Functional range of movement of the hand : declination angles to reachable space

 The measurement of the range of hand joint movement is an essential part of clinical practice and rehabilitation. Current methods use three finger joint declination angles of the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints. In this paper we propose an alternate form of measurement for the finger movement. Using the notion of reachable space instead of declination angles has significant advantages. Firstly, it provides a visual and quantifiable method that therapists, insurance companies and patients can easily use to understand the functional capabilities of the hand. Secondly, it eliminates the redundant declination angle constraints. Finally, reachable space, defined by a set of reachable fingertip positions, can be measured and constructed by using a modern camera such as Creative Senz3D or built-in hand gesture sensors such as the Leap Motion Controller. Use of cameras or optical-type sensors for this purpose have considerable benefits such as eliminating and minimal involvement of therapist errors, non-contact measurement in addition to valuable time saving for the clinician. A comparison between using declination angles and reachable space were made based on Hume's experiment on functional range of movement to prove the efficiency of this new approach.

A holistic measurement model of movement competency in children

Different countries have different methods for assessing movement competence in children; however, it is unclear whether the test batteries that are used measure the same aspects of movement competence. The aim of this paper was to (1) investigate whether the Test of Gross Motor Development (TGMD-2) and Körperkoordinations Test für Kinder (KTK) measure the same aspects of children’s movement competence and (2) examine the factorial structure of the TGMD-2 and KTK in a sample of Australian children. A total of 158 children participated (M age = 9.5; SD = 2.2). First, confirmatory factor analysis examined the independent factorial structure of the KTK and TGMD-2. Second, it was investigated whether locomotor, object control and body coordination loaded on the latent variable Movement Competency. Confirmatory factor analysis indicated an adequate fit for both the KTK and TGMD-2. An adequate fit was also achieved for the final model. In this model, locomotor (r = .86), object control (r = .71) and body coordination (r = .52) loaded on movement competence. Findings support our hypothesis that the TGMD-2 and KTK measure discrete aspects of movement competence. Future researchers and practitioners should consider using a wider range of test batteries to assess movement competence.

Nonparametric discovery of movement patterns from accelerometer signals

Monitoring daily physical activity plays an important role in disease prevention and intervention. This paper proposes an approach to monitor the body movement intensity levels from accelerometer data. We collect the data using the accelerometer in a realistic setting without any supervision. The ground-truth of activities is provided by the participants themselves using an experience sampling application running on their mobile phones. We compute a novel feature that has a strong correlation with the movement intensity. We use the hierarchical Dirichlet process (HDP) model to detect the activity levels from this feature. Consisting of Bayesian nonparametric priors over the parameters the model can infer the number of levels automatically. By demonstrating the approach on the publicly available USC-HAD dataset that includes ground-truth activity labels, we show a strong correlation between the discovered activity levels and the movement intensity of the activities. This correlation is further confirmed using our newly collected dataset. We further use the extracted patterns as features for clustering and classifying the activity sequences to improve performance.

Proximate cues to phases of movement in a highly dispersive waterfowl, anas superciliosa

BACKGROUND: Waterfowl can exploit distant ephemeral wetlands in arid environments and provide valuable insights into the response of birds to rapid environmental change, and behavioural flexibility of avian movements. Currently much of our understanding of behavioural flexibility of avian movement comes from studies of migration in seasonally predictable biomes in the northern hemisphere. We used GPS transmitters to track 20 Pacific black duck (Anas superciliosa) in arid central Australia. We exploited La Niña conditions that brought extensive flooding, so allowing a rare opportunity to investigate how weather and other environmental factors predict initiation of long distance movement toward freshly flooded habitats. We employed behavioural change point analysis to identify three phases of movement: sedentary, exploratory and long distance oriented movement. We then used random forest models to determine the ability of meteorological and remote sensed landscape variables to predict initiation of these phases. RESULTS: We found that initiation of exploratory movement phases is influenced by fluctuations in local weather conditions and accumulated rainfall in the landscape. Initiation of long distance movement phases was found to be highly individualistic with minor influence from local weather conditions. CONCLUSIONS: Our study reveals how individuals utilise local conditions to respond to changes in resource distribution at broad scales. Our findings suggest that individual movement decisions of dispersive birds are informed by the integration of multiple weather cues operating at different temporal and spatial scales.

