Dart Thrower Research Articles

The Effect of Priority Assignment the Role of Evaluator and Executive in Collaborative Training on the Acquisition of Kinematic and Accuracy of Dart Throwing Skill

Background: Collaborative training can enhance individual learning, but the effect of role assignment on skill acquisition is unclear. Objectives: Therefore, this study aims to explore the influence of the evaluator and executor roles on the accuracy and kinematic indicators of dart throwing skill. Methods: Forty-eight female university students (mean age = 21.71 ± 1.14 years) participated in the study. Following dart throwing familiarization, participants were randomly assigned to individual group (IG), first-performer (FPG), and first-evaluator groups (FEG) (as a dyad condition) with alternating role orders. All groups completed a pre-test of 10 dart throws while kinematics was recorded via video camera. Practice consisted of 20 blocks of 6 trials (n = 120 physical trials for IG; n = 60 evaluation and n = 60 physical trials for FPG and FEG). Post-tests 1 and 2 directly followed after role reversals for dyads after each 60 trials in the acquisition phase. Accuracy was assessed via mean radial and variable errors. Kinematics (elbow release angle, average angular velocity, elbow range of motion) were analyzed using Kinovea software. Results: A two-way ANOVA revealed the FPG exhibited a significantly smaller release angle compared to IG. However, no significantly differences observed between FEG and IG for kinematic variables. Accuracy improved significantly from pre-to post-test at the three groups. Individual group led to higher accuracy than FPG, and frist-performer group had higher RE than the first-evaluator. Conclusions: The findings of this study support the benefits of observational learning in the early stages of learning. Also, priority assignment the role of evaluator and executive can influences motor performance in a dyadic approach.

Effector-specific improvements in action prediction in left-handed individuals after short-term physical practice

Research has established the influence of short-term physical practice for enhancing action prediction in right-handed (RH) individuals. In addition to benefits of physical practice for these later assessed perceptual-cognitive skills, effector-specific interference has been shown through action-incongruent secondary tasks (motor interference tasks). Here we investigated this experience-driven facilitation of action predictions and effector-specific interference in left-handed (LH) novices, before and after practicing a dart throwing task. Participants watched either RH (n = 19) or LH (n = 24) videos of temporally occluded dart throws, across a control condition and three secondary-task conditions: tone-monitoring, RH or LH force monitoring. These conditions were completed before and after physical practice throwing with the LH. Significantly greater improvement in prediction accuracy was shown post-practice for the LH- versus RH-video group. Consistent with previous work, effector-specific interference was shown, exclusive to the LH-video group. Only when doing the LH force monitoring task did the LH-video group show secondary task interference in prediction accuracy. These data support the idea that short-term physical practice resulted in the development of an effector-specific motor representation. The results are also consistent with other work in RH individuals (showing RH motor interference) and hence rule out the interpretation that these effector specific effects are due to the disruption of more generalized motor processes, thought to be lateralized to the left-hemisphere of the brain.

Evaluation of a cadaveric wrist motion simulator using marker-based X-ray reconstruction of moving morphology.

Surgical intervention is a common option for the treatment of wrist joint arthritis and traumatic wrist injury. Whether this surgery is arthrodesis or a motion preserving procedure such as arthroplasty, wrist joint biomechanics are inevitably altered. To evaluate effects of surgery on parameters such as range of motion, efficiency and carpal kinematics, repeatable and controlled motion of cadaveric specimens is required. This study describes the development of a device that enables cadaveric wrist motion to be simulated before and after motion preserving surgery in a highly controlled manner. The simulator achieves joint motion through the application of predetermined displacements to the five major tendons of the wrist, and records tendon forces. A pilot experiment using six wrists aimed to evaluate its accuracy and reproducibility. Biplanar X-ray videoradiography (BPVR) and X-Ray Reconstruction of Moving Morphology (XROMM) were used to measure overall wrist angles before and after total wrist arthroplasty. The simulator was able to produce flexion, extension, radioulnar deviation, dart thrower's motion and circumduction within previously reported functional ranges of motion. Pre- and post-surgical wrist angles did not significantly differ. Intra-specimen motion trials were repeatable; root mean square errors between individual trials and average wrist angle and tendon force profiles were below 1° and 2 N respectively. Inter-specimen variation was higher, likely due to anatomical variation and lack of wrist position feedback. In conclusion, combining repeatable intra-specimen cadaveric motion simulation with BPVR and XROMM can be used to determine potential effects of motion preserving surgeries on wrist range of motion and biomechanics.

