A Scoping Review of Grasp and Handwriting Performance in School-Age Children.

OBJECTIVE: Handwriting is a critical functional skill that impacts academic participation and progress. Occupational therapists address components of grasp in their handwriting intervention as it is commonly assumed that grasp affects legibility, fluency, and endurance, yet research studies examining this relationship are limited. METHOD: We used scoping review methodology to map existing research on grasp and handwriting performance in school-age children and to identify gaps in the literature. RESULTS: Thirteen articles met search criteria and were categorized by grasp patterns and handwriting performance, and grasp force and handwriting performance. Findings suggest an inefficient grasp can lead to decreased handwriting legibility and fatigue. The current literature is inconclusive and several gaps were identified. CONCLUSION: Additional studies should address research gaps through inclusion of children with special needs and interventions including lengthier handwriting tasks representative of a typical school day.

The effect of wheelchair propulsion style on changes in time spent in extreme wrist orientations after a bout of fatiguing propulsion.

This study compared how wheelchair propulsion styles affect changes in percentage of time spent in extreme wrist orientations, which have been associated with median nerve injury, after a fatiguing bout of propulsion. Twenty novice, non-disabled adult males learned arcing (ARC) and semicircular (SEMI) propulsion styles and utilised each to perform a wheelchair fatigue protocol. ARC and SEMI did not significantly differ in terms of changes after the fatigue protocol in percentage of time spent in extreme flexion/extension or radial/ulnar deviation at the push phase beginning or end. A pattern was observed, although not significant, of greater increases in percentage of time spent in extreme wrist extension and ulnar deviation during the push phase beginning and ulnar deviation during the push phase end while utilising SEMI relative to ARC. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles. Practitioner Summary: How wheelchair propulsion styles change with fatigue in terms of extreme wrist orientations was examined. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles and point towards the need for future research on individual differences utilising propulsion styles.

Comparison of metabolic cost, performance, and efficiency of propulsion using an ergonomic hand drive mechanism and a conventional manual wheelchair.

OBJECTIVE: To compare the metabolic cost (oxygen uptake per unit time [V˙o2 consumption], heart rate, and number of pushes), performance (velocity and distance traveled), and efficiency (oxygen uptake per distance traveled [Vo2 efficiency]) of propulsion using a novel ergonomic hand drive mechanism (EHDM) and a conventional manual wheelchair (CMW). DESIGN: Repeated-measures crossover design. SETTING: Semicircular track. PARTICIPANTS: Adult full-time manual wheelchair users with spinal cord injuries (N=12; mean age ± SD, 38.8±12.4y; mean body mass ± SD, 73.7±13.3kg; mean height ± SD, 173.6±11.1cm) who were medically and functionally stable and at least 6 months postinjury. INTERVENTION: Participants propelled themselves for 3.5 minutes at a self-selected pace in a CMW and in the same chair fitted with the EHDM. MAIN OUTCOME MEASURES: Velocity, distance traveled, number of pushes, V˙o2 consumption, Vo2 efficiency, and heart rate were compared by wheelchair condition for the last 30 seconds of each trial using paired t tests (α=.01). RESULTS: The CMW condition resulted in more distance traveled (33.6±10.8m vs 22.4±7.8m; P=.001), greater velocity (1.12±0.4m/s vs .75±.30m/s; P=.001), and better Vo2 efficiency (.10±.03mL·kg(-1)·m(-1) vs .15±.03mL·kg(-1)·m(-1); P<.001) than the EHDM condition, respectively. No significant differences were found between the 2 conditions for number of pushes (27.5±5.7 vs 25.7±5.4; P=.366), V˙o2 consumption (6.43±1.9mL·kg(-1)·min(-1) vs 6.19±1.7mL·kg(-1)·min(-1); P=.573), or heart rate (100.5±14.5 beats per minute vs 97.4±20.2 beats per minute; P=.42). CONCLUSIONS: The results demonstrate that metabolic costs did not differ significantly; however, performance and efficiency were sacrificed with the EHDM. Modifications to the EHDM (eg, addition of gearing) could rectify the performance and efficiency decrements while maintaining similar metabolic costs. Although not an ideal technology, the EHDM can be considered as an alternative mode of mobility by wheelchair users and rehabilitation specialists.