Measurement error causes scale-dependent threshold erosion of biological signals in animal movement data

Recent advances in telemetry technology have created a wealth of tracking data available for many animal species moving over spatial scales from tens of meters to tens of thousands of kilometers. Increasingly, such data sets are being used for quantitative movement analyses aimed at extracting fundamental biological signals such as optimal searching behavior and scale-dependent foraging decisions. We show here that the location error inherent in various tracking technologies reduces the ability to detect patterns of behavior within movements. Our analyses endeavored to set out a series of initial ground rules for ecologists to help ensure that sampling noise is not misinterpreted as a real biological signal. We simulated animal movement tracks using specialized random walks known as Lévy flights at three spatial scales of investigation: 100-km, 10-km, and 1-km maximum daily step lengths. The locations generated in the simulations were then blurred using known error distributions associated with commonly applied tracking methods: the Global Positioning System (GPS), Argos polar-orbiting satellites, and light-level geolocation. Deviations from the idealized Lévy flight pattern were assessed for each track after incrementing levels of location error were applied at each spatial scale, with additional assessments of the effect of error on scale-dependent movement patterns measured using fractal mean dimension and first-passage time (FPT) analyses. The accuracy of parameter estimation (Lévy μ, fractal mean D, and variance in FPT) declined precipitously at threshold errors relative to each spatial scale. At 100-km maximum daily step lengths, error standard deviations of ≥10 km seriously eroded the biological patterns evident in the simulated tracks, with analogous thresholds at the 10-km and 1-km scales (error SD ≥ 1.3 km and 0.07 km, respectively). Temporal subsampling of the simulated tracks maintained some elements of the biological signals depending on error level and spatial scale. Failure to account for large errors relative to the scale of movement can produce substantial biases in the interpretation of movement patterns. This study provides researchers with a framework for understanding the limitations of their data and identifies how temporal subsampling can help to reduce the influence of spatial error on their conclusions.

Post-exercise depression in corticomotor excitability after dynamic movement: a general property of fatiguing and non-fatiguing exercise

Transcranial magnetic stimulation has been used to study changes in central excitability associated with motor tasks. Recently, we reported that a finger flexion–extension task performed at a maximal voluntary rate (MVR) could not be sustained and that this was not due to muscle fatigue, but was more likely a breakdown in central motor control. To determine the central changes that accompany this type of movement task, we tracked motor-evoked potential (MEP) amplitude from the first dorsal interosseous (FDI) and abductor pollicis brevis (APB) muscles of the dominant hand in normal subjects for 20 min after a 10 sec index finger flexion–extension task performed at MVR and at a moderate sustainable rate (MSR) and half the MSR (MSR/2). The FDI MEP amplitude was reduced for up to 6–8 min after each of the tasks but there was a greater and longer-lasting reduction after the MSR and MSR/2 tasks compared to the MVR task. There was a similar reduction in the amplitude of the FDI MEP after a 10 sec cyclic index finger abduction–adduction task when the FDI was acting as the prime mover. The amplitude of the MEP recorded from the inactive APB was also reduced after the flexion–extension tasks, but to a lesser degree and for a shorter duration. Measurements of short-interval cortical inhibition revealed an increase in inhibition after all of the finger flexion–extension tasks, with the MSR task being associated with the greatest degree of inhibition. These findings indicate that a demanding MVR finger movement task is followed by a period of reduced corticomotor excitability and increased intracortical inhibition. However, these changes also occur with and are greater with slower rates of movement and are not specific for motor demand, but may be indicative of adaptive changes in the central motor pathway after a period of repetitive movement.

Movement ecology of nomadic arid zone waterfowl

This thesis provides insights into the spatial and temporal patterns of movement in nomadic waterfowl, the response of birds to rapid environmental change, behavioural flexibility of avian movements and the ability of birds to locate seemingly unpredictable water bodies in vast arid landscapes.

Construct validity of the pictorial scale of perceived movement skill competence

Objectives: The Pictorial Scale of Perceived Movement Skill Competence (PMSC) assesses young children's perceptions of movement skill competence: 12 perceived Fundamental Movement skills (FMS; based on the Test of Gross Motor Development 2nd edition TGMD-2) and six Active Play activities (e.g. cycling). The main study purpose was to assess whether children's movement perception scores fit within the imposed constructs of Active Play and FMS by testing the latent structure and construct validity of the PMSC.

Design: Construct validation study.

Methods: Participants were part of the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT). The latent structure of the PMSC responses was tested through confirmatory factor analysis (CFA) and Bayesian Structural Equation Modeling (BSEM). Internal consistency was conducted using polychoric correlation-based alphas.

Results: The 303 children (boys 53.1%, n = 161) were aged 4-5 years (M = 4.7, SD = 0.46). The final model had an 18 item 3-factor solution with good fit indices (using CFA and BSEM). Factors were: Active Play (Bike, Board Paddle, Climb, Skate/Blade, Scooter, and Swim), Object Control - Hand Skills (Bounce, Catch, Hit, Throw), and FMS skills with a leg action (Gallop, Hop, Jump, Leap, Run, Step Slide, Kick, Roll). Alpha reliability values were: Active Play (0.78), Object Control-Hand Skills (0.76) and FMS-Dynamic Leg (0.84).