The Effect of Attention Focus on Heart Rate During Dart Throws In Recreation Dart Players

The Heart Rate Variability (HRV), which affects dart shot performance, is an important psycho-physiological parameter in that it provides data on the sympathetic also parasympathetic sections of the Central Nervous System. The purpose of the present study was to examine the effect of Internal and External Attention Foci on Heart Rates during dart shot. A total of 34 students, who were studying at Physical Education Sports Sciences Faculty, participated in the study. According to the t-test results, the HF/LF ratio measured under External Attention focus conditions was higher than the HF/LF ratio measured under Internal Attention conditions. This explains that there is a relationship between autonomic nervous system activity and fine motor skill performance. The heart rate changed according to the attention focus during motor skill (p

O243: The effect of midcarpal fusions on dart thrower’s motion: a cadaveric study

Abstract Introduction Midcarpal osteoarthritis can be managed with several types of partial wrist fusion. Limited information is available regarding their effects on functional movement. Many daily activities require a coupled wrist movement, from radial extension to ulnar flexion, termed dart thrower’s motion (DTM). This study aimed to compare the effect of four different midcarpal fusions on DTM. Methods Twelve fresh-frozen cadaveric specimens were dissected. Sequential loading of tendons into radial extension and ulnar flexion enabled full DTM to be measured using goniometry. Specimens were tested at baseline and following each fusion, performed sequentially using Kirschner wires: (1) scaphocapitate fusion, (2) lunocapitate fusion with scaphoid excision, (3) four-corner fusion with scaphoid excision and (4) three-corner fusion with scaphoid and triquetral excision. A one-way ANOVA and Tukey test established the significance of differences in range of motion. Results Each procedure significantly decreased DTM compared with intact wrists. Scaphocapitate fusion resulted in the smallest mean reduction in movement from 78°–70° (p=0.0014). Four-corner fusion produced the greatest reduction in DTM from 78°–63° (p<0.0001). There was a significant difference in DTM between four-corner and scaphocapitate fusions (p=0.0338). There was no significant difference in the range of postoperative DTM between lunocapitate, three-corner, or four-corner fusions. Conclusion DTM was minimally affected by scaphocapitate fusion and maximally affected by four-corner fusion, with a significant difference seen between these two operations. However, as a 44°–87° range of DTM was maintained for four-corner fusions, this is felt to be adequate for function. These results could aid preoperative decision-making.

The effects of mental fatigue on fine motor performance in humans and its neural network connectivity mechanism: a dart throwing study.

While it is well known that mental fatigue impairs fine motor performance, the investigation into its neural basis remains scant. Here, we investigate the impact of mental fatigue on fine motor performance and explore its underlying neural network connectivity mechanisms. A total of 24 healthy male university students were recruited and randomly divided into two groups: a mental fatigue group (MF) and a control group (Control). Both groups completed 50 dart throws, while electroencephalography (EEG) data were collected. Following the Stroop intervention, participants in the MF group exhibited a decrease in Stroop task accuracy and throwing performance, and an increase in reaction time along with VAS and NASA scores. The EEG data during dart-throwing revealed that the network connectivity strength of theta oscillations in the frontal and left central regions was significantly higher in the MF group compared with the Control group, while the network connectivity strength of alpha oscillations in the left parietal region was significantly enhanced. The interregional connectivity within the theta and alpha rhythm bands, particularly in the frontal-central-parietal network connections, also showed a significant increase in the MF group. Mental fatigue impairs dart throwing performance and is accompanied by increased connectivity in alpha and theta.

Do Different Times of The Day Affect Dart Throwing Performance?