Using the "visual target grip test" to identify sincerity of effort during grip strength testing.

UNLABELLED: We devised a sincerity of effort assessment based on "tricking" a person into exerting maximal effort by providing incorrect visual feedback. The assessment involves deriving a target line from nonvisual peak gripping force, instructing participants to reach it with each grip repetition, and then secretly changing its position, which requires doubling the force necessary to reach it. Accordingly, participants are tricked into exerting more force than intended to reach the deceptive target line. We examined the validity of this test by comparing force values between "trick" and "non-trick" trials in 30 healthy participants. The study design used was a prospective cohort. Providing incorrect visual feedback caused significantly greater increases in force during submaximal effort (69%) than during maximal effort (28%). This test effectively detected submaximal effort (sensitivity=0.83 and specificity=0.93). Although this test is not safe for patients during initial therapy, it may be appropriate for patients who can safely exert maximal grip force. LEVEL OF EVIDENCE: Not applicable.

Identifying sincerity of effort based on the combined predictive ability of multiple grip strength tests.

STUDY DESIGN: Retrospective Cohort. INTRODUCTION: Detecting sincerity of effort (SOE) of grip strength remains a frustrating and elusive task for hand therapists because there are no valid, reliable, or widely accepted assessments for identifying feigned effort. Some therapists use various combinations of different SOE tests in an attempt to identify feigned effort, but there is lack of evidence to support this practice. PURPOSE: The present study examined the ability of a combination of three grip strength tests commonly used in the clinic to detect SOE: the five rung grip test, rapid exchange grip test, and coefficient of variation. A secondary purpose was to compare the predictive ability between the logistic and linear regression models. METHODS: Healthy participants (n=146) performed the three SOE tests exerting both maximal and submaximal efforts. We compared the ability of two regression models, the logistic and linear models, to predict sincere versus insincere efforts. RESULTS: Combining the three tests predicted SOE better than each test alone. Yet, the full logistic model, which was the best predictor of SOE, explained only 42% of variance and correctly classified only 58% of the efforts. CONCLUSIONS: Our findings do not support the clinical practice of combining these three tests to detect SOE. LEVEL OF EVIDENCE: Not applicable.

Using the force-time curve to determine sincerity of effort in people with upper extremity injuries.

UNLABELLED: This was a prospective cohort study. In a previous study, the slopes of the force-time (F-T) curve were shown to differentiate between maximal and submaximal grip effort in healthy participants. The objective of the study was to examine if the slopes of the F-T curve can determine the sincerity of effort in people with upper extremity injuries. Forty participants with unilateral upper extremity injury performed maximal and submaximal grip efforts. The F-T curve was recorded, and the slopes of the force-generation and force-decay phases were calculated. Repeated-measures analysis of variance revealed significantly steeper slopes for maximal than those for submaximal efforts. However, receiver operating characteristic curves showed that, at best, the slope of the force-generation phase yielded overall error rates of 55% for women and 60% for men. Therefore, sensitivity and specificity values were insufficient to effectively differentiate maximal from submaximal efforts. The slopes of the F-T curve did not validly measure the sincerity of effort in participants with upper extremity injury, perhaps, because they were protective of their injured hand and, thus, exerted only submaximal effort even at their best grip attempt. LEVEL OF EVIDENCE: Not applicable.

Validity, reliability, and responsiveness of a digital version of the visual analog scale.

