some differences in kinematic variables that may be age-related or body size. Further studies using sheep walking at similar Froude numbers are necessary to exclude the body size.

Gait Analysis of Amputee Dogs Using a Pressure-Sensitive Walkway.

OBJECTIVE: The aim of this study was to perform gait analysis using a pressure-sensitive walkway in dogs submitted to high (total) or low amputation (partial) of one forelimb or hindlimb. STUDY DESIGN: A total of 39 dogs met the inclusion criteria. The reasons for the amputations were motor vehicle accidents in 38 dogs and possible limb malformation in 1 dog. The amputee dogs were divided into four groups: G1 (n = 10)-high forelimb; G2 (n = 10)-low forelimb; G3 (n = 9)-high hindlimb; and G4 (n = 10)-low hindlimb. For kinetic evaluation, the dogs were walked across a pressure-sensitive walkway. RESULTS: In dogs with forelimb amputation, the percentage of body weight (%BW) distribution on the contralateral forelimb was 50.7% in cases of high amputation and 55.5% in cases of low amputation, while the %BW distribution on the hindlimbs, mainly in the ipsilateral hindlimb, was 27.9% in cases of high amputation and 27.1% in cases of low amputation. In cases of high amputation of the hindlimb, the %BW distribution was 71.5% on the forelimbs and 29.7% on the contralateral hindlimb, while in cases of low amputation, the distribution was mainly for the contralateral hindlimb and ipsilateral forelimb. No statistical difference was noted between the amputation levels, except for the contralateral limb in cases of low and high amputation of the hindlimbs concerning the overload percentage and %BW distribution. CONCLUSION: The amputation level of one forelimb did not influence the %BW distribution; however, in the hindlimb, this was higher for the contralateral limb in dogs submitted to high amputation.

Histological, Immunohistochemical, Biomechanical, and Wettability Evaluations of the Leukocyte- and Platelet-Rich Fibrin Membranes Derived from Canine Blood.

This study aimed to perform histological, immunohistochemical, biomechanical, and wettability assessments of leukocyte- and platelet-rich fibrin (L-PRF) membranes obtained from the blood of healthy dogs. Ten client-owned Labrador Retriever dogs were enrolled. Blood samples were obtained from the external jugular vein using a vacuum tube without anticoagulant, which was immediately centrifuged at 400g for 12 min in a dedicated centrifuge. The L-PRF clot was removed from the tube, and the red clot was released from the buffy coat using a spatula. The membrane was produced using a PRF box. Histological examination identified the three portions of the L-PRF membranes. The first portion was composed mainly of red blood cells with the presence of a low number of leukocytes among them. The second portion was composed of white blood cells, mainly neutrophils. The third portion was composed of the fibrin network which was characterized by acidophilic staining. The immunohistochemical analysis showed that vascular endothelial growth factor and platelet-derived growth factor were expressed in all samples at different intensities, both in cellular components and fibrin mesh. The tensile test and wettability assessments were measured in membranes 30 min and 3 h after production. The 30 min L-PRF membranes supported twice the ultimate tensile strength compared to 3 h L-PRF membranes. The wettability of the 30 min sample membranes was statistically higher than the 3 h sample membranes. In conclusion, the centrifugation protocol allowed production of the L-PRF membrane using canine blood and this was confirmed by histological and immunohistochemical analysis. The mechanical resistance and wettability of the L-PRF membrane were significantly reduced over time.

Owner׳s Perception for Detecting Feline Body Condition Based on Questionnaire and Scores.

To evaluate the owner׳s ability to identify body condition in cats, based on questionnaire and scores, as well as to obtain others׳ information about the cat and the owner that may be related to the body condition. Seventy-seven owned cats, aged above 11 months, were evaluated. Initially, information was obtained on age, sex, breed, and whether they had been neutered. Next, owners were asked to fill a questionnaire: the first section was about the cat׳s diet type, feeding regime, and activity level, and the second section was on the owners׳ diet, physical activity, and physical condition. The owners estimated body condition of their cats before and after seeing drawings with images. The authors also estimated body condition. Only a 5-point visual scale showed significant difference between the cat׳s body score assigned by the owner before and after seeing drawings, and before seeing drawings compared with the cat׳s body score assigned by the authors. A weak positive correlation was detected between cat׳s body score assigned by the 2 authors and access to any type of cat climbing systems, and weak negative correlation was detected for the variable spayed or neutered. The cat׳s physical activity level showed weak negative correlation with cat׳s body score. There was a strong positive correlation between cat׳s body weight and cat׳s body score. The owners showed ability to identify body condition in cats after seeing the drawings in both visual scales, and there was a relationship between cat׳s body weight and body condition score.

Development and mechanical properties of a locking T-plate / Desenvolvimento e as propriedades mecânicas de uma placa bloqueada em formato de T

This study aimed to develop a locking T-plate and to evaluate its mechanical properties in synthetic models. A titanium 2.7mm T-plate was designed with a shaft containing three locked screw holes and one dynamic compression hole, and a head with two locked screw holes. Forty T-shaped polyurethane blocks, and 20 T-plates were used for mechanical testing. Six bone-plate constructs were tested to failure, three in axial compression and three in cantilever bending. Fourteen bone-plate constructs were tested for failure in fatigue, seven in axial compression and seven in cantilever bending. In static testing higher values of axial compression test than cantilever bending test were observed for all variables. In axial compression fatigue testing all bone-plate constructs withstood 1,000,000 cycles. Four bone-plate constructs failure occurred before 1,000,000 cycles in cantilever bending fatigue testing. In conclusion, the locking T-plate tested has mechanical properties that offer greatest resistance to fracture under axial loading than bending forces.(AU)

O objetivo deste estudo foi desenvolver uma placa bloqueada em formato de T e avaliar as propriedades mecânicas em um modelo sintético. Uma placa-T em liga de titânio 2,7mm foi desenhada com uma haste contendo três orifícios para parafusos bloqueados e um orifício para realização de compressão dinâmica. 40 blocos de poliuretano em formato de T e 20 placas-T foram utilizados para os ensaios mecânicos. Seis montagens osso-placa foram testados até a falha, sendo três em força de compressão axial e três em flexão engastada. 14 montagens osso-placa foram testadas até a falha em fatiga, sendo 7 em força de compressão axial e 7 em flexão engastada. No teste estático, os valores mais altos foram observados em todas as variáveis no teste de compressão axial quando comparado à flexão engastada. Já nos testes de fadiga na força de compressão axial, todas as montagens osso-placa resistiram à 1000000 de ciclos. No teste de fadiga em flexão engastada, quatro montagens osso-placa falharam antes de alcançarem 1000000 de ciclos. Em conclusão, a placa-T estudada apresenta propriedades mecânicas que oferecem uma melhor resistência em estabilizar as fraturas na atuação das forças de compressão axial que nas forças de flexão.(AU)