Reasons for performing study: Although there is anecdotal evidence of clinical effectiveness of chiropractic in treatment of equine back pain, little scientific work has been reported on the subject. Objectives: To quantify the effect of chiropractic manipulations on back and limb kinematics in horse locomotion. Methods: Kinematics of 10 Warmblood horses were measured over ground at walk and trot at their own preferred speed, before and one hour and 3 weeks after chiropractic treatment that consisted of manipulations of the back, neck and pelvic area. Speed was the same during all measurements for each horse. Results: Chiropractic manipulations resulted in increased flexion-extension range of motion (ROM) (P
Gómez Álvarez CB, Rhodin M, Byström A, Back W, van Weeren PR (2009) Back kinematics of healthy trotting horses during treadmill versus over ground locomotion, Equine Veterinary Journal 41 (3) pp. 297-300
Reasons for performing study: Treadmill locomotion is frequently used for training of sport horses, for diagnostic purposes and for research. Identification of the possible biomechanical differences and similarities between the back movement during treadmill (T) and over ground (O) locomotion is essential for the correct interpretation of research results. Objectives: To compare the kinematics of the thoracolumbar vertebral column in treadmill and over ground locomotion in healthy horses. Methods: Six sound Dutch Warmblood horses trotted on a T and O during 10 s at their own preferred velocity (mean ± s.d. 3.6 ± 0.3 m/s T and 3.6 ± 0.1 m/s O), which was the same in both conditions. Kinematics of the vertebral column was captured by infrared cameras using reflective skin markers attached over the spinous processes of selected vertebrae and other locations. Flexion-extension and lateral bending range of motion (ROM), angular motion pattern (AMP) and intravertebral pattern symmetry (IVPS) of 5 vertebral angles (T6-T10-T13, T10-T13-T17, T13-T17-L1, T17-L1-L3 and L1-L3-l5) were calculated. Neck angle, linear and temporal stride parameters and protraction-retraction angles of the limbs were also calculated. Results: The vertical ROM (flexion-extension) was similar in both conditions, but the horizontal ROM (lateral bending) of the lumbar angles T17-L1-L3 and L1-L3-L5 was less during T locomotion (mean ± s.d. difference of 1.8 ± 0.6 and 1.7 ± 0.9°, respectively, P>0.05). During O locomotion, the symmetry pattern of the lumbar vertebral angles was diminished from 0.9 to 0.7 (1 = 100% symmetry) indicating increased irregularity of the movement (P>0.05). No differences were found in the basic linear and temporal stride parameters and neck angle. Potential relevance: Vertebral kinematics during treadmill locomotion is not identical to over ground locomotion, but the differences are minor. During treadmill locomotion lumbar motion is less, and caution should be therefore taken when interpreting lumbar kinematics.
Waldern NM, Wiestner T, von Peinen K, Gómez Álvarez CG, Roepstorff L, Johnston C, Meyer H, Weishaupt MA (2009) Influence of different head-neck positions on vertical ground reaction forces, linear and time parameters in the unridden horse walking and trotting on a treadmill, Equine Veterinary Journal 41 (3) pp. 268-273
Reasons for performing study: It is believed that the head-neck position (HNP) has specific effects on the loading pattern of the equine locomotor system, but very few quantitative data are available. Objective: To quantify the effects of 6 different HNPs on forelimb-hindlimb loading and underlying temporal changes. Methods: Vertical ground reaction forces of each limb and interlimb coordination were measured in 7 high level dressage horses walking and trotting on an instrumented treadmill in 6 predetermined HNPs: HNP1 - unrestrained; HNP2 - elevated neck, bridge of the nose in front of the vertical; HNP3 - elevated neck, bridge of the nose behind the vertical; HNP4 - low and flexed neck; HNP5 - head and neck in extreme high position; and HNP6 - forward downward extension of head and neck. HNP1 served as a velocity-matched control. Results: At the walk, the percentage of vertical stride impulse carried by the forehand (Izfore) as well as stride length and overreach distance were decreased in HNP2, HNP3, HNP4 and HNP5 when compared to HNP1. At the trot, Izfore was decreased in HNP2, HNP3, HNP4 and HNP5. Peak forces in the forelimbs increased in HNP5 and decreased in HNP6. Stance duration in the forelimbs was decreased in HNP2 and HNP5. Suspension duration was increased in HNP2, HNP3 and HNP5. Overreach distance was shorter in HNP4 and longer in HNP6. Conclusions: In comparison to HNP1 and HNP6, HNPs with elevation of the neck with either flexion or extension at the poll as well as a low and flexed head and neck lead to a weight shift from the forehand to the hindquarters. HNP5 had the biggest effect on limb timing and load distribution. At the trot, shortening of forelimb stance duration in HNP5 increased peak vertical forces although Izfore decreased. Potential relevance: Presented results contribute to the understanding of the value of certain HNPs in horse training.