UNLABELLED: The design used in this study was a prospective cohort. Pain intensity levels recorded by the digital version of the visual analog scale (VAS-D) are easy to both score and share with other health care professionals. The purpose of the study was to examine the test-retest reliability, concurrent validity, and responsiveness of the VAS-D. Thirty-three people with upper extremity injuries reported pain intensity levels before and after performing four maximal grip contractions (pre- and postgripping). Our version of the VAS-D had high test-retest reliability (r=0.96) and good concurrent validity (r=0.84-0.97) with both the paper version of the VAS (VAS-P) and the verbal numerical rating scale (NRS-V). Responsiveness of the VAS-D was indicated by a significant increase in pain levels from pre- to postgripping. Similar responsiveness to that of the VAS-P and NRS-V was indicated by similar effect size coefficients and analysis of variance of pain change scores. In conclusion, the VAS-D is a reliable, valid, and responsive measure of pain intensity for people with upper extremity injuries. However, differences in accuracy (resolution) among the VAS-D, VAS-P, or NRS-V may render the three pain scales not fully compatible. LEVEL OF EVIDENCE: Not applicable.

Influence of pain associated with musculoskeletal disorders on grip force timing.

STUDY DESIGN: Retrospective repeated-measures design. INTRODUCTION: Pain is a common symptom associated with musculoskeletal conditions. PURPOSE: This study examined if pain resulting from a unilateral upper extremity musculoskeletal injury compromises the person's ability to rapidly initiate and release handgrip. METHODS: Delays in initiating and releasing a handgrip were determined for 28 individuals with "low pain" and 12 individuals with "high pain" in the injured upper extremity. All participants had no pain in the uninjured upper extremity. RESULTS: The high-pain group was 10% slower in initiating and releasing a grip than the low-pain group, in both injured and uninjured upper extremities, for both maximal and submaximal grips. In addition, delay in grip initiation was, on average, 8% longer for the injured than for the uninjured upper extremity. CONCLUSIONS: Unilateral musculoskeletal pain appears to delay grip initiation and relaxation bilaterally, perhaps due to a centrally mediated mechanism. LEVEL OF EVIDENCE: n/a.

Driving simulator sickness: an evidence-based review of the literature.

OBJECTIVE: Guided by the Occupational Therapy Practice Framework: Domain and Process (2nd edition; American Occupational Therapy Association, 2008), we conducted an evidence-based review on simulator sickness (SS). METHOD: We searched Web of Science, PubMed, SafetyLit, Google Scholar, and recently published literature. We used the American Academy of Neurology's classification criteria to extract data from 10 studies and assign each a level of 1-4, with "1" indicating the highest level of evidence. We grouped studies that addressed SS into client factors, context and environment factors, and activity demands. RESULTS: Client factors (i.e., older clients [>70 yr; Level B], women [Level B]) and context/environment factors (e.g., refresh rates, scenario design and duration, simulator configuration, and calibration; Level B) probably increase the rates of SS, whereas activity demands (vection, speed of driving, and postural instability; Level C) possibly contribute to SS. CONCLUSION: We classified factors contributing to SS and identified the need for randomized trials to identify causes of SS.

Traffic violations versus driving errors of older adults: informing clinical practice.

Certain driving errors are predictive of crashes, but whether the type of errors evaluated during on-road assessment is similar to traffic violations that are associated with crashes is unknown. Using the crash data of 5,345 older drivers and expert reviewers, we constructed a violation-to-error classification based on rater agreement. We examined the effects of predictor variables on crash-related injuries by risk probability using logistic regression. Drivers' mean age was 76.08 (standard deviation = 7.10); 45.7% were women. Of drivers, 44.6% sustained crash-related injuries, and female drivers had a higher injury probability (44%) than male drivers (29%). Lane maintenance, yielding, and gap acceptance errors predicted crash-related injuries with almost 50% probability; speed regulation (34%), vehicle positioning (25%), and adjustment-to-stimuli (21%) errors predicted crash-related injuries to a lesser degree. We suggest injury prevention strategies for clinicians and researchers to consider for older drivers, especially older women.

Validity and critical driving errors of on-road assessment for older drivers.

