Tuber Sacrale Research Articles

Water depth and speed may have an opposite effect on the trunk vertical displacement in horses trotting on a water treadmill.

To measure the trunk vertical displacement (VD) in horses trotting on a water treadmill (WT) at different water depths (WDs) and speeds. 6 sound Standardbred horses (median age 12 years [IQR:10.5-12]). The horses were trotted on a WT at 2 speeds (3.5 m/s and 5 m/s) and during 4 conditions: dry treadmill (DT), WD at mid-cannon (WD-CAN), mid-radius (WD-RAD), and shoulder (WD-SHOUL). The dorsoventral movement was obtained with accelerometers placed over the withers, thoracolumbar junction (T18), tuber sacrale (TS), and sacrum (S5). The VD was defined with the median value of the upward (Up) and downward (Down) amplitudes of the vertical excursion during each stride. The difference of VD at each sensor location was compared between the DT and the 3 WDs, and between the 2 trotting speeds for the same condition. The VD amplitudes were significantly increased at any sensor location when trotting in water at WD-CAN and WD-RAD compared to DT (P < .05 for all), with the highest increase at WD-RAD and T18. When the speed increased from 3.5 to 5 m/s, the VD amplitudes were significantly decreased at T18 at each water level (P = .03), and at WD-RAD only for the withers and TS (P = .03). Both water depth and speed affect the trunk VD in horses at trot on a WT with an opposite effect. The VD increases when increasing the WD up to mid-radius, while the VD decreases when increasing the trotting speed, with the main effects observed at the thoracolumbar junction.

Effect of Femoral Head and Neck Osteotomy on Canines' Functional Pelvic Position and Locomotion.

Simple SummaryRemoval of the femoral head and neck is a common surgical procedure used to provide pain relief in dogs with severe hip-related diseases. We investigated the chronic effect of the surgery on movement and position of the pelvis. Dog owners completed a questionnaire regarding their dog’s rehabilitation. An orthopaedic examination, anatomical measurements, and pressure-sensitive walkway analysis were conducted on all of the dogs. According to the questionnaire results, nine of ten dogs had returned to normal physical activity level, and the owners of the dogs considered the outcome of the surgery to be good or excellent. However, the dogs had less muscle mass, less hip extension, and less weight bearing on the operated limb when standing. The trot of the dogs was unaffected; no differences emerged between the operated and non-operated limb regarding length of stance or swing time of step or weight bearing during step. Pelvic position did not change in a specific way; i.e., the pelvis did not tilt towards or away from the surgically treated limb.The long-term effect of femoral head and neck osteotomy (FHO) on the locomotory system of dogs was evaluated. The study comprised an owner questionnaire and an orthopaedic examination, anatomical measurements, and pressure-sensitive walkway analysis for dogs. Linear mixed effect models were used for statistical analysis. Ten dogs with a median of 2.5 years since their unilateral FHO were included. According to the questionnaire results, nine dogs had returned to a normal physical activity level. Muscle atrophy (p = 0.005), less extension in the coxofemoral joint (p = 0.003), and less static weight bearing on the FHO limb (p = 0.003) were observed. No consistent pattern regarding tilt or position of the pelvis was noted when measuring height of the tuber ischii (p = 0.39). Five of the dogs tilted away from, and five towards the FHO side when measured from the tuber sacrale with a Myrin goniometer. No differences regarding stance time, swing time, or peak pressure between the FHO and non-FHO limb were seen in trot (p = 0.70, p = 0.26, and p = 0.91, respectively). Over the long term, the FHO limb has muscle atrophy, decreased coxofemoral extension, and decreased static weight bearing. However, this does not seem to affect the trot of the dogs. Dog owners considered the outcome of surgery to be good or excellent.

