Consistent Movement Patterns Research Articles

Alternative migratory strategies related to life history differences in the Walleye (Sander vitreus)

BackgroundWhile Pace of Life Syndrome predicts behavioural differences between individuals with differential growth and survival, testing these predictions in nature is challenging due to difficulties with measuring individual behaviour in the field. However, recent advances in acoustic telemetry technology have facilitated measurements of individual behaviour at scales not previously possible in aquatic ecosystems.MethodsUsing a Walleye (Sander vitreus) population inhabiting Black Bay, Lake Superior, we examine whether life history characteristics differ between more and less mobile individuals as predicted by Pace of Life Syndrome. We tracked the movement of 192 individuals from 2016 to 2019 using an acoustic telemetry study, relating patterns in annual migratory behaviour to individual growth, and seasonal changes in optimal thermal-optical habitat.ResultsWe observed two consistent movement patterns in our study population—migratory individuals left Black Bay during late summer to early fall before returning to the bay, whereas residents remained within the bay year-round. The average maximum length of migrant Walleye was 5.5 cm longer than residents, and the sex ratios of Walleye caught during fall surveys was increasingly female-biased towards the mouth of Black Bay, suggesting that a majority of migrants were females. Further, Walleye occupancy outside of Black Bay was positively associated with increasing thermal-optical habitat.ConclusionsWalleye in Black Bay appear to conform to Pace of Life Syndrome, with migrant individuals gaining increased fitness through increased maximum size, which, given size-dependent fecundity in this species, likely results in greater reproductive success (via greater egg deposition vs. non-migrants). Further, apparent environmental (thermal) controls on migration suggest that migratory Walleye (more so than residents) may be more sensitive to changing environmental conditions (e.g., warming climate) than residents.

Extensive oceanic mesopelagic habitat use of a migratory continental shark species

The identification of movement and behaviour patterns, as well as inter- and intra-population connectivity is crucial in order to implement effective and functional management and conservation measures for threatened migratory species such as tope (Galeorhinus galeus). Yet, previous studies struggled to elucidate clear and consistent movement and depth usage patterns of adult tope in the Northeast Atlantic, suggesting a high plasticity in the migration and behaviour. We deployed pop-up satellite archival tags on adult tope during their seasonal summer aggregations in the inner German Bight of the south-eastern North Sea and near a presumed mating site in southwest Scotland. Depth distribution and migration pathways were derived from time series data with location processing. Four individuals followed migration trajectories leaving coastal areas and crossed the European shelf slope into oceanic areas of the Northeast Atlantic, remaining fully pelagic for the rest of the deployment duration. These sharks showed far-ranging migration trajectories and undertook regular and frequent diel vertical migrations, reaching daytime depths of over 700 m. Vertical migration patterns closely overlapped with biological mesopelagic habitat structures and closely tracked the diel migration of organisms from deep scattering layers derived from hydroacoustic recordings. It is hypothesized that adult tope regularly utilize oceanic habitats, foraging on mesopelagic layers in an environment generally considered of low prey density.

Continuous inter-limb coordination deficits in children with unilateral spastic cerebral palsy

BackgroundContinuous inter-limb coordination and the ability to offset perturbations to a movement pattern (i.e., stability) are important factors in efficient motor performance. Patients with movement disorders often show deficits in coordination and stability, although little is known about these features in children with cerebral palsy. The purpose of this study was to identify the continuous inter-limb coordination and stability deficits in children with cerebral palsy and determine if improvement occurs with upper extremity intervention. MethodsChildren with cerebral palsy participated in bimanual or unimanual intensive therapy. Continuous inter-limb coordination between the arms and between the more-affected arm and leg was evaluated using relative phase analysis during four gross motor tasks, including in-place marching and standing with asymmetric and symmetric arm swing. A control group of children with cerebral palsy and a group of typically developing children were also evaluated. FindingsChildren with cerebral palsy displayed coordination deficits compared to typically developing children (p<0.01), yet both groups presented similarly poor levels of stability (p=0.39). Compared to standing, adding legs to the task negatively impacted the coordination (p<0.01) and stability (p<0.01) of all children. Both groups improved coordination between the arms post-intervention (p<0.05 for all cases), however neither group improved stability (p>0.05 for all cases). InterpretationRelative phase analysis successfully provided a sensitive measurement of coordination and stability in pathologic and non-pathologic populations. Findings indicate that all children have difficulty producing consistent movement patterns and suggest that both bimanual and unimanual interventions can improve continuous coordination in children with cerebral palsy.

