Remote centre-of-motion control algorithms of 6-RRCRR parallel robot assisted surgery system (PRAMiSS)

In this paper a 6-RRCRR parallel robot assisted minimally invasive surgery/microsurgery system (PRAMiSS) is introduced. Remote centre-of-motion (RCM) control algorithms of PRAMiSS suitable for minimally invasive surgery and microsurgery are also presented. The programmable RCM approach is implemented in order to achieve manipulation under the constraint of moving through the fixed penetration point. Having minimised the displacements of the mobile platform of the parallel micropositioning robot, the algorithms also apply orientation constraint to the instrument and prevent the tool tip to orient due to the robot movements during the manipulation. Experimental results are provided to verify accuracy and effectiveness of the proposed RCM control algorithms for minimally invasive surgery.

Capture, hold, release: an ontology of motion capture

In proposing an ontology of motion capture, this paper identifies three modalities — capture, hold, release — to conceptualise the peculiar affordances of motion capture technology in its relationship to a performer's movement. Motion capture is unique among contemporary moving image media in its capacity to re-perform a performer'srecorded movement a potentially limitless number of times, e.g. as applied to innumerable different CG characters. Unlike live-action film or even rotoscoping (motion capture's closest equivalent), the movement extracted from the captured performance lives on, but only by way of the inimagable (non-visible) domain of motion data.Motion data 'holds' movement itself in inimagable form, and 'releases' it in the domain of the digital moving image. This tri-fold conception relates an important dimension of (Heideggerian) Being to the idea of movement as fundamental to an ontology or 'being' of motion capture. At the same time, the proposed ontology challenges the 'illusion of life' metaphor as the accepted definition of (motion capture) animation.The Oscar's Special Rules for the Animated Feature Film Award asserts that 'by itself' motion capture does not qualify as an animation method. The notion that a technology could do or be anything 'by itself' affords a conceptual leap toward Heideggerian thinking on the nature of Being as embodied in temporality, in which past, present and future are unified.In its capacity to operate outside the domain of the digital moving image, the concept of 'movement itself' not only articulates an ontology of motion capture: motion capture itself can be understood to be brought into being by movement, thus also challenging the notion that capture technology has a parasitic relationship to a performer's originary performance.

Her Majesty moves: Sarah Bernhardt, Queen Elizabeth and the development of motion pictures

Sarah Bernhardt, the greatest theatrical star of the late nineteenth century, enabled and even promoted the association of early film with the British monarchy. She did this literally, by playing the role of Queen Elizabeth in Queen Elizabeth (Les Amours de la Reine Elisabeth, Henri Desfontaines and Louis Mercanton, 1912). Bernhardt also promoted the association of the cinema with monarchy symbolically, making the medium a new empathetic vehicle for the development of celebrity mystique and global power.

A randomised trial of the Flinders Program to improve patient self-management competencies in a range of chronic conditions : study rationale and protocol

Background: Supporting self management is seen as an important health service strategy in dealing with the large and increasing health burden of chronic conditions. Several types of self-management programs are available. Evidence to date suggests that disease specific and lay-led self management programs provide only part of the support needed for improved outcomes. The Flinders Program is promising as a generic self management intervention, which can be combined with targeted disease specific and lay-led interventions, but it has yet to be evaluated for a range of chronic conditions using a rigorous controlled trial design. This paper gives the rationale for a randomised controlled trial and process evaluation of the Flinders Program of chronic condition self-management in community practice, and details and justifies the design of such a study.Method: The design for a randomised trial and associated process evaluation, suited to evaluation of a complex and behavioural intervention as it is applied in actual practice, is presented and justified.Conclusion: A randomised trial of the Flinders Program is required and a functional design is presented. Results from this trial, currently underway, will test the effectiveness of the Flinders Program in improving patient competencies in self-management of chronic conditions in practice conditions. A process evaluation alongside the trial will explore system, provider and patient factors associated with greater and lesser Program effectiveness.

