The Effect of Red and Blue on Gross and Fine Motor Tasks: Confirming the Inverted-U Hypothesis

Previous studies have shown that the color red can affect basic motor functioning. However, these studies utilized simple gross motor tasks rather than those assessing complex fine motor skills. Moreover, these empirical studies were theoretically based on the threat–behavior link in human and non-human animals, and neglected the relationship between arousal and motor performance. According to the Yerkes–Dodson law and the inverted-U hypothesis in sport psychology, for simple motor tasks, high arousal (associated with the color red) is more advantageous than low arousal (associated with the color blue); for complex motor tasks, low arousal (blue color) is more advantageous than high arousal (red color). The current research examined the effect of color on different kinds of motor skills (fine motor and gross motor) based on the inverted U-hypothesis. In Experiment 1, we examined the effect of red and blue on dart-throwing performance, whereas in Experiment 2, we examined the effect of red and blue on grip strength performance. The results showed that performance of fine motor skill (dart-throwing) in the blue condition was better than in the red condition, and performance of gross motor skill (handgrip) in the red context was better than in the blue context. These results indicate that the type of motor skill assessed moderates the influence of red and blue on motor performance.

Corticospinal Excitability of the Lower Limb Muscles During the Anticipatory Postural Adjustments: A TMS Study During Dart Throwing

Objective: To investigate whether the changes in the corticospinal excitability contribute to the anticipatory postural adjustments (APAs) in the lower limb muscles when performing the ballistic upper limb movement of the dart throwing.Methods: We examined the primary motor cortex (M1) excitability of the lower limb muscles [tibialis anterior (TA) and soleus (SOL) muscles] during the APA phase by using transcranial magnetic stimulation (TMS) in the healthy volunteers. The surface electromyography (EMG) of anterior deltoid, triceps brachii, biceps brachii, TA, and SOL muscles was recorded and the motor evoked potential (MEP) to TMS was recorded in the TA muscle along with the SOL muscle. TMS at the hotspot of the TA muscle was applied at the timings immediately prior to the TA onset. The kinematic parameters including the three-dimensional motion analysis and center of pressure (COP) during the dart throwing were also assessed.Results: The changes in COP and EMG of the TA muscle occurred preceding the dart throwing, which involved a slight elbow flexion followed by an extension. The correlation analysis revealed that the onset of the TA muscle was related to the COP change and the elbow joint flexion. The MEP amplitude in the TA muscle, but not that in the SOL muscle, significantly increased immediately prior to the EMG burst (100, 50, and 0 ms prior to the TA onset).Conclusion: Our findings demonstrate that the corticospinal excitability of the TA muscle increases prior to the ballistic upper limb movement of the dart throwing, suggesting that the corticospinal pathway contributes to the APA in the lower limb in a muscle-specific manner.

Music-Assisted Training for Dart Throwing Novices: Post-Training Effects on Heart Rate and Performance Accuracy

While previous research has suggested that lowering athletes’ heart rates can enhance sports performance, it is unknown whether slow-paced music might induce a lower heart rate and thereby improve some types of motor performance. In this study, we investigated the effects of different types of music during dart-throw training on both heart rate and dart-throwing performance in 45 ( M age = 19.7, SD = 0.31 years) novice dart throwers who were randomly assigned to either a Slow Music Group (SMG), a Fast Music Group (FMG), or a Control Group (CG). All participants completed three dart-throwing blocks - Pre-Test, Practice, and Post-Test. During the Practice block, participants practiced dart-throwing with either slow-paced, fast-paced or no music according to their assigned group. We recorded the participants’ heart rates and total dart-throwing accuracy scores during Pre-Test and Post-Test. Music-assisted dart-throw training with slow-paced music was effective in significantly inhibiting a performance-related increase in heart rate and was associated with the greatest dart throwing improvement after training.

PREDICTION OF STOCK RETURNS MAY BE FALLACIOUS: A STOCHASTIC CONFIRMATION OF MALKIEL’S ASSERTION ON DARTBOARD INVESTMENTS

Several studies on portfolio construction reveal that sensible strategies essentially yield the same results as their nonsensical inverted counterparts; moreover, random portfolios managed by Malkiel’s dart-throwing monkey would outperform the cap-weighted benchmark index. Forecasting the future development of stock returns is an important aspect of portfolio assessment. Similar to the ostensible arbitrariness of portfolio selection methods, it is shown that there is no substantial difference between the performances of “best” and “trivial” forecasts - even under euphemistic model assumptions on the underlying price dynamics. A certain significance of a predictor is found only in the following special case: the best linear unbiased forecast is used, the planning horizon is small, and a critical relation is not satisfied.

In Vivo Measurement of Wrist Movements during the Dart-Throwing Motion Using Inertial Measurement Units

Background: This study investigates the dart-throwing motion (DTM) by comparing an inertial measurement unit-based system previously validated for basic motion tasks with an optoelectronic motion capture system. The DTM is interesting as wrist movement during many activities of daily living occur in this movement plane, but the complex movement is difficult to assess clinically. Methods: Ten healthy subjects were recorded while performing the DTM with their right wrist using inertial sensors and skin markers. Maximum range of motion obtained by the different systems and the mean absolute difference were calculated. Results: In the flexion–extension plane, both systems calculated a range of motion of 100° with mean absolute differences of 8°, while in the radial–ulnar deviation plane, a mean absolute difference of 17° and range of motion values of 48° for the optoelectronic system and 59° for the inertial measurement units were found. Conclusions: This study shows the challenge of comparing results of different kinematic motion capture systems for complex movements while also highlighting inertial measurement units as promising for future clinical application in dynamic and coupled wrist movements. Possible sources of error and solutions are discussed.

