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- PublicationUse of body worn sensors to predict ankle injuries using screening toolsBackground The Single Leg Squat (SLS) is an important screening tool in predicting those at an increased risk of ankle injuries as it relates to landing, running and cutting tasks. However, clinical analysis of this exercise is often completed visually with relatively poor intra-rater reliability. More detailed analysis of SLS completed in biomechanics laboratories is time-consuming and costly. Recent developments in body worn sensors may allow for quick assessments that produce valid and reliable data.Objective To explore a model for leveraging data obtained from wearable sensors to aid in ankle injury risk factor screening.Design A single case study design, with qualitative analysis of quantitative data.Setting University research laboratory.Participants A single participant (female, age = 24 years; height = 158 cm, body mass = 47 kg) was chosen. The participant was familiar with the SLS exercise and had completed it as part of their exercise routine for the past year.Interventions The participant completed 10 left SLS repetitions. These were recorded using the sensors and repetitions where the participant lost balance were noted. Loss of balance was defined as when the subject was unable to maintain single leg stance during the downward or upward phase of the movement and placed their other foot on the ground for support.Main outcome measurements Visual analysis showed signals from the wearable sensors (accelerometer Y and gyroscope Z) were altered when the participant lost their balance compared to signals obtained when the participant maintained balance.Conclusions These preliminary results indicate that body worn sensors may be able to automatize screening tools such as the SLS. An automated system for characterising and quantifying deviations from good form could be developed to aid clinicians and researchers. Such a system would provide objective and reliable data to clinicians and allow researchers to analyse movements quicker and in a more naturalistic setting.
- PublicationQuantification of postural control deficits in patients with recent concussion: An inertial-sensor based approachBackground: The aim of this study was to quantify postural control ability in a group with concussion compared with a healthy control group. Method: Fifteen concussion patients (4 females, 11 males) and a group of fifteen age- and sex-matched controls were recruited. Participants were tested during the performance of the three stance variants (bilateral, tandem and unilateral) of the balance error scoring system standing on a force place, while wearing an inertial measurement unit placed at the posterior aspect of the sacrum. Findings: The area of postural sway was computed using the force-plate and the '95% ellipsoid volume of sway' was computed from the accelerometer data. Concussed patients exhibited increased sway area (1513 mm2 [95% CI: 935 to 2091 mm2] vs 646 mm2 [95% CI: 519 to 772 mm2]; p = 0.02) and sway volume (9.46 m3 s− 6 [95% CI: 8.02 to 19.94 m3 s− 6] vs 2.68 m3 s− 6 [95% CI: 1.81 to 3.55 m3 s− 6]; p = 0.01) in the bilateral stance position of the balance error scoring system. The sway volume metric also had excellent accuracy in identifying task 'errors' (tandem stance: 91% accuracy [95% CI: 85–96%], p < 0.001; unilateral stance: 91% accuracy [95% CI: 86–96%], p < 0.001). Interpretation: Individuals with concussion display increased postural sway during bilateral stance. The sway volume that was calculated from the accelerometer data not only differentiated a group with concussion from a healthy control group, but successfully identified when task errors had occurred. This may be of value in the development of a pitch-side assessment system for concussion.
Scopus© Citations 37 788
- PublicationLower extremity function during gait in participants with first time acute lateral ankle sprain compared to controlsLaboratory analyses of chronic ankle instability populations during gait have elucidated a number of anomalous movement patterns. No current research exists analysing these movement patterns in a group in the acute phase of lateral ankle sprain (LAS) injury. It is possible that participants with an acute LAS display movement patterns continuous with their chronically impaired counterparts. Sixty eight participants with acute LAS and nineteen non-injured participants completed five gait trials. 3D lower extremity temporal kinematic and kinetic data were collected from 200ms pre- to 200ms post-heel strike (period 1) and from 200ms pre- to 200ms post-toe off (period 2). During period 1, the LAS group displayed increased knee flexion with increased net extensor pattern at the knee joint, increased ankle inversion with a greater inversion moment, and reduced ankle plantar flexion, compared to the non-injured control group. During period 2, the LAS group displayed decreased hip extension with a decrease in the flexor moment at the hip, and decreased ankle plantar flexion with a decrease in the net plantar flexion moment, compared to the non-injured control group. These results indicate that participants with acute LAS display coordination strategies which may play a role in the onset of chronicity or recovery.
Scopus© Citations 25 878
- PublicationA Wearable Sensor-Based Exercise Biofeedback System: Mixed Methods Evaluation of FormuliftBackground: Formulift is a newly developed mobile health (mHealth) app that connects to a single inertial measurement unit (IMU) worn on the left thigh. The IMU captures users movements as they exercise, and the app analyzes the data to count repetitions in real time and classify users exercise technique. The app also offers feedback and guidance to users on exercising safely and effectively. Objective: The aim of this study was to assess the Formulift system with three different and realistic types of potential users (beginner gym-goers, experienced gym-goers, and qualified strength and conditioning [S&C] coaches) under a number of categories: (1) usability, (2) functionality, (3) the perceived impact of the system, and (4) the subjective quality of the system. It was also desired to discover suggestions for future improvements to the system. Methods: A total of 15 healthy volunteers participated (12 males; 3 females; age: 23.8 years [SD 1.80]; height: 1.79 m [SD0.07], body mass: 78.4 kg [SD 9.6]). Five participants were beginner gym-goers, 5 were experienced gym-goers, and 5 were qualified and practicing S&C coaches. IMU data were first collected from each participant to create individualized exercise classifiers for them. They then completed a number of non exercise-related tasks with the app. Following this, a workout was completed using the system, involving squats, dead lifts, lunges, and single-leg squats. Participants were then interviewed about their user experience and completed the System Usability Scale (SUS) and the user version of the Mobile Application Rating Scale (uMARS). Thematic analysis was completed on all interview transcripts, and survey results were analyzed. Results: Qualitative and quantitative analysis found the system has good to excellent usability. The system achieved a mean (SD) SUS usability score of 79.2 (8.8). Functionality was also deemed to be good, with many users reporting positively on the systems repetition counting, technique classification, and feedback. A number of bugs were found, and other suggested changes to the system were also made. The overall subjective quality of the app was good, with a median star rating of 4 out of 5 (interquartile range, IQR: 3-5). Participants also reported that the system would aid their technique, provide motivation, reassure them, and help them avoid injury. Conclusions: This study demonstrated an overall positive evaluation of Formulift in the categories of usability, functionality, perceived impact, and subjective quality. Users also suggested a number of changes for future iterations of the system. These findings are the first of their kind and show great promise for wearable sensor-based exercise biofeedback systems.
Scopus© Citations 16 437
- PublicationShort Bouts of Gait Data and Body-Worn Inertial Sensors Can Provide Reliable Measures of Spatiotemporal Gait Parameters from Bilateral Gait Data for Persons with Multiple SclerosisBackground: Wearable devices equipped with inertial sensors enable objective gait assessment for persons with multiple sclerosis (MS), with potential use in ambulatory care or home and community-based assessments. However, gaitdata collected in non-controlled settings is often fragmented and may not provide enough information forreliable measures. We evaluate a novel approach, extracting pre-defined numbers of gait cycles from the fulllength of a walking task, and their effects on the reliability of spatiotemporal gait parameters. Methods: The present study evaluates intra-session reliability of spatiotemporal gait parameters for short bouts of gaitdata extracted from the full length of the walking tasks to 1) determine the effects of the length of the walkingtask on the reliability of calculated measures and 2) identify spatiotemporal gait parameters that can providereliable measures for gait assessments and reference data in different settings. Thirty-seven participants (37) diagnosed with relapsing-remitting MS (EDSS rage 0 to 4.5) executed two trials,walking 20m each, with inertial sensors attached to their right and left shanks. Previously published algorithms were applied to identify gait events from the medio-lateral angular velocity. Short bouts of gait data wereextracted from each trial, with lengths varying from 3 to 9 gait cycles. Twenty-one measures of spatiotemporalgait parameters were calculated. Intraclass correlation coefficients (ICCs) were calculated to evaluate how the degree of agreement between the two trials of each participant varied with the number of gait cycles included inthe analysis. Results: Spatiotemporal gait parameters calculated as the mean across included gait cycles reach excellent reliabilityfrom three gait cycles. Stride time variability and asymmetry, as well as stride velocity variability and asymmetry, reach good reliability from six gait cycles and should be further explored for persons with MS, whilestride time asymmetry and step time asymmetry do not seem to provide reliable measures and should bereported carefully. Conclusion: Short bouts of gait data, including at least six gait cycles of bilateral data, can provide reliable gait measurements for persons with MS, opening new perspectives for gait assessment using wearable devices in non-controlled environments, to support monitoring of symptoms of persons with neurological diseases.
- PublicationAn investigation into the acute effects of electrical muscle stimulation on cardiopulmonary function in a chronic obstructive pulmonary disease patient - a pilot case studyChronic obstructive pulmonary disease (COPD) patients commonly find it difficult to participate in conventional aerobic exercise training owing to limited cardiopulmonary reserve, excessive dyspnoea and muscle fatigue. Recent studies have shown that significant improvements in oxygen consumption can be gained post 6-week electrical muscle stimulation (EMS) training. Low frequency currents elicit a sustained and significant aerobic response and may be appropriate for COPD patients, who cannot exercise in a conventional manner. A recent study compared the acute metabolic response among COPD patients during resistance training and EMS, using a tetanic frequency of 75 Hertz (Hz), however no investigations have reported on the acute effects of EMS on cardiopulmonary function in a COPD population, using low frequency stimulation current.
- PublicationA pilot investigation into the effects of electrical muscle stimulation training on physical fitness in an adult cystic fibrosis populationCystic Fibrosis (CF) is the most common life-limiting genetic disease in caucasians. Skeletal muscle weakness and exercise intolerance is prevalent in people with cystic fibrosis. Although higher levels of fitness have been associated with better quality of well-being and improved eight year survival training among individuals with CF is limited due to fatigue, hypoxaemia and dyspnoea.Neuromuscular electrical stimulation (NMES) has demonstrated improvements in muscle strength, exercise tolerance and aerobic capacity in cardiorespiratory disease populations, while having minimal impact on oxygen saturation levels and heart rate.
- PublicationA pilot investigation into the effects of electrical muscle stimulation training on physical fitness in an adult cystic fibrosis populationCystic Fibrosis (CF) is the most common life-limiting genetic disease in Caucasians.  Progressive respiratory and gastro intestinal disease are the predominant clinical manifestations of the disease. As a consequence of general de-conditioning, skeletal muscle weakness and exercise intolerance is prevalent among patients with CF.  Although higher levels of fitness have been associated with better quality of wellbeing and eight-year survival, training among individuals with CF is limited due to fatigue, hypoxemia and dyspnoea.  Electrical muscle stimulation (EMS) has demonstrated improvements in muscle strength, exercise tolerance and aerobic capacity in chronic cardio respiratory disease populations, while having minimal impact on heart rate (HR) and oxygen saturation levels. [4,5]
- PublicationObjective quantification of a clinical dynamic balance assessmentObjective: To investigate whether addition of inertial sensor data can provide additional insight into the nature of postural stability deficits during a clinical dynamic balance assessment, with a view to enhancing accuracy of post-concussion monitoring protocols. Design: Descriptive laboratory study. Setting: University performance laboratory. Participants: Fifteen physically active adults (age 234 years, height 1758 cm, weight 67.58 kg). Interventions: An inertial measurement unit (IMU) was mounted at the level of the 4th lumbar vertebra. Subjects completed repeated Y-Balance tests (YBT) 10 minutes and immediately prior to a modified 60 second Wingate anaerobic fatiguing test. Post-fatigue YBTs were completed immediately following the test, and at 10 and 20 minutes.Outcome measures: Normalised YBT reach distances, and IMU derived RMS acceleration, velocity and angular velocity. Main results: Prior to the fatiguing intervention, participants demonstrated excellent stability/reliability for all reach directions (Intra-class correlation coefficient 0.872-0.994). Significantly lower reach distances (P<0.05) were observed immediately post-fatigue for the postero-medial and postero-lateral, but not anterior reach direction. Observed deficits returned to pre-fatigue levels by 10 minutes. However, IMU derived measures of postural stability remained significantly reduced (P<0.05) for up to 20 minute post-fatigue. Conclusions: These results demonstrate the ability of both traditional YBT reach distances and inertial sensor data to detect centrally driven postural stability deficits. However, the inertial sensor provided a greater degree of granularity in characterising the nature of these postural stability deficits. This suggests that addition of IMUs to clinical balance measurement tests/protocols may better detect deficits associated with concussion.
- PublicationWearable sensing and mobile devices: the future of post-concussion monitoring?In the past decade, concussion has received large amounts of attention in public, medical and research circles. While our understanding of the nature and management of concussion has greatly improved, there are still major limitations which need to be addressed surrounding the identification of the injury, determining when an individual is safe to return to normal activity, and what factors may contribute to the development of post-concussion syndrome (PCS).The current model of concussion management involves a triage evaluation in the acute stage of injury, focusing on the classic signs and symptoms of concussion. Next, the clinician attempts to evaluate key components of cerebral function through clinical symptom evaluation, and traditional assessments of motor and neurocognitive function . The development of the sports concussion assessment tool (SCAT) saw a massive leap forward in the strategies employed in the management of concussion, as it acknowledged the multifactorial nature of concussion, and provided a standardised means for clinicians to assess the many domains of cerebral function . While these methods have demonstrated some promise in the acute stage, they are not designed for serial monitoring (particularly in instances where PCS develops) , and provide us with very little clinically relevant information that can assist clinicians in the return to learn/ sport/ performance process.