Foot Biomechanics in the Normal Horse: A study of the Hoof Force Distribution in the Forelimb with a New Measuring Method

The foot of the horse is a complex organ which is frequently responsible for lameness. As Leach and Crawford (1983) stated earlier, more knowledge is necessary to consider applications in orthopedics, therapeutics, farriery, racetrack design, the choice of the racetrack surface and the selection of athlete horses. The purpose of this study was to determine the normal distribution of the vertical hoof forces on the forelimb at the walk and trot. The ground reaction force was studied especially using force plates [Leach and Dagg (1983), Dalin and Jcffcott (1985)]. For the foot biomechanics analysis, it has been preferred to develop a new measuring instrument: a force measuring hipposandal derived from the device used by Marey (1894), Bjorck (1958), Frederick (1967) and Frederick and Henderson (1970). This paper presents the first application of this Horse Force Measuring System (HFMS)

Kinematic discrimination of ataxia in horses is facilitated by blindfolding

BACKGROUND: Agreement among experienced clinicians is poor when assessing the presence and severity of ataxia, especially when signs are mild. Consequently, objective gait measurements might be beneficial for assessment of horses with neurological diseases. OBJECTIVES: To assess diagnostic criteria using motion capture to measure variability in spatial gait-characteristics and swing duration derived from ataxic and non-ataxic horses, and to assess if variability increases with blindfolding. STUDY DESIGN: Cross-sectional. METHODS: A total of 21 horses underwent measurements in a gait laboratory and live neurological grading by multiple raters. In the gait laboratory, the horses were made to walk across a runway surrounded by a 12-camera motion capture system with a sample frequency of 240 Hz. They were made to walk normally and with a blindfold in at least three trials each. Displacements of reflective markers on head, fetlock, hoof, fourth lumbar vertebra, tuber coxae and sacrum derived from three to four consecutive strides were processed and descriptive statistics, receiver operator characteristics (ROC) to determine the diagnostic sensitivity, specificity and area under the curve (AUC), and correlation between median ataxia grade and gait parameters were determined. RESULTS: For horses with a median ataxia grade ≥2, coefficient of variation for the location of maximum vertical displacement of pelvic and thoracic distal limbs generated good diagnostic yield. The hoofs of the thoracic limbs yielded an AUC of 0.81 with 64% sensitivity and 90% specificity. Blindfolding exacerbated the variation for ataxic horses compared to non-ataxic horses with the hoof marker having an AUC of 0.89 with 82% sensitivity and 90% specificity. MAIN LIMITATIONS: The low number of consecutive strides per horse obtained with motion capture could decrease diagnostic utility. CONCLUSIONS: Motion capture can objectively aid the assessment of horses with ataxia. Furthermore, blindfolding increases variation in distal pelvic limb kinematics making it a useful clinical tool

RUNNER’S STRIDE ANALYSIS UNDER FIELD CONDITIONS

The purpose of this study was to analyse the strides of middle distance runners using a new ambulatory gait analysis system adapted to field and track conditions. Nine middle distance runners performed a locomotor test which consisted of three step-tests close to their anaerobic threshold with an increase of 0.5 m.s-1 between each step-test. The increase in velocity was correlated to an increase in stride length (p< 0.001), and a decrease of stride symmetry and regularity (p< 0.05) and a decrease of left and right stance duration (p< 0.05). Wavelet analysis provided a pictorial description of gait particularities which could be of interest for trainers or practitioners

Surgical Treatment of Spinal Meningiomas in the Elderly (≥75 Years): Which Factors Affect the Neurological Outcome? An International Multicentric Study of 72 Cases

