Wireless Inertial Sensors Research Articles

Walking performance differs between people with multiple sclerosis who perform distinct types of exercise.

Aim: To determine whether walking performance differed between people with multiple sclerosis (MS) who performed distinct types, volumesand intensities of exercise.Materials& methods: Forty-five people with relapsing-remitting MS performed two trials of the 2-minwalk test, one at a preferred speed and another at a fast speed. Gait metrics were measured by wireless inertial sensors. Participants reported the type (aerobic, resistance), volumeand intensity of exercise performed.Results: Walking speed reserve and gait variability were better in participants who performed combined aerobic and resistance exercises compared with those who performed aerobic-only exercise.Conclusion: Walking performance differs in people with mild MS disability based on the type and volume of exercise performed.

Inertial Measuring System to Evaluate Gait Parameters and Dynamic Alignments for Lower-Limb Amputation Subjects.

The study aims to construct an inertial measuring system for the application of amputee subjects wearing a prosthesis. A new computation scheme to process inertial data by installing seven wireless inertial sensors on the lower limbs was implemented and validated by comparing it with an optical motion capture system. We applied this system to amputees to verify its performance for gait analysis. The gait parameters are evaluated to objectively assess the amputees' prosthesis-wearing status. The Madgwick algorithm was used in the study to correct the angular velocity deviation using acceleration data and convert it to quaternion. Further, the zero-velocity update method was applied to reconstruct patients' walking trajectories. The combination of computed walking trajectory with pelvic and lower limb joint motion enables sketching the details of motion via a stickman that helps visualize and animate the walk and gait of a test subject. Five participants with above-knee (n = 2) and below-knee (n = 3) amputations were recruited for gait analysis. Kinematic parameters were evaluated during a walking test to assess joint alignment and overall gait characteristics. Our findings support the feasibility of employing simple algorithms to achieve accurate and precise joint angle estimation and gait parameters based on wireless inertial sensor data.

Inertial Sensor Gait Analysis of Trendelenburg Gait in Patients Who Have Hip Osteoarthritis

BackgroundGait abnormalities such as Trendelenburg gait (TG) in patients who have hip osteoarthritis (OA) have traditionally been evaluated using clinicians’ visual assessment. Recent advances in portable inertial gait sensors offer more sensitive, quantitative methods for gait assessment in clinical settings. This study sought to compare sensor-derived metrics in a cohort of hip OA patients when stratified by clinical TG severity. MethodsThere were 42 patients who had hip OA and were grouped by TG severity (mild, moderate, and severe) through visual assessment by a single arthroplasty surgeon who had > 30 years of experience. After informed consent, wireless inertial sensors placed at the midpoint of the intercristal line collected gait parameters including pelvic shift, support time, toe-off symmetry, impact, and cadence. Clinical data on hip strength, range of motion, and Kellgren-Lawrence grade were collected. ResultsWorsening TG severity had a higher mean Kellgren-Lawrence grade (2.5 versus 3.2 versus 3.4; P = .014) and reduced passive hip abduction (P = .004). Severe TG group demonstrated predominantly contralateral pelvic shift (n = 9 of 10, 90.0%), while ipsilateral shift was more frequently detected in moderate (n = 10 of 18, 55.6%) and mild groups (n = 9 of 14, 64.3%; P = .021). Contralateral single support time bias was greatest in severe TG (35.7% versus 50.0 versus 90.0%; P = .027). Asymmetric toe-off, impact, and support times were observed in all groups. ConclusionsTraditional understanding of TG is that truncal shift occurs to the ipsilateral side. Using sensor-based measurements, the present study demonstrates a shift of the weight-bearing axis toward the contralateral side with increasing TG severity, which has not been previously described. Inertial sensors are feasible, quantitative gait measuring tools, and may reveal subtle patterns not readily discernible by traditional methods.

Links between Neuroanatomy and Neurophysiology with Turning Performance in People with Multiple Sclerosis.