Ontogenetic Variation in Movements and Depth Use, and Evidence of Partial Migration in a Benthopelagic Elasmobranch

Tope (Galeorhinus galeus) is a highly mobile elasmobranch in the temperate to subtropical northeast Atlantic. It is highly migratory and has been shown to display complex movement patterns, such as partial migration, in the southern hemisphere. In the northeast Atlantic, previous mark-recapture studies have struggled to identify movement patterns and the species behaviour is poorly described, yet identification of migratory behaviors and habitats of importance for the species is of paramount importance for effective management. Here, we combined fisheries independent survey data with mark-recapture (MR) data to investigate the distribution of different age classes of tope across the northeast Atlantic. We further investigated depth use in detail with archival electronic tags and a pop-up satellite archival tag (PSAT). We suggest previous studies struggling to find consistent movement patterns using MR data were confounded by a combination of site fidelity, partial migration by females and increasing depth and home range of juveniles. Survey and MR data showed immature tope less than 40 cm were caught exclusively in continental shelf waters less than 45 m deep, showing a significant relationship between habitat depth and total length. Immature individuals seemed to remain on the continental shelf, while mature tope of both genders were caught in both shelf and offshore waters. This use of deeper water habitats by mature tope was further supported by archival tags, which indicated individuals use both shallow (<200 m depth) and deep-water habitats, diving to depths of 826 m; the deepest record for this species. The PSAT tag tracked the horizontal movements of an adult male, which confirmed utilisation of both shallow inshore and deep offshore habitats. Most tope remained within 500 km of their tagging site, although some mature females had a larger, more southerly range, including connectivity with the Mediterranean. This study clearly demonstrates the highly migratory habits of tope, and suggests larger individuals divide their time between shallow and deep-water habitats. It shows the northeast Atlantic tope population should benefit from consistent management throughout its range.

The effect of the A-frame on forelimb kinematics in experienced and inexperienced agility dogs

Limited research has evaluated the kinematics of agility dogs over different equipment despite the growing popularity of recreational and competitive agility. A-frames are associated with a higher risk of injury; these risks could be related to how dogs approach the equipment. We hypothesised that forelimb (FL) and spinal kinematics would differ throughout the different phases of negotiating the A-frame: incline, apex, decline, and between experienced and inexperienced agility dogs. Eight agility dogs of mixed breed and age, all trained on the A-frame participated in the study. Participants were divided into two groups: inexperienced dogs (ID: &lt;4 years training; n=4) and experienced dogs (ED: &gt;4years training; n=4), and undertook 3 runs over the A-frame. Reflective markers were placed on each dog’s carpus (Ca), radiohumeral (RH) and scapulohumerus (SH) joints, Atlas, C3 and L3. Video footage was transferred to Dartfish™ to enable FL joint angles to be calculated for the approach (last stride), incline (FL contact), apex (FL over), decline (FL touchdown and FL departure). The range of movement (ROM) for spinal markers was also calculated. Wilcoxon signed rank analyses, with Bonferroni correction applied (P&lt;0.02), indicated if kinematics differed for ED and ID between the phases. Similar kinematic patterns were observed through all phases for C3 and L3, however a greater ROM was found for ED: C3 and ID: L3. For Atlas, ED stayed in flexion for all phases whilst ID movement varied: approach-incline extension, incline-apex: flexion, apex to decline extension followed by flexion. No significant differences in FL joint angles existed (P&gt;0.02). No significant differences in kinematic measures were seen between ED and ID dogs in any phase of the A-frame. ED demonstrate consistent movement patterns; ID vary their head and neck position more, and exaggerate their apex jump. Rounding the A-frame apex could encourage a less-extreme technique in ID.

Consistency of a lumbar movement pattern across functional activities in people with low back pain

BackgroundLimitation in function is a primary reason people with low back pain seek medical treatment. Specific lumbar movement patterns, repeated throughout the day, have been proposed to contribute to the development and course of low back pain. Varying the demands of a functional activity test may provide some insight into whether people display consistent lumbar movement patterns during functional activities. Our purpose was to examine the consistency of the lumbar movement pattern during variations of a functional activity test in people with low back pain and back-healthy people. Methods16 back-healthy adults and 32 people with low back pain participated. Low back pain participants were classified based on the level of self-reported functional limitations. Participants performed 5 different conditions of a functional activity test. Lumbar excursion in the early phase of movement was examined. The association between functional limitations and early phase lumbar excursion for each test condition was examined. FindingsPeople with low back pain and high levels of functional limitation demonstrated a consistent pattern of greater early phase lumbar excursion across test conditions (p<0.05). For each test condition, the amount of early phase lumbar excursion was associated with functional limitation (r=0.28–0.62). InterpretationOur research provides preliminary evidence that people with low back pain adopt consistent movement patterns during the performance of functional activities. Our findings indicate that the lumbar spine consistently moves more readily into its available range in people with low back pain and high levels of functional limitation. How the lumbar spine moves during a functional activity may contribute to functional limitations.

