Manual Dexterity Test Research Articles

The Relationship Between Serum Lead Level and Neurobehavioral Performance

Background: Lead is one of the metals, which has an important role in the industry. Objectives: We designed a study to assess the serum lead level in battery manufacturing workers and its association with neurobehavioral performance. Methods: In this cross-sectional, 154 individuals who worked in a battery factory participated. Venous blood samples were collected for measuring blood lead levels by atomic absorption method. Three selected tests of neuropsychological performance approved by World Health Organization were conducted, including simple reaction time (SRT), Benton Visual Retention Test (BVRT), and Santa Ana manual dexterity test. Results: The present study demonstrates a positive correlation between blood lead levels and work experience. The higher blood lead levels and longer work experience were associated with lower scores on the Benton Visual Test. Simple reaction time showed a significant relationship with the work experience. Conclusions: The results of this study suggest that occupational exposure to lead can induce a neurobehavioral dysfunction in battery manufacturing workers. Thus neurobehavioral assessment in health surveillance of exposed workers can be effective in the early detection of cognitive impairment.

Serum neurofilament light chain level associations with clinical and cognitive performance in multiple sclerosis: A longitudinal retrospective 5-year study

Background: A limited number of studies investigated associations between serum neurofilament light chain (sNfL) and cognition in persons with multiple sclerosis (PwMS). Objective: To assess cross-sectional and longitudinal associations between sNfL levels, clinical, and cognitive performance in PwMS and age-matched healthy controls (HCs). Materials: One hundred twenty-seven PwMS (85 relapsing–remitting MS/42 progressive MS), 20 clinically isolated syndrome patients, and 52 HCs were followed for 5 years. sNfL levels were measured using the single-molecule array (Simoa) assay and quantified in picograms per milliliter. Expanded Disability Status Scale (EDSS), walking, and manual dexterity tests were obtained. At follow-up, Brief International Cognitive Assessment for MS (BICAMS) was utilized. Cognitively impaired (CI) status was derived using HC-based z-scores. Age-, sex-, and education-adjusted analysis of covariance (ANCOVA) and regression models were used. Multiple comparison–adjusted values of q < 0.05 were considered significant. Results: In PwMS, sNfL levels were cross-sectionally associated with walking speed (r = 0.235, q = 0.036), manual dexterity (r = 0.337, q = 0.002), and cognitive processing speed (CPS; r =−0.265, q = 0.012). Baseline sNfL levels predicted 5-year EDSS scores (r = 0.25, q = 0.012), dexterity (r = 0.224, q = 0.033), and CPS (r =−0.205, q = 0.049). CI patients had higher sNfL levels (27.2 vs. 20.6, p = 0.016) and greater absolute longitudinal sNfL increase when compared with non-CI patients (4.8 vs. 0.7, p = 0.04). Conclusion: Higher sNfL levels are associated with poorer current and future clinical and cognitive performance.

556 A Pilot Study on the Recovery Rate in Patients Who Receive Propofol Sedation During Upper Endoscopy (EGD)

INTRODUCTION: Procedural sedation for gastrointestinal endoscopy has shifted towards the use of propofol instead of moderate sedation. While medications used for moderate sedation produce delayed psychomotor recovery, patients receiving propofol often report a subjective return to baseline by the time they leave the recovery area following brief endoscopic procedures. Patients are advised to take the day off of work, abstain from major decisions and have an adult accompany them home. This comes at a societal cost as both the patient and caregiver must miss a full day of work. Willey et al. previously studied the rate of recovery for patients receiving moderate sedation with fentanyl and midazolam for upper endoscopy (EGD) finding that average psychomotor recovery was only 64.4 ± 4.4% of baseline and that the letter cancellation test (LCT) and manual dexterity test (MDT) were the most powerful predictors of recovery. We hypothesize that patients receiving propofol sedation will experience a discrete period of psychomotor depression, followed by rapid improvement. METHODS: IRB approval was obtained and 30 outpatients undergoing EGD (divided into three equal age groups) were enrolled (Table 1). To determine normal score variability within each age group the LCT and the MDT were given twice in the pre-procedure period to each patient. Each patient also took the tests upon awakening in recovery and a follow up 30 minutes post-procedure. A patient's recovery status was defined as a 30 minute post-procedure test score within 2 standard deviations of the average score for their age cohort. RESULTS: Overall and within each age group, patients experienced a decrease in performance in the immediate post-procedure period on both the LCT and the MDT. Figure 1 All groups showed improvement on the 30 minute post-procedure test, although full recovery was only achieved 40.0 to 90.0% of the time (overall average of 73.3%) with the LCT and 90.0 – 100% of the time (overall average 90%) for the MDT (Table 2). CONCLUSION: In comparison to previously published results of moderate sedation, propofol sedation demonstrates an improved psychomotor recovery profile. The two tests utilized for this pilot study cannot be considered to provide a full evaluation of psychomotor recovery. We hope that this prospective data may ultimately be used to develop an easily accessible, inexpensive tool to assess psychomotor recovery at the bedside.