The Effects of Manipulating Task Difficulty and Feedback Frequency on Children’s Dart Throwing Accuracy and Consistency

In the present study we investigated the effects of manipulating task difficulty (constant vs. progressive difficulty) and frequency of knowledge of results (KR) on the accuracy and consistency of children’s performance of a novel fine motor coordination task (dart throwing). We assigned 69 right-handed physical education (PE) students ( M age = 10.73, SD = 0.89 years) to progressive (PDG) or constant difficulty (CDG) groups. PDG and CDG were each split into three subgroups who received varying KR frequency (100%KR, 50%KR, and 33%KR), creating a total of six groups. We increased difficulty in the PDG by manipulating the distance to the target (2 m, 2.37 m, and 3.56 m), while distance to the target was constant for CDG throughout the experiment (2.37 m). We conducted performance assessments during familiarization (pre-test), acquisition (post-test), and retention (retention testing) learning phases under both normal condition (NC) and a time pressure condition (TPC). Repeated-measures analysis of variance revealed a significant effect of difficulty manipulation on skill learning under both NC and TPC. Further analyses revealed that skill learning was enhanced by progressive difficulty manipulation. However, learning was not affected by KR frequency changes. Progressive difficulty practice enhanced both accuracy and consistency, specifically at retention testing. These results suggest that motor learning in children may be enhanced by practicing with progressive increases in difficulty. PE teachers are encouraged to gradually introduce difficulty levels in motor learning tasks that require high accuracy.

Biomechanical Comparison of Dart-Throw Motions after Partial Wrist Fusions

Background Multiple partial wrist fusions exist for the management of arthritic disease. Limited information is available on their effect on wrist range of motion in the dart-throwing direction of wrist motion, even though it is used in most activities of daily living. Purpose The purpose of this study was to measure the retained motion for different orientations of dart-throwing motion for seven different partial wrist fusions and proximal row carpectomy (PRC). Methods Eight fresh frozen right cadavers were tested with the wrist intact and followed simulated fusions. Fusions were performed using an external fixation technique and included scaphocapitate, scapholunate (SL), capitolunate, radiolunate, radioscapholunate, scaphotrapeziotrapezoid, 4 corner fusion, and PRC. Results In the intact wrist, the average arc of wrist motion with the wrist oriented at 20 degrees away from the flexion-extension axis was significantly larger than at any other orientation of motion. All partial wrist fusions and the PRC had significantly smaller average dart-throw arc of motion compared with intact at an orientation 20 and 25 degrees away from flexion-extension. The SL fusion provided a significantly larger arc of motion than most of the other fusions at most orientations. Conclusion/Clinical Relevance This study provides a comprehensive compilation of the range of motion in a functional plane, “the dart-throw motion,” for limited wrist fusions and PRC. These data provide the clinician with important information that can be used to educate patients regarding expectations after surgery.

Internal Mechanics of a Subject-Specific Wrist in the Sagittal Versus Dart-Throwing Motion Plane in Adult and Elder Models: Finite Element Analyses

Introduction: Most of the wrist motions occur in a diagonal plane of motion, termed the dart-throwing motion (DTM) plane; it is thought to be more stable compared with movement in the sagittal plane. However, the effect of the altered carpus motion during DTM on the stress distribution at the radiocarpal joint has yet to be explored. Aim: To calculate and compare the stresses between the radius and two carpal bones (the scaphoid and the lunate) in two wrist positions, extension and radial extension (position in DTM), and between an adult and an elder model. Methods: A healthy wrist of a 40-year-old female was scanned using Magnetic Resonance Imaging in two wrist positions (extension, radial extension). The scans were transformed into three-dimensional models and meshed. Finite element (FE) analyses in each position of the wrist were conducted for both adult and elder models, which were differentiated by the mechanical properties of the ligaments. The distal surfaces of the carpal bones articulating with the metacarpals were loaded by physically accurate tendon forces for each wrist position. Results: The von Mises, shear stresses and contact stresses were higher in the extension model compared with the radial-extension model and were higher for the radius-scaphoid interface in the adult model compared with the elder model. In the radius-scaphoid interface, the stress differences between the two wrist positions were smaller in the elder model (11.5% to 22.5%) compared with the adult model (33.6–41.5%). During radial extension, the contact area at the radius-lunate interface was increased, more so in the adult model (222.2%) compared with the elder model (127.9%), while the contact area at the radius-scaphoid was not affected by the position of the wrist in the adult model (100.9%) but decreased in the elder model (50.2%) during radial extension. Conclusion: The reduced stresses during radial extension might provide an explanation to our frequent use of this movement pattern, as the reduced stresses decrease the risk of overuse injury. Our results suggest that this conclusion is relevant to both adults and elder individuals.