Effect of Ground and Raised Poles on Kinematics of the Walk

Walking over poles is a commonly employed training and rehabilitation tool and it is crucial to understand its effect on equine locomotion, particularly joint range of motion (ROM). The study aimed to compare the effect of ground poles (GP) and raised poles (RP) on limb kinematics and poll, wither and pelvic ROM at walk. It was hypothesized that walking over poles would increase joint ROM but have no effect on poll, wither and pelvic ROM compared to no poles (NP). Forty-one horses were walked in-hand over NP, GP (10 cm) and RP (26 cm) in a crossover design. Limb kinematics were determined via two-dimensional motion capture (240 Hz). Poll, wither, tubera sacrale, and left/right tuber coxae ROM were determined by inertial motion units (100 Hz). Multivariable mixed effects linear regression analyses were carried out. Walking over poles increased limb joint ROM, through increased swing flexion, compared to NP. There was a greater effect over RP compared to GP. Significant reductions in craniocaudal ROM of the wither, tuber coxae and tuber sacrale were observed over GP and RP. Mediolateral ROM of tuber coxae and tuber sacrale increased over GP and RP and was greatest over RP. Wither ROM was increased over RP only. Set-up and height of the poles used here may not extrapolate to other scenarios. Walking over poles appears to be effective at increasing joint ROM via an increase in mid swing flexion, without vertical excursion of the trunk, compared to normal locomotion, which supports the use of poles for rehabilitation.

Differential Rotational Movement of the Thoracolumbosacral Spine in High-Level Dressage Horses Ridden in a Straight Line, in Sitting Trot and Seated Canter Compared to In-Hand Trot.

Simple SummaryAs part of the investigative process of “loss of athletic performance”, quantitative data may help veterinary decision making when assessing equine back dysfunction. Ranges of motion of differential rotational movement were quantified between adjacent inertial measurement units, which were attached to the skin over the thoraco–lumbo–sacral area in 10 dressage horses. Differential rotational movements were collected during trot in-hand and ridden in sitting trot/canter during straight-line locomotion. For the thoracic area, differential heading values were smaller in sitting trot and canter compared to trotting in-hand. Compared to trotting in-hand the thoraco-lumbar differential pitch values were higher in sitting trot and canter. The lumbo-sacral region, differential pitch values were increased in canter compared to trotting in-hand and differential heading values were higher in sitting trot compared to canter. Compared to in-hand, reduced heading values were measured in the cranial–thoracic area and increased in the caudal–thoracic and lumbar area. Pitch values increased with ridden exercise from the caudal–thoracic to the sacral area. Back movement alters when ridden compared to an unloaded condition. Understanding back movement whilst being ridden will help advance our understanding on equine back movement and assist with decision making.Assessing back dysfunction is a key part of the investigative process of “loss of athletic performance” in the horse and quantitative data may help veterinary decision making. Ranges of motion of differential translational and rotational movement between adjacent inertial measurement units attached to the skin over thoracic vertebrae 5, 13 and 18 (T5, T13, T18) lumbar vertebra 3 (L3) and tuber sacrale (TS) were measured in 10 dressage horses during trot in-hand and ridden in sitting trot/canter. Straight-line motion cycles were analysed using a general linear model (random factor: horse; fixed factor: exercise condition; Bonferroni post hoc correction: p < 0.05). At T5-T13 the differential heading was smaller in sitting trot (p ≤ 0.0001, 5.1° (0.2)) and canter (p ≤ 0.0001, 3.2° (0.2)) compared to trotting in-hand (7.4° (0.4)). Compared to trotting in-hand (3.4° (0.4)) at T18-L3 differential pitch was higher in sitting trot (p ≤ 0.0001, 7.5° (0.3)) and canter (p ≤ 0.0001, 6.3° (0.3)). At L3-TS, differential pitch was increased in canter (6.5° (0.5)) compared to trotting in-hand (p = 0.006, 4.9° (0.6)) and differential heading was higher in sitting trot (4° (0.2)) compared to canter (p = 0.02, 2.9° (0.3)). Compared to in-hand, reduced heading was measured in the cranial–thoracic area and increased in the caudal–thoracic and lumbar area. Pitch increased with ridden exercise from the caudal–thoracic to the sacral area.