Gómez Alvarez CB, Rhodin M, Bobber MF, Meyer H, Weishaupt MA, Johnston C, Van Weeren PR (2006) The effect of head and neck position on the thoracolumbar kinematics in the unridden horse., Equine veterinary journal. Supplement (36) pp. 445-451
REASONS FOR PERFORMING STUDY: In many equestrian activities a specific position of head and/or neck is required that is dissimilar to the natural position. There is controversy about the effects of these positions on locomotion pattern, but few quantitative data are available. OBJECTIVES: To quantify the effects of 5 different head and neck positions on thoracolumbar kinematics of the horse. METHODS: Kinematics of 7 high level dressage horses were measured walking and trotting on an instrumented treadmill with the head and neck in the following positions: HNP2 = neck raised, bridge of the nose in front of the vertical; HNP3 = as HNP2 with bridge of the nose behind the vertical; HNP4 = head and neck lowered, nose behind the vertical; HNP5 = head and neck in extreme high position; HNP6 = head and neck forward and downward. HNP1 was a speed-matched control (head and neck unrestrained). RESULTS: The head and neck positions affected only the flexion-extension motion. The positions in which the neck was extended (HNP2, 3, 5) increased extension in the anterior thoracic region, but increased flexion in the posterior thoracic and lumbar region. For HNP4 the pattern was the opposite. Positions 2, 3 and 5 reduced the flexion-extension range of motion (ROM) while HNP4 increased it. HNP5 was the only position that negatively affected intravertebral pattern symmetry and reduced hindlimb protraction. The stride length was significantly reduced at walk in positions 2, 3, 4 and 5. CONCLUSIONS: There is a significant influence of head/neck position on back kinematics. Elevated head and neck induce extension in the thoracic region and flexion in the lumbar region; besides reducing the sagittal range of motion. Lowered head and neck produces the opposite. A very high position of the head and neck seems to disturb normal kinematics. POTENTIAL RELEVANCE: This study provides quantitative data on the effect of head/neck positions on thoracolumbar motion and may help in discussions on the ethical acceptability of some training methods.
Rhodin M, Gómez álvarez CB, Byström A, Johnston C, van Weeren PR, Roepstorff L, Weishaupt MA (2009) The effect of different head and neck positions on the caudal back and hindlimb kinematics in the elite dressage horse at trot, Equine Veterinary Journal 41 (3) pp. 274-279
Reasons for performing study: Dressage involves training of the horse with the head and neck placed in a position defined by the rider. The best position for dressage training is currently under debate among riders and trainers, but there are few scientific data available to confirm or disprove the different views. Objective: To evaluate the kinematic effects of different head and neck positions (HNPs) in elite dressage horses ridden at trot. Methods: Seven high-level dressage horses were subjected to kinetic and kinematic measurements when ridden on a treadmill with the head and neck in 5 different positions. Results: Compared to free trot on loose reins the HNP desired for collected trot at dressage competitions increased T6 vertical excursion, increased sacral flexion and decreased limb retraction after lift-off. Further increasing head or head and neck flexion caused few additional changes while an extremely elevated neck position increased hindlimb flexion and lumbar back extension during stance, increased hindlimb flexion during swing and further increased trunk vertical excursion. Conclusions: The movements of the horse are significantly different when ridden on loose reins compared to the position used in collected trot. The exact degree of neck flexion is, however, not consistently correlated to the movements of the horse's limbs and trunk at collected trot. An extremely elevated neck position can produce some effects commonly associated with increased degree of collection, but the increased back extension observed with this position may place the horse at risk of injury if ridden in this position for a prolonged period. Potential relevance: Head and neck positions influence significantly the kinematics of the ridden horse. It is important for riders and trainers to be aware of these effects in dressage training.