Multiple sclerosis is accompanied by decreased mobility and various adaptations affecting neural structure and function. Therefore, the purpose of this project was to understand how motor cortex thickness and corticospinal excitation and inhibition contribute to turning performance in healthy controls and people with multiple sclerosis. In total, 49 participants (23 controls, 26 multiple sclerosis) were included in the final analysis of this study. All participants were instructed to complete a series of turns while wearing wireless inertial sensors. Motor cortex gray matter thickness was measured via magnetic resonance imaging. Corticospinal excitation and inhibition were assessed via transcranial magnetic stimulation and electromyography place on the tibialis anterior muscles bilaterally. People with multiple sclerosis demonstrated reduced turning performance for a variety of turning variables. Further, we observed significant cortical thinning of the motor cortex in the multiple sclerosis group. People with multiple sclerosis demonstrated no significant reductions in excitatory neurotransmission, whereas a reduction in inhibitory activity was observed. Significant correlations were primarily observed in the multiple sclerosis group, demonstrating lateralization to the left hemisphere. The results showed that both cortical thickness and inhibitory activity were associated with turning performance in people with multiple sclerosis and may indicate that people with multiple sclerosis rely on different neural resources to perform dynamic movements typically associated with fall risk.

Smartphone-Based Wearable Gait Monitoring System Using Wireless Inertial Sensors

This paper presents a wearable virtual reality system with a wireless network of inertial sensors for lower limb monitoring. The system comprises seven sensor nodes sending data wirelessly to a master node. The information is then collected, organized, and sent to a screening device via a serial interface. An application executed either on a smartphone or a personal computer features an avatar which represents the received data and mimics the sensed movements of the patient, providing online feedback during and after the execution of a therapy. The data resulting from the therapy execution can be uploaded to a web server to facilitate the assessment and decision-making by health professionals. A pendulum featuring a rotary optical encoder is used for sensor functional behavior validation. In addition, the orientation angles measured by the proposed system are compared with respect to measurements from the motion analysis software Kinovea. The delay between the patient's body movement and the avatar is 33 ms, which is acceptable for visual feedback. This system is portable, inexpensive and enables a patient to complete physical therapy sessions at home or anywhere, with the advantage of enabling visual feedback through an avatar during rehabilitation therapy and allowing the reproduction of a therapy session for further analysis.

71 Lameness responses to a single exercise bout following dietary supplementation of Saccharomyces cerevisiae fermentation product in young horses

Yearling Quarter Horses (mean ± SEM; 561 ± 3 d; 373.3 ± 5 kg BW; 13 fillies, 14 colts) were used in a randomized complete block to test the hypothesis that dietary supplementation of a postbiotic Saccharomyces cerevisiae fermentation product (SCFP) mitigates lameness following a single exercise bout in young horses. For the 76-d trial, yearlings were fed a basal diet of 1% BW/d (as-fed) grain-based horse feed formulated without added microbials (SafeChoice® Original, Nutrena) twice daily plus ad libitum Coastal bermudagrass (Cynodon datylon) hay, and water. Horses were grouped by age, sex, and BW and randomly assigned to 1) concentrate only (CON; n = 10), 2) concentrate top dressed with 46 mg/kg SCFP (TRT 1; n = 8), or 3) concentrate top dressed with 92 mg/kg SCFP (TRT 2; n = 9). Objective lameness assessments were obtained by a wireless Inertial Sensor System (ISS) followed by a subjective evaluation performed by a licensed veterinarian. All horses underwent a baseline lameness assessment on d 0, followed by 2 lameness assessments on d 76 (pre-exercise, and post-exercise). Objective lameness evaluations were performed at the trot for 2 30 m, back-and-forth passes, wearing the wireless ISS lameness analysis system and evaluated in triplicate per assessment. For the subjective lameness analysis, horses were additionallytrotted in a circle in both directions within a 16 × 14 m area and evaluated by an individual licensed veterinarian using the American Association of Equine Practitioners (AAEP) lameness scale. Data were analyzed using PROC GLM in SAS v9.4 with diet and time included as fixed effects. When analyzing AAEP lameness evaluations, no differences were detected for dietary treatment or diet × time interactions related to primary (P = 0.55; P = 0.98), secondary (P = 0.43; P = 0.78), or tertiary (P = 0.77; P = 0.77) limbs. Additionally, no dietary treatment effects or diet × time interactions were detected using the wireless ISS for front Q score (P = 0.19; P = 0.92) or hind pushoff Q score (P = 0.53; P = 0.27). Furthermore, there was no effect of dietary treatment on hind impact Q score (P = 0.68). However, there tended to be a diet × time interaction (P = 0.06) whereby horses on TRT 2 tended to have a lower hind impact Q score. Additionally, post-exercise front Q scores increased over time (P ≤ 0.01) compared with both baseline and pre-exercise values regardless of dietary treatment. These results indicate the intensity of exercise may not have been sufficient to lead to dietary differences related to gait asymmetry.