Similar prevalence of acetabular labral tear in professional ballet dancers and sporting participants

OBJECTIVE: To compare the prevalence of acetabular labral tear in male and female professional ballet dancers with age-matched and sex-matched sporting participants and to determine the relationship to clinical findings and cartilage defects. DESIGN: Case-control study. SETTING: Clinical and radiology practices. PARTICIPANTS: Forty-nine (98 hips) male and female professional ballet dancers (current and retired) with median age 30 years (range: 19-64 years) and 49 (98 hips) age-matched and sex-matched sporting participants. INDEPENDENT VARIABLES: Group (ballet or sports), sex, age, hip cartilage defects, history of hip pain, Hip and Groin Outcome Score, passive hip internal rotation (IR), and external rotation range of movement (ROM). MAIN OUTCOME MEASURES: Labral tear identified with 3T magnetic resonance imaging (MRI). RESULTS: Labral tears were identified in 51% of all 196 hips. The prevalence did not differ significantly between the ballet and sporting participants (P = 0.41) or between sexes (P = 0.34). Labral tear was not significantly associated with clinical measures, such as pain and function scores or rotation ROM (P > 0.01 for all). Pain provocation test using IR at 90° of hip flexion had excellent specificity [96%, 95% confidence intervals (CIs), 0.77%-0.998%] but poor sensitivity (50%, 95% CI, 0.26%-0.74%) for identifying labral tear in participants reporting hip pain. Older age and cartilage defect presence were independently associated with an increased risk of labral tear (both P < 0.001). CONCLUSIONS: The prevalence of labral tear in male and female professional ballet dancers was similar to a sporting population. Labral tears were not associated with clinical findings but were related to cartilage defects, independent of aging. CLINICAL RELEVANCE: Caution is required when interpreting MRI findings as labral tear may not be the source of the ballet dancer's symptoms.

Canadian Society for Exercise Physiology position stand : the use of instability to train the core in athletic and nonathletic conditioning

The use of instability devices and exercises to train the core musculature is an essential feature of many training centres and programs. It was the intent of this position stand to provide recommendations regarding the role of instability in resistance training programs designed to train the core musculature. The core is defined as the axial skeleton and all soft tissues with a proximal attachment originating on the axial skeleton, regardless of whether the soft tissue terminates on the axial or appendicular skeleton. Core stability can be achieved with a combination of muscle activation and intra-abdominal pressure. Abdominal bracing has been shown to be more effective than abdominal hollowing in optimizing spinal stability. When similar exercises are performed, core and limb muscle activation are reported to be higher under unstable conditions than under stable conditions. However, core muscle activation that is similar to or higher than that achieved in unstable conditions can also be achieved with ground-based free-weight exercises, such as Olympic lifts, squats, and dead lifts. Since the addition of unstable bases to resistance exercises can decrease force, power, velocity, and range of motion, they are not recommended as the primary training mode for athletic conditioning. However, the high muscle activation with the use of lower loads associated with instability resistance training suggests they can play an important role within a periodized training schedule, in rehabilitation programs, and for nonathletic individuals who prefer not to use ground-based free weights to achieve musculoskeletal health benefits.

Ice and pulsed electromagnetic field to reduce pain and swelling after distal radius fractures

Objective: To examine the relative effectiveness of ice therapy and/or pulsed electromagnetic field in reducing pain and swelling after the immobilization period following a distal radius fracture.Methods: A total of 83 subjects were randomly allocated to receive 30 minutes of either ice plus pulsed electromagnetic field (group A); ice plus sham pulsed electromagnetic field (group B); pulsed electromagnetic field alone (group C), or sham pulsed electromagnetic field treatment for 5 consecutive days (group D). All subjects received a standard home exercise programme. A visual analogue scale was used for recording pain; volumetric displacement for measuring the swelling of the forearm; and a hand-held goniometer for measuring the range of wrist motions before treatment on days 1, 3 and 5.Results: At day 5, a significantly greater cumulative reduction in the visual analogue scores as well as ulnar deviation range of motion was found in group A than the other 3 groups. For volumetric measurement and pronation, participants in group A performed better than subjects in group D but not those in group B.Conclusion: The addition of pulsed electromagnetic field to ice therapy produces better overall treatment outcomes than ice alone, or pulsed electromagnetic field alone in pain reduction and range of joint motion in ulnar deviation and flexion for a distal radius fracture after an immobilization period of 6 weeks.

No difference in 1RM strength and muscle activation during the barbell chest press on a stable and unstable surface