Gómez Álvarez CB, Wennerstrand J, Bobbert MF, Lamers L, Johnston C, Back W, Van Weeren PR (2007) The effect of induced forelimb lameness on thoracolumbar kinematics during treadmill locomotion, Equine Veterinary Journal 39 (3) pp. 197-201
Reasons for performing study: Lameness has often been suggested to result in altered movement of the back, but there are no detailed studies describing such a relationship in quantitative terms. Objectives: To quantify the effect of induced subtle forelimb lameness on thoracolumbar kinematics in the horse. Methods: Kinematics of 6 riding horses was measured at walk and at trot on a treadmill before and after the induction of reversible forelimb lameness grade 2 (AAEP scale 1-5). Ground reaction forces (GRF) for individual limbs were calculated from kinematics. Results: The horses significantly unloaded the painful limb by 11.5% at trot, while unloading at walk was not significant. The overall flexion-extension range of back motion decreased on average by 0.2° at walk and increased by 3.3° at trot (P
Gómez Alvarez CB (2008) [The back of the horse: a bridge between the extremities, but functionally not enough understood]., Tijdschr Diergeneeskd 133 (19) pp. 804-806
Gómez Álvarez CB, Bobbert MF, Lamers L, Johnston C, Back W, Van Weeren PR (2008) The effect of induced hindlimb lameness on thoracolumbar kinematics during treadmill locomotion, Equine Veterinary Journal 40 (2) pp. 147-152
Reasons for performing study: There are no detailed studies describing a relationship between hindlimb lameness and altered motion of the back. Objectives: To quantify the effect of induced subtle hindlimb lameness on thoracolumbar kinematics in the horse. Methods: Kinematics of 6 riding horses were measured during walk and trot on a treadmill before and during application of pressure on the sole of the left hindlimb using a well-established sole pressure model. Reflective markers were located at anatomical landmarks on the limbs, back, head and neck for kinematic recordings. Ground reaction forces (GRF) in individual limbs were calculated from kinematics to detect changes in loading of the limbs. Results: When pressure on the sole of the hindlimb was present, horses were judged as lame (grade 2 on the AAEP scale 1-5) by an experienced clinician. No significant unloading of this limb was found in the group of horses (unloading was observed in 4 animals, but was not detectable in the other 2), but statistically significant effects on back kinematics were detected. The overall flexion-extension (FE) range of motion (ROM) of the vertebral column was increased at walk, especially in the thoracic segments. Axial rotation (AR) ROM of the pelvis was also increased. At trot, the FE ROM was decreased only in the segment L3-L5-S3. During the stance phase of the lame limb, the segment T6-T10-T13 was more flexed and the neck was lowered at both gaits; the thoracolumbar segments were more extended at walk and trot. There were no significant changes in the stride length or protraction-retraction angles in any of the limbs. Conclusions: Subtle hindlimb lameness provoked slight but detectable changes in thoracolumbar kinematics. The subtle lameness induced in this study resulted in hyperextension and increased ROM of the thoracolumbar back, but also in decreased ROM of the lumbosacral segment and rotational motion changes of the pelvis. Potential relevance: Even subtle lameness can result in changes in back kinematics, which emphasises the intricate link between limb function and thoracolumbar motion. It may be surmised that, when chronically present, subtle lameness induces back dysfunction.