OBJECTIVES: We examined the validity of our on-road driving assessment to quantify its outcomes. METHOD: Older drivers (N = 127) completed a driving assessment on a standardized road course. Measurements included demographics, driving errors, and driving test outcomes; a categorical global rating score (pass-fail); and the sum of maneuvers (SMS) score (0-273). RESULTS: There were significant differences in the SMS (F = 29.9, df = 1, p < or = .001) between drivers who passed the driving test and those who failed. The SMS cutoff value of 230 points was established as the criterion because it yielded the most optimal combination of sensitivity (0.91) and specificity (0.87). The strongest predictors of failure were adjustment to stimuli and lane maintenance errors. CONCLUSION: The SMS differentiated between passing and failing drivers and can be used to inform clinical decision making.

The impact of roadway intersection design on driving performance of young and senior adults.

OBJECTIVE: To test the effectiveness of the FHWA guidelines for intersection design. METHODS: In an experimental design we used kinematics measures from an instrumented vehicle and behavioral (error) data collected during on-road evaluations to quantify the effects of improved versus unimproved intersections (turn phase) and to determine if these intersections were safer (vehicular stability and driver confidence) for both older (65-85 years) and younger (25 -45) drivers. We analyzed kinematics data with a 2 x 2 repeated measures ANOVA and behavioral data (driving errors yes, no) with Wilcoxon sign rank test (within subject variable: intersection improved vs. unimproved) and Wilcoxon rank sum test (between subject variable: age, younger vs. older driver). RESULTS: Kinematics measures (turn phase), showed three maneuvers had statistically significantly lesser side forces (measured by lateral acceleration and combined acceleration) for the improved conditions, and four maneuvers had statistically significantly greater, yet appropriate, speeds for the improved conditions. Lesser side forces indicated improved lateral stability and increased speed indicated greater confidence. Drivers made fewer errors on two of the improved intersections; but across all maneuvers, older drivers appeared to make fewer errors on the improved intersections. CONCLUSIONS: This study brings empirical intersection design and safety information for engineers and city planners to consider as they plan and develop intersections. Future researchers may want to use the conceptual and analytical framework of this study to determine the effectiveness of other FHWA guidelines. Given that these intersection design guidelines benefit younger and older drivers alike, plausible policy-making opportunities are opened in the design of safe roadway systems, to benefit the broad spectrum of adult drivers.

The Effect of Propulsion Style on Wrist Movement Variability During the Push Phase After a Bout of Fatiguing Propulsion.

BACKGROUND: Wheelchair propulsion has been linked to overuse injuries regardless of propulsion style. Many aspects of the arcing (ARC) and semicircular (SEMI) propulsion styles have been compared, but differences in intracycle movement variability, which have been linked to overuse injuries, have not been examined. OBJECTIVE: To explore how ARC and SEMI affect changes in intracycle wrist movement variability after a fatiguing bout of propulsion. DESIGN: Repeated measures crossover design. SETTING: Wheelchair rollers and wheelchair fatigue course in a research laboratory. PARTICIPANTS: Twenty healthy, nondisabled adult men without previous wheelchair experience. INTERVENTIONS: Participants learned ARC and SEMI and used each to perform a wheelchair fatigue protocol. MAIN OUTCOME MEASUREMENTS: Thirty seconds of propulsion on rollers were recorded by motion-capture cameras before and after a fatigue protocol for each propulsion style on 2 testing days. Angular wrist orientations (flexion/extension and radial/ulnar deviation) and linear wrist trajectories (mediolateral direction) were computed, and intracycle movement variability was calculated as standard deviations of the detrended and filtered values during the push phase beginning and end. Paired samples t tests were used to compare ARC and SEMI based on the percent changes from pre- to postfatigue protocol. RESULTS: Both propulsion styles resulted in increased intracycle wrist movement variability postfatigue, but observed increases did not significantly differ between ARC and SEMI. CONCLUSIONS: This study evinces that intersubject variability exceeded average changes in intracycle wrist movement variability for both propulsion styles. Neither propulsion style resulting in a greater change in intracycle movement variability may suggest that no single propulsion style is ideal for everyone. The large intersubject variability may indicate that the propulsion style resulting in the smallest increase in intracycle movement variability after a fatiguing bout of propulsion may differ for each person and may help explain why wheelchair users self-select to use different propulsion styles.

