Placing sensors is a non-invasive procedure. The head sensor is fastened on the head with a custom-made holder. The sensor on the withers is attached with a surcingle. The sacrum sensor is easily stuck using double adhesive tape. The sensors on the cannon bones are placed in custom-made holsters fixed to brushing boots. The sensors do not disturb the normal movement pattern of the horse. The standard setup consists of 7 sensors.
- Head sensor
- Withers sensor
- Sacrum sensor
- Left hind leg sensor
- Left front leg sensor
- Right front leg sensor
- Right hind leg sensor
- What is measured: 3D acceleration, rotation speed, orientation
- How often: 200 times per second
- Synchronization among sensors: better than 100 ns
- Data quality check is done at the end of each trial.
Types of assessments
- In hand (including lunging)
Types of examination gaits
- Canter (left-lead and right-lead)
The upper-body symmetry parameters are used to estimate to what extent the horse’s gait is symmetrical at key positions on the upper body of the horse. These parameters are based on vertical motion and displacement. At each of these positions, the horse’s body moves up and down in a cyclic fashion exactly two times each stride. In healthy horses, this signal is symmetrical.
The symmetry index ranges from -1 to 1. A value of 0 indicates perfect symmetry. A value of ±1 indicates maximum asymmetry. The sign depends on the affected limb.
Min__diff & Max__diff
Min_diff is the difference between first and second minimum peaks in vertical displacement signal. Max_diff is the difference between first and second maximum peaks in vertical displacement signal. A value of 0 indicates perfect symmetry.
Timing of footfalls
The timing of footfalls is the expression of rhythm, defined as the order of placing the hoofs on the ground in a complete stride.
Stride duration & Number of strides
The stride duration is the time required to complete one stride. Stride duration is the inverse of tempo, defined as the number of strides per minute.
The number of strides is the total number of strides during one trial.
The swing intensity is the range of motion of one stride (protraction & retraction) and it is used for expressing the moments of impact and the beats per leg.
The time differences on the X-axis of the graph for the lateral advanced placement and the diagonal advanced placement show differences for instance between a four-beat ‘canter’ and a proper 3-beat canter.
Stance & Swing duration per leg
The stance duration per leg is the time in which the limb is in contact with the ground during the limb motion cycle.
The swing duration per leg is the time in which the limb is free from contact with the ground during the limb motion cycle.
Protraction & Retraction
Protraction is the angle of the cannon bone moving forward (cranial).
Retraction is the angle of the cannon bone moving backward (caudal).
The following parameters are measured:
- Maximal protraction/retraction
- Retraction/Protraction at the end of the stance phase of a leg
The EquiMoves application plots the curve of one stride including protraction and retraction.
- The protraction of the leg shows the maximal protraction as an event.
- The protraction at the beginning of the stance phase of a leg is displayed in the plot as an event.
- The retraction of the leg shows the maximal retraction as an event.
- The retraction at the end of the stance phase of a leg is displayed in the plot as an event.
Abduction & Adduction
Abduction is the angle of the cannon bone moving away from the midsagittal plane.
Adduction is the angle of the cannon bone moving toward the midsagittal plane.
In the EquiMoves application, the average of a selected part of a stride is displayed as the average of maximum adduction/abduction per stride.
Duty factor or relative stance phase
The duty factor or the relative stance phase is the average stance phase per leg divided by the stride duration. It shows the duration of the stance phase of a specified limb as a proportion of the total limb cycle duration or stride duration. In the EquiMoves application, duty factor is expressed as an average of all legs.
The EquiMoves software splits the trial in different gaits and events. Events are defined as straight line or left/right circle. At the timeline of the trial, information about the gait, event, nerve-block and flexion test is given.
With the EquiMoves software it is quite easy to compare different measurements of a horse. The upper body parameters and the limb-related parameters from different measurements can be compared in time.
The EquiMoves software generates a report of the measurements, split in events and gaits.
- General version: measurement summary, upper-body symmetry, timing of footfalls, protraction and retraction angles, adduction and abduction angles in trot
- Extended version: includes results for all types of examination gaits
Request more information
If you are interested in using EquiMoves in your activities please send us a message and we will be happy to give you more information.
EquiMoves will be presented by Filipe Bragança on 21st of October at 19:00 during the Science of Equine Locomotion Symposium. The symposium is an online event taking place on 30th of September and 21st of October 2020. … Read more →
Improving gait classification in horses by using inertial measurement unit (IMU) generated data and machine learning
F. M. Serra Bragança, S. Broomé, M. Rhodin, S. Björnsdóttir, V. Gunnarsson, J. P. Voskamp, E. Persson-Sjodin, W. Back, G. Lindgren, M. Novoa-Bravo, C. Roepstorff, B. J. van der Zwaag, P. R. Van Weeren & E. Hernlund, 20… Read more →