(1) Background: With the increasing life expectancy in the Western world, an increasing number of old patients presents with spinal meningioma. Considering the benign nature of these tumors, the functional outcome remains of great importance, since more people reach old age in general conditions of well-being and satisfactory autonomy. (2) Methods: We conducted an international multicenter retrospective study to investigate demographic, clinical and radiological data in a population of elderly patients (≥75 years of age) undergoing surgery for SM from January 2000 to December 2020 in four European referral centers. The aim was to identify prognostic and predictive factors for a good postoperative functional outcome. (3) Results: 72 patients were included in the study. Complete tumor resection (Simpson I or II) was achieved in 67 (95.7%) cases. Intraoperative complications were reported in 7 (9.9%) patients while postoperative complications were found in 12 (16.7%). An excellent general postoperative status (McCormick I and II) was achieved in 65.3%. Overall, surgical resection had a good impact on patients’ functional outcome (86.1% either showing an improvement or maintaining a good preoperative status). Uni- and multivariate analyses found that both age and preoperative modified McCormick independently correlated with relative outcome (coeff = −0.058, p = 0.0251; coeff = 0.597, p < 0.0001) and with postoperative status (coeff = 0.058, p = 0.02507; coeff = 0.402, p = 0.00027), respectively. (4) Conclusions: Age and preoperative modified McCormick were found to be independent prognostic factors. Nevertheless, advanced age (≥75), per se, did not seem to contraindicate surgery, even in those with severe preoperative neurological deficits. The functional results sustain the need for surgical resection of SM in the elderly

A continuous series of 27 adult patients treated for L5-S1 isthmic spondylolisthesis by combined approach: Clinical and radiological outcomes at 1 year follow-up

Through this single-center consecutive prospective study, we evaluated the results of a combinedapproach for L5-S1 isthmic spondylolisthesis, using a polyetheretherketone (PEEK) interbody lordoticcage during anterior approach and pedicle screw-based posterior fixation. Between 2010 and 2014,27 adult patients were treated for L5-S1 isthmic spondylolisthesis (high and low grades) by a combi-ned approach with a minimum follow-up of one year. Clinical outcome was assessed before surgicaltreatment and at four months and one year after surgery by: VAS, Oswestry Index (ODI) and Rolland-Morris scores. Two observers evaluated the following radiological parameters: pelvic incidence, pelvictilt, lumbar lordosis, segmental lordosis L5-S1, anterior and posterior disc height, spinal vertical axis(SVA), SVA/sacro-femoral distance (SFD) ratio. Fusion was evaluated on the CT scan at one-year follow-up. Blood loss, surgery time and complications were also collected. The mean age was 47.7 years (± 16.9).The VAS, ODI and Rolland-Morris scores were significantly improved postoperatively, decreased from 7.5(± 1.45); 48 (± 19.25); 15.3 (± 4.67) before the surgery to 3.8 (± 2.55); 28.7 (± 19.58) and 7.76 (± 7.21)respectively at one year after the surgery (P = 0.05). The mean follow-up was 3.3 years. Mean surgery timewas 193.7 min (± 37). Fusion was obtained in 100% of cases. Segmental lordosis L5-S1, pelvic tilt, slip-page, anterior and posterior L5-S1 disc height were significantly improved postoperatively, they passedfrom 20.1; 22.6; 35.3%; 26.4%; 17.9% to 29.5; 20.6; 20.3%; 64.4%; 36.3% respectively. Combined surgicalprocedure meets the required goals of surgery in the treatment of adults L5-S1 isthmic spondylolisthesis

Comparing subjective and objective evaluation of show jumping competition and warm-up arena surfaces

The development of safety and quality standards for equestrian surfaces needs to be based on objective, repeatable measurements which allow comparisons between surfaces. These measurements should incorporate the assessment of surface performance by riders. This study provides data from objective and subjective assessment of functional properties of high-level show jumping competition and warm-up arenas. Twenty-five arenas in nine international show jumping events were evaluated by mechanical insitu testing with a surface tester, rider assessments using visual analogue scales (198 riders provided 749 arena evaluations), descriptions of arena constructions and by laboratory tests of surface material. Mixed models were used to present subjective evaluation of rider perception of the functional properties for each arena while controlling for rider and event. The association between objective and subjective assessments were also explored creating mixed models, controlling for rider and event. Mechanical measurements of impact firmness, and to a lesser extent cushioning and grip, had a significant positive association with the riders’ perception. Responsiveness as assessed by the Orono biomechanical surface tester (OBST) was negatively associated with the riders’ perceptions, which suggests riders and the OBST had different concepts of this functional property and that further developments of the OBST might be necessary. Objectively measured uniformity showed no useful association with riders’ perception. Even though arena assessments were made by top level riders, a substantial inter-rider variation was demonstrated