Validity and reliability of the DANU sports system for walking and running gait assessment.

Objective. Gait assessments have traditionally been analysed in laboratory settings, but this may not reflect natural gait. Wearable technology may offer an alternative due to its versatility. The purpose of the study was to establish the validity and reliability of temporal gait outcomes calculated by the DANU sports system, against a 3D motion capture reference system.Approach. Forty-one healthy adults (26 M, 15 F, age 36.4 ± 11.8 years) completed a series of overground walking and jogging trials and 60 s treadmill walking and running trials at various speeds (8-14 km hr-1), participants returned for a second testing session to repeat the same testing.Main results. For validity, 1406 steps and 613 trials during overground and across all treadmill trials were analysed respectively. Temporal outcomes generated by the DANU sports system included ground contact time, swing time and stride time all demonstrated excellent agreement compared to the laboratory reference (intraclass correlation coefficient (ICC) > 0.900), aside from ground contact time during overground jogging which had good agreement (ICC = 0.778). For reliability, 666 overground and 511 treadmill trials across all speeds were examined. Test re-test agreement was excellent for all outcomes across treadmill trials (ICC > 0.900), except for swing time during treadmill walking which had good agreement (ICC = 0.886). Overground trials demonstrated moderate to good test re-test agreement (ICC = 0.672-0.750), which may be due to inherent variability of self-selected (rather than treadmill set) pacing between sessions.Significance. Overall, this study showed that temporal gait outcomes from the DANU Sports System had good to excellent validity and moderate to excellent reliability in healthy adults compared to an established laboratory reference.

Wearables for running gait analysis: A study protocol.

Quantitative running gait analysis is an important tool that provides beneficial outcomes to injury risk/recovery or performance assessment. Wearable devices have allowed running gait to be evaluated in any environment (i.e., laboratory or real-world settings), yet there are a plethora of different grades of devices (i.e., research-grade, commercial, or novel multi-modal) available with little information to make informed decisions on selection. This paper outlines a protocol that will examine different grades of wearables for running gait analysis in healthy individuals. Specifically, this pilot study will: 1) examine analytical validity and reliability of wearables (research-grade, commercial, high-end multimodal) within a controlled laboratory setting; 2) examine analytical validation of different grades of wearables in a real-world setting, and 3) explore clinical validation and usability of wearables for running gait analysis (e.g., injury history (previously injured, never injured), performance level (novice, elite) and relationship to meaningful outcomes). The different grades of wearable include: (1) A research-grade device, the Ax6 consists of a configurable tri-axial accelerometer and tri-axial gyroscope with variable sampling capabilities; (2) attainable (low-grade) commercial with proprietary software, the DorsaVi ViMove2 consisting of two, non-configurable IMUs modules, with a fixed sampling rate and (3) novel multimodal high-end system, the DANU Sports System that is a pair of textile socks, that contain silicone based capacitive pressure sensors, and configurable IMU modules with variable sampling rates. Clinical trial registration: Trial registration: NCT05277181.

Wearables for Running Gait Analysis: A Systematic Review.

BACKGROUND: Running gait assessment has traditionally been performed using subjective observation or expensive laboratory-based objective technologies, such as three-dimensional motion capture or force plates. However, recent developments in wearable devices allow for continuous monitoring and analysis of running mechanics in any environment. Objective measurement of running gait is an important (clinical) tool for injury assessment and provides measures that can be used to enhance performance. OBJECTIVES: We aimed to systematically review the available literature investigating how wearable technology is being used for running gait analysis in adults. METHODS: A systematic search of the literature was conducted in the following scientific databases: PubMed, Scopus, Web of Science and SPORTDiscus. Information was extracted from each included article regarding the type of study, participants, protocol, wearable device(s), main outcomes/measures, analysis and key findings. RESULTS: A total of 131 articles were reviewed: 56 investigated the validity of wearable technology, 22 examined the reliability and 77 focused on applied use. Most studies used inertial measurement units (n = 62) [i.e. a combination of accelerometers, gyroscopes and magnetometers in a single unit] or solely accelerometers (n = 40), with one using gyroscopes alone and 31 using pressure sensors. On average, studies used one wearable device to examine running gait. Wearable locations were distributed among the shank, shoe and waist. The mean number of participants was 26 (± 27), with an average age of 28.3 (± 7.0) years. Most studies took place indoors (n = 93), using a treadmill (n = 62), with the main aims seeking to identify running gait outcomes or investigate the effects of injury, fatigue, intrinsic factors (e.g. age, sex, morphology) or footwear on running gait outcomes. Generally, wearables were found to be valid and reliable tools for assessing running gait compared to reference standards. CONCLUSIONS: This comprehensive review highlighted that most studies that have examined running gait using wearable sensors have done so with young adult recreational runners, using one inertial measurement unit sensor, with participants running on a treadmill and reporting outcomes of ground contact time, stride length, stride frequency and tibial acceleration. Future studies are required to obtain consensus regarding terminology, protocols for testing validity and the reliability of devices and suitability of gait outcomes. CLINICAL TRIAL REGISTRATION: CRD42021235527.

