Comparative Kinematic Analysis of Hurdle Clearance Technique in Dogs: A Preliminary Report.

Although the jumping characteristics of agility dogs have been examined in recent years, there is currently a lack of data related to the suspension phase. The purpose of the present study was to investigate the biomechanics of the suspension phase of the agility jump and to analyze the kinematic differences in dogs with different jumping abilities. Two groups of dogs of the same height category (large dogs) competing at different skill levels and assessed as excellent jumpers (n = 4) and less-skilled jumpers (n = 3), respectively, were analyzed and statistically compared. Excellent jumpers showed longer and faster jumps with flatter jump trajectories than less-skilled jumpers. In less-skilled jumpers, the distance in front of the hurdle was notably greater than the distance behind it, while the difference between these two distances was less in excellent jumpers. Length and duration of the jump, maximal height of the jumping trajectory, take-off and landing distances to the hurdle, time of occurrence of maximal jump height, and time of change in back orientation essentially defines the suspension phase of the agility jump. This study presents preliminary evidence that the kinematic characteristics of hurdle clearance are different in excellent jumper dogs and in less-skilled jumper dogs.

Surface Electromyography of the Longissimus and Gluteus Medius Muscles in Greyhounds Walking and Trotting on Ground Flat, Up, and Downhill.

In the field of canine rehabilitation, knowledge of muscle function in the therapeutic exercises prescribed is needed by physical therapists and veterinary surgeons. To gain insight into the function of longissimus dorsi (LD) and gluteus medius (GM) muscles in dogs, five Greyhounds performing leash walking and trotting on the ground flat, up (+7%), and downhill (-7%) were studied by surface electromyography, and the mean and maximum activity was compared. For the same incline, the surface electromyography (sEMG) of LD was higher (p < 0.05) at the trot than at the walk. In LD muscle, trotting uphill showed significantly higher maximum activity than any other exercise. A change of +7% incline or -7% decline affected (increased or decreased, respectively) the mean sEMG of the LD and GM muscles of dogs walking or trotting on the ground. When combined, the influence of gait and incline on electromyographic activity was analyzed, and walking at certain inclines showed no difference with trotting at certain inclines. Walking and trotting up and downhill added separate therapeutic value to flat motion. The results of the present study might contribute to a better understanding of the function of LD and GM muscles in dogs, this being especially useful for the field of canine rehabilitation.

Validation of a new objective index to measure spinal mobility: the University of Cordoba Ankylosing Spondylitis Metrology Index (UCOASMI).

Spinal mobility measures are subject to high variability and subjectivity. Automated motion capture allows an objective and quantitative measure of mobility with high levels of precision. To validate the University of Cordoba Ankylosing Spondylitis Metrology Index (UCOASMI), an index measure of spinal mobility, based on automated motion capture, validation studies included the following: (1) validity, tested by correlation--Pearson's r--between the UCOASMI and the mobility index Bath Ankylosing Spondylitis Metrology Index (BASMI), and a measure of structural damage, the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS); (2) reliability, with internal consistency tested by Cronbach's alpha, test-retest by intraclass correlation coefficient (ICC) after 2 weeks, and error measurement, by variation coefficient (VC) and smallest detectable difference (SDD); and (3) responsiveness, by effect size (ES) in a clinical trial of anti-TNF. Patients for the different studies all had ankylosing spondylitis. Validity studies show correlation between the BASMI (r = 0.881) and the mSASSS (r = 0.780). Reliability studies show an internal consistency of Cronbach's α = 0.894, intra-observer ICC = 0.996, test-retest ICC = 0.996, and a measurement error of VC = 2.80% and SDD = 0.25 points. Responsiveness showed an ES after 24 weeks of treatment of 0.48. In all studies, the UCOASMI's performance was better than that of the BASMI. The UCOASMI is a validated index to measure spinal mobility with better metric properties than previous indices.

Assessment of spinal mobility in ankylosing spondylitis using a video-based motion capture system.

This paper describes the use of a video-based motion capture system to assess spinal mobility in patients with ankylosing spondylitis (AS). The aim of the study is to assess reliability of the system comparing it with conventional metrology in order to define and analyze new measurements that reflect better spinal mobility. A motion capture system (UCOTrack) was used to measure spinal mobility in forty AS patients and twenty healthy subjects with a marker set defining 33 3D measurements, some already being used in conventional metrology. Radiographic studies were scored using the modified Stoke Ankylosing Spondylitis Spine Score index (mSASSS). Test-retest reliability studies were performed on the same day and over a two-week period. Motion capture shows very high reliability with Intraclass Correlation Coefficient values ranging from 0.89 to 0.99, low Standard Error of the Measurement (0.37-1.33 cm and 1.58°-6.54°), correlating very well with the Bath Ankylosing Spondylitis Metrology Index (BASMI) (p < 0.001) and, in some individual measures (cervical flexion, cervical lateral flexion, back inclination, shoulder-hip angle and spinal rotation), with mSASSS (p < 0.01). mSASSS also added significantly to the variance in multivariate linear regression analysis to certain measures (back inclination, cervical flexion and cervical lateral flexion). Quantitative results obtained with motion capture system using the protocol defined show to be highly reliable in patients with AS. This technique could be a useful tool for assessing the outcome of the disease and for monitoring the evolution of spinal mobility in AS patients.

Intracranial portion of the trochlear nerve and dorsal oblique muscle composition in dog: a structural and ultrastructural study.

In the present investigation the right intracranial portion of the trochlear nerves and dorsal oblique muscle of the right ocular globe were removed from six adult dogs and analyzed by light and electron microscopy. Unmyelinated fibers were observed in the analyzed nerves. The number, diameter, area, and density of myelinated fibers were determined, as were corresponding axon area and diameter and myelin sheath thickness. Frequency histograms of myelin sheath thickness and fiber size show a bimodal distribution with a similar proportion of large and small fibers. Muscle samples were taken from the central portion of the muscle belly, subsequently frozen, cut, and stained with m-ATPase at pH 4.6. Fibers were classified as Type 1 or Type 2 according to their reaction to the m-ATPase and detailed morphologic and morphometric studies were made. The muscles showed two clearly distinct layers, a central layer and a peripheral layer, chiefly composed of Type 2 fibers. The fibers in the central layer were larger in size than those in the peripheral layer.