Bobbert MF, Gómez Álvarez CB, Van Weeren PR, Roepstorff L, Weishaupt MA (2007) Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion, Journal of Experimental Biology 210 (11) pp. 1885-1896
The purpose of this study was to determine whether individual limb forces could be calculated accurately from kinematics of trotting and walking horses. We collected kinematic data and measured vertical ground reaction forces on the individual limbs of seven Warmblood dressage horses, trotting at 3.4 m s -1 and walking at 1.6 m s-1 on a treadmill. First, using a segmental model, we calculated from kinematics the total ground reaction force vector and its moment arm relative to each of the hoofs. Second, for phases in which the body was supported by only two limbs, we calculated the individual reaction forces on these limbs. Third, we assumed that the distal limbs operated as linear springs, and determined their force-length relationships using calculated individual limb forces at trot. Finally, we calculated individual limb force-time histories from distal limb lengths. A good correspondence was obtained between calculated and measured individual limb forces. At trot, the average peak vertical reaction force on the forelimb was calculated to be 11.5±0.9 N kg-1 and measured to be 11.7±0.9 N kg -1, and for the hindlimb these values were 9.8±0.7 N kg -1 and 10.0±0.6 N kg-1, respectively. At walk, the average peak vertical reaction force on the forelimb was calculated to be 6.9±0.5 N kg-1 and measured to be 7.1±0.3 N kg -1, and for the hindlimb these values were 4.8±0.5 N kg -1 and 4.7±0.3 N kg-1, respectively. It was concluded that the proposed method of calculating individual limb reaction forces is sufficiently accurate to detect changes in loading reported in the literature for mild to moderate lameness at trot.
Lameness detection can be challenging in dogs, as reflected in the reported low inter-rater agreement when visually assessing lameness. The aim of this study was to use an inertial sensor-based system to detect and quantify induced distal and proximal limb disturbances mimicking supporting and swinging limb lameness in dogs trotting on a treadmill by measuring vertical head and pelvic movement symmetry. Ten clinically sound dogs were equipped with inertial measurement units that were attached to the head, pelvis and right distal forelimb. Vertical head and pelvic movement symmetry were measured while dogs trotted on a treadmill, before and after the induction of moderate support or swinging fore- and hindlimb lameness. Four symmetry variables were calculated: the differences in displacement between the two lowest and between the two highest values of the head and pelvis per stride, respectively. These variables were defined as minimum head difference (HDmin), maximum head difference (HDmax), minimum pelvic difference (PDmin) and maximum pelvic difference (PDmax).
Compensatory limb loading has been studied in lame dogs; however, little is known about how these compensations relate to motion of the head and pelvis, assessment of which is an important component of lameness examinations. The aim of this study was to describe the patterns of vertical head and pelvic motion symmetry at the trot in dogs with induced supporting limb lameness in the forelimbs or hind limbs. Ten sound dogs were trotted on a treadmill before and after temporary induction of moderate lameness (grade 2/5) in each limb. Reflective markers were located on the head, pelvis and right forelimb, and kinematic data were captured with a motion capture system. Upper body symmetry parameters were calculated, including differences between the highest (HDmax) and lowest (HDmin) positions of the head, and between the highest (PDmax) and lowest (PDmin) positions of the mid-pelvis, with a value of zero indicating symmetry. The head was lowered more during the sound limb stance phase and lowered less during the lame limb stance phase in supporting forelimb lameness (HDmin: 4.6 mm in dogs when sound, ?18.3 mm when left limb lameness was induced and 20.5 mm when right limb lameness was induced). The mid-pelvis was lowered more during the sound limb stance phase and lowered and lifted less during the lame limb stance phase in supporting hind limb lameness (PDmin: 1 mm in dogs when sound, ?10.1 mm in left limb lameness and 8.4 mm in right limb lameness). The hip of the lame side, measured at the level of the greater trochanter, had an increased downwards displacement during the lame limb swing phase (?21 mm in left hind limb lameness, P = 0.005; 23.4 mm in right hind limb lameness, P = 0.007). Asymmetry in the lowering of the head or mid-pelvis is a more sensitive indicator of supporting forelimb and hind limb lameness, respectively, than asymmetry in the raising of the head. Increased displacement of the hip (?hip drop? of the lame side during its swing phase) is a good indicator of hind limb lameness in dogs.