Effectiveness of robot-assisted gait training in children with cerebral palsy: a bicenter, pragmatic, randomized, cross-over trial (PeLoGAIT)

BackgroundWalking ability is a priority for many children with cerebral palsy (CP) and their parents when considering domains of importance regarding treatment interventions. Partial body-weight supported treadmill training has become an established therapeutic treatment approach to address this demand. Further, new robotic rehabilitation technologies have increasingly been implemented in the clinical setting to allow for longer training sessions with increased step repetitions while maintaining a consistent movement pattern. But the current evidence about its clinical effectiveness in pediatric rehabilitation is weak. The aim of this research project is therefore to investigate the effectiveness of robot-assisted gait training on improvements of functional gait parameters in children with cerebral palsy.Methods/DesignChildren aged 6 to 18 years with bilateral spastic cerebral palsy who are able to walk at least 14 m with or without walking aids will be recruited in two pediatric therapy centers in Switzerland. Within a pragmatic cross-over design with randomized treatment sequences, they perform 5 weeks of robot-assisted gait training (three times per week with a maximum of 45 min walking time each) or a 5-week period of standard treatment, which is individually customized to the needs of the child and usually consists of 1–2 sessions of physiotherapy per week and additional hippotherapy, circuit training as well as occupational therapy as necessary. Both interventions take place in an outpatient setting. The percentage score of the dimension E of the Gross Motor Function Measure-88 (GMFM-88) as primary outcome as well as the dimension D of the GMFM-88, 6-minute and 10-meter walking tests as secondary outcomes are assessed before and at the end of each intervention period. Additionally, a 5-week follow-up assessment is scheduled for the children who are assigned to the standard treatment first. Treatment effects, period effects as well as follow-up effects are analyzed with paired analyses and independent test statistics are used to assess carry-over effects.DiscussionAlthough robot-assisted gait training has become an established treatment option to address gait impairments, evidence for its effectiveness is vague. This pragmatic trial will provide important information on its effects under clinical outpatient conditions.Trial registrationClinicalTrials.gov: NCT00887848. Registered 23 April 2009.

Level walking in adults with and without Developmental Coordination Disorder: An analysis of movement variability

Several studies have shown that Developmental Coordination Disorder (DCD) is a condition that continues beyond childhood. Although adults with DCD report difficulties with dynamic balance, as well as frequent tripping and bumping into objects, there have been no specific studies on walking in this population. Some previous work has focused on walking in children with DCD but variation in the tasks and measures used has led to inconsistent findings. The aim of the current study therefore was to examine the characteristics of level walking in adults with and without DCD. Fifteen adults with DCD and 15 typically developing (TD) controls walked barefoot at a natural pace up and down an 11m walkway for one minute. Foot placement measures and velocity and acceleration of the body were recorded, as well as measures of movement variability. The adults with DCD showed similar gait patterns to the TD group in terms of step length, step width, double support time and stride time. The DCD group also showed similar velocity and acceleration to the TD group in the medio-lateral, anterior–posterior and vertical direction. However, the DCD group exhibited greater variability in all foot placement and some body movement measures. The finding that adults with DCD have a reduced ability to produce consistent movement patterns is discussed in relation to postural control limitations and compared to variability of walking measures found in elderly populations.

KINESIOLOGIC AND METABOLIC RESPONSES OF PERSONS WITH CEREBRAL PALSY TO SUSTAINED EXERCISE ON A PETRA RACE RUNNER

The purpose of this study was to investigate if the performance and metabolic response of cerebral palsy (CP)-athletes to a sustained submaximal exercise on a Petra Race Runner (PRR) was confirm their CP-ISRA classification. Furthermore, the impact of fatigue on the quality of propulsive movement was assessed. Nine athletes with CP from CP-ISRA classes CP1 up to CP6 took part in a 12 minute Cooper Test using a PRR. Changes in heart rate, blood lactate and pace per minute were monitored throughout the test. Results showed that heart rate rose immediately to high levels (a mean of over 160 after the first minute), and was sustained at this level through the test. Blood lactate concentration increased in a curvilinear pattern, but was subject to much inter-individual difference. Analysis from video recordings showed that participants maintained a very consistent movement pattern (step-length, stride frequency) as they became fatigued in the later stages of the Cooper test. The results clearly demonstrated the limitations of using the CP-ISRA classes for PRR competition. No evidence was generated showing an adverse impact of sustained submaximal PRR on the quality of propulsive movement.