Background: Dart sport has become a sport that has recently become widespread among sports branches and its popularity is increasing rapidly day by day. With this popularization, research on darts is increasing. It is stated that athletes can do the training they do at any time of the day with a much better performance at a different time, as in many changing conditions. In addition, at a different time of day, fatigue may be reached later or recovery may occur more quickly. For these reasons, knowing the effect of training at different times of the day is important for both the coach and the athlete. Objectives: The aim of this study was to investigate the effect of different times of the day on throwing performance in darts, an indoor skill in which focus, attention, concentration are at the forefront and environmental factors are less effective than outdoor skill. Methods: In this study, 16 dart athletes (8 boys, 8 girls) with a sport age of 2 - 3 years and an age of 12 - 14 years, who did not have any health problems in Mardin province, participated voluntarily: 2 m and 2.37 m from two different distances at 8.00 and 17.00, 1 day apart. Before the dart throws, the Daily Rhythm Determination Scale for Children was administered to the participants. The center of the dartboard was placed at eye level for each subject. After the throws, the Perceived Difficulty Scale was applied. In the analysis examining the relationship between perceived degree of difficulty, morningness-eveningness and throwing, the subjects’ evening throwing scores and evening perceived degree of difficulty scores were examined; a negative and significant relationship was observed in the eveningist group (r = -1, P = 0.01). No significant relationship was observed in the morning group. Results: In the study, a statistically significant difference was found between the subjects’ morning and evening throws at 2 m and 2.37 cm. In both morning and evening groups, it was determined that the throwing performance increased in the evening measurements. Conclusions: As a result, this study concluded that there is an effect of time of day in dart sport and that dart throws made in the evening give better results than dart throws made in the morning. Based on these results, it is recommended that a program should be made by the coaches considering the school programs and daily routines to reduce the effect of time of day. It is thought that this study will be important for chronobiological researches to reveal the factors affecting performance as well as the effect of time of day in darts sport.

Quantum Computing with Dartboards.

We present a physically appealing and elegant picture for quantum computing, using rules constructed for a game of darts. A dartboard is used to represent the state space in quantum mechanics, and the act of throwing the dart is shown to have close similarities to the concept of measurement or collapse of the wave function in quantum mechanics. The analogy is constructed in arbitrary dimensional spaces, that is, using arbitrary dimensional dartboards, and for such arbitrary spaces this also provides us a "visual" description of uncertainty. Finally, connections between qubits and quantum computing algorithms are also made, opening the possibility to construct analogies between quantum algorithms and coupled dart throws.

Understanding the biomechanics of the forearm during the dart thrower's motion.

This study investigated the contribution of different forearm muscles, namely the flexor carpi ulnaris, extensor carpi radialis longus and brevis, extensor carpi ulnaris and flexor carpi radialis, during the dart thrower's motion. Thirteen healthy participants were recruited. The forearm muscle activation patterns during the dart thrower's motion were measured using surface electromyography. The average root mean square for the extensor carpi ulnaris was found to be the highest during the dart thrower's motion. Muscle activations during the dart thrower's motion were heterogeneous among the participants. The results suggest the rehabilitation protocol for patients with wrist injuries should be reconsidered.

Clinical measurement of functional dart thrower's motion in patients with unilateral wrist conditions undergoing nonoperative or postoperative hand therapy

Cross-sectional and descriptive study BACKGROUND: Functional dart thrower's motion (F-DTM) is an obliquely oriented wrist motion that occurs in activities such as throwing and drinking from a cup. There is limited data on clinical measurement of F-DTM. The purpose of this study was to 1) describe and establish reference scores for F-DTM measurement for nonoperative and postoperative wrist patients 2) compare F-DTM between the affected and nonaffected sides and 3) determine F-DTM score agreement across three consecutive trials. Two certified hand therapists evaluated F-DTM in consecutive adult patients with a unilateral wrist condition undergoing nonoperative or postoperative therapy. Three trials of goniometer measurements for radial extension (RE) and ulnar flexion (UF) were assessed on the nonaffected and affected wrists. A total arc F-DTM was computed. Mean, 95% confidence intervals (CI), and Cohen's d effect size described side-to-side differences in RE, UF, and total arc F-DTM. Agreement in scores across trials was assessed with an intraclass correlation coefficient (ICC). Thirty-one nonoperative (mean ± SD age=40.0 ± 13.9 years, 74% female, 94% right hand dominant) and 44 postoperative patients (mean ± SD age=44.9 ± 14.9 years, 66% female, 84% right hand dominant) were enrolled. The average side-to-side difference, in degrees, in the nonoperative group was -6.4 (95% CI: -9.4 to -3.4, Cohen's d=0.8) for RE, -10.4 (-16.7 to -4.0, d=0.6) for UF, and -16.8 (-24.3 to -9.2, d=0.8) for total arc F-DTM. The average side-to-side difference in the postoperative group was -33.6 (-38.8 to -28.3, d=1.9) for RE, -34.7 (-40.6 to -28.7, d=1.8) for UF, and -68.2 (-77.9 to -58.5, d=2.1) for total arc F-DTM. The range of ICCs for F-DTM measurements was 0.82-0.96. Goniometer measurement of F-DTM is a clinically feasible method to quantify functional motion loss in an injured wrist population, particularly patients with postoperatively managed wrist conditions.

