Two types of memory-based (pantomime) reaches distinguished by gaze anchoring in reach-to-grasp tasks.

Comparisons of target-based reaching vs memory-based (pantomime) reaching have been used to obtain insight into the visuomotor control of reaching. The present study examined the contribution of gaze anchoring, reaching to a target that is under continuous gaze, to both target-based and memory-based reaching. Participants made target-based reaches for discs located on a table or food items located on a pedestal or they replaced the objects.

Long- but not short-term tool-use changes hand representation.

Tool-use has been found to change body representation. For example, participants who briefly used a mechanical grabber to pick up objects perceived their forearms to be longer immediately after its use (e.g.

Bimanual joint action: correlated timing or "bimanual" movements accomplished by two people.

A crew of two rowing together in perfect synchrony is an example of a task that requires each performer to maintain meticulous timing when coordinating their movements with the other. At the individual level, temporal coordination of the limbs has been observed in bimanual pointing movements even when made to targets of different distance. Timing of the arms is not independent; rather there is a natural temporal coupling.

Complexity of movement preparation and the spatiotemporal coupling of bimanual reach-to-grasp movements.

There is a movement preparation cost for bimanual asymmetric reaching movements compared to bimanual symmetric movements. This is likely caused by the complex spatiotemporal coupling of bimanual asymmetric movements. The spatiotemporal coupling of bimanual reach-to-grasp movements has been investigated, but not the potential movement preparation costs.

Gaze anchoring guides real but not pantomime reach-to-grasp: support for the action-perception theory.

Reach-to-grasp movements feature the integration of a reach directed by the extrinsic (location) features of a target and a grasp directed by the intrinsic (size, shape) features of a target. The action-perception theory suggests that integration and scaling of a reach-to-grasp movement, including its trajectory and the concurrent digit shaping, are features that depend upon online action pathways of the dorsal visuomotor stream. Scaling is much less accurate for a pantomime reach-to-grasp movement, a pretend reach with the target object absent.

The quality of placebos used in randomized, controlled trials of lumbar and pelvic joint thrust manipulation-a systematic review.

Background Context: Spinal manipulative therapy (SMT) has been attributed with substantial non-specific effects. Accurate assessment of the non-specific effects of SMT relies on high-quality studies with low risk of bias that compare with appropriate placebos.

Purpose: This review aims to characterize the types and qualities of placebo control procedures used in controlled trials of manually applied, lumbar and pelvic (LP)-SMT, and to evaluate the assessment of subject blinding and expectations.

The Effects of Music Salience on the Gait Performance of Young Adults.

Background: The presence of a rhythmic beat in the form of a metronome tone or beat-accentuated original music can modulate gait performance; however, it has yet to be determined whether gait modulation can be achieved using commercially available music.

Objective: The current study investigated the effects of commercially available music on the walking of healthy young adults. Specific aims were (a) to determine whether commercially available music can be used to influence gait (i.

Relationship between chiropractic teaching institutions and practice characteristics among Canadian doctors of chiropractic: a random sample survey.

Objective: The objectives of this study were to determine if faction membership among Canadian doctors of chiropractic (DCs) is associated with differences in educational program characteristics among English-speaking Canadian and United States chiropractic colleges and to determine if those differences are expressed in terms of surveyed attitudes and behaviors regarding treatment efficacy, radiographic imaging, vaccinations, and interprofessional referrals. This study also aims to identify if educational programs may be a potential source of multiple professional identities.

Methods: A randomly selected sample of Canadian DCs, stratified across the English-speaking provinces, was surveyed by mail.

Manual asymmetries in the kinematics of a reach-to-grasp action.

In the present study, we manipulated the perceived demand of an ecologically valid task to investigate the possible presence of manual asymmetries in a reach-to-grasp action. Participants reached, grasped and sipped from a water glass under low (nearly empty) and high (nearly full) demand conditions. Participants reached to grasp in closed-loop, open-loop and delay visual conditions.

Work activities and musculoskeletal discomforts amongst active older Albertans on alternative employment trajectories.

Background: Bridge employment (scheduled paid work after retirement age) may promote successful aging and continued health, as work can be an important component of daily physical activity. Appropriate work demands for older adults are neither well-established nor well-applied, however, and excessive loading or increased perceptions of discomfort may negate the health benefits of work activity.

Objective: This study examined work status and musculoskeletal discomfort (MSD) amongst older Albertans.

Obstacle Avoidance amongst Parkinson Disease Patients Is Challenged in a Threatening Context.

We examined whether people with Parkinson disease (PD) have difficulty negotiating a gait obstruction in threatening (gait path and obstacle raised above floor) and nonthreatening (gait path and obstacle at floor level) contexts. Ten PD patients were tested in both Meds OFF and Meds ON states, along with 10 age-matched controls. Participants completed 18 gait trials, walking 4.

Oral hapsis guides accurate hand preshaping for grasping food targets in the mouth.

Preshaping the digits and orienting the hand when reaching to grasp a distal target is proposed to be optimal when guided by vision. A reach-to-grasp movement to an object in one's own mouth is a natural and commonly used movement, but there has been no previous description of how it is performed. The movement requires accuracy but likely depends upon haptic rather than visual guidance, leading to the question of whether the kinematics of this movement are similar to those with vision or whether the movement depends upon an alternate strategy.

