Standard FFT-based turbulent phase screen generation method has very large errors due to the undersampling of the low frequency components. Subharmonic methods are the main low frequency components compensating methods to improve the accuracy, but the residual errors are still large. In this paper I propose a new low frequency ...

When humans use vision to gauge the travel distance of an extended forward movement, they often underestimate the movement's extent. This underestimation can be explained by leaky path integration, an integration of the movement to obtain distance. Distance underestimation occurs because this integration is imperfect and contains a leak that ...

This study explored the effect of TV size, illumination, and viewing angle on preferred viewing distance in high-definition liquid crystal display televisions (HDTV). Results showed that the mean preferred viewing distance was 2856 mm. TV size and illumination significantly affected preferred viewing distance. The larger the screen size, the greater the ...

Organic light-emitting diodes (OLEDs) have attracted great attention because of their potential applications in full-color displays and solid-state lights. In the continual effort to search for ideal materials for OLEDs, small molecules with bipolar transporting character are extremely attractive as they offer the possibility to achieve efficient and stable OLEDs ...

Nitric oxide (NO) can induce apoptosis (programmed cell death) at micromolar or higher doses. Although cell death via NO-induced apoptosis has been studied quite extensively, the targeted delivery of such doses of NO to infected or malignant tissues has not been achieved. The primary obstacle is indiscriminate NO release from ...

Citation information: Leung T-W, Flitcroft DI, Wallman J, Lee TH, Zheng Y, Lam CS-Y & Kee C-S. A novel instrument for logging nearwork distance. Ophthalmic Physiol Opt 2011, 31, 137-144. doi: 10.1111/j.1475-1313.2010.00814.x ABSTRACT: Purpose:  To validate a novel ultrasonic sensor for logging reading distances. In addition, this device was used ...

In this paper, two new organic light emitting diodes in near infrared (NIR) range were fabricated based on acceptor-donor-acceptor (A-D-A) and donor-acceptor-donor (D-A-D) oligomers. We found that, the electroluminescent (EL) spectra of these oligomers which have the wavelength range from 900 to 1150 nm. The maximum external quantum efficiencies (EQE) ...

Shoulder impingement is a common condition presumed to contribute to rotator cuff disease. Impingement can occur externally with the coracoacromial arch or internally with the glenoid rim. Normal scapulothoracic motions that occur during arm elevation include upward rotation, posterior tilting, and either internal or external rotation. These scapulothoracic motions and ...

Enhanced white-light emission was achieved by loading green- and red-light-emitting donor-acceptor pairs in the separate micellar cores and blue-light-emitting polymers around their periphery. Fluorescence resonance energy transfer was enabled between a donor and an acceptor in cores, but was suppressed among these three light-emitting species by micellar coronas, which resulted ...

It was the purpose of our study to examine the kinematics of the pelvis and torso and determine their relationship to the kinematics of the shoulder in high-school baseball pitchers. A single group, repeated-measures design was used to collect pelvis, torso, and shoulder kinematics throughout the pitching motion. Subjects threw ...

Measuring the motion of the scapula and humerus with sub-millimeter levels of accuracy in six-degrees-of-freedom (6-DOF) is a challenging problem. The current methods to measure shoulder joint motion via the skin do not produce clinically significant levels of accuracy. Thus, the purpose of this study was to validate a non-invasive ...

There is an assumption that baseball athletes who reside in warm-weather climates experience larger magnitude adaptations in throwing shoulder motion and strength compared with their peers who reside in cold-weather climates. (1) The warm-weather climate (WWC) group would exhibit more pronounced shoulder motion and strength adaptations than the cold-weather climate ...

The aim of this study was to evaluate two methods of clinical assessment for external rotation of the shoulder to optimise the diagnosis of hyperlaxity in patients being selected for surgery for stabilisation of chronic anterior instability. External rotation was evaluated in 70 healthy student volunteers by two examiners (intertester ...

Abnormal scapular movement is widely believed to be an important factor in clinical pathology of the shoulder joint complex. Validated non-invasive techniques for measuring scapular movement have been developed, but the effect of marker placement on accuracy is unknown. The objective of this study was to determine the accuracy and ...

Purpose. The purpose of this study was to describe horizontal and vertical translation of the elbow and elbow angle in two planes and three speeds during manual wheelchair overground propulsion in individuals with tetraplegia. Methods. Seven individuals with tetraplegia who used manual wheelchairs wheeled overground at three different speeds were recruited for ...

We hypothesize that an anatomic repair of the distal biceps tendon would recreate native tendon moment arm and forearm rotation, while a nonanatomic insertion would compromise moment arm and forearm rotation. Isometric supination torque was measured at 60° of pronation, neutral, and 60° of supination for the native distal biceps ...