The Influence of Mobile Device Type on Camera-Based Monitoring of Neck Movements for Cervical Rehabilitation

We developed a mobile application for cervical rehabilitation that uses a non-invasive camera-based head-tracker sensor for monitoring neck movements. The intended user population should be able to use the mobile application in their own mobile device, but mobile devices have different camera sensors and screen dimensions that could affect the user performance and neck movement monitoring. In this work, we studied the influence of mobile devices type on camera-based monitoring of neck movements for rehabilitation purposes. We conducted an experiment to test whether the characteristics of a mobile device affect neck movements when using the mobile application with the head-tracker. The experiment consisted of the use of our application, containing an exergame, in three mobile devices. We used wireless inertial sensors to measure the real-time neck movements performed while using the different devices. The results showed that the effect of device type on neck movements was not statistically significant. We included the sex factor in the analysis, but there was no statistically significant interaction between sex and device variables. Our mobile application proved to be device-agnostic. This will allow intended users to use the mHealth application regardless of the type of device. Thus, future work can continue with the clinical evaluation of the developed application to analyse the hypothesis that the use of the exergame will improve therapeutic adherence in cervical rehabilitation.

Short Communication: changes in gait after 12 wk of shoeing in previously barefoot horses.

Farriery can impact gait symmetry and lameness outcomes, but there is limited scientific data documenting these effects. We hypothesized that shoeing previously barefoot horses with plain stamp shoes on the hind hooves would increase gait symmetry, alter hock angles and increase range of motion, and improve lameness scores more than shoeing with traditional fullered shoes. At the start of the study, gait symmetry via wireless inertial motion sensors (IMS), kinematic gait analysis (hock angle and range of motion), and American Association for Equine Practitioner's (AAEP) lameness scoring were completed for 14 barefoot horses. Horses were then trimmed and hind hooves were shod (wk 0) in three-quarter fullered shoes or plain stamp style shoes. Horses were trimmed and re-shod at week 6. At the end of 12 wk, the IMS analysis, kinematic gait analysis, and lameness scoring were repeated. Differences between shod and barefoot values were calculated for each horse, and impact of shoe type was analyzed via t-test. Significance was determined at P ≤ 0.05. No differences were observed in the IMS scores, hock angles or range of motion, or AAEP lameness scores between horses shod in fullered or plain stamp shoes (P ≥ 0.08). As no variables were determined to be significantly different between the two shoe types, data from all horses were combined to analyze the differences between the barefoot and shod state. Shoeing increased the maximum angle of the right and left hocks (P ≤ 0.03) and the minimum angle of the left (P = 0.02) but not right hock (P = 0.23) relative to barefoot conditions. No differences in hock range of motion were observed in either hock. Lower AAEP lameness scores were observed in horses when shod compared with barefoot (P = 0.001). In conclusion, shoeing previously barefoot horses improved AAEP lameness scores and increased hock angles, regardless of the type of shoe.

Reliability and Validity of Inertial Sensor Assisted Reaction Time Measurement Tools among Healthy Young Adults

The assessment of movement reaction time (RT) as a sideline assessment is a valuable biomarker for mild TBI or concussion. However, such assessments require controlled laboratory environments, which may not be feasible for sideline testing during a game. Body-worn wearable devices are advantageous as being cost-effective, easy to don and use, wirelessly transmit data, and ensure unhindered movement performance. This study aimed to develop a Drop-stick Test System (DTS) with a wireless inertial sensor and confirm its reliability for different standing conditions (Foam versus No Foam) and task types (Single versus Dual), and postures (Standing versus sitting). Fourteen healthy young participants (seven females, seven males; age 24.7 ± 2.6 years) participated in this study. The participants were asked to catch a falling stick attached to the sensor during a drop test. Reaction Times (RTs) were calculated from data for each trial from DTS and laboratory camera system (gold standard). Intraclass correlation coefficients (ICC 3,k) were computed to determine inter-instrument reliability. The RT measurements from participants using the camera system and sensor-based DTS showed moderate to good inter-instrument reliability with an overall ICC of 0.82 (95% CI 0.78-0.85). Bland-Altman plots and 95% levels of agreement revealed a bias where the DTS underestimated RT by approximately 50 ms.