Differences in gait complexity and variability between children with and without Developmental Coordination Disorder

We used elliptical Fourier analysis (EFA) to examine potential differences in the complexity and variability of gait of children with ( N = 10) and without ( N = 10) Developmental Coordination Disorder (DCD). Children with DCD generated movement patters with larger variability and complexity than typically developing (TD) children. In addition, children with DCD exhibited greater asymmetry in their movement patterns compared to TD children. Our results suggest that children with DCD have significantly greater difficulty producing consistent movement patterns both across their left and right legs and over repeated strides. EFA techniques show promise for distinguishing between different groups of individuals.

Beyond floricentrism: The pollination function of inflorescences

AbstractMating by outcrossing plants depends on the frequency and quality of the interaction between pollen vectors and individual flowers. However, the historical focus of pollination biology on individual flowers (floricentrism) cannot produce a complete understanding of the role of pollination in plant mating because mating is an aggregate process, which depends on the reproductive outcomes of all of a plant’s flowers. Simultaneous display of multiple flowers in an inflorescence increases a plant’s attractiveness to pollinators, which should, in general, enhance mating opportunities. However, whenever pollinators visit multiple flowers on an inflorescence, self‐pollination among flowers can reduce the pollen available for export to other plants (pollen discounting) and can increase the incidence of inbreeding depression for embryos and offspring. Therefore, the size of floral displays that maximize mating frequency and quality generally balance the benefits of attractiveness against the costs of self‐pollination. This balance can shift considerably if different flowers serve female and male functions at one time (sexual segregation) and flowers are arranged in inflorescences so that pollinators visit female flowers before male flowers. However, the effectiveness of sexual segregation depends on the extent to which a particular inflorescence architecture induces consistent movement patterns by pollinators. In general, the consistency of pollinator movement patterns varies with inflorescence architecture and differs between pollinator types. Such variation creates many options for the evolution of the diverse inflorescence characteristics observed within angiosperms, which can be appreciated only by moving beyond a floricentric perspective of the role of pollination in plant mating.

Haptic Perception of Virtual Surfaces: Scaling Subjective Qualities and Interstimulus Differences

We examined, in two experiments, the perceptual scaling of the properties of haptically examined virtual surfaces, and the way in which these properties subjectively combine. Participants used a consistent movement pattern to explore, with a stylus, virtual surfaces generated by a force-feedback device. In experiment 1, four surface properties (bump size, friction, resistance to normal force, and vibration amplitude) were varied individually, in separate blocks of trials. Free magnitude estimates of the subjective dimensions corresponding to these properties showed that all four dimensions conformed closely to the power law, except at very low stimulus values. Exponents for bump size (0.80) and stiffness (1.01) were consistent with values established in earlier work with direct touch of real surfaces. Surprisingly, the exponent for stickiness, not previously measured, was much higher than those for other dimensions (1.49). In experiment 2, dimensional combinations were analyzed by asking subjects to give magnitude estimates of the subjective difference between pairs of surfaces differing in one or two properties. Magnitude estimates of a given one-dimensional difference were generally larger when the subject was pressing down firmly on the surfaces, than when only gentle downward pressure was required; this result suggests that forces generated when a surface is haptically examined are interpreted as invariant indicators of the magnitudes of the surface properties themselves. Estimates of one-dimensional differences were also used to make predictions of two-dimensional differences, under assumptions of dimensional integrality and separability. The results fell between these two sets of predictions, indicating only modest integration of surface properties examined with indirect touch.

Interobserver Reliability of General Practice Physiotherapists in Rating Aspects of the Movement Patterns of Skilled Violinists

In the music medicine literature, experienced clinicians recommend the visual observation of musicians performing on their instruments to identify movement patterns that potentially increase the risk of an injury. Visual assessment of functional task performance is a skill used clinically by many health care professionals to enhance decision-making regarding the best management and treatment strategies for a particular client. Little research exists, however, to identify whether consistent movement patterns would be identified during such a procedure and whether there are particular injury risk features that can be identified reliably by a group of practitioners. This study asked a group of experienced clinical physiotherapists to rate movement patterns of 30 skilled violinists performing a violin-playing task to evaluate whether similar scores would result. Results indicated that these therapists varied widely in their rating methods, and interrater reliability scores ranged from mostly poor to fair. These scores occurred regardless of the presence or absence of playing-related injuries in the violinists. A small sample of available intrarater scores showed better consistency, although still not of high reliability. Further research may indicate whether physiotherapists or health care practitioners experienced in observing a complex task such as violin playing would show greater interrater reliability in using such a scoring system.