Reliability, validity and responsiveness of the squares test for manual dexterity in people with Parkinson’s disease

ObjectiveImpaired manual dexterity is one of the major disorder in people with Parkinson’s Disease (PwPD). However, there is limited research examining the measurement properties, especially the validity and responsiveness of the tools used to assess manual dexterity. The aim of this study was to examine reliability, validity, and responsiveness of the Squares Test (ST) in PwPD. Patients and MethodsFifty-seven PwPD and 50 healthy people, all of whom were right-handed, were recruited. The ST, Nine-Hole Peg Test, Unified Parkinson’s Disease Rating Scale (UPDRS), and Hoehn and Yahr scale were performed in ON state. For responsiveness analysis, the ST and UPDRS motor score (UPDRS-III) were also performed in OFF state. ResultsThe ST showed excellent test-retest reliability. The ST was found to correlate significantly with other outcome measures, which indicated good concurrent validity. PwPD demonstrated significantly lower scores of the ST than healthy people, which demonstrated satisfactory known-groups validity. The ST had excellent discriminant validity. The ST scores of 52 for more affected hand and 62 for less affected hand were shown to best discriminate between PwPD and healthy people. The ST is high internal responsiveness based on standardized effect size and standardized response mean (0.79 and 1.88, respectively for more affected hand and 0.85 and 1.83, respectively for less affected hand), and also PwPD had better performance based on the ST in ON state than in OFF state (p < 0.001 for both hands). Moderate correlations were found between the change scores of the ST and UPDRS-III, which reflected adequate external responsiveness. ConclusionsThe ST is a reliable, valid and responsive measurement tool for assessing manual dexterity in PwPD.

Purdue Manual Dexterity Scores: A Cohort Study of Community Dwelling Elderly

The Purdue Pegboard Test (PPT) is a manual dexterity test that requires the manipulation of pegs, washers, and collars. Our population for this research intervention focused on the geriatric community due to the lack of recent available normative data. Much of the existing data was collected using the Purdue Pegboard model 32020 which is no longer available for purchase. Our objective was to gather normative data for community-dwelling seniors. The purpose of this study was to provide updated normative data for hand therapists to use in clinical practice to determine if seniors have dexterity deficits.

Assessing likelihood of using the Bruininks-Oseretsky test of motor proficiency to predict preclinical performance of dental students.

ObjectiveThe acquisition of motor skills is a key competency for the practice of dentistry, and innate abilities have been shown to influence motor performance. Thus, finding the most efficient manual dexterity tests may predict performance of dental students. The current study used the Bruininks–Oseretsky Test of Motor Proficiency, to assess motor skills of first year (D1) and second year (D2) dental students.Materials and methodsThree fine motor subsets of the BOT‐2—fine motor precision, fine motor integration, and manual dexterity—were administered to D1 and D2 dental students in 2017 and 2018. The BOT‐2 subset scores of D1 students were compared with those of D2 students, who had preclinical dental experiences. For D2 students, we tested for correlations between BOT‐2 subset scores and performance scores in a preclinical operative dentistry course.ResultsNo differences were found between D1 and D2 students for any BOT‐2 subtest scores (all Ps > .09). No correlations were found between total scores of each BOT‐2 subtest and the operative dentistry course for D2 students (all Ps > .20).ConclusionsOur results suggested the BOT‐2 was not predictive of manual skills of dental applicants or preclinical dental students. Although we assumed students would perform well with instruction, practice, and feedback, we were unable to determine whether innate abilities influenced acquisition of manual dexterity skills. More research about the acquisition of technical clinical skills in dentistry is required.