Cognitive-motor interference in people with mild to moderate multiple sclerosis, in comparison with healthy controls

BackgroundReduced motor and cognitive dual-task capacity is found to be more common among people with multiple sclerosis (MS), than among healthy populations. However, studies in larger samples of MS conducted using a more stringent methodology, which includes comparisons to healthy controls, are needed. Thus, the primary aim of this study was to explore the effects on motor and cognitive dual-tasking in people with mild to moderate overall MS-disability, in comparison to healthy controls. A second aim was to explore the differences in dual-task performance on a cognitive task between two motor tasks in people with mild to moderate MS and healthy controls. MethodsThis case-control study evaluated dual-task performance of the motor tasks standing with eyes closed (hereafter standing) and walking and a cognitive task assessing selective executive functions (auditory-Stroop test). Fifty-five people with MS (mild MS, n = 28; moderate MS, n = 27), and 30 healthy controls participated. Standing and walking were assessed using wireless inertial measurement unit sensors (APDM). Standing (three 30 s trials) was measured using sway area and root mean square sway, while walking (2 min) was measured using speed, stride length, and step time. Auditory-Stroop was measured using accuracy and response time. During dual-task assessments, each subject was instructed to pay equal attention to both tasks. Statistical significance was considered if p < .05. ResultsInstanding no significant within-group differences in the standing measures were found between single-task and dual-task performance. However, dual-task performance differed significantly between all groups (moderate MS > mild MS > healthy controls), except between mild and moderate MS in sway area. Inwalking, all groups slowed down speed and shortened stride length during dual-task condition compared to single-task condition. Moderate MS performed significantly poorer than mild MS and healthy controls in dual-task walking, but mild MS did not differ from healthy controls. In thecognitivetask only mild MS increased significantly in auditory-Stroop response time during walking. In healthy controls, the performance of auditory-Stroop was not affected by dual-tasking. Moderate MS had significantly longer response time in dual-task auditory-Stroop compared to the other groups, but no differences were observed between mild MS and healthy controls. Only mild MS had significantly longer response time during walking than during standing. ConclusionThis study showed that cognitive-motor interference in people with MS is present also in the early phases of the disease. This was shown during dual-tasking with slower walking and a longer response time in the cognitive task compared to healthy controls. Moderate MS performed poorer in almost every aspect of the motor and cognitive assessments in dual-task condition, compared to mild MS and healthy controls. Furthermore, during standing, people with MS performed poorer in standing measures compared to healthy controls. Additionally, healthy controls showed no cognitive interference during motor tasks.The results suggest that standardized regular assessment of dual-tasking in MS care might increase the individual's knowledge of dual-task capacity and contribute to understanding of possible related consequences. However, feasible assessment equipment and specific motor-cognitive dual-task training interventions for people with MS need to be developed.

Retraction Note: Human motion capture system in sports performance based on Internet of Things technology and wireless inertial sensor

Retraction Note: Human motion capture system in sports performance based on Internet of Things technology and wireless inertial sensor

Comparison of gait parameters under single- and dual-task conditions between children with specific learning disorder and typically developing children

BackgroundChildren with specific learning disorder (SLD) have some cognitive and postural stability problems compared to typically developing (TD) children. Their single and dual-task gait performance may be affected depending on these problems. Research questionAre there any differences between the gait parameters of children with SLD and TD under single- and dual-task conditions? MethodsA comparative-descriptive study was conducted among 35 children with SLD and 33 TD children. All participants were assessed for gait parameters using a custom wireless inertial sensor under single and dual-task conditions. In the dual-task gait tests, there were the following tasks: to carry a glass of water and to tell apart the color of the paper. ResultsThe children with SLD exhibited gait deterioration in both single and dual-task gait (p < 0.05). Dual-task cost cognitive values were higher in children with SLD (p < 0.05). SignificanceThis study highlights the worse gait performance of children with SLD under single- and dual-task conditions compared with TD children. However, interventions for their gait impairments are limited. At this point, SLD specialists can focus on multitasking to improve their walking skills.

Two-Step Validation of a New Wireless Inertial Sensor System: Application in the Squat Motion

The use of Inertial Measurement Units (IMUs) can provide embedded motion data to improve clinical application. The objective of this study was to validate a newly designed IMU system. The validation is provided through two main methods, a classical sensor validation achieved on a six-degrees-of-freedom hexapod platform with controlled linear and rotation motions and a functional validation on subjects performing squats with segmental angle measurement. The kinematics of the sensors were measured by using an optoelectronic reference system (VICON) and then compared to the orientation and raw data of the IMUs. Bland–Altman plots and Lin’s concordance correlation coefficient were computed to assess the kinematic parameter errors between the IMUs and VICON system. The results showed suitable precision of the IMU system for linear, rotation and squat motions.