Conclusion: Young children can distinguish between movement perceptions. The factors reflect the hypothesized structure in terms of FMS being distinguished from Active Play. Further research should investigate how and if these constructs change in children over time.

Assessing programs for monitoring threatened species – a tale of three honeyeaters (Meliphagidae)

We critically evaluated population-monitoring programs for three endangered species of Australian honeyeater: the helmeted honeyeater, Lichenostomus melanops cassidix, the black-eared miner, Manorina melanotis, and the regent honeyeater, Xanthomyza phrygia (Meliphagidae). Our results challenge the common assumption that meaningful monitoring is possible in all species within the five-year lifetime of recovery plans. We found that the precision achievable from monitoring programs not only depends on the monitoring technique applied but also on the species' biology. Relevant life-history attributes include a species' pattern of movement, its home-range size and its distribution. How well understood and predictable these attributes are will also influence monitoring precision. Our results highlight the large degree of variability in precision among monitoring programs and the value of applying power analysis before continuing longer-term studies. They also suggest that managers and funding agencies should be mindful that more easily monitored species should not receive preferential treatment over species that prove more difficult to monitor.

The first 50 years of the annual endowed accounting research lecture series at the University of Melbourne

Carnegie and Edwards (2001) suggest that the formation of an organisational body is just one of the 'signals of movement' within the dynamic process of professionalisation of an occupation and they list the sponsoring of professorial posts and research activities at universities as further examples. While the literature on this process in Australia does refer to the sponsorship of chairs of accounting (Carnegie & Williams, 2001), little has been written identifying the range of other areas of sponsorship by the organised accounting bodies. This paper presents details of the first fifty years presentations of the Annual Accounting Research Lectures held at The University of Melbourne, Australia. They have been presented continuously since 1940, when they were inaugurated with sponsorship from the Commonwealth Institute of Accountants. The paper presents the first complete listing of details relating to the presenter (including name, gender, residency and occupational area), title of the paper, date of presentation (where known) and details of publication (where appropriate). The initial and subsequent motivation for the presentation of the series and the influence of the lectures in promoting research and fostering relations between the professional bodies and the university, during a period of great significance in the development of accounting education and the professionalisation of accounting in Australia, is also discussed.

Preliminary study of the effect of low-intensity home-based physical therapy in chronic stroke patients

This study was a preliminary examination of the effect of low-intensity home-based physical therapy on the performance of activities of daily living (ADL) and motor function in patients more than 1 year after stroke. Twenty patients were recruited from a community stroke register in Nan-Tou County, Taiwan, to a randomized, crossover trial comparing intervention by a physical therapist immediately after entry into the trial (Group I) or after a delay of 10 weeks (Group II). The intervention consisted of home-based physical therapy once a week for 10 weeks. The Barthel Index (BI) and Stroke Rehabilitation Assessment of Movement (STREAM) were used as standard measures for ADL and motor function. At the first follow-up assessment at 11 weeks, Group I showed greater improvement in lower limb motor function than Group II. At the second follow-up assessment at 22 weeks, Group II showed improvement while Group I had declined. At 22 weeks, the motor function of upper limbs, mobility, and ADL performance in Group II had improved slightly more than in Group I, but the between-group differences were not significant. It appears that low-intensity home-based physical therapy can improve lower limb motor function in chronic stroke survivors. Further studies will be needed to confirm these findings.

Does weight status influence associations between children's fundamental movement skills and physical activity?

This study sought to determine whether weight status influences the association among children's fundamental movement skills (FMS) and physical activity (PA). Two hundred forty-eight children ages 9-12 years participated. Proficiency in three object-control skills and two locomotor skills was examined. Accelerometers objectively assessed physical activity. Body mass index was calculated to determine weight status. Correlations between physical activity and FMS proficiency were evident among boys and girls. No significant interaction was apparent when examining FMS proficiency scores, PA variables, and weight status. Future studies should examine a broader range of skills and types of activities to better characterize this relationship and to inform the promotion of movement skill proficiency and PA.