EXAMINING THE BENEFITS OF SOMATOSENSORY GAME MACHINE ON SENIORS WITH DEMENTIA-TAKING THE EXAMPLE OF ONE YUNLIN COUNTY'S DAYCARE CENTER WITH SENIORS

This research adopted a quasi-experimental design in which purposive sampling was used. The research site was the National Cheng Kung University Hospital Dou-Liou Branch dementia daycare center, from which 30 patients with dementia who were ≥ 65 years old were recruited. During the research, participants were randomly assigned to either the experimental or control groups. During the research, eight participants withdrew due to personal reasons; 22 participants completed the research. The research spanned 12 weeks, from 21 September to 31 December 2017. The experimental group included four male dementia patients (76.25 ± 6.61 years), of which three had mild dementia and one had moderate dementia; and seven female dementia patients (80.14 ± 6.38 years), of which four had mild dementia and three had moderate dementia. In the control group, there were five seniors male dementia patients (80.8 ± 1.6 years), of which three had mild dementia and two had moderate dementia; and six female dementia patients (82.83 ± 8.93 years), of which three had mild dementia and three had moderate dementia. The present research employed an interactive drum-beating somatosensory game, “Taiko no Tatsujin”. Results showed that differences in the experimental group across the 12-week program reached statistical significance (p =.046*). The Jamar dynamometer was used to measure the grip strength of both hands of the participants; the experimental group showed significant improvement across the 12 weeks (p≦.001***). The Minnesota manual dexterity test was used to measure bilateral hand coordination of the participants. Though there were significant differences in the performance between the experimental and control groups (p≦.001***), both groups improved the time taken to complete the test across the 12 weeks.

The Effect of Variations in Force Feedback in a Virtual Reality Environment on the Performance and Satisfaction of Dental Students.

The aim of this study was to investigate the transfer of skills between various levels of force feedback (FFB) using the Simodont dental trainer (Moog, Nieuw-Vennep, the Netherlands). Students practiced a manual dexterity exercise in a virtual reality environment at a standard level of FFB and then were tested at the standard and an altered level of FFB. In addition, the students' satisfaction with the training exercise was evaluated. One hundred twenty-six first-year dental students were randomly distributed into four groups and underwent a manual dexterity test in the virtual reality environment with automatic assessment after a 3-month period of practicing with standard FFB. The test consisted of drilling with the standard FFB and an altered level of FFB to evaluate the effect on performance. After the test, the participants completed a questionnaire. The results showed that 74% of the students who passed completed between one of three and three of three successful attempts at FFB levels at which they had not previously practiced. The results of this study imply that if students practice a sufficient amount of time at one level of FFB, a skill is transferable from one level of FFB to another.

Biomechanical Evaluation of Three-Dimensional Printed Dynamic Hand Device for Patients With Chronic Stroke.

Provision of adequate task-oriented training can be difficult for stroke survivors with limited hand movement. The current passive devices are mainly intended for gross grasp and release training. Additional assistive devices are required to improve functional opposition. This paper investigated the functional recovery of chronic stroke patients after using a three-dimensional (3D) printed dynamic hand device (3D-DHD) as an adjunct to conducting a task-oriented approach (TOA). Ten participants were randomly assigned to either the 3D-DHD group (n = 5) or the control group (n = 5). The TOA was used for the 3D-DHD group by using the 3D-DHD twice a week for four weeks, followed by a two-week home program. Only the TOA was used for the control group. The outcome measures, including the box and blocks test (BBT) of manual dexterity and prehensile strength, were conducted at baseline and at follow-up at four and six weeks later. The 3D-DHD group exhibited significantly superior improvements to the control group in the BBT and the palmar pinch force test. Both the groups had significant within-group improvements in the BBT and in all strength measures compared with baseline measurements. The use of 3D-DHD could position stroke-affected hands in coordinated functional opposition and had the potential to facilitate manual dexterity and advanced prehensile movement.

Manual Dexterity Test is a Better Predictor of Disability than Walking Speed in Multiple Sclerosis: A Large Outpatient Analysis (P3.2-007)

Manual Dexterity Test is a Better Predictor of Disability than Walking Speed in Multiple Sclerosis: A Large Outpatient Analysis (P3.2-007)

Functional and structural asymmetry in primary motor cortex in Asperger syndrome: a navigated TMS and imaging study

Motor functions are frequently impaired in Asperger syndrome (AS). In this study, we examined the motor cortex structure and function using navigated transcranial magnetic stimulation (nTMS) and voxel-based morphometry (VBM) and correlated the results with the box and block test (BBT) of manual dexterity and physical activity in eight boys with AS, aged 8–11 years, and their matched controls. With nTMS, we found less focused cortical representation areas of distinct hand muscles in AS. There was hemispheric asymmetry in the motor maps, silent period duration and active MEP latency in the AS group, but not in controls. Exploratory VBM analysis revealed less gray matter in the left postcentral gyrus, especially in the face area, and less white matter in the precentral area in AS as compared to controls. On the contrary, in the right leg area, subjects with AS displayed an increased density of gray matter. The structural findings of the left hemisphere correlated negatively with BBT score in controls, whereas the structure of the right hemisphere in the AS group correlated positively with motor function as assessed by BBT. These preliminary functional (neurophysiological and behavioral) findings are indicative of asymmetry, and co-existing structural alterations may reflect the motor impairments causing the deteriorations in manual dexterity and other motor functions commonly encountered in children with AS.