Altered thoracolumbar position during application of craniocaudal spinal mobilisation in clinically sound leisure horses

Manual therapy techniques are commonly used by physiotherapists in the management of back pain to restore a pain-free range of motion and function in humans. However, there is a lack of research to support the proposed kinematic effects of manual therapy in the horse. This study investigated the kinematic effects of craniocaudal spinal mobilisation (CCSM) on the thoracolumbar spine in asymptomatic leisure horses. Markers were fixed to T10, T13, T17, L1, L3, the highest point of the wither and the tuber sacrale on thirteen horses that were positioned squarely. The CCSM technique consisted of two parts: (1) carpal flexion of either forelimb to 90° to maintain the horse in a tripod position, and (2) the application of a cranial to caudal force to the forehand via the ipsilateral point of the shoulder. Movement changes of the thoracolumbar markers from baseline to maximum flexion when the CCSM was applied was recorded as ‘depth’ (mm) relative to a fixed line drawn from the tuber sacrale to the maximal point of the withers. The change in angle (°) of each marker relative to the same markers was also recorded. Data were collected via video and analysed with Dartfish™ software. Increases in maximum thoracolumbar angle (P&lt;0.05) and reductions in thoracolumbar depth (P&lt;0.05) were found with CCSM. These results indicate CCSM induced flexion in the thoracolumbar spine, supporting its potential to improve range of motion and function in horses. Further studies to understand whether the changes observed during CCSM translate to treatment of back pain are warranted.

Quantification of Equine Sacral and Iliac Motion During Application of Manual Forces and Comparison Between Motion Capture With Skin-Mounted and Bone-Fixated Sensors

Diagnosis of sacroiliac dysfunction in horses includes manual motion palpation of the equine ilium and sacrum. Motion of the ilium and sacrum during manual force application to the equine pelvis has been measured previously in vitro. The aim of this study was to measure the amount and direction of motion in vivo, including comparison of bone-fixated and skin-mounted inertial sensors. Sensors were skin-mounted over tuber sacrale (TS) and third sacral spinous process of six Thoroughbred horses and later attached via Steinmann pins inserted into the same bony landmarks. Orientations of each TS and sacrum were recorded by one investigator during six trials of manual force applied to the pelvis, inducing cranial, caudal, and oblique rotations. Mean values were reported in Euler angles for the three orthogonal planes lateral bending, flexion–extension (FE), and axial rotation (AR). Differences between skin- and bone-fixated markers were determined with significance set at P < .05. The largest mean values recorded during rotations applied to the pelvises were for FE, (2.08° ± 0.35°) with bone-fixated sensors. AR gave the largest values recorded with skin mountings (1.70° ± 0.48°). There was a poor correlation between skin-mounted and bone-fixated markers with AR being the orthogonal plane in which results from skin mounting were closest to results from bone-fixated sensors Bony kinematics during external movement applied to the pelvis cannot be predicted from skin-mounted sensors, due to differences between skin- and bone-mounted sensors.

A sphere fitting approach to determine the hip joint centre of the horse

Accurate identification of the hip joint centre (HJC) is crucial for the correct estimation of knee and hip joint loads and kinematics, which is particularly relevant in orthopaedic surgery and musculoskeletal modelling. Several methods have been described for calculation of the HJC in humans, however, no studies have used these methods in the horse despite a similar need for improved evaluation of hip joint biomechanics in rehabilitation and musculoskeletal modelling. This preliminary study uses the commonly used functional method (least-squares sphere fit) to determine the HJC in three equid cadavers. Bone pins with reflective markers attached were drilled into the tuber coxae (TC), tuber ischium (TI), tuber sacrale (TS), greater trochanter (GT), third trochanter (TT) and lateral femoral condyle (FC) of the uppermost limb of the cadavers positioned in lateral recumbency. Three repetitions of passive movements consisting of pro-and retraction, ab- and adduction and circumduction were performed. The HJC was calculated using a least-squares sphere fitting method and presented as a distance from the TC based on a percentage of the TC to TI vector magnitude. Mean (± standard deviation) of the HJC is located 52.4% (± 3.9) caudally, 0.2% (± 6.5) dorsally, and 19.8% (± 4.2) medially from the TC. This study is the first to quantify the HJC in horses ex vivo using a functional method. Further work (in vivo and imaging) is required to validate the findings of the present study.

