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BACKGROUND: Impaired dexterity is an early motor symptom in Parkinson's disease (PD) that significantly impacts the daily activity of patients; however, what constitutes complex dexterous movements remains controversial. OBJECTIVE: To explore the characteristics of finger dexterity in mild-to-moderate stage PD. METHODS: We quantitatively assessed finger dexterity in 48 mild-to-moderate stage PD patients and 49 age-matched controls using a simple alternating two-finger typing test for 15 seconds. Time-series analyses of various kinematic parameters with machine learning were compared between sides and groups. RESULTS: Both the more and less affected hands of patients with PD had significantly lower typing frequency and slower typing velocity than the non-dominant and the dominant hands of controls (p = 0.019, p = 0.016, p < 0.001, p < 0.001). The slope of the typing velocity decreased with time, indicating a sequence effect in the PD group. A typing duration of 6 seconds was determined sufficient to discriminate PD patients from controls. Typing error, repetition, and repetition rate were significantly higher in the more affected hands of patients with PD than in the non-dominant hand of controls (p < 0.001, p = 0.03, p < 0.001). The error rate was constant, whereas the repetition rate was steep during the initiation of typing. A predictive model of the more affected hand demonstrated an accuracy of 70% in differentiating PD patients from controls. CONCLUSION: Our study demonstrated complex components of impaired finger dexterity in mild-to-moderate stage PD, namely bradykinesia with sequence effects, error, and repetition at the initiation of movement, suggesting that multiple neural networks may be involved in dexterity deficits in PD.

Asunto(s)

Dedos , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/complicaciones , Destreza Motora , Mano , Movimiento

RESUMEN

We investigated morphologic changes in the corticospinal tract (CST) to understand the mechanism underlying recovery of hand function after lesion of the CST at the C4/C5 border in seven macaque monkeys. All monkeys exhibited prominent recovery of precision grip success ratio within a few months. The trajectories and terminals of CST from the contralesional (n = 4) and ipsilesional (n = 3) hand area of primary motor cortex (M1) were investigated at 5-29 months after the injury using an anterograde neural tracer, biotinylated dextran amine (BDA). Reorganization of the CST was assessed by counting the number of BDA-labeled axons and bouton-like swellings in the gray and white matters. Rostral to the lesion (at C3), the number of axon collaterals of the descending axons from both contralesional and ipsilesional M1 entering the ipsilesional and contralesional gray matter, respectively, were increased. Caudal to the lesion (at C8), axons originating from the contralesional M1, descending in the preserved gray matter around the lesion, and terminating in ipsilesional Laminae VI/VII and IX were observed. In addition, axons and terminals from the ipsilesional M1 increased in the ipsilesional Lamina IX after recrossing the midline, which were not observed in intact monkeys. Conversely, axons originating from the ipsilesional M1 and directed toward the contralesional Lamina VII decreased. These results suggest that multiple reorganizations of the corticospinal projections to spinal segments both rostral and caudal to the lesion originating from bilateral M1 underlie a prominent recovery in long-term after spinal cord injury.

Asunto(s)

Dedos , Traumatismos de la Médula Espinal , Animales , Dedos/patología , Destreza Motora , Tractos Piramidales , Traumatismos de la Médula Espinal/patología , Axones/patología , Macaca mulatta , Médula Espinal/patología , Recuperación de la Función

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Finger dexterity is manifested by coordinated patterns of muscle activity and generalization of learning across contexts. Some fingers flex, others extend, and some are immobile. Whether or not the neural control processes of these direction-specific actions are independent remains unclear. We characterized behavioral principles underlying learning and generalization of dexterous flexion and extension movements, within and across hands, using an isometric dexterity task that precisely measured finger individuation, force accuracy, and temporal synchronization. Two cohorts of participants trained for 3 days in either the flexion or extension direction. All dexterity measures in both groups showed post-training improvement, although finger extension exhibited inferior dexterity. Surprisingly, learning of finger extension generalized to the untrained flexion direction, but not vice versa. This flexion bias was also evident in the untrained hand. Our study indicates direction-specific control circuits for learning of finger flexion and extension that interact by partially, but asymmetrically, transferring between directions.