The Functionality of the Bio-Mechanical Prosthetic Finger When Compared With Results on Standardized and Functional Assessments: A Single-Case Study

ABSTRACT Introduction The purpose of this study was to examine the functionality of the bio-mechanical prosthetic finger (BPF). The researchers administered various assessments to examine how the BPF performed in comparison with the affected hand without the BPF, as well as the unaffected hand. Materials and Methods A single subject participant with amputations at the proximal phalanx of the third and fourth digits was recruited for this study. The subject was assessed without a prosthetic device and while wearing a BPF on each digit. The researchers also assessed the uninvolved hand for comparison. The following standardized assessments were administered: Minnesota Manual Dexterity Test, Jamar Hand Function Test, and Box and Blocks Test. Two qualitative questionnaires and The Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire were also administered to examine the participant's abilities and satisfaction with and without the prosthetic device. Results The results were analyzed to assess the difference in performance with and without the prosthetic device as compared with the unaffected side. The results indicated that the participant performed at a higher level on all assessments while using the BPF. In addition, the participant reported a higher level of comfort and satisfaction while using the prosthesis. Conclusions The results of the study showed that the BPF is a viable option for digit amputations to restore function in daily tasks.

The Effect of Memory Span and Manual Dexterity on Hearing Aid Handling Skills in New and Experienced Hearing Aid Users.

Purpose The aim of the study was to determine the effect of memory function and manual dexterity on new and experienced hearing aid users' abilities to use and care for their hearing aids. Method New and experienced hearing aid users were administered the Practical Hearing Aid Skills Test-Revised (PHAST-R; Doherty & Desjardins, 2012 ), a measure of a hearing aid user's ability to use and care for their hearing aids. The test was administered during their 30-day hearing aid check or yearly hearing evaluation appointment. Participants were also administered the Digit Span Test of memory function ( Wechsler, 1997 ) and the Nine-Hole Peg Test of manual dexterity ( Mathiowetz, Weber, Kashman, & Volland,1985 ). Results Participants with poorer memory span function performed significantly poorer on the PHAST-R than participants with better memory span. However, no significant relationship between manual dexterity and PHAST-R performance was observed. Experienced hearing aid users who were recently reoriented on how to use and care for their hearing aids performed significantly better on the PHAST-R compared to new hearing aid users and experienced hearing aid users who had not received a hearing aid orientation within the last year. Cleaning the hearing aid and telephone use were the 2 PHAST-R tasks that all hearing aid clients needed the most recounseling on. Conclusion Memory span is significantly related to an individual's ability to correctly use and care for their hearing aids regardless of whether they are new or experienced hearing aid users.

A Touch-Observation and Task-Based Mirror Therapy Protocol to Improve Sensorimotor Control and Functional Capability of Hands for Patients With Peripheral Nerve Injury.

To develop a practical program in the early phase after nerve repair for more rapid return of function. To investigate the effects of touch-observation and task-based mirror therapy on the sensorimotor outcomes of patients with nerve repair. An assessor-blinded study with a randomized controlled design. University hospital. We recruited 12 patients with median or ulnar nerve repair between the level of midpalm and elbow referred by the plastic surgeons. The patients were randomized into touch-observation and task-based mirror therapy or control groups, and both groups received training for 12 wk. The Semmes-Weinstein monofilament (SWM) test, two-point discrimination test, Purdue Pegboard Test (PPT), Minnesota Manual Dexterity Test (MMDT), and pinch-holding-up activity test were assessed at pretreatment, immediately after treatment, and 12 wk after the last treatment. The experimental group showed greater improvements in the results of the pinch-holding-up activity test and the PPT Unilateral Pin Insertion, Bilateral Pin Insertion, and Assembly subtests. However, change on the SWM test revealed no significant difference between the two groups. Touch-observation and task-based mirror therapy is an effective but low-cost treatment protocol to optimize sensorimotor control and functional capability of the upper limb in patients with peripheral nerve injury.