Body lean angle in sound dressage horses in-hand, on the lunge and ridden

Animals can minimise the risk of falling by leaning into a curve. The aims of this study were: (1) to quantify the difference between observed (measured by an inertial measurement unit, IMU) and predicted body lean angle (calculated as a cyclist when turning) in horses; and (2) to compare circles versus straight lines ridden versus in-hand and trot with canter, and investigate the influence of age, rein and ridden work quality in trot (Fédération Equestre Internationale grading scale 1–10) in horses. Thirteen non-lame horses were assessed prospectively in a non-random, cross-sectional survey. The horses were trotted in straight lines, lunged and ridden on both reins. A global positioning system-aided IMU attached to the skin over the tuber sacrale quantified body lean and recorded the velocity and the radius, which were used to calculate predicted lean. Horses ≤ 6 years of age leant more than predicted (mean ± standard deviation 2.9 ± 2.6°) and more than horses ≥ 7 years old (0.4 ± 3°) (P = 0.01). Horses that scored ≥ 7 in ridden work quality leant less than predicted (−1.1 ± 2.7°) and less than horses which scored ≤ 6 in ridden work quality (2.4 ± 1.5°) (P = 0.02). There were no significant differences between trot and canter, either on the lunge or ridden (P = 0.3), or between left and right reins (P = 0.2). Asymmetry of body lean between reins may be abnormal and may be helpful for recognition of lameness.

Association of a Subjective Muscle Score With Increased Angles of Flexion During Sitting Trot in Dressage Horses

Dressage requires the horse to be supple through the thoracolumbosacral region, and movement should allow for efficient locomotion and expression, but excessive thoracolumbosacral movement is likely to be detrimental to the soft tissues of the vertebral column. It is not known how development of the musculature relates to thoracolumbosacral movement in the ridden dressage horse. The aim of the study was to investigate the relationship between grading of muscle development and back kinematics. Thirty-five horses (Novice to Grand Prix level) in active dressage training were ridden in sitting trot in a straight line by their normal rider on an artificial surface. Thoracolumbosacral angles were derived from high-speed motion capture. Muscle scores were assigned based on visual assessment and manual palpation of the left and right sides of the neck, abdomen, thoracic and lumbosacral (LS) regions, pelvis, and hindlimbs. Our findings suggest that there is a relationship between muscle scores and kinematics of the back in ridden dressage horses. There was an association between neck trunk, thoracolumbar, LS angles, and dorsoventral difference between withers and tuber sacrale markers and muscle scores. Muscle scores assigned during clinical examination were related to the back kinematics of dressage horses ridden at a collected trot. Observations from this study suggest that thoracic, abdominal, and LS muscle development is important for achieving gait patterns which are desirable, according to equitation texts, at the collected trot.

Measurement of Motion During Manipulation of the Equine Pelvis

IntroductionManipulation of the equine ilium and sacrum is utilised to assess range of motion at the SIJ. Motion of the ilium and sacrum during manual force application to the equine pelvis has been measured previously in vitro. The aim of this study was to measure the amount and direction of motion in vivo including comparison of bone fixated and skin mounted sensors.MethodsOrientation sensors were skin‐mounted over tuber sacrale (TS) and 3rd sacral spinous process (SP) of six standing Thoroughbred horses. Orientations of each TS and sacrum were recorded by one investigator during six trials of manual force applied to the pelvis, inducing cranial, caudal and oblique rotations. The study was repeated with the sensors mounted onto pins implanted into TS and SP. Mean values were reported in Euler angles for the three orthogonal planes lateral bend (LB), flexion‐extension (F‐E) and axial rotation (AR). Correlation between skin and bone fixated markers (Spearman R) was determined with significance set at P&lt;0.05.ResultsThe largest mean values recorded during rotations applied to the pelvises were for F‐E (2.08 ± 0.35o) with bone fixated sensors. Axial rotation gave the largest values recorded with skin‐mountings (1.70 ± 0.48o). There was poor correlation between skin‐mounted and bone implanted markers.ConclusionsBony kinematics during external movement applied to the pelvis cannot be predicted from skin‐mounted sensors, due to differences between skin‐ and bone‐mounted sensors. Manipulation of the equine pelvis can be expected to produce motion in the plane of F‐E, but axial movement should be interpreted with caution due to the potential effects of skin motion.Ethical Animal ResearchEthical approval for animal use was obtained by the institutional animal ethics committee (University of Queensland). Sources of funding: Rural Industries Research and Development Council, Australia. Competing interests: none.