The use of the coefficient of variation in detecting sincerity of effort: a meta-analysis.

The coefficient of variation (CV) is used to determine sincerity of effort of strength measurements. However, there is a controversy in the literature concerning its validity and effectiveness. We used a meta-analytic approach and calculated the effect size between maximal and submaximal efforts for the CV of grip, elbow flexion and knee extension. We summarized findings concerning stability, sensitivity and specificity of the CV. We found large effect sizes (d > or = 0.8) for all comparisons indicating that submaximal efforts were more variable than maximal efforts. We also found large error rates and low stability of the CV. The error rates and stability values of the CV are unacceptable from both a clinical and a medico-legal standpoint. Therefore, the use of the CV for assessing sincerity of effort needs to be questioned.

Wheelchair ergonomic hand drive mechanism use improves wrist mechanics associated with carpal tunnel syndrome.

Among conventional manual wheelchair (CMW) users, 49% to 63% experience carpal tunnel syndrome (CTS) that is likely induced by large forces transmitted through the wrist and extreme wrist orientations. The ergonomic hand drive mechanism (EHDM) tested in this study has been shown to utilize a more neutral wrist orientation. This study evaluates the use of an EHDM in terms of wrist orientations that may predispose individuals to CTS. Eleven adult full-time CMW users with spinal cord injury participated. Motion data were captured as participants propelled across a flat surface, completing five trials in a CMW and five trials in the same CMW fitted with the EHDM. Average angular wrist orientations were compared between the two propulsion styles. Use of the EHDM resulted in reduced wrist extension and ulnar deviation. The shift to more neutral wrist orientations observed with EHDM use may reduce median nerve compression.

Development of an item bank for a computerised adaptive test of upper-extremity function.

PURPOSE: The purpose of this study was to determine the psychometric characteristics of an upper-extremity item bank as a precursor to developing a computer adaptive patient reported outcome instrument. The Activity dimension of the World Health Organization's International Classification of Functioning, Disability and Health (ICF) provided the conceptual framework for the items. METHOD: Factor and Rasch analyses were used to evaluate the psychometric properties of the item bank, including: monotonicity, local independence, dimensionality, item difficulty hierarchy and match between sample ability and item difficulty. RESULTS: Monotonicity of the rating scale was supported. Nine item pairs were locally dependent, and thus one item from each pair was removed from subsequent analyses. There was evidence for two unidimensional constructs; gross upper-extremity and fine hand. Both constructs showed good internal consistency and person separation. In general, the order of item difficulty within each construct replicated the hypothesised item difficulty order. The fine hand construct had a ceiling effect. CONCLUSIONS: The above study of our newly developed upper-extremity item bank empirically verified the intended item difficulty order, identified separate constructs (i.e. gross upper-extremity and fine hand) and provided insights into eliminating the ceiling effect of one of the constructs. These findings are critical precursors to the development of upper-extremity components of the ICF Activity Measure, an ICF-based, CAT located on the web at: www.icfmeasure.phhp.ufl.edu.

A comparison of the ability of two upper extremity assessments to measure change in function.

STUDY DESIGN: Retrospective Measurement Comparison. INTRODUCTION: Upper extremity musculoskeletal disorders affect millions, thus, discerning optimal assessments for measuring change in upper extremity function is critical. PURPOSE OF THE STUDY: To compare responsiveness (ability to measure change) of the Disabilities of Arm, Shoulder, and Hand (DASH) and Upper Extremity Functional Index (UEFI). METHODS: Statistical analyses included Rasch analysis to place the instruments on the same scale, analysis of variance to compare change scores, correlations to compare change scores with global ratings, and the use of receiver operating characteristic (ROC) curves to determine meaningful change scores and overall