IDF21-0164 Effect of stimulating footwear on gait and posture in people with Diabetes and foot complications

Background: The maintenance of human posture and gait requires the central integration of afferent information and is highly dependent on the somatosensory information from the plantar cutaneous mechanoreceptors. Normal foot structure sends undistorted signals to the brain due to the proper stimulation of mechanoreceptors in the foot soles and therefore brain responds properly by adjusting the skeletal framework into good posture. In the case of abnormal foot structure, the brain receives distorted signals due to poor stimulation of mechanoreceptors. As a result, the brain generates alternate signals to deal with these abnormalities, resulting in poor gait and posture. Aim: The main intention of this study was to develop a new footwear with ultrasonic sensors that emit ultrasonic waves at a lower frequency of 35 kHz to properly stimulate plantar mechanoreceptors. The objective of this study was to evaluate the effect of the above footwear on gait and posture of people with diabetic neuropathy, with foot deformity (bow knee, bilateral genu valgum, leg length discrepancy, abnormal foot arch) and also with foot and/or joint discomfort after 15days of wearing it for 10minutes each day. Method: A total of 5 (3 men and 2 women) subjects volunteered for this study. Informed consent was obtained from each participant. Subjects were prepared using a specialized wireless inertial sensor as per the protocol and were asked to walk freely on the sensorized platform for measuring their plantar pressure and also their spatial temporal parameters. Data was captured using Plantar pressure measuring device and wearable inertial system (BTSBioengineering, Italy). For data analysis, three trials were recorded. A single best trial was selected for processing and reporting. After completion of the initial assessment, subjects were asked to wear the test footwear as a therapy for 10 minutes every day for 15 days. When the switch is on the sensors will emit ultrasound at a frequency of 35 kHz. Following the completion of the 15-days, the subjects were re-evaluated using plantar pressure measuring device and wearable inertial system. Then a comparison was made between the data collected before and after therapy. Results: See Table 1 and Table 2.Table 1Results of Spatial temporal data before and after the therapy. Open table in a new tab Table 2Results of Plantar pressure data before and after the therapy. Open table in a new tab Discussion: The spatiotemporal data, in Table 1, shows a considerable improvement after using the developed footwear. There was a considerable decrease in double limb support time and increase in single limb support, indicating that the subject was able to minimize the contact time of the foot during walking which significantly minimizes foot plantar pressure loading which is the precursor of diabetic foot ulcer. Also, there was a significant increase in cadence and gait velocity after completion of therapy. The plantar pressure data, in Table 2, indicates an increase in the foot contact area which significantly improve the foot pressure distribution, leads to reduction in peak plantar pressure. Also, there was a shift in the maximum pressure from lateral foot to medial foot which shows the distribution of body weight shifted from lateral to medial which is the sign for good posture.

The Validity of the Energy Expenditure Criteria Based on Open Source Code through two Inertial Sensors

Through this study, we developed and validated a system for energy expenditure calculation, which only requires low-cost inertial sensors and open source R software. Five healthy subjects ran at ten different speeds while their kinematic variables were recorded on the thigh and wrist. Two ActiGraph wireless inertial sensors and a low-cost Bluetooth-based inertial sensor (Lis2DH12), assembled by SensorID, were used. Ten energy expenditure equations were automatically calculated in a developed open source R software (our own creation). A correlation analysis was used to compare the results of the energy expenditure equations. A high interclass correlation coefficient of estimated energy expenditure on the thigh and wrist was observed with an Actigraph and Sensor ID accelerometer; the corrected Freedson equation showed the highest values, and the Santos-Lozano vector magnitude equation and Sasaki equation demonstrated the lowest one. Energy expenditure was compared between the wrist and thigh and showed low correlation values. Despite the positive results obtained, it was necessary to design specific equations for the estimation of energy expenditure measured with inertial sensors on the thigh. The use of the same formula equation in two different placements did not report a positive interclass correlation coefficient.