The so-called anxiolytic and anxiogenic drugs are considered to cause, respectively, increases and decreases in plus-maze open arm exploration, without modifying locomotor activity occurring in the closed arms in an elevated plus-maze when the animals are tested in an illuminated environment. Simply testing animals in the dark also increases open ...

Impaired motor control of the upper extremity after stroke may be related to lost sensory, motor, and integrative functions of the brain. Artificial activation of sensory afferents might improve control of movement by adding excitatory drive to sensorimotor control structures. The authors evaluated the effect of wrist tendon vibration (TV) ...

The purpose of this experiment was to examine upper-body bench throw performance during tests that specifically target different aspects of functional performance. A pool of 26 male, semi-professional rugby league players (age: 23 ± 3 years, height: 180.8 ± 5.6 cm, mass: 95.7 ± 13.0 kg, estimated 1 repetition maximum ...

A variety of laser or light-based devices have been developed for skin rejuvenation. This study evaluates the efficacy (at the microscopic level) of a combination of pneumatic energy, broadband light, and profusion tip-delivered epidermal growth factor (EGF). Healthy adult Japanese volunteers were recruited for this study. The posterior parts of ...

OBJECTIVE: To explore manual wheelchair propulsion strategies for ramp ascent and descent in snow and snow-ice-grit conditions. DESIGN: Cross-sectional study. SETTING: Climatic Engineering and Testing Chamber (Ottawa, Canada). PARTICIPANTS: Manual wheelchair users (N=11) who typically self-propel their wheelchair in winter. INTERVENTIONS: Ramp ascent and descent at 3 grades (1:10, 1:12, ...

Bilateral interference, referring to the tendency of movements of one arm to disrupt the intended movements made simultaneously with the other arm, is often observed in a task that involves differential planning of each arm movement during sensorimotor adaptation. In the present study, we examined two questions: 1) how does ...

This study examined the joint motions and movement patterns of the kinetic chain in the ballistic skill of performing the windmill pitch. Seventeen healthy girls who were currently playing competitive fast-pitch softball volunteered for the study. Subjects were instructed to perform 5 successful fastball windmill style deliveries. We selected 1 ...

Clinical measurement, reliability. To compare intrarater and interrater reliability of shoulder internal rotation (IR) passive range of motion measurements utilizing a standard supine position and a sidelying position. Glenohumeral IR range of motion deficits are often noted in patients with shoulder pathology. Excellent intrarater reliability has been found when measuring ...

The purposes of this study were (a) to describe the detailed movements of the shoulder complex during the cocking phase in tennis serve and (b) to determine the contribution of the scapular rotation to the peak shoulder external rotation attained at the end of the cocking phase. Twenty tennis players ...

The posterior parietal cortex (PPC) contains viewer-centered spatial maps important for reaching movements. It is known that spatial reaching deficits emerge when this region is damaged, yet less is known about temporal deficits that may also emerge because of a failure in sensory-spatial transformations. This work introduces a new geometric ...

BACKGROUND: The aim of this study was to determine whether immobilization of an arm has detrimental effects on driving performance. METHODS: Thirty-six healthy officers-in-training were assigned a sequence of fiberglass splints (left and right-sided above-the-elbow thumb spica and below-the-elbow splints) with use of a randomized higher-order crossover design. Runs were ...

This study examined the effect of swimming speed on inter-arm coordination and the inter-relationships between swimming speed, inter-arm coordination, and other stroke parameters, in a group of competitive unilateral arm amputee front crawl swimmers. Thirteen highly-trained swimmers were filmed underwater during a series of 25-m front crawl trials of increasing ...

The present study investigated the intrarater reliability, interrater reliability and minimal detectable change at the 90% confidence interval (MDC(90)) of active shoulder range of motion measurements using digital inclinometry. Two investigators each measured two repetitions of active flexion, abduction, external rotation (ER), and internal rotation (IR) on the nondominant shoulder ...

This preliminary study aimed to quantify the magnitude of the peak shoulder distraction force during the bowling action of female cricket fast bowlers. An eight camera Vicon motion analysis system operating at 120 Hz recorded the fast bowling actions of 18 Australian female fast bowlers. A three segment inverse solution ...

The effectiveness of wrist guards and modifying elbow posture for reducing impact-induced accelerations at the wrist and elbow, for the purpose of decreasing upper extremity injury risk during forward fall arrest, has not yet been documented in living people. A seated human pendulum was used to simulate the impact conditions ...

Equifinality, during arm reaching movements, relates to the capacity of the neuromuscular system to attain the same final position in the presence or absence of transient perturbations. There have been several controversies regarding equifinality in the literature. A brief elastic perturbation, applied during a fast arm movement or just before ...

Because the human shoulder has many degrees of freedom that allow redundant means of producing the same net humerothoracic motion, there are many impediments to objective, repeatable assessment of shoulder function in vivo. Devices designed to date have suffered from poor reliability. In this study we introduce a new device ...