Measurement error of 3D kinematic and kinetic measures during overground endurance running in recreational runners between two test sessions separated by 48 h.

OBJECTIVE: The purpose of this study was to quantify the measurement error of 3D kinematic and kinetic measures during overground endurance running between two sessions separated by 48 h. APPROACH: Thirteen recreational runners were assessed on two occasions while running overground, over embedded force plates and through an array of 3D cameras. MAIN RESULTS: In the sagittal, frontal and transverse planes, over the entire stance phase, the typical error of kinematic variables ranged from 1.33°-6.16° for the hip, 1.38°-6.01° for the knee and 0.48°-7.36° for the ankle. Over the same time period and planes typical error of peak-joint moments ranged from 0.04-0.54 Nm · Kg-1 for the hip, 0.06-0.37 Nm · Kg-1 for the knee and 0.01-0.15 Nm · Kg-1 for the ankle. SIGNIFICANCE: Results suggest 3D kinematic and kinetic measures of the stance phase in overground-endurance running are reliable between sessions separated by 48 h. The measurement error reported here could inform sample-size estimates for future studies and provide smallest-detectable changes for the interpretation of interventions performed over a similar time scale.

Exergaming (XBOX Kinect™) versus traditional gym-based exercise for postural control, flow and technology acceptance in healthy adults: a randomised controlled trial.

BACKGROUND: The use of exergaming is a potential alternative to traditional methods of balance training, which can be repetitive and somewhat monotonous. The purpose of this study was to assess the effects of exergaming using XBOX Kinect™ versus traditional gym-based exercise with no virtual stimuli (TGB) on postural control, technology acceptance, flow experience and exercise intensity, in young healthy adults. METHODS: Fifty healthy active adults (age: 33.8 ± 12.7 years, height: 172.9 ± 11.9 cm, weight: 75 ± 15.8 kg) were recruited; 44 completed both baseline and post-intervention data collection. Participants were randomised (blind card) allocation to one of two groups: (1) received balance training using the XBOX Kinect™ and (2) performed traditional gym-based exercise. Exercises were matched for intensity, duration and movement patterns across groups. All participants completed three, 30-minute, exercise sessions a week for four weeks. Postural sway was measured using a Kistler™ Force platform during unipedal standing. Mean heart rate (HR) and rate of perceived exertion (RPE) were collected during each exercise session to determine and verify that intensity of exercise was matched between groups. Technology acceptance was measured with the Unified Theory of Acceptance and Use of Technology (UTAUT) and flow experience with the Flow State Scale (FSS). RESULTS: Heart rate was matched between groups and BORG RPE was significantly lower in the Kinect™ group. There were significant between-group differences in postural sway in the medial-lateral direction and CoP. There were also significant differences in technology acceptance between groups for performance expectancy, social influence and behavioral intention, with higher values in the Kinect exercise group. The flow state scale showed significant differences between the groups on several dimensions, with higher values in the Kinect exercise group. CONCLUSION: Objective physiological demand of exercise (HR) was matched across groups, but the exergaming group perceived it as being less demanding and of lower intensity. This suggests that exergaming may offer an alternative method of rehabilitation exercise through improved concordance. Balance training in healthy adults using the Kinect is both accepted and intrinsically motivating. TRIAL REGISTRATION: Retrospectively registered on 27th July 2016. Trial number NCT02851017.

Comparison of short-term energy intake and appetite responses to active and seated video gaming, in 8-11-year-old boys.