Acute effects of axial loading on postural control during walking and turning in people with multiple sclerosis: A pilot study

BackgroundImpaired sensory integration is heavily involved in gait control and accentuates fall risk in individuals with multiple sclerosis (MS). While axial loading has been found beneficial, little is known about the effect of non-specific axial loads on gait parameters and mobility tasks in those with MS. Research Question: What are the effects of non-specific axial loading via weighted vests on walking and turning in those with MS. MethodsTwelve participants with MS and eleven age- and gender-matched healthy controls participated in a cross-sectional study. All participants completed five trials of continuous walking with turns wearing weighted vests at 0%, 2%, 4%, 5%, and then 0% of their body weight. Gait parameters were measured using wireless inertial sensors. A 2 (group) x 5 (vest weight) multivariate analysis of variance (MANOVA) was performed to determine any significant differences between groups and across weighted vests for each gait variable. Post-hoc analysis and paired t-tests with corresponding effect sizes were also conducted. ResultsA significant between groups main effect was found for group (F (6100) = 14.74, p = .000) in multiple gait parameters (p < 0.05), although no significant main effect was found for weighted vest. Within group analyses indicated significantly increased cadence and gait speed across varying weighted vests for both MS and control groups (p < 0 >05). Increased vest weight from 0%PRE to 2% also had large effect on shortening double support time and increasing stride length in the MS group. SignificanceThis study provided preliminary evidence that non-specific axial loads of varying weights appear to improve certain gait parameters. As such, this modality may offer mobility benefit and serve as an accessible home-based intervention alternative aimed at improving walking in individuals with MS.

Wireless inertial sensor system for hammer throwing

Abstract The aim of this study is to integrate an inertial sensor inside a hammer to allow a realtime feedback. In the first step we build our own prototype to measure the radial acceleration. In the second step there is a validation with an infrared camera system. It is a comparison between the radial acceleration along the wire axis, that is measured by the sensor against the velocity that is delivered by the infrared camera system. As a result, significant correlation was observed between the measured velocity and the acceleration (r = 0.99, p &lt; 0.001). These suggest that this system can used in the training to improve the technique of the hammer throw.

D-H Parameter Method-based Wearable Motion Tracking

Motion capture is a key technology for robots to accurately understand pedestrian intentions in the scene of human-machine integration. Due to the limited spatial distance and easy obstruction by obstacles, traditional optical motion capture systems often lose detection targets. This paper proposes a wearable motion tracking method based on D-H parameter method. By binding multiple wireless inertial sensor units composed of accelerometers, magnetic flux sensors and gyroscopes to various moving parts of the user’s body, accurate and robust tracking of moving targets is achieved. This method uses the known pose information of the root node to find the pose state of each level in the reference coordinate system, and establishes the human body joint rotation model and the bone position state model. The results show that the motion tracking method proposed in this paper reduces 9 degrees of freedom compared with the traditional forward kinematics method, and the algorithm efficiency is increased by about 20%, which can accurately obtain the posture characteristics of the human body. It can be seen that the D-H parameter method is reasonable for the wearable human body motion tracking.

Objective lameness assessment in horses used for equine-assisted therapy in Rio Grande do Sul State, Brazil

ABSTRACT: Equine-assisted therapy is a method used since ancient times to rehabilitate individuals. The biomechanics provided by horses and the friction between their back and the riders’ saddle generate impulses that are transmitted to riders’ central nervous system; thus, these horses must be healthy enough to enable the desired therapeutic effect. The aim of the current study is to investigate lameness prevalence and intensity in equine-assisted therapy horses in Rio Grande do Sul State. The adopted methodology consisted of the objective evaluation of lameness based on Lameness Locator® wireless inertial sensors, which were placed in the 21 horses assessed in six equestrian centers in Rio Grande do Sul State. Results have shown that 90.1% of the assessed horses presented lameness in the hind (54.2%) and forelimbs (45.8%), as well as that 72% of them with presented mild lameness degree. This outcome has evidenced the need, and significance, of assessing these horses’ locomotor system. To support effective therapy and protect equine welfare, it is essential that veterinarians should regularly monitor these animals in order to treat and prevent disease. Even subtle lameness can influence the generated stimuli; thus, it is an important factor to be taken into consideration when selecting equine-assisted therapy.

Monitoring toppling failures using wireless inertial measurement unit sensors

A topple is a common rock slope failure – and usually the cause of a rockfall – that depends on the slope and rock geometries. This paper presents a laboratory simulation and field generation of a single-column rock topple failure. Innovative inertial measurement unit (IMU) sensors were used to collect three-dimensional acceleration and angular velocity data during four laboratory experiments to understand and characterise general toppling behaviours. A topple is identified by the gradual change in at least two gravity accelerations, the continuous increase in at least one of the angular velocities and a significant change in the linear acceleration in the direction of toppling. A field experiment showed similar sensor data patterns to those observed from the laboratory experiments. An isolated-block stability analysis of a single-column topple provides the basis for incorporating the IMU sensors into the development of future monitoring and early warning systems.