Application of modified progressive static splinting for treatment of traumatic metacarpophalangeal joint stiffness

Objective To investigate the application and efficacy of modified progressive static splinting (National Invention Patent No. 201610777015.8) in the treatment of traumatic metacarpophalangeal joint stiffness. Methods From October 2016 to December 2017, 32 cases (97 fingers) of traumatic metacarpophalangeal joint stiffness were treated in our hospital. Among them, 16 cases (48 fingers) were given routine rehabilitation and progressive static splinting (group A) and 16 cases (49 fingers) were given routine rehabilitation and modified progressive static splinting (group B). The active and passive range of motion (AROM, PROM), visual analogue scale (VAS), Minnesota Manual Dexterity Test (MMDT), Disability of the Arm, Shoulder and Hand (DASH) questionnaire, Semmes-Weinstein Monofilaments Examination (SWME) of the two groups were compared before and 2, 4, 6 weeks after the treatment. Results Before the rehabilitation treatment, there was no significant difference in AROM, PROM, VAS, MMDT time, DASH and SWME value between the two groups (P>0.05). After the treatment, AROM and PROM increased significantly, MMDT time shortened significantly, DASH and VAS scores decreased significantly, and SWME value increased significantly (P< 0.05). After the treatment, AROM and PROM of group B were significantly greater than those of group A, MMDT time of group B was significantly shorter than that of group A, DASH and VAS scores of group B were significantly lower than those of group A, and SWME value of group B was significantly smaller than that of group A (P < 0.05). Conclusion The modified progressive static splinting is better than traditional progressive static splinting in the treatment of traumatic metacarpophalangeal joint stiffness. The treatment process is more comfortable. It is easier to improve the dexterity of the hand and the ability of daily activities. It is worthy of clinical application. Key words: Metacarpophalangeal joint; Rehabilitation; Splinting; 3D printing

The Computerized General Neuropsychological INPH Test revealed improvement in idiopathic normal pressure hydrocephalus after shunt surgery.

The Computerized General Neuropsychological INPH Test (CoGNIT) provides the clinician and the researcher with standardized and accessible cognitive assessments in patients with idiopathic normal pressure hydrocephalus (INPH). CoGNIT includes tests of memory, executive functions, attention, manual dexterity, and psychomotor speed. Investigations of the validity and reliability of CoGNIT have been published previously. The aim of this study was to evaluate CoGNIT's sensitivity to cognitive change after shunt surgery in patients with INPH. Forty-one patients with INPH (median Mini-Mental State Examination score 26) were given CoGNIT preoperatively and at a postoperative follow-up 4 months after shunt surgery. Scores were compared to those of 44 healthy elderly control volunteers. CoGNIT was administered by either a nurse or an occupational therapist. Improvement after shunt surgery was seen in all cognitive domains: memory (10-word list test, p < 0.01); executive functions (Stroop incongruent color and word test, p < 0.01); attention (2-choice reaction test, p < 0.01); psychomotor speed (Stroop congruent color and word test, p < 0.01); and manual dexterity (4-finger tapping, p < 0.01). No improvement was seen in the Mini-Mental State Examination score. Preoperative INPH test scores were significantly impaired compared to healthy control subjects (p < 0.001 for all tests). In this study the feasibility for CoGNIT to detect a preoperative impairment and postoperative improvement in INPH was demonstrated. CoGNIT has the potential to become a valuable tool in clinical and research work.Clinical trial registration no.: NCT01618500 (clinicaltrials.gov).

The association between handedness and clinicodemographic characteristics in people with multiple sclerosis: a brief report.

A relationship between handedness and clinicodemographic profiles of people with multiple sclerosis was sought using data from the Multiple Sclerosis Partners Advancing Technology Health Solutions network of 10 multiple sclerosis centers in the USA and Europe. Handedness data were available for 8888 multiple sclerosis patients, of which 917 (10.3%) were left-handed. Clinicodemographic profiles of right versus left-handed multiple sclerosis patients were similar except for a slightly increased proportion of men who were left-handed, and slightly reduced performance on the manual dexterity test using the non-dominant hand in left-handed patients. We found no evidence to suggest a prognostic implication of handedness in multiple sclerosis.

Correlation of proximal and distal muscle strength with upper limb functional ability in patients with essential tremor.