Excessive and untimely scapular dyskinesis during the throwing motion has been associated with several shoulder injuries. The scapula provides attachment for many soft tissue structures. Therefore, many have hypothesized that posterior shoulder tightness may alter proper scapular kinematics. As posterior shoulder tightness increases, so will forward scapular posture. Baseball players ...

Among hypnotized subjects passing a challenge suggestion of arm rigidity, how might patterns of motor activity (strategies) contribute to the illusion that the elbow cannot be bent? Kinematic analyses of upper limb and trunk were performed. Nonhypnotized subjects carefully enacted a set of prescribed strategies typifying responses possibly adopted by ...

The clinical use of digital levels, for joint measurement, may be a viable alternative to standard goniometry. The purpose of this study was to determine the intra- and intertester reliability of a construction grade digital level compared to the standard universal goniometer for measurements for active assisted shoulder range of ...

Despite the infinitely many ways to grasp a spherical object, regularities have been observed in the posture of the arm and the grasp orientation. In the present study, we set out to determine the factors that predict the grasp orientation and the final joint angles of reach-to-grasp movements. Subjects made ...

The purpose of this study was to compare the forces and moments of the whole upper limb, analyzing forces and moments at the shoulder, elbow and wrist joints simultaneously during manual wheelchair propulsion of persons with different levels of spinal cord injury (SCI) on a treadmill. Fifty-one people participated in ...

A case of a patient with glenohumeral joint arthritis is presented which demonstrated the three-dimensional shoulder motion before and after total shoulder arthroplasty. Pre-operative shoulder motion differed compared to normal controls, while post-operatively her glenohumeral-to-scapulothoracic motion ratios were restored to near normal ratios.

Recent studies of position-related proprioceptive sense have provided evidence of a nonpreferred left arm advantage in right-handed individuals. The present study sought to determine whether similar asymmetries might exist in "dynamic position" sense. Thirteen healthy, right-handed adults were blindfolded and seated with arms placed on instrumented manipulanda. In Part 1, ...

The speed of arm movements is normally increased by increasing agonist muscle activity, but in overarm throwing, an additional effect on speed may come from exploitation of interaction torques (a passive torque associated with motion at adjacent joints). We investigated how the central nervous system (CNS) controls interaction torques at ...

In this article, we outline a method for computing Achilles tendon moment arm. The moment arm is computed from data collected using two reliable measurement instruments: ultrasound and video-based motion capture. Ultrasound is used to measure the perpendicular distance from the surface of the skin to the midline of the ...

CONTEXT: Pathologies such as anterior instability and impingement are common in baseball and have been linked to decreases in internal rotation (IR) and concurrent increases in external rotation (ER). In addition, alterations to scapular position have been identified in this population, but the chronology of these adaptations is uncertain. OBJECTIVES: ...

It is well known that circadian rhythms modulate human physiology and behavior at various levels. However, chronobiological data concerning mental and sensorimotor states of motor actions are still lacking in the literature. In the present study, we examined the effects of time-of-day on two important aspects of the human motor ...

BACKGROUND: During the pitching motion, velocity is generated by the upper extremity kinetic chain on internal rotation of the shoulder and trunk translational/rotational motion. This generation of power places significant forces and torques on the elbow and shoulder. Elbow valgus torque and shoulder rotational torque are theoretically linked to elbow ...

Voluntary adduction-abduction movements of one arm in the horizontal plane discharge a reaction torque which would rotate the trunk in the direction opposite to arm acceleration. Rotation is impeded by muscular fixation chains that exert forces counterbalancing the reaction torque. We examined how two different fixation chains cooperate in stabilising ...

The control of wrist rotations is critical for normal upper limb function, yet has received little attention. In this study, we characterized path shape of wrist rotations in order to better understand the biomechanical and neural factors governing their control. Subjects performed step-tracking wrist rotations in eight directions "at a ...

BACKGROUND: The amount of the olecranon that can be removed without substantially affecting the kinematics and stability of the elbow is controversial. The purpose of this study was to determine the effect of serial resections of the olecranon on elbow kinematics and stability. METHODS: Eight fresh, previously frozen cadaver arms ...

HYPOTHESIS: A recent ultrasound study has shown that impingement phenomenon was observed in healthy shoulders. We hypothesized that nonpathologic contact beneath the coracoacromial arch occurs in normal shoulders. MATERIALS AND METHODS: Seven fresh-frozen cadaveric shoulders were studied. Each specimen was attached to a custom-designed shoulder-positioning device. A 22-N force was ...

During everyday locomotion we encounter a range of obstacles which require specific motor responses, for example a narrow aperture forces us to rotate the shoulders to pass through. Research has demonstrated that the decision to rotate the shoulders is body scaled (Warren & Whang, 1987) and that the visuo-motor system ...