Do Different Times of The Day Affect Dart Throwing Performance?

ackground: Dart sport has become a sport that has recently become widespread among sports branches and its popularity is increasing rapidly day by day. With this popularization, research on darts is increasing. It is stated that athletes can do the training they do at any time of the day with a much better performance at a different time, as in many changing conditions. In addition, at a different time of day, fatigue may be reached later or recovery may occur more quickly. For these reasons, knowing the effect of training at different times of the day is important for both the coach and the athlete. Objectives: The aim of this study was to investigate the effect of different times of the day on throwing performance in darts, an indoor skill in which focus, attention, concentration are at the forefront and environmental factors are less effective than outdoor skill. Methods: In this study, 16 dart athletes (8 boys, 8 girls) with a sport age of 2 - 3 years and an age of 12 - 14 years, who did not have any health problems in Mardin province, participated voluntarily: 2 m and 2.37 m from two different distances at 8.00 and 17.00, 1 day apart. Before the dart throws, the Daily Rhythm Determination Scale for Children was administered to the participants. The center of the dartboard was placed at eye level for each subject. After the throws, the Perceived Difficulty Scale was applied. In the analysis examining the relationship between perceived degree of difficulty, morningness-eveningness and throwing, the subjects’ evening throwing scores and evening perceived degree of difficulty scores were examined; a negative and significant relationship was observed in the eveningist group (r = -1, P = 0.01). No significant relationship was observed in the morning group. Results: In the study, a statistically significant difference was found between the subjects’ morning and evening throws at 2 m and 2.37 cm. In both morning and evening groups, it was determined that the throwing performance increased in the evening measurements. Conclusions: As a result, this study concluded that there is an effect of time of day in dart sport and that dart throws made in the evening give better results than dart throws made in the morning. Based on these results, it is recommended that a program should be made by the coaches considering the school programs and daily routines to reduce the effect of time of day. It is thought that this study will be important for chronobiological researches to reveal the factors affecting performance as well as the effect of time of day in darts sport.

Virtual Reality based Gaze-sensitive Aiming Task Platform: Role of Attention Allocation in Task Performance for Individuals with Autism and Typically Developing Individuals.

Individuals with Autism Spectrum Disorder (ASD) often exhibit difficulty in movement preparation and allocating attention towards different Regions of Interest (ROIs) of a visual stimulus. Though research has alluded to differences in movement preparation for aiming tasks between individuals with ASD and typically developing (TD) individuals, there is limited evidence (true for near-aiming tasks) on the contribution of the window (i.e., time duration) of movement preparation (i.e., the planning window preceding movement initiation) on one's aiming performance. However, investigation of the contribution of this planning window on one's performance in far-aiming task remains as majorly unexplored. Again, often one's eye movement leads the initiation of hand movement (for task execution) indicating the importance of monitoring one's eye movement in the planning stage, critical for far-aiming task. Most of the studies (in conventional settings) examining the role of gaze behavior on aiming performance have involved TD individuals and only a few involving individuals with ASD. Here, we have designed Virtual Reality (VR)-based Gaze-sensitive far-aiming (dart throw) task and monitored the looking pattern of participants while they interacted with the task environment. We carried out a study with 40 participants (20 in each of ASD and TD groups) to understand how the participant groups differed in task performance and gaze fixation within the movement planning window. We observed difference in the scan path and last fixation within the movement planning window before triggering the release of the dart with relevance to task performance.