Despite being considered as a benign, genetic and monosymptomatic disorder, ET is a poorly understood entity with etiological and pathological heterogeneity. The aim of the present study was to examine the relation between proximal and distal muscle strength and upper limb functionality and tremor severity in patients with essential tremor (ET). The study enrolled 25 tremor patients followed at the neurology clinic of a university hospital and 19 healthy controls. Demographic data, risk factors, disease duration and dominant hand of the participants were recorded. Back and leg strength was assessed using a back and leg dynamometer and hand dynamometer and pinchmeter were used to determine hand strength. Functional ability of the participants was evaluated using the Minnesota Manual Dexterity Test (MMDT), Perdue Pegboard (PPBT) and Nine Hole Peg Test (NHPT). Tremor severity was assessed using the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS) and the Lower Extremity Clinical Tremor Assessment Scale (LECTAS). A significant difference was found in the average back and leg muscle strength between ET patients and healthy controls (p < 0.05). The mean values for right/left hand muscle strength were not significantly different between the two groups (p > 0.05). Among the upper limb functional ability tests, significant differences were found between the two groups in the mean time to complete NHPT, Minnesota placing subtest and PPBT test (p < 0.05). While gender and risk factors were not significantly different between the two groups (p > 0.05), there was a significant difference with respect to the educational level (p < 0.01). No significant difference was found between back and leg muscle strength and FTMTRS and LECTAS (p > 0.05). A negative correlation and a significant association were found between average strength measurements obtained with the left hand dynamometer and FTMTRS in the ET group (p = 0.030, r = - 0.434). A positive correlation and a significant association were found between left hand strength and mean turning time in the MMDT in the control group (p = 0.041, r = 0.473). ET patients experience loss of proximal muscle strength and functional disability. Further studies are planned to investigate the effects of physical therapy modalities targeting increased proximal muscle strength on tremor severity and functional ability in ET patients.

Poor estimates of motor variability are associated with longer grooved pegboard times for middle-aged and older adults.

Goal-directed movements that involve greater motor variability are performed with an increased risk that the intended goal will not be achieved. The ability to estimate motor variability during such actions varies across individuals and influences how people decide to move about their environment. The purpose of our study was to identify the decision-making strategies used by middle-aged and older adults when performing two goal-directed motor tasks and to determine if these strategies were associated with the time to complete the grooved pegboard test. Twenty-one middle-aged (48 ± 6 yr; range 40-59 yr, 15 women) and 20 older adults (73 ± 4 yr; range 65-79 yr, 8 women) performed two targeted tasks, each with two normalized target options. Decision-making characteristics were not associated with time to complete the test of manual dexterity when the analysis included all participants, but slower pegboard times were associated with measures of greater movement variability during the target-directed actions. When the data were clustered on the basis of pegboard time rather than age, relatively longer times for the faster group were associated with greater motor variability during the prescribed tasks, whereas longer times for the slower group were associated with increased risk-seeking behavior (α) and greater variability in the targeted actions. NEW & NOTEWORTHY This study was the first to examine the association between decision-making choices and an NIH Toolbox test of manual dexterity (grooved pegboard test) performed by middle-aged and older adults. Significant associations were observed between decision-making choices and time to complete the test when the analyses were based on pegboard times rather than chronological age. This result indicates that decision-making choices of middle-aged and older adults, independent of age, were associated with time to complete a test of manual dexterity.

Restoring Natural Forearm Rotation in Transradial Osseointegrated Amputees

Osseointegrated transradial prostheses have the potential to preserve the natural range of wrist rotation, which improves the performance of activities of daily living and reduces compensatory movements that potentially lead to secondary health problems over time. This is possible by enabling the radius and the ulna bone to move with respect to each other, restoring the functionality of the original distal-radioulnar joint. In this paper, we report on psychophysics tests performed on an osseointegrated transradial amputee with the aim to understand the extent of mobility of the implants that is required to preserve the natural forearm rotation. Based on these experiments, we designed and developed an attachment device between the implants and the hand prosthesis that serves as an artificial distal radio-ulnar joint. This device was fitted on an osseointegrated transradial amputee and its functionality assessed by means of the Southampton Hand Assessment Procedure (SHAP) and the Minnesota Manual Dexterity test (MMDT). We found that the axial rotation of the implants is required to preserve forearm rotation, to distribute loads equally over the two implants (60% radius - 40% ulna), and to enable loading of the implants without unpleasant feelings for the patient. Higher function was recorded when our attachment device enabled forearm rotation: SHAP from 61 to 71, MMDT from 258s to 231s. Natural forearm rotation can be successfully restored in transradial amputees by using osseointegration and our novel mechanical attachment to the hand prosthesis.