Effect of Pelvic Tilt on Synchronisation and Stability of Riders in Sitting Trot

IntroductionRider movement may influence horse‐rider interaction, yet little is known about what physical attributes affect postural stability. This study aimed to compare pelvic control and postural stability of riders on the floor and whilst riding.Methods33 riders were assessed by a physiotherapist and subjectively graded according to ability to tilt the pelvis in isolation: 1 = poor, 2 = better plus compensations, which were either A = lumbar spine inclusion B = full body lean, 3 = good. Riders wore markers on (1) greater trochanter of the femur, (2) iliac crest, (3) greater tubercle of the humerus. A marker was placed over the horse's tuber sacrale (4). Two‐dimensional high‐speed motion‐capture (240 Hz) recorded four strides of collected sitting trot in a straight line from the left side. Distance between markers was measured at midstance, maximum hindlimb protraction and retraction. Synchronisation was determined by the difference in time (secs) between the tuber sacrale of the horse and pelvis of the rider at these stride points. One‐way ANOVA was used to compare synchronisation between groups. Student's independent t‐test was used to compare marker distance.ResultsFor pelvic tilt, no grade 3 riders were seen. Grade 2 riders were more synchronised with the horse during left hind diagonal suspension phase (P = 0.011) and had smaller horizontal distances between markers 1–2, 2–3 and 1–3 respectively at all points of the stride (midstance: P&lt;0.042; hindlimb protraction: P&lt;0.049; hindlimb retraction: P&lt;0.013). Comparing compensation types, grade A riders were better synchronised with the horse at midstance phase (P = 0.014).ConclusionsResults suggest that control of pelvic movement may have an impact on horse‐rider synchronisation.Ethical Animal ResearchThis project was approved by the Animal Health Trust Clinical Research Ethics Committee. Explicit owner informed consent for participation in this study is not stated. Sources of funding: The Elise Pilkington Charitable Trust, British Dressage and Dr. Bechtolsheimer. Competing interests: none.

Vertical Displacement of the Equine Pelvis When Trotting on an Aqua Treadmill

IntroductionHydrotherapy is increasingly applied within the equine industry for rehabilitation and therapy. Substantial anecdotal evidence exists suggesting the benefits of its application but while there is extensive literature on the use of aqua‐treadmills in humans and canines there is comparatively little in equines. Therefore, limited research exists supporting the role of the aqua‐treadmill in current therapy practices. This study aimed to investigate the effect of water depth on pelvic movement during aqua‐treadmill exercise.MethodsEight horses were trotted on an aqua‐treadmill at four water depths specifically measured to individual horses (P3, fetlock, MC3, carpus). Pelvic displacement was recorded using an optical motion capture system to collect coordinates from markers placed on the tuber sacrale, tuber coxae, withers and lumbar spine. Data were processed using custom written scripts (Matlab®) and ANOVA was performed.ResultsAll subjects demonstrated a significant increase in vertical displacement of the pelvis as water depth increased from P3 to carpus while displacement symmetry was not significantly altered with a change in water depth.ConclusionsThe common practice of increasing water depth to intensify the physical demands of the exercise while maintaining the desired movement symmetry is supported. Having knowledge of how a horse moves on an aqua‐treadmill is vital for tailoring specific therapy in order to most successfully rehabilitate the horse from injury. Investigation of the effects of increasing water depth on asymmetric horses should be carried out to further support its application as a tool for rehabilitation.Ethical Animal ResearchEthical approval was obtained from the Ethics Review Committee at Moulton College. Owner consent was granted for all subjects and all horses were handled in compliance with British Horse Society standards throughout the trials. Sources of funding: Thomas Harrison Trust at Moulton College. Competing interests: none.