Asunto(s)

Dedos , Destreza Motora , Humanos , Mano/fisiología , Movimiento/fisiología , Aprendizaje

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Aim: The study aimed to describe the finger dexterity in office workers of an Asian population. Methods: One hundred twenty-seven right-handed office workers, aged 21-50 with a similar split of male and female, were recruited with finger dexterity measured by the O'Connor Finger Dexterity Test. The grip strength, tip and lateral pinch strength of both hands were also measured. Results: This study provided the percentile score of the O'Connor Finger Dexterity Test of both males and females in the Asian population. Raw scores of below 218 and 213 seconds in male and female participants respectively reach the 90th percentile, and above 237 and 235 seconds in male and female below the 10th percentile. Results showed no significant difference in local mean scores across different age groups, between male and female and with varying hours of working in typing, filing, and writing. A significant difference was only found in finger dexterity and years of working as office workers. No significant correlation was found between the finger dexterity with grip strength, tip and lateral pinch of the dominant right hand. The results were similar to the original normative score with similar work skills and demands. Conclusion: The mean scores could be used as a valid reference for local occupational therapists to evaluate the finger dexterity of office workers. However, caution has to be taken that conclusions drawn can be biased because of the relatively small sample size, and the results cannot be generalized to represent a wider Asian population.

RESUMEN

In a recent study, we demonstrated that the ventral striatum (VSt) controls finger movements directly during the early recovery stage after spinal cord injury (SCI), implying that the VSt may be a part of neural substrates responsible for the recovery of dexterous finger movements. The VSt is accepted widely as a key node for motivation, but is not thought to be involved in the direct control of limb movements. Therefore, whether a causal relationship exists between the VSt and motor recovery after SCI is unknown, and the role of the VSt in the recovery of dexterous finger movements orfinger movements in general after SCI remains unclear. In the present study, functional brain imaging in a macaque model of SCI revealed a strengthened functional connectivity between motor-related areas and the VSt during the recovery process for precision grip, but not whole finger grip after SCI. Furthermore, permanent lesion of the VSt impeded the recoveryof precision grip, but not coarse grip. Thus, the VSt was needed specifically for functional recovery of dexterous finger movements. These results suggest that the VSt is the key node of the cortical reorganization required for functional recovery of finger dexterity.

Asunto(s)

Dedos , Destreza Motora/fisiología , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Estriado Ventral/fisiología , Animales , Neuroimagen Funcional , Agonistas de Receptores de GABA-A/farmacología , Macaca , Destreza Motora/efectos de los fármacos , Muscimol/farmacología , Tomografía de Emisión de Positrones , Recuperación de la Función/efectos de los fármacos , Traumatismos de la Médula Espinal/diagnóstico por imagen , Estriado Ventral/diagnóstico por imagen , Estriado Ventral/efectos de los fármacos

RESUMEN

OBJECTIVE: The study aim was to examine the hand function (hand strength and dexterity) and intervention effects of training in adults with Prader-Willi syndrome (PWS). METHODS: Six adults with PWS (two females; mean age 26.14 years) underwent hand muscle strength and dexterity training for 3 months (2 hours per week). The following hand function tests were performed pre- and post-intervention: (1) hand grip, lateral pinch, and tip pinch hand strength tests, (2) the Box and Block test (BBT) for gross manual dexterity and (3) the Purdue Pegboard test for finger dexterity. RESULTS: Before treatment, all subjects showed lower hand grip, lateral pinch, tip pinch strength, and poorer manual/finger dexterity relative to healthy adults. After training, hand function scores improved on many test items, but only the left hand tip pinch and the right hand BBT performance showed significant improvements. CONCLUSIONS: All subjects showed lower hand strength and poorer manual/finger dexterity compared with healthy adults; this should be considered during physical training programs. Owing to limitations in the intervention intensity and possible subject behavioral deficits, further research is needed to clarify the effects of this intervention on hand function in PWS patients.