Degenerative lumbosacral stenosis has been suspected to have a dynamic component, especially regarding encroachment of the L7 nerve roots exiting the lumbosacral foramina. Angled cross-sectional imaging of the neuroforamina has been found improve the accuracy of the diagnosis of stenosis in humans. In this anatomic study, foraminal apertures were evaluated by MRI at the entry, middle, and exit zones of the nerve roots in 30 dogs that were clinically affected by lumbosacral disease. Standard vs. oblique planar orientation and neutral vs. hyperextended positioning of the lumbosacral area were compared by measuring the median values for entry, middle, and exit zones. The neuroforaminal area acquired using oblique plane acquisition was significantly smaller than standard parasagittal measurements. Furthermore, standard parasagittal neuroforaminal dimensions in the hyperextended position were significantly smaller than standard parasagittal measurements in the neutral position. This statistical difference was even more pronounced for neuroforaminal dimension evaluated in the oblique plane and hyperextended position. Positioning of the dog during imaging has a significant effect on neuroforaminal dimension, corroborating the notion that spinal position may influence neural claudication in clinically affected patients. Reductions in neuroforaminal dimension are more evident on oblique planar image acquisition, suggesting that this approach may be more useful than parasagittal imaging as a tool for identifying subtle changes in L7 neuroforaminal dimensions in cases of canine lumbosacral stenosis.
Early detection of disease by an animal owner may motivate them to seek early veterinary
advice. Presentation before a more advanced clinical manifestation is evident could lead to
more effective treatment and thus benefit the animal's health and welfare. Accelerometers
are able to detect changes in specific activities or behaviours, thus indicating early signs of
possible adverse health events. The objective of this validation study was to determine
whether the detection of eight behavioural states: walk, trot, canter/gallop, sleep, static/inactive,
eat, drink, and headshake, by an accelerometer device was sufficiently accurate to be
useful in a clinical setting. This fully independent external validation estimated the accuracy
of a specific triaxial, collar-mounted accelerometer on a second-by second basis in 51
healthy dogs of different breeds, aged between 6 months and 13 years, weighing >10 kg.
The overall diagnostic effectiveness was estimated as:%record correctly classified of >
95% in walk, trot, canter/gallop, eat, drink and headshake and >90% in sleep and static/inactive.
The positive predictive values ranged from 93±100%, while the negative predictive
values ranged from 96±100%, with exception of static/inactive (86%).This was probably
because dogs were placed in unfamiliar kennels where they did not exhibit their typical resting
behaviour. The device is worn on a collar, making its use feasible for anyone wanting to
monitor their dog's behaviour. The high accuracy in detecting various kinds of behaviour
appears promising in assessing canine health and welfare states.
Swinging limb lameness is defined as a motion disturbance ascribed to a limb in swing phase. Little is known about its biomechanics in dogs, particularly about the body motions that accompany it, such as vertical head and pelvic motion asymmetry. The aim of this study was to describe the changes in vertical head and pelvic motion asymmetry in dogs with induced swinging limb motion disturbance, mimicking a swinging limb lameness. Fore- and hind-limb lameness was induced in ten sound dogs by placing a weight (200 g) proximal to the carpus or tarsus, respectively. Marker-based motion capture by eight infrared light emitting video cameras recorded the dogs when trotting on a treadmill. Body symmetry parameters were calculated, including differences between the two highest positions of the head (HDmax) and pelvis (PDmax) and between the two lowest positions of the head (HDmin) and pelvis (PDmin), with a value of zero indicating perfect symmetry.
Lameness is commonly encountered in veterinary practice, however precise visual lameness detection requires experience. This skill is challenging to teach: exposure of students to many patients is needed to learn the necessary perceptual skills; however patients might not be readily available. Video recordings of patients can be useful, but depend on the quality of recording and variety of cases available. They are limited to two dimensional views which don?t fully replicate a real-life three dimensional examination.
Following on the success of an equine lameness training tool (www.lamenesstrainer.com) developed at the Royal Veterinary College; a 3D virtual canine lameness tool is being developed to teach students to reliably recognize canine lameness. We collected 3D motion capture data from 10 non-lame Labrador retrievers at walk and trot on a treadmill. Data were captured using eight Oqus7 cameras (Qualisys, Sweden). The movement of these dogs was recorded based on 32 reflective markers positioned over key anatomical locations. Marker positions for twenty steady strides for one dog were averaged to drive the skeleton movement of a matching 3D dog model in Autodesk MotionBuilder. The final clips were rendered to show a realistic-looking shaded wireframe of the dog model at normal walk and trot. Varying types and degrees of lameness were then introduced to this animation based on previous kinematic studies.
Next stages of work will involve the inclusion of this model in a tool to enable it to be used for veterinary education; once validated it will be released as an Open Educational Resource.