The Effect of Trotting Speed, Direction and Line of Travel on Asymmetry in Standardbred Racehorses During High‐Speed Locomotion on the Racetrack

AimsTo evaluate the effects of racing and training conditions on motion symmetry we set out to quantify hindlimb symmetry using an objective inertial sensor‐based system in a cohort of in‐training Standardbred racehorses during high‐speed trotting and to assess the influence of speed, line taken (straight vs. bend) and direction of travel (clockwise vs. anticlockwise).MethodsEight Standardbred racehorses in full training were instrumented with a GPS‐enhanced inertial sensor located at the tuber sacrale and trotted around an oval racetrack at a range of speeds and in both directions. Symmetry index (SI), MinDiff, MaxDiff, vector sum (VS) and range of motion (ROM) were quantified for the hindlimbs for each stride using vertical displacement data derived from the inertial output.ResultsA total of 9108 strides were collected on the track. Overall, all horses displayed a right hindlimb asymmetry or ‘lameness’. Horses were more asymmetrical when trotting around bends compared with on straights. The main factor influencing asymmetry was trotting around a clockwise bend. Speed had a small but significant influence on asymmetry that varied between measures.ConclusionsThe inertial sensor system was suitable for collecting on‐track, high‐speed locomotion data. The magnitude of asymmetry was dependent on direction, possibly indicating subclinical lameness or laterality in these horses.Practical significanceThe inertial sensor system is practical for on‐track objective high‐speed lameness evaluation. Further studies with larger numbers of objectively sound and lame Standardbred horses are needed to determine the effect of lameness on high‐speed trotting. The influence of factors such as training regimes and racing equipment should also be evaluated.Ethical animal researchAll procedures were performed with approval of the Royal Veterinary College Ethics Committee. The study was carried out in accordance with local regulations and in collaboration with the Swiss National Stud and Vetsuisse Bern. Informed consent was obtained from the owners of all horses used. Approval no. 2012/P358. Sources of funding: None. Competing interests: None.

Paravertebral malignant peripheral nerve sheath tumour (MPNST) in a horse

SummaryA 10‐year‐old Lipizzaner gelding was presented with intermittent ataxia and hindlimb weakness. Ultrasonographic examination identified a mass cranial to the tuber sacrale. A provisional diagnosis of a soft tissue sarcoma was made based on a biopsy specimen. Owing to the extensive nature of the tumour and the associated poor prognosis, the horse was subjected to euthanasia on humane grounds. A post mortem examination revealed a locally infiltrative soft mass within the left lumbosacral epaxial musculature. Histologically, an infiltrative neoplasm predominantly composed of pleomorphic spindle or stellate‐shaped cells was identified. Neoplastic cells exhibited strong S‐100 protein and GFAP expression and variable vimentin, NSE, NGFR and myoglobin expression. They were uniformly negative for pan‐cytokeratin, melan A, laminin and desmin. The ultrastructural examination revealed pleomorphic cells with long cytoplasmic processes and an absence of melanosomes. Based on these results, a diagnosis of malignant peripheral nerve sheath tumour was made. This report contributes further information to assist in the diagnosis of these poorly defined neoplasms in animals, especially when they occur in uncommon locations.

Paravertebral Malignant Peripheral Nerve Sheath Tumour (MPNST) in a Horse

Summary A 10-year-old Lipizzaner gelding was presented with intermittent ataxia and hindlimb weakness. Ultrasonographic examination identified a mass cranial to the tuber sacrale .A provisional diagnosis of a soft tissue sarcoma was made based on a biopsy specimen. Owing to the extensive nature of the tumour and the associated poor prognosis, the horse was subjected to euthanasia on humane grounds. A post mortem examination revealed a locally infiltrative soft mass within the left lumbosacral epaxial musculature. Histologically, an infiltrative neoplasm predominantly composed of pleomorphic spindle or stellate-shaped cells was identified. Neoplastic cells exhibited strong S-100 protein and GFAP expression and variable vimentin, NSE, NGFR and myoglobin expression. They were uniformly negative for pan-cytokeratin, melan A, laminin and desmin. The ultrastructural examination revealed pleomorphic cells with long cytoplasmic processes and an absence of melanosomes. Based on these results, a diagnosis of malignant peripheral nerve sheath tumour was made. This report contributes further information to assist in the diagnosis of these poorly defined neoplasms in animals, especially when they occur in uncommon locations.