Asunto(s)

Lateralidad Funcional/fisiología , Fuerza de la Mano/fisiología , Síndrome de Prader-Willi/fisiopatología , Adulto , Femenino , Humanos , Masculino , Proyectos Piloto , Adulto Joven

RESUMEN

Impaired finger dexterity occurs in Parkinson's disease (PD) and has been considered a limb-kinetic apraxia associated with primary sensory cortical dysfunction. To study the role of nigrostriatal dopamine loss and elementary parkinsonian motor deficits in impaired finger dexterity of PD. Thirty-two right-handed untreated PD patients and 30 right-handed healthy controls were included. All patients underwent [18F] FP-CIT positron emission tomography studies. We examined the associations among unilateral coin rotation (CR) score, Unified Parkinson's Disease Rating Scale (UPDRS) subscores for bradykinesia and rigidity of the corresponding arm, and contralateral regional striatal dopamine transporter (DAT) uptake. We also measured the effect of oral levodopa dose on CR scores and UPDRS subscores. PD patients performed worse than controls on the CR task. Unilateral arm UPDRS bradykinesia scores were associated with DAT uptake in the contralateral putamen. The left CR score was associated with left arm bradykinesia and rigidity scores and DAT uptake in the right posterior putamen, whereas no such associations were found for the right CR score. There was a significant effect of handedness on the association of putamen DAT uptake with CR scores, but not with UPDRS subscores. An oral levodopa challenge improved CR scores and UPDRS subscores on both sides. Impaired finger dexterity in PD is related to elementary parkinsonian motor deficits and nigrostriatal dopamine loss. Impaired dominant hand dexterity associated with nigrostriatal dopamine loss seems to be compensated to some extent by the dominant cerebral cortex specialized for controlling precise finger movements.

Asunto(s)

Apraxias/etiología , Cuerpo Estriado/metabolismo , Dopamina/deficiencia , Neuronas Dopaminérgicas/patología , Dedos/fisiopatología , Hipocinesia/etiología , Enfermedad de Parkinson/fisiopatología , Sustancia Negra/metabolismo , Anciano , Antiparkinsonianos/uso terapéutico , Apraxias/metabolismo , Apraxias/fisiopatología , Brazo/fisiopatología , Cuerpo Estriado/diagnóstico por imagen , Cuerpo Estriado/fisiopatología , Dopamina/metabolismo , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Femenino , Lateralidad Funcional , Humanos , Hipocinesia/metabolismo , Hipocinesia/fisiopatología , Imagenología Tridimensional , Levodopa/uso terapéutico , Masculino , Persona de Mediana Edad , Destreza Motora , Rigidez Muscular , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/tratamiento farmacológico , Tomografía de Emisión de Positrones , Índice de Severidad de la Enfermedad , Sustancia Negra/diagnóstico por imagen , Sustancia Negra/fisiopatología

RESUMEN

OBJECTIVE: The somatosensory temporal discrimination threshold (STDT), defined as the shortest time interval required for two tactile stimuli to be perceived as separate, is longer in patients with Parkinson's disease (PD). In this review, we discuss STDT findings in healthy subjects and in PD patients and the relationship between altered STDT and motor disturbances. METHODS: A search was conducted on PubMed for papers dealing with PD and temporal discrimination published from January 1990 to July 2017. RESULTS: Abnormal STDT in PD correlates with disease duration, disease severity and degree of nigrostriatal dopamine loss, and responds to dopaminergic medication. In PD, a prolonged STDT does not correlate, or only marginally correlates, with clinically assessed bradykinesia of finger tapping. By contrast, a prolonged STDT correlates with the variability in amplitude and speed of finger tapping as assessed by means of neurophysiological techniques and may contribute to impaired finger dexterity in PD. CONCLUSIONS: We suggest that abnormal temporal processing of sensory information in PD generates incorrect signals for the execution and control of voluntary movements. SIGNIFICANCE: This review sheds light on unsolved questions regarding the relationship between STDT alterations and motor disturbances in PD and proposes directions for future research on this topic.

Asunto(s)

Discriminación en Psicología/fisiología , Enfermedad de Parkinson/fisiopatología , Percepción del Tiempo/fisiología , Percepción del Tacto/fisiología , Potenciales Evocados Somatosensoriales/fisiología , Humanos

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Miracle fruit (Synsepalum dulcificum) seed oil (MFSO) contains phytochemicals and nutrients reported to affect musculoskeletal performance. The purpose of this study was to assess the safety and efficacy of a compression wristband containing MFSO on its ability to measurably improve the hand and finger motor skills of participants. Healthy right-handed participants (n = 38) were randomized in this double-blind, placebo-controlled study of MFSO and vehicle wristbands. Subjects wore the wristband on their left hand 4-6 weeks and then only on their right hand 2-4 weeks; the contralateral untreated hand served as an additional control. Twelve hand/finger motor skills were measured using quantitative bio-instrumentation tests, and subject self-assessment questionnaires were conducted. With each hand, in 9/12 tests, the MFSO group showed a clinically meaningful average improvement compared with an average worsening in the vehicle group. Statistical superiority to the control treatment group was exhibited in 9/12 tests for each hand (p < .01). After discontinuing the MFSO wristband on the left hand, test values regressed toward baseline levels. Subjects favored the MFSO wristband over the control, rating it as effective in improving their motor skills. Use of the MFSO wristband may improve an individual's manual dexterity skills and ability to maintain this performance.