Animal movement in dynamic landscapes : interaction between behavioural strategies and resource distributions

Most ecological and evolutionary processes are thought to critically depend on dispersal and individual movement but there is little empirical information on the movement strategies used by animals to find resources. In particular, it is unclear whether behavioural variation exists at all scales, or whether behavioural decisions are primarily made at small spatial scales and thus broad-scale patterns of movement simply reflect underlying resource distributions. We evaluated animal movement responses to variable resource distributions using the grey teal (Anas gracilis) in agricultural and desert landscapes in Australia as a model system. Birds in the two landscapes differed in the fractal dimension of their movement paths, with teal in the desert landscape moving less tortuously overall than their counterparts in the agricultural landscape. However, the most striking result was the high levels of individual variability in movement strategies, with different animals exhibiting different responses to the same resources. Teal in the agricultural basin moved with both high and low tortuosity, while teal in the desert basin primarily moved using low levels of tortuosity. These results call into question the idea that broad-scale movement patterns simply reflect underlying resource distributions, and suggest that movement responses in some animals may be behaviourally complex regardless of the spatial scale over which movement occurs.

Movements of a nomadic waterfowl, Grey Teal Anas gracilis, across inland Australia – results from satellite telemetry spanning fifteen months

We used lightweight satellite transmitters to follow the movements of 17 Grey Teal Anas gracilis between September 2003 and November 2004 in two contrasting landscapes, the agricultural districts of southern Australia and the desert landscapes of the interior. Tagged birds moved large distances (up to 343 km) between occupied sites in a short period (hours), remained in the vicinity of those sites for extended periods (months), ventured up to 453 km from their point of release and travelled more than 2000 km in one year. We describe patterns of movement in a nomadic waterfowl for 15 months from September 2003, a period of severe drought. Based on the current analysis there appears to be no remarkable difference in the observed patterns of movement of those released in the agricultural landscapes and those released in the desert. As in waterfowl elsewhere, movements appear to occur in response to changes in local food abundance that threaten survival or the imperative to move in order to breed successfully. In Grey Teal, the proximate cues for movement transcend the local landscape and some birds are responding to temporary cues hundreds of kilometres distant. This is in contrast to the universal seasonal cues associated with migration systems elsewhere.

Energetics of interlimb coordination

While the traditional dependent variables of motor skill learning are accuracy and consistency of movement outcome, there has been increasing interest in aspects of motor performance that are described as reflecting the ‘energetics’ of motor behaviour. One defining characteristic of skilled motor performance is the ability to complete the task with minimum energy expenditure (Sparrow & Newell, 1998). A further consideration is that movements also have costs in terms of cognitive ‘effort’ or ‘energy’. The present project extends previous work on energy expenditure and motor skill learning within a coordination dynamics framework. From the dynamic pattern perspective, a coordination pattern lowest on the 11KB model potential curve (Haken, Kelso & Bunz, 1985) is more stable and least energy is required to maintain pattern stability (Temprado, Zanone, Monno & Laurent, 1999). Two experiments investigated the learning of stable and unstable coordination patterns with high metabolic energy demand. An experimental task was devised by positioning two cycle ergometers side-by-side, placing one foot on each, with the pedals free to move independently at any metronome-paced relative phase, Experiment 1 investigated practice-related changes to oxygen consumption, heart rate, relative phase, reaction time and muscle activation (EMG) as participants practiced anti-phase, in-phase and 90°-phase cycling. Across six practice trials metabolic energy cost reduced and AE and VE of relative phase declined. The trend in the metabolic and reaction time data and percent co-contraction of muscles was for the in-phase cycling to demonstrate the highest values, anti-phase the lowest and 90°-phase cycling in-between. It was found that anti- and in-phase cycling were both kinematically stable but anti-phase coordination revealed significantly lower metabolic energy cost. It was, therefore, postulated that of two equally stable coordination patterns, that associated with lower metabolic energy expenditure would constitute a stronger attractor. Experiment 2 was designed to determine whether a lower or higher energy-demanding coordination pattern was a stronger attractor by scanning the attractor layout at thirty-degree intervals from 0° to 330°. The initial attractor layout revealed that in-phase was most stable and accurate, but the remaining coordination patterns were attracted to the low energy cost anti-phase cycling. In Experiment 2 only 90°- phase cycling was practiced with a post-test attractor layout scan revealing that 90°-phase and its symmetrical partner 270°-phase had become attractors of other coordination patterns. Consistent with Experiment 1, practicing 90°-phase cycling revealed a decline in AE and VE and a reduction in metabolic and cognitive cost. Practicing 90°-phase cycling did not, however, destabilise the in-phase or anti-phase coordination patterns either kinematically or energetically. In summary, the findings suggest that metabolic and mental energy can be considered different representations of a ‘global’ energy expenditure or ‘energetic’ phenomenon underlying human coordination. The hypothesis that preferred coordination patterns emerge as stable, low-energy solutions to the problem of inter-and intra-limb coordination is supported here in showing that the low-energy minimum of coordination dynamics is also an energetic minimum.