The Effect of Large Visual Illusion and External Focus of Attention on Gaze Behavior and Learning of Dart Throw Skill

Research has shown that large visual illusions and an external focus of attention can improve novice’s motor learning. However, the combined effects of these approaches and the underlying mechanisms have yet to be studied. Therefore, the present study examined the effects of a large visual illusion and an external focus on the learning of a dart throwing task in novices and measured the perceptual mechanisms underpinning learning using quiet eye. Forty novice participants were randomly divided into four groups: large visual illusion, external focus of attention, combined large visual illusion and external focus of attention, and control group. The study consisted of a pretest, a practice phase, an immediate retention test, a 24-hr retention test, and a transfer test. Results revealed that all groups increased throwing accuracy and quiet eye duration from pretest to immediate retention. In the immediate retention, 24-hr retention, and transfer test, large visual illusion had greater accuracy and longer quiet eye duration than the control group. In addition, there were no significant differences between the visual illusion and external focus groups for throwing accuracy and quiet eye duration. The findings suggest that combining large visual illusion and external focus can independently improve motor learning but combining these manipulations does not have additive benefits.

Effects of attentional focus and cognitive load on novice dart throwing: Evidence from quiet eye duration and pupillary responses

The purpose of the present study was to investigate the effects of attentional focus and cognitive-load on motor performance, quiet-eye-duration, and pupil dilation. 18 participants completed a dart throwing task under four conditions, internal or external focus with high or low cognitive-load. Cognitive-load was created by a secondary tone detection task. During each trial participants pupil size and eye movements were recorded along with accuracy data of the dart throw. Results revealed that decreased cognitive-load increased accuracy while high load increased pupil size (p's < 0.05). An external focus resulted in the greatest accuracy while an external focus with high cognitive-load resulted in the longest quiet-eye-durations (p's < 0.05). Based on these findings an increase in pupil size is related to greater cognitive-load but doesn't explain the improvement in task performance. Likewise, an external focus of attention improved performance but was not strongly related to quiet-eye-duration. Results are further discussed in the article.

Grip strength, functional range and anthropometric dimensions, and indication on fulfilling occupations in the home and workplace: A cross-sectional study

Introduction Little is known about the relationship between the types of grip strength, functional range, anthropometric measures, and function in the home and workplace. The study aimed to determine their relationships and explore their contributions to performing usual work duties and overall function in participants with and without hand and wrist injury. Method Forty-four participants were measured on Maximal Voluntary Isometric Grip Strength, Rapid Exchange Grip Contractions and Isometric Endurance, Forearm Length and Volumetry, and the Dart Thrower’s Motion (DTM) measure. They completed the Patient Rated Wrist and Hand Evaluation and the Disabilities of the Arm, Shoulder and Hand Work Module. Results The grip measures significantly correlated with Volumetry (r = 0.62–0.74) in participants with and without hand and wrist injury. The Isometric Endurance and DTM measure of the non-injured hand were found to be contributing factors for participants with hand and wrist injury when returning to usual work duties and overall function. Conclusion The non-injured hand function plays a role in the overall function for participants with hand and wrist injuries. Isometric Endurance and DTM measure could assist clinicians in determining suitable rehabilitation targets, resulting in a better function required for occupations in the home or workplace.

Effect of Various Wrist and Forearm Motions on Distal Radius Forces.

Background Dart throw motions are frequently used during rehabilitation but the ideal orientation of a dart throw motion is unknown. Questions/Purposes The purpose of this study was to measure the axial force on the distal radius during different dart throw motions with the wrist and forearm in various positions. Our hypothesis was that there would be a significant difference on the axial force between various forearm positions and different dart throw orientations. Methods Eight fresh frozen cadaver wrists were moved through 10 different orientations of a dart throw motion with the forearm in neutral, in pronation, and during a dynamic forearm rotation motion while the axial force was measured. Results Significantly smaller axial force occurred with the forearm in pronation than during the dynamic forearm motion. The shorter dart throw motions which were oriented equally toward the flexion/extension and radioulnar deviation axes had significantly smaller distal radius forces than nearly all of the other dart throw motions. Conclusion/Clinical Relevance Rehabilitation protocols incorporating a dart throw motion may be of benefit after injury or surgery. To minimize the axial force transmitted through a healing distal radius fracture, short dart throw motions, oriented at 45 degrees from the sagittal and coronal planes, with the forearm in pronation, might be preferable for range of motion activities during rehabilitation.