Asunto(s)

Destreza Motora/efectos de los fármacos , Extractos Vegetales/química , Synsepalum/química , Adulto , Anciano , Método Doble Ciego , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven

RESUMEN

Objective: The key factor for potency of the teeth is their muscular strength. The dominant hand plays an important role in most of the daily muscular activities involving dental procedure. There are many factors, which may affect the grip strength, and very few studies especially in India have shown their correlation with grip strength. Work related musculoskeletal disorders (WRMSD) are an important occupational health problem affecting dental practitioners. This study assessed the prevalence of WRMSD in dental interns in relation to the thumb length and hand grip strength. Material and Methods: Thumb length template, jammer dynamometer, nine-hole peg board, and RULA assessment. Methods: Thumb length was measured by thumb length template. Grip strength was measured by jammer dynamometer, unilateral hand finger dexterity was measured by ninehole pegboard, and work related musculoskeletal disorder was assessed by RULA. Results: Thumb length was positively correlated with grip strength and work related musculoskeletal disorder. Thumb length was negatively correlated with unilateral hand finger dexterity among dental professionals. Conclusion: Thumb length is a better predictor for measuring hand grip strength and work related musculoskeletal disorder, than unilateral hand finger dexterity.

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Objetivo: O fator chave para a potência do dentes é a força muscular dos mesmos. A mão dominante tem um papel importante nas atividades musculares diárias envolvendo procedimentos odontológicos. Há vários fatores que influenciam a força de preensão e poucos estudos, especialmente na Índia, mostra as correlações com a força de preensão. Desordens musculoesqueléticas relacionadas a trabalho (DMRT) são um importante problema ocupacional de saúde entre profissionais da Odontologia. Este trabalho verificou a prevalência de DMRTs em residentes de Odontologia e sua relação com o comprimento do polegar e a força de preensão manual. Material e Métodos: Materiais utilizados foram o gabarito de comprimento do polegar, um dinamômetro Jamar, um tabuleiro de 9 perfurações e o instrumento RULA. Métodos: O comprimento polegar foi medido pelo gabarito; a força de preensão foi medida no dinamômetro Jamer; a destreza manual unilateral foi verificada utilizando-se o tabuleiro perfurado e as desordens musculoesqueléticas associadas ao trabalhos foram determinadas pelo instrumento RULA. Resultados: O comprimento polegar apresentou correlação positiva com a força de preensão e com a presença de desordens musculoesqueléticas relacionadas ao trabalho. O comprimento polegar foi negativamente correlacionado com a destreza manual unilateral entre os profissionais da Odontologia. Conclusão: O comprimento polegar é melhor preditor para a força de preensão manual e presença de desordens musculoesqueléticas relacionas ao trabalho, do que a destreza manual unilateral.

Asunto(s)

Fuerza Compresiva , Odontólogos , Personal de Salud , Dolor Musculoesquelético

RESUMEN

Almost all stroke patients experience a certain degree of fine motor impairment, and impeded finger movement may limit activities in daily life. Thus, to improve the quality of life of stroke patients, designing an efficient training device for fine motor rehabilitation is crucial. This study aimed to develop a novel fine motor training glove that integrates a virtual-reality based interactive environment with vibrotactile feedback for more effective post stroke hand rehabilitation. The proposed haptic rehabilitation device is equipped with small DC vibration motors for vibrotactile feedback stimulation and piezoresistive thin-film force sensors for motor function evaluation. Two virtual-reality based games ``gopher hitting'' and ``musical note hitting'' were developed as a haptic interface. According to the designed rehabilitation program, patients intuitively push and practice their fingers to improve the finger isolation function. Preliminary tests were conducted to assess the feasibility of the developed haptic rehabilitation system and to identify design concerns regarding the practical use in future clinical testing.