Signal characteristics of spontaneous facial expressions: automatic movement in solitary and social smiles

The assumption that the smile is an evolved facial display suggests that there may be universal features of smiling in addition to the basic facial configuration. We show that smiles include not only a stable configuration of features, but also temporally consistent movement patterns. In spontaneous smiles from two social contexts, duration of lip corner movement during the onset phase was independent of social context and the presence of other facial movements, including dampening. These additional movements produced variation in both peak and offset duration. Both onsets and offsets had dynamic properties similar to automatically controlled movements, with a consistent relation between maximum velocity and amplitude of lip corner movement in smiles from two distinct contexts. Despite the effects of individual and social factors on facial expression timing overall, consistency in onset and offset phases suggests that portions of the smile display are relatively stereotyped and may be automatically produced.

Three-Dimensional in Vivo Kinematics of the Shoulder during Humeral Elevation.

Shoulder kinematics, including scapular rotation relative to the trunk and humeral rotation relative to the scapula, were examined during humeral elevation in three vertical planes via video analysis of intracortical pins. Helical axis parameters provided an easily interpretable description of shoulder motion not subject to the limitations associated with Cardan/Euler angles. Between 30 and 150° of elevation in each plane, the scapula rotated almost solely about an axis perpendicular to the scapula. Additional scapular rotation appeared to support the notion that the scapula moves "toward" the plane of elevation. Humeral rotation took place mainly in the plane of the scapula independent of the plane of elevation. Many parameters of shoulder complex kinematics were quite similar across all planes of elevation, suggesting a consistent movement pattern with subtle differences associated with the plane of elevation.

Sequential analysis of cattle location: Day-to-day movement patterns

Studies were conducted in Texas and Colorado to determine if there were consistent movement patterns of grazing cattle. Based on optimal foraging theory, we hypothesized that cattle would select the same area of a pasture to graze for several days in a row. In the Colorado study, the location of cattle was observed each morning for 6 weeks. The 50-ha pasture was separated into 10 sections. The calculated number of cattle that moved from one section to another was analyzed using a transition matrix. Cattle were rarely observed in the same section of the pasture on two successive mornings. In the Texas study, the location of cattle after they began grazing was observed each morning for eight seasonal trials lasting 6–15 days. The 248-ha pasture was divided into 63 units based on plant community, slope, aspect, elevation and distance from water. Cluster analysis was used to group these units into five separate areas. Clusters were based on the amount of grazing in each unit during the trials. The number of cattle that moved from one area to another during successive mornings (calculated from expected values) was analyzed using a transition matrix. Separate analyses were made for spring, summer and winter periods. There was no consistent movement pattern across all seasons. Cattle seldom grazed in the same area for more than two successive mornings. The transitions on successive mornings from areas separated by the greatest distance generally occurred less often than expected by chance. The hypothesis that cattle would select the same area to graze for several successive mornings was rejected. In both studies, cattle appeared to graze nearby areas on the following morning.

Effects of Unequal Distances and Handedness on Timing Patterns for Simultaneous Movements of Arms and Legs

Abstract Previous research on the ability of people to perform simultaneous movements involving speed and accuracy showed a consistent movement pattern whenever the two limbs moved unequal distances. It was not clear whether the pattern was a function of handedness or the greater distance moved by the preferred hand. The purpose of the present experiment was to study the effect of distance and handedness on movement patterns. Five movement tasks using two simultaneous movements of arms and/or legs were used. The data indicated that for the tasks involving unequal distances the limb having the greater distance to move starts first and finishes last. Also, individual variability for contact time difference (failure to finish the two parts of the movement simultaneously) was greater than that for starting time difference (failure to start both parts together).

Timing of Two Simultaneous Movements of Arms and Legs

Abstract The ability of people to perform simultaneous movements involving speed and accuracy, and the relationships among the several time measures for these movements were studied. Five movement tasks using two simultaneous movements of arms and legs were performed. Reliability of time measures ranged between 0.830 and 0.988. There were no significant differences between the two tasks involving an arm and a leg. Reaction time for tasks involving an arm and leg was slower than for tasks involving two arms. An increase in task complexity resulted in an increase in starting time difference and contact time difference. Common variance between tasks for several time measures was relatively high. For all tasks, except the one using identical movements for the two arms, a consistent movement pattern was found in which the right hand started first and finished last.