Exercise or Swiss balls are increasingly being used with conventional resistance exercises. There is little evidence supporting the efficacy of this approach compared to traditional resistance training on a stable surface. Previous studies have shown that force output may be reduced with no change in muscle electromyography (EMG) activity while others have shown increased muscle EMG activity when performing resistance exercises on an unstable surface. This study compared 1RM strength, and upper body and trunk muscle EMG activity during the barbell chest press exercise on a stable (flat bench) and unstable surface (exercise ball). After familiarization, 13 subjects underwent testing for 1RM strength for the barbell chest press on both a stable bench and an exercise ball, each separated by at least 7 days. Surface EMG was recorded for 5 upper body muscles and one trunk muscle from which average root mean square of the muscle activity was calculated for the whole 1RM lift and the concentric and eccentric phases. Elbow angle during each lift was recorded to examine any range-of-motion differences between the two surfaces. The results show that there was no difference in 1RM strength or muscle EMG activity for the stable and unstable surfaces. In addition, there was no difference in elbow range-of-motion between the two surfaces. Taken together, these results indicate that there is no reduction in 1RM strength or any differences in muscle EMG activity for the barbell chest press exercise on an unstable exercise ball when compared to a stable flat surface. Moreover, these results do not support the notion that resistance exercises performed on an exercise ball are more efficacious than traditional stable exercises.

Muscle damage and inflammation during recovery from exercise

Unaccustomed exercise consisting of eccentric (i.e., lengthening) muscle contractions often results in muscle damage characterized by ultrastructural alterations in muscle tissue, clinical signs and symptoms (e.g., reduced muscle strength and range of motion, increased muscle soreness and swelling, efflux of myocellular proteins). The time course of recovery following exercise-induced muscle damage depends on the extent of initial muscle damage, which in turn is influenced by the intensity and duration of exercise, joint angle/muscle length and muscle groups used during exercise. The effects of these factors on muscle strength, soreness and swelling are well characterized. By contrast, much less is known about how they affect intramuscular inflammation and molecular aspects of muscle adaptation/remodeling. Although inflammation has historically been viewed as detrimental for recovery from exercise, it is now generally accepted that inflammatory responses-if tightly regulated-are integral to muscle repair and regeneration. Animal studies have revealed that other cell types including mast cells, eosinophils, CD8 and T regulatory lymphocytes, fibro-adipogenic progenitors and pericytes also help to facilitate muscle tissue regeneration. However, more research is required to determine whether these cells respond to exercise-induced muscle damage. A large body of research has investigated the efficacy of physicotherapeutic, pharmacological and nutritional interventions for reducing the signs and symptoms of exercise-induced muscle damage, with mixed results. More research is needed to examine if/how these treatments influence inflammation and muscle remodeling during recovery from exercise.

The effects of military body armour on trunk and hip kinematics during performance of manual handling tasks

Musculoskeletal injuries are reported as burdening the military. An identified risk factor for injury is carrying heavy loads; however, soldiers are also required to wear their load as body armour. To investigate the effects of body armour on trunk and hip kinematics during military-specific manual handling tasks, 16 males completed 3 tasks while wearing each of 4 body armour conditions plus a control. Three-dimensional motion analysis captured and quantified all kinematic data. Average trunk flexion for the weightiest armour type was higher compared with control during the carry component of the ammunition box lift (p < 0.001) and sandbag lift tasks (p < 0.001). Trunk rotation ROM was lower for all armour types compared with control during the ammunition box place component (p < 0.001). The altered kinematics with body armour occurred independent of armour design. In order to optimise armour design, manufacturers need to work with end-users to explore how armour configurations interact with range of personal and situational factors in operationally relevant environments. Practitioner Summary: Musculoskeletal injuries are reported as burdening the military and may relate to body armour wear. Body armour increased trunk flexion and reduced trunk rotation during military-specific lifting and carrying tasks. The altered kinematics may contribute to injury risk, but more research is required.

On the perceived location of global motion

We measured the effects of coherent motion of one set of dots on the perceived location of Gaussian envelopes formed by luminance modulation of a second set of dots. Perceived shifts in envelope location in the direction of coherent motion were obtained even when the dots forming the envelopes did not physically move in the direction of coherent motion. In such cases, perceived shifts coincided with stimulus configurations that permitted motion integration of the envelope dots with the coherently moving dots, for example, when envelope dots moved in random directions as opposed to being static. In subsequent experiments we explored the type of motion integration underlying the positional shifts obtained. We discounted the possibility that the visual system incorrectly attributes motion signals associated with coherently moving dots to envelope dots by demonstrating that positional shifts could be obtained even when the coherent dots were laterally displaced to either side of the envelope dots such that the regions occupied by the dots did not overlap. We also discounted spatio-temporal summation within the receptive fields of low-spatial-frequency motion-sensitive mechanisms by demonstrating that positional shifts persisted even when the dot displays were high-pass filtered. These results, coupled with the observation that the proportion of coherently moving dots required to produce positional shifts correlated well with global motion thresholds measured for the same dot configurations, suggests that visual processes which underlie motion-dependent positional shifts are based at least in part on cooperative interactions of the type implicated in global motion.