Ultrasonographic evaluation of the coxofemoral joint region in young foals

The purpose of this study was to map the coxofemoral region in foals to obtain ultrasonographic reference values for the interpretation of potentially pathological findings in hip joints. Using a 7.5 MHz linear transducer, 38 examinations were carried out: 10 (20 joints) on cadavers and 28 (55 joints) on live healthy foals up to 8 weeks of age. The chosen plane of examination was caudolateral-craniomedial oblique on an imaginary line connecting the greater trochanter and the cranial edge of the tuber sacrale. The relatively thin muscular layer covering the coxofemoral joint allowed good image quality. The evaluated structures included the bone surface of the ilium and acetabulum, the subchondral bone on the femoral head and greater trochanter, the joint cartilage on the femoral head, the fibrocartilaginous acetabular labrum, the femoral capital physis, the cartilaginous layer covering the greater trochanter, the joint capsule and the presence of visible synovial fluid and the gluteal muscles. A bilateral anatomical frozen section in the plane of examination was made in one cadaver. A good correlation was found between ultrasonographic and corresponding anatomical measurements on the frozen section. This study indicated that ultrasound is a valuable diagnostic tool which can provide good image quality in neonates.

Quantification of equine sacral and iliac motion during gait: A comparison between motion capture with skin‐mounted and bone‐fixated sensors

Information regarding movement at the ilium and sacrum in nonlame horses during normal gait may assist in understanding the biomechanics of the equine sacroiliac joint. To determine the amount and direction of motion at the ilium and sacrum using 3D orientation sensors during walk and trot in sound Thoroughbreds. To compare results from sensors fixed to the skin with results from sensors fixed to bone-implanted pins. Three 3D wireless orientation sensors were mounted to the skin over the tuber sacrale (TS) and sacrum of 6 horses and motion at the ilium and sacrum was recorded for lateral bending (LB) flexion-extension (F-E) and axial rotation (AR) during walk and trot. This process was repeated with the orientation sensors mounted to the same pelvic landmarks via Steinmann pins. Mean walk values were greater than trot values using pin-mounted sensors for all planes of movement (P < 0.05). Walk had 1.64 ± 0.22° (mean ± s.e.) more LB than trot (pin-mounted) yet 0.68 ± 0.22° less than trot when skin-mounted; 3.45 ± 0.15° more F-E (pin- and skin-mounted), and 4.99 ± 0.4° more AR (pin-mounted), but trot had 3.4 ± 0.40° more AR than walk with skin mounting. Using pinned sensors for trot resulted in less LB (2.47 ± 0.22°), F-E (1.12 ± 0.15°) and AR (10.62 ± 0.40°); and for walk less F-E (1.12 ± 0.15°) and AR (2.15 ± 0.40°) compared to skin-mounted. Poor correlation existed between mean values for skin- and pin-mounted data for walk and trot, for all planes of motion. Movements were smaller at trot with bone-fixated sensors compared to walk, suggesting increased muscular control of movement at the trot. The apparent increase in skin motion at the trot and no clear correlation between skin- and bone-mounted sensors indicates inaccuracies when measuring sacral and iliac movement with skin mounting.