The acute effects of active and seated video gaming on energy intake (EI), blood glucose, plasma glucagon-like peptide-1 (GLP-17-36) and subjective appetite (hunger, prospective food consumption and fullness) were examined in 8-11-year-old boys. In a randomised, crossover manner, twenty-two boys completed one 90-min active and one 90-min seated video gaming trial during which food and drinks were provided ad libitum. EI, plasma GLP-17-36, blood glucose and subjective appetite were measured during and following both trials. Time-averaged AUC blood glucose was increased (P=0·037); however, EI was lower during active video gaming (1·63 (sem 0·26) MJ) compared with seated video gaming (2·65 (sem 0·32) MJ) (P=0·000). In a post-gaming test meal 1 h later, there were no significant differences in EI between the active and seated gaming trials. Although estimated energy expenditure was significantly higher during active video gaming, there was still no compensation for the lower EI. At cessation of the trials, relative EI (REI) was significantly lower following active video gaming (2·06 (sem 0·30) MJ) v. seated video gaming (3·34 (sem 0·35) MJ) (P=0·000). No significant differences were detected in time-averaged AUC GLP-17-36 or subjective appetite. At cessation of the active video gaming trial, EI and REI were significantly less than for seated video gaming. In spite of this, the REI established for active video gaming was a considerable amount when considering the total daily estimated average requirement for 8-11-year-old boys in the UK (7·70 MJ).

Assessing the Physiological Cost of Active Videogames (Xbox Kinect) Versus Sedentary Videogames in Young Healthy Males.

OBJECTIVES: The aims of this study were twofold: (1) to compare the physiological costs of active videogames (AVGs) and sedentary videogames (SVGs) and (2) to compare the exercise intensities attained during AVGs with the exercise intensity criteria for moderate and vigorous physical activity, as stated in current physical activity recommendations for improving public health. MATERIALS AND METHODS: Nineteen young males participated in the study (age, 23 ± 3 years; height, 178 ± 6 cm; weight, 78 ± 15 kg). Participants completed a maximum oxygen uptake ([Formula: see text]) test and a gaming session, including AVGs ("Reflex Ridge," "River Rush," and "Boxing" for the Microsoft [Redmond, WA] Kinect™) and SVGs ("FIFA 14" [Electronic Arts, Burnaby, BC, Canada] and "Call of Duty" [Activision, Santa Monica, CA]). Heart rate (HR) and oxygen uptake [Formula: see text]) were recorded continuously during all videogames. Rating of perceived exertion (RPE) was taken every 3 minutes during AVGs and SVGs. Energy expenditure (EE), expressed as metabolic equivalents (METs), was calculated. One MET was defined as the volume of oxygen consumed at rest in a seated position and is equal to 3.5 mL of O2/kg of body mass/minute. The exercise intensity for each game was expressed as a percentage of [Formula: see text] and percentage of age-predicted maximum HR (HRmax). RESULTS: Exercise intensity (percentage HRmax, percentage [Formula: see text], and RPE) and EE (METs) were significantly higher during active gaming compared with sedentary gameplay (P < 0.01). AVGs elicited moderate levels of exercise intensity (64-72 percent HRmax) in line with current recommended physical activity guidelines. CONCLUSIONS: Our results indicate AVGs provoke physiological responses equivalent to a moderate-intensity physical activity.

Defining ambulatory bouts in free-living activity: Impact of brief stationary periods on bout metrics.

The aim of this study was to assess the effect of varying the maximum resting period between consecutive ambulatory bouts in community-based outcomes. Ambulation was assessed in 97 community-dwelling older adults (mean (SD) age 69.2 (7.7) years) using an accelerometer (activPAL™) worn on the upper thigh for 7 consecutive days. The volume, pattern and variability of ambulation were calculated over a range of maximum resting periods (1-30s). Outcomes with a maximum resting period from 1 to 6s did not vary due to device functionality. Non-linear regression (power law, r(2) > 0.99) showed that increasing the maximum resting period from 6 to 30s resulted in changes in volume (increased duration spent walking, and decreased number of bouts), variability (S2 increased) and pattern (α decreased), and a linear relationship with an increase in average bout length. With a MRP of 6s, 6% of the cohort achieved the public health guidelines of 150 min of ambulation/week accumulated in bouts ≥ 10 min, which increased to 40% using a maximum resting period of 30s. Modifying the maximum resting period impacts on volume, pattern and variability measures of community based ambulation, and attainment of public health guidelines. This highlights the need for standardised algorithms to aid interpretation and explicit reporting of the maximum resting period to aid comparison between studies.