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.

Anodal tDCS accelerates on-line learning of dart throwing

Transcranial direct current stimulation (tDCS) has been shown to enhance or block online learning of motor skills, depending on the current direction. However, most research on the use of tDCS has been limited to the study of relatively simple motor tasks. The purpose of the present study was to examine the influence of anodal (a-tDCS) and cathodal (c-tDCS) direct current stimulation on the online learning during a single session of dart throwing. Fifty-eight young adults were randomized to a-tDCS, c-tDCS, or SHAM groups and completed a pre-test block of dart throws, a 20-minute practice block of throws while receiving their stimulation condition, and a post-test block of dart throws. The results showed that a-tDCS accelerated the skill learning of dart throwing more than SHAM and c-tDCS conditions. The SHAM and c-tDCS conditions were not different. We conclude that a-tDCS may have a positive effect in a single training session which would be ideal in a recreational game environment where repeated practice is not common.

Moderate movement variability is optimal in massive practiced dart throws

Background and Study Aim. Movement variability is one of the fundamental topics concerning the control of human movement. In recent years, researches have focused on various aspects of variability, which has changed the noise to useful variable on human movement. Present study investigated movement variability level in high skilled dart players that repeated throws over many years.&#x0D; Material and Methods. Seven experienced dart players (three women and four men) were threw 36 darts in three sets (each set 12 throws) from a standard distance (2.37 meters), while the kinematic features of the shoulder, elbow, and wrist were recorded during the throws. Qualisys motion capture system with six cameras was used to record the kinematics of the elbow.&#x0D; Results: entropy analysis revealed that greater variability in movement angle, velocity and acceleration resulted in better dart throwing performance but after reach to this level, throw variability was decreased. The remarkable point in these findings was that variability was constant across all samples despite the varied range of experience in throwing darts from 2.37 meters distance. Entropy analysis showed that in the throws of highly experienced individuals, variation led to greater throwing efficiency.&#x0D; Conclusions: these findings suggest that variability in a throwing activity, which revealed that moderate movement variability results in optimal throwing performance when dart throw has massive amount of practice during many years.

How Much Scaphoid Can be Safely Resected? A Biomechanical Analysis of the Effects of Distal Scaphoid Resection.

Resection of the distal pole of the scaphoid has been advocated as a simple alternative to other wrist salvage procedures for scaphoid nonunion advanced collapse and scaphotrapezio-trapezoid arthritis. However, the extent of scaphoid that may be resected without adversely affecting carpal kinematics has never been clearly defined. Seven cadaveric upper extremities were tested in a custom motion wrist simulator. A 3-stage sequential sectioning of the distal scaphoid protocol was performed in 25% increments then cyclic active wrist flexion-extension and dart thrower's motion trials were recorded. The extent of distal scaphoid resection had no effect on overall wrist range of motion. The lunate assumed a more extended position following resection of the distal scaphoid compared to intact. At 25%, 50%, and 75% of distal scaphoid resection, the lunate extended to 13.32° ± 9.4°, 23.43° ± 7.5°, and 15.81° ± 16.9°, respectively. The capitate migrated proximally with 25% and 50% distal scaphoidectomy, and proximally and radially with 75% of the scaphoid resected. Resection of 75% of the scaphoid resulted in unstable wrist kinematics. Resection of up to 25% of the distal scaphoid did not significantly influence carpal kinematics and induced mild lunate extension deformity. Resection of 50% of the scaphoid induced further and potentially clinically significant lunate extension and dorsal intercalated segment instability. Further removal of 75% of the distal scaphoid induced capitate migration radially and unpredictable wrist kinematics. Consequently, removal of over 25% of the scaphoid should be avoided or supplemented with partial wrist fusion.