Changes in postural sway frequency and complexity in altered sensory environments following whole body vibrations.

Studies assessing whole body vibration (WBV) have produced largely positive effects, with some neutral, on postural control with frequencies between 25 and 40 Hz. However no conclusive evidence indicates that 25-40 Hz elicits the optimal beneficial effects. To address this issue, a larger range of vibration intensity (10-50 Hz at peak-to-peak amplitudes of 2 and 5mm) was employed while increasing the postural complexity (altered somatosensory and/or visual information) to assess acute effects of 4-min of WBV on postural control.

Hand shaping using hapsis resembles visually guided hand shaping.

The reach-to-grasp movement is composed of a number of movement elements including hand transport, hand shaping, and grasping. These movement elements are featured in grasping when it is guided by vision, when it is guided by haptic input from the non-reaching hand or other body parts, and when it is guided by off-line perceptual (remembered) knowledge. An unanswered question is how is the reach-to-grasp movement achieved when all information about the target must be acquired by the grasping hand? The answer to this question was obtained by asking participants to reach for three randomly presented food items that varied in size: an orange slice, a small round donut ball, or a blueberry.

Walking with music is a safe and viable tool for gait training in Parkinson's disease: the effect of a 13-week feasibility study on single and dual task walking.

This study explored the viability and efficacy of integrating cadence-matched, salient music into a walking intervention for patients with Parkinson's disease (PD). Twenty-two people with PD were randomised to a control (CTRL, n = 11) or experimental (MUSIC, n = 11) group. MUSIC subjects walked with an individualised music playlist three times a week for the intervention period.

Challenging context affects standing reach kinematics among Parkinson's disease patients.

The standing reach movement requires coordinated activation of postural and focal motor responses. For PD patients, both components of this reaching task exhibit evidence of motor deficit. In the present experiment, we examined these motor responses during a standing reaching task in a challenging environmental context.

Novel challenges to gait in Parkinson's disease: the effect of concurrent music in single- and dual-task contexts.

Objective: To investigate the effect of concurrent music on parkinsonian gait in single- and dual-task contexts.

Design: A counterbalanced repeated-measure design.

Setting: A university balance research laboratory.

Bilateral impairments of skilled reach-to-eat in early Parkinson's disease patients presenting with unilateral or asymmetrical symptoms.

Previous studies have described limb and hand movement abnormalities in a reach-to-eat task in advanced Parkinson's disease (PD) and animal models of PD. The present study was directed toward examining reach-to-eat movements in early PD patients untreated with medication, along with a follow-up examination of a PD patient sub-group who were treated with a symptomatically stable dosage of dopamine replacement. Analysis of the reach-to-eat movement was made using blinded assessment under a validated scoring system, and comparisons were made on the total reach score and reach sub-component scores.

Parkinsonian deficits in context-dependent regulation of standing postural control.

This study explored whether patients with Parkinson's disease alter the regulation of upright standing according to constraints imposed by the environmental context. The provision of context-dependent adaptations was inferred from the presence of adjustments to standing postural control that would serve to reduce fall risk when balance was challenged by a threatening environmental context. Participants were asked to stand as still as possible in two environmental context conditions that differed in the level of imposed postural threat: LOW threat and HIGH threat.

The effect of anxiety on the regulation of upright standing among younger and older adults.

We tested the hypothesis that fall anxiety would differentially influence the regulation of upright standing among younger and among older adults. Fall anxiety was imposed by a manipulation of environmental context that increased the threat to postural control by introducing the potential for injurious consequences should a fall occur. Fifteen younger and 15 older adults participated in this study.

Parkinsonian deficits in sensory integration for postural control: temporal response to changes in visual input.

This study investigated the effect of Parkinson's disease (PD) on the time course for postural control following the removal and reinsertion of visual information. Twelve medicated PD patients (PD) and 12 age matched control (CTRL) subjects performed two 45-s quiet standing trials, during which visual feedback was available (0-15s), deprived (15-30s), and then restored (30-45s). The 45s test trial was divided into 5s time bins to compare the time-based effect of sensory reorganization during deprivation and reintegration.

Age-dependent differences in the time course of postural control during sensory perturbations.

Background And Aims: With research demonstrating that older adults are more likely to sustain a loss of balance than younger adults, the need for an account of age-related differences in postural control is apparent. Several measures of balance reported in the literature have assessed balance using an average or summative measure over the course of a trial, typically lasting several seconds. One limitation related to these measures is the inability to assess the time-course of postural control occurring throughout the trial.

Age-dependent differences in the attentional demands of obstacle negotiation.

Background: Although the attention directed to gait does increase as an impending obstacle nears, it remains unclear whether the allocation of attentional resources differs between the precrossing phase of obstacle negotiation and the crossing phase of this task. This study compared the attentional demands associated with steady-state walking and the precrossing and crossing phases of an obstacle-negotiation task between young and older adults.

Methods: Fifteen younger and 15 older adults participated in this study.