1 Stutz JC, et al. Vet Rec Open 2018;5:e000237. doi:10.1136/vetreco-2017-000237 Effect of three types of horseshoes and unshod feet on selected non- podal forelimb kinematic variables measured by an extremity mounted inertial measurement unit sensor system in sound horses at the trot under conditions of treadmill and soft geotextile surface exercise Joëlle Christina Stutz, 1 Beatriz Vidondo, 1,2 Alessandra Ramseyer, 1 Ugo Ettore Maninchedda, 1 Antonio M Cruz 1,3 Horses and other equids 1 Institute suisse de médicine équine, University of Bern, Bern, Switzerland 2 Veterinary Public Health Institute, University of Bern, Bern, Switzerland 3 Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain Correspondence to Dr Antonio M Cruz, University Cardenal Herrera-CEU, CEU Universities; antonio. cruzmadorran@uchceu.es To cite: Stutz JC, Vidondo B, Ramseyer A, et al. Effect of three types of horseshoes and unshod feet on selected non-podal forelimb kinematic variables measured by an extremity mounted inertial measurement unit sensor system in sound horses at the trot under conditions of treadmill and soft geotextile surface exercise. Veterinary Record Open 2018;5:e000237. doi:10.1136/ vetreco-2017-000237 Received 21 June 2017 Revised 11 April 2018 Accepted 25 April 2018 ABSTRACT Therapeutic farriery is part of the management of certain orthopaedic conditions. Non-podal parameters are important as most horses shod with therapeutic shoes are expected to perform again and the choice of shoe type may be infuenced by the effects they may have on gait. The aim of this prospective study was to evaluate the effects of three different shoe designs and unshod front feet on forelimb non-podal kinematic variables using an extremity mounted inertial measurement unit (IMU) system under conditions of treadmill and overground exercise on a soft geotextile surface at the trot. Ten sound horses with no underlying orthopaedic problem were instrumented with eight IMUs at distal radii, tibia and third metacarpal/tarsal regions. Measurements were performed during four consecutive days. During the frst three days, the three shoe types were randomly selected per horse and day. On the fourth day, all horses were tested unshod. Data were collected at the trot on a treadmill, and on a soft geotextile surface. Specifcally designed software and a proprietary algorithm processed the accelerometer and gyroscope signals to obtain orientation and temporal data to describe selected kinematic variables predetermined by the system. Repeated-measures analysis of variance (ANOVA) was used to assess differences between shoe type and surface. The presence of shoes produced signifcant changes in spatiotemporal variables which seemed to be related to shoe mass rather than shoe design as there were no signifcant differences found between different shoe types. Shod horses showed a gait characterised by an increased range of motion (ROM) of the fore limbs. Previously reported effects of the investigated shoes on podal kinematics do not seem to affect the investigated kinematic variables indicating perhaps a compensatory effect occurring at some level in the extremity. INTRODUCTION Proper and adequate shoeing is important for a horse’s soundness, promotes a functional foot, may prevent lameness and influences a horse’s performance. 1 2 Shoes affect the hoof expansion mechanism, and have a direct biomechanical influence on the inertia of the distal and proximal limb loading. 3 Ther- apeutic farriery is part of the management of certain orthopaedic conditions due to its ability to modify the kinematics and kinetics of the hoof-ground interaction 4 5 by manipu- lating shoe weight, shoe length, shoe width, hoof pads, toe of the shoe and toe/heel/side wedges. 6–9 Numerous types of shoes have been devel- oped and their use is implemented world- wide as an important part of the treatment regime of horses affected with some equine lameness. 10 Kinematic measures of the effect of shoe by means of an optical system has shown an increase in maximal height of the flight arc of the hoof, greater flexion of the coffin, fetlock and carpal joints during the swing phase, which provide an ‘animation’ of the trot attributed to the weight of the shoe. 8 Doubling the weight however, did not show any changes in stride length, stride duration or breakover time, but increased maximal height of the hoof, fetlock and carpus during the swing phase, which is in agreement with the previous observation. 9 During recent years, there has been an increasing interest in the quantitative