Asunto(s)

Dedos/fisiopatología , Guantes Protectores , Mano/fisiología , Destreza Motora , Modalidades de Fisioterapia/instrumentación , Rehabilitación/instrumentación , Rehabilitación de Accidente Cerebrovascular , Diseño de Equipo , Humanos

RESUMEN

BACKGROUND: The Nine Hole Peg Test (NHPT) is a simple, quick assessment often used by occupational therapists to assess finger dexterity. OBJECTIVE: The purpose of this study was to standardize the NHPT in Bangladesh so Bangladeshi therapists can administer and interpret this test with relevant cultural norms. METHOD: This study includes an inter-rater reliability (IRR) study and a normative study with Bangladeshi participants. RESULTS: In the IRR study, four raters were placed into 6 teams of two to establish reliability between individuals in each team. Intra-Class Correlation (ICC) results showed a high inter-rater reliability with ICC average ratings of 0.882-0.998 between individual raters of each team. Culturally relevant norms were developed for the NHPT using a sample of 180 participants (females, n=90 and males, n=90) ranging in age from 18 to 60 years. The data from the 1st trials were analyzed between age categories of both 5 and 10-year increments. Normative data was found to be clinically significant across collapsed age groups: 18-39, 40-49, and 50-60 years of age for each gender. CONCLUSION: These age categories were used to standardize the NHPT in Bangladesh, making it a culturally relevant finger dexterity test for the Bangladeshi population.

Asunto(s)

Dedos/fisiología , Destreza Motora/fisiología , Adolescente , Adulto , Bangladesh , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Terapia Ocupacional , Valores de Referencia , Análisis y Desempeño de Tareas , Adulto Joven

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INTRODUCTION: Manual ability and performance of dexterity tasks require both gross and fine hand motions and coordination. The aim of this study was to determine the level of manual dexterity (capacity) and investigate its relationship with manual ability (performance) in children with cerebral palsy. METHOD: This study was designed as a cross-sectional study of 30 children with cerebral palsy (aged 8-15 years). In order to assess gross manual dexterity the Box and Block Test was used. Manual ability was assessed according to Manual Ability Classification System (MACS). RESULTS: A relationship between the level of manual ability impairment and performance on manual dexterity tasks was expressed. Participants at MACS level IV demonstrated slowest times and transferred the smallest number of blocks (p<0.01). This study also found that correlation between Gross Motor Function Classification Scale (GMFCS) and MACS is statistically significant (p<0.001). All hand skills were more impaired in the non-dominant hand compared to the dominant hand but there were no statistically significant difference (p=0.06). CONCLUSION: The results suggest that gross manual dexterity is a good predictor of manual abilities in children with cerebral palsy. These results provide better understanding of the relationship between manual dexterity and activity limitations and lend credibility to the use of these classification systems and assessments in order to optimize treatment planning and evaluate interventions and progress. Hippokratia 2014; 18 (4): 310-314.

RESUMEN

BACKGROUND: Practicing yoga has been shown to improve motor functions and attention. Though attention is required for fine motor and discrimination tasks, the effect of yoga breathing techniques on fine motor skills and visual discrimination has not been assessed. AIM: To study the effect of yoga breathing techniques on finger dexterity and visual discrimination. MATERIALS AND METHODS: The present study consisted of one hundred and forty subjects who had enrolled for stress management. They were randomly divided into two groups, one group practiced high frequency yoga breathing while the other group practiced breath awareness. High frequency yoga breathing (kapalabhati, breath rate 1.0 Hz) and breath awareness are two yoga practices which improve attention. The immediate effect of high frequency yoga breathing and breath awareness (i) were assessed on the performance on the O'Connor finger dexterity task and (ii) (in) a shape and size discrimination task. RESULTS: There was a significant improvement in the finger dexterity task by 19% after kapalabhati and 9% after breath awareness (P<0.001 in both cases, repeated measures ANOVA and post-hoc analyses). There was a significant reduction (P<0.001) in error (41% after kapalabhati and 21% after breath awareness) as well as time taken to complete the shape and size discrimination test (15% after kapalabhati and 15% after breath awareness; P<0.001) was also observed. CONCLUSION: Both kapalabahati and breath awareness can improve fine motor skills and visual discrimination, with a greater magnitude of change after kapalabhati.