Evaluation of discriminant analysis based on dorsoventral symmetry indices to quantify hindlimb lameness during over ground locomotion in the horse

Advances in gait analysis techniques have led to assessment tools that can aid in detecting and quantifying lameness; here, bilateral tubera coxae and pelvic movement during over ground locomotion are compared in order to investigate a practical method to assess hindlimb lameness in the horse. To evaluate which parameters from anatomical landmarks on trunk and proximal hindlimbs are the best indicators of degree and side of hindlimb lameness. Fifteen horses (age 11-23 years, 6 nonlame and 9 unilaterally hindlimb lame horses 1/10 to 2/10 lame) were fitted with 4 inertial sensors: tuber sacrale, left and right tubera coxae and withers; 889 strides were collected from 6 trot trials per horse. Horses were assessed for lameness by a qualified equine orthopaedic surgeon from videos. Vertical displacement data for each sensor were used to calculate symmetry indices as well as published Fourier analysis based parameters. Linear discriminant analysis was used to determine the most discriminative parameters for 2 scenarios: grading of severity of lameness and identification of the affected limb. Pelvic energy ratio gave the best indication for the degree of lameness. Directional symmetry index of the tubera coxae sensors yielded the highest discriminative power for identification of the lame limb. A good indication of the degree of hindlimb lameness can be obtained from vertical displacement data of the pelvic midline, collected from inertial sensors during over ground locomotion. The trunk mounted inertial sensor system allows for a time efficient collection of a representative database from horses with differing grade and site of lameness in a clinical setting. This is crucial for future work on a robust definition of the best parameters for lameness classification under practical conditions.

Identification of Equine Subclinical Lameness Induced by Pressure to the Sole of Fore- or Hindlimb

Lameness has been investigated in past studies with kinematic analyses, and the features of lameness have been qualitatively and quantitatively analyzed. The output was, however, limited to visible lameness that was scored by experienced clinicians. Subclinical supporting lameness that was induced by subtle pressure to the sole of limb, but that could not be detected by visual check, has yet to be extensively analyzed. To find specific kinematic parameters that were influenced by such subclinical lameness of the fore- or hindlimb, we produced subclinical, subtle and mild lameness in five sound horses by applying slight pressure to the sole. Trot on a treadmill was recorded by a high-speed camera. Symmetric properties of acceleration of the head and the tuber sacrale were disturbed in mild fore- and hindlimb lameness, respectively. In subclinical forelimb lameness, no obvious changes in the symmetric properties of the head, the withers, or the tuber sacrale were observed; however, the vertical lift-off acceleration of the treated forelimb was decreased. In the case of subclinical hindlimb lameness, the lift-off points of both the treated and sound hindlimb shifted posteriad. These findings may contribute to further investigations of subclinical lameness aiming to establish new procedures for early detection of subclinical musculoskeletal disease, which would enable more timely treatment.

Ultrasound-assisted collection of cerebrospinal fluid from the lumbosacral space in equids

To describe ultrasonographic landmarks for use in collection of CSF from the lumbosacral region in equids. Prospective study. 37 equids (27 with neurologic disease and 10 with nonneurologic disease). Standing equids (n = 17) were sedated with detomidine hydrochloride (0.006 to 0.01 mg/kg [0.003 to 0.005 mg/lb], IV) followed by butorphanol tartrate (0.01 mg/kg, IV) and restrained with a nose twitch for collection of CSF. The CSF was collected from 20 laterally recumbent equids (10 sedated and 10 immediately after euthanasia). Anatomic landmarks were identified ultrasonographically. Height at the dorsal point of the shoulders, body weight, depth of the spinal needle, number of attempts to collect CSF, and cytologic evaluation of CSF were recorded. Lumbosacral puncture cranial to the cranial border of the most superficial location of both tuber sacrale along the midline was consistently successful for CSF collection (35/37 equids). Two horses had anatomic abnormalities that precluded CSF collection. Mean number of attempts to collect CSF per animal was 1.1. Height and body weight were strongly correlated with needle depth for CSF collection. Pelvic and sacral displacement was observed in several laterally recumbent animals, which resulted in discrepancies of the midline between the cranial and caudal aspects of the vertebral column. In most equids, the spinal needle was aligned on the midline of the caudal aspect of the vertebral column. Ultrasonography was a useful aid for collection of CSF from the lumbosacral space and decreased the risk of repeated trauma and contamination in equids.