Retraining function in people with Parkinson's disease using the Microsoft kinect: game design and pilot testing.

BACKGROUND: Computer based gaming systems, such as the Microsoft Kinect (Kinect), can facilitate complex task practice, enhance sensory feedback and action observation in novel, relevant and motivating modes of exercise which can be difficult to achieve with standard physiotherapy for people with Parkinson's disease (PD). However, there is a current need for safe, feasible and effective exercise games that are appropriate for PD rehabilitation. The aims of this study were to i) develop a computer game to rehabilitate dynamic postural control for people with PD using the Kinect; and ii) pilot test the game's safety and feasibility in a group of people with PD. METHODS: A rehabilitation game aimed at training dynamic postural control was developed through an iterative process with input from a design workshop of people with PD. The game trains dynamic postural control through multi-directional reaching and stepping tasks, with increasing complexity across 12 levels of difficulty. Nine people with PD pilot tested the game for one session. Participant feedback to identify issues relating to safety and feasibility were collected using semi-structured interviews. RESULTS: Participants reported that they felt safe whilst playing the game. In addition, there were no adverse events whilst playing. In general, the participants stated that they enjoyed the game and seven of the nine participants said they could imagine themselves using the game at home, especially if they felt it would improve their balance. The Flow State Scale indicated participants were immersed in the gameplay and enjoyed the experience. However, some participants reported that they found it difficult to discriminate between different types and orientations of visual objects in the game and some also had difficulty with the stepping tasks, especially when performed at the same time as the reaching tasks. CONCLUSION: Computer-based rehabilitation games using the Kinect are safe and feasible for people with PD although intervention trials are needed to test their safety, feasibility and efficacy in the home.

The role of exergaming in Parkinson's disease rehabilitation: a systematic review of the evidence.

UNLABELLED: Evidence for exercise based computer games (exergaming) as a rehabilitation tool for people with Parkinson's disease (PD) is only now emerging and is yet to be synthesised. To this end, we conducted a systematic review of the exergaming literature to establish what is known about the safety, feasibility and effectiveness of exergaming for rehabilitation of motor symptoms experienced by people with PD. Seven electronic databases were searched for key terms surrounding exergaming and PD. Data were extracted by two reviewers independently. From an initial yield of 1217 articles, seven were included in the review. Six studies used commercial games with the Nintendo Wii fit platform. The scientific quality of reporting was generally good, however the overall methodological design of studies was weak, with only one randomised controlled trial being reported. SAFETY: Participant safety was not measured in any of the studies. Feasibility: People with PD were able to play exergames, improve their performance of gameplay and enjoyed playing. However, one study observed that people with PD had difficulty with fast and complex games. Effectiveness: Six studies showed that exergaming elicited improvements in a range of clinical balance measures or reduction in the severity of motor symptoms. Results from the only randomised controlled trial showed that exergaming was as effective as traditional balance training for people with PD to improve the UPDRS II, standing balance and cognition, with improvements in both groups retained 60 days after the training ended. In conclusion, exergaming is an emerging tool to help rehabilitate motor skills in people with PD. Although we were able to establish that exergaming is feasible in people with PD, more research is needed to establish its safety and clinical effectiveness, particularly in the home. The use of commercial games may be too difficult for some people with PD and exergames tailored specifically to the rehabilitation needs and capabilities of people with PD are required for optimal efficacy, adherence and safety.

Accuracy of the Microsoft Kinect sensor for measuring movement in people with Parkinson's disease.

BACKGROUND: The Microsoft Kinect sensor (Kinect) is potentially a low-cost solution for clinical and home-based assessment of movement symptoms in people with Parkinson's disease (PD). The purpose of this study was to establish the accuracy of the Kinect in measuring clinically relevant movements in people with PD. METHODS: Nine people with PD and 10 controls performed a series of movements which were measured concurrently with a Vicon three-dimensional motion analysis system (gold-standard) and the Kinect. The movements included quiet standing, multidirectional reaching and stepping and walking on the spot, and the following items from the Unified Parkinson's Disease Rating Scale: hand clasping, finger tapping, foot, leg agility, chair rising and hand pronation. Outcomes included mean timing and range of motion across movement repetitions. RESULTS: The Kinect measured timing of movement repetitions very accurately (low bias, 95% limits of agreement <10% of the group mean, ICCs >0.9 and Pearson's r>0.9). However, the Kinect had varied success measuring spatial characteristics, ranging from excellent for gross movements such as sit-to-stand (ICC=.989) to very poor for fine movement such as hand clasping (ICC=.012). Despite this, results from the Kinect related strongly to those obtained with the Vicon system (Pearson's r>0.8) for most movements. CONCLUSIONS: The Kinect can accurately measure timing and gross spatial characteristics of clinically relevant movements but not with the same spatial accuracy for smaller movements, such as hand clasping.

Within trial validation and reliability of a single tri-axial accelerometer for gait assessment.

Gait is a sensitive biomarker of decline in both cognitive and physical function. Therefore, the collection of gait data is an important feature of clinical assessments. Accelerometer-based body worn sensors are quickly becoming the preferred tool for assessing gait because they are small, useable in a wide variety of settings, offer more continuous spatio-temporal analysis and are inexpensive when compared with traditional gait assessment methodologies. The purpose of this study was to determine the validity and within test reliability of a low cost body worn movement sensor with associated algorithms to assess gait in a large group of older and younger healthy adults. We collected gait data over intermittent walks on an instrumented walkway for a within trial validation and also used the same accelerometer derived gait data for a within test reliability analysis. ICCs for validation and reliability were >0.756 and >0.965, respectively.

A comparison of methods to detect postural transitions using a single tri-axial accelerometer.

Two algorithms for evaluating postural transitions (PTs) in cohorts of 40 healthy younger and 40 older adults are described and evaluated. The time of sit-to-stand (SiSt) and stand-to-sit (StSi) transitions and their duration were measured with two tri-axial accelerometers, one on the chest and one on the lower back. Each algorithm was optimized for these sensor placements. The first algorithm for sensor placement on the chest used a scalar product and vertical velocity estimates. The second algorithm for sensor placement on the lower back used a vector magnitude and a discrete wavelet transform. Both algorithms performed excellently in PT classification for younger and older adults (>86%). However, the chest based sensor and algorithm were better for estimating transition duration (TD) with ICCs to video analysis ranging from 0.678 to 0.969.

Immune reconstitution inflammatory syndrome among HIV-infected South African infants initiating antiretroviral therapy.

OBJECTIVES: To determine the incidence, clinical manifestations and risk factors for immune reconstitution inflammatory syndrome (IRIS) in young children initiating highly active antiretroviral therapy (HAART). DESIGN: A prospective cohort of antiretroviral-naïve HIV-infected children less than 24 months of age enrolled in a treatment strategies trial in Johannesburg, South Africa. METHODS: Among 169 HIV-infected children initiating HAART, April 2005 to November 2006, the records of 83 children suspected to have IRIS within 6 months of starting treatment were reviewed to determine whether they met criteria for IRIS. Seven were excluded due to incomplete follow-up. Pretreatment and post-treatment characteristics of children with and without IRIS were compared. RESULTS: Overall, 34/162 (21%) children developed IRIS at a median of 16 days (range 7-115 days) post-HAART initiation. Bacille Calmette-Guérin reaction was most common occurring in 24/34 (71%) children, primarily injection site lesions and/or ipsilateral axillary lymphadenitis with abscess. Other IRIS conditions (not mutually exclusive) included Mycobacterium tuberculosis (n = 12), cytomegalovirus pneumonia (n = 1), Streptococcus pneumonia sepsis (n = 1), and severe seborrheic dermatitis (n = 1). Children with IRIS were younger (median age 7 vs. 10 months, P = 0.007) with a lower CD4 cell percentage (median 13.9 vs. 19.2, P = 0.009) at HAART initiation than controls. After 24 weeks on HAART, 62% of IRIS cases vs. 28% of controls had HIV RNA more than 400 copies/ml (P = 0.001), odds ratio = 2.88 (95% confidence interval = 1.14-7.29) after adjusting for baseline factors. CONCLUSION: Infants and young children with advanced HIV disease initiating HAART are at high risk for developing IRIS, leading to additional morbidity and possibly impairing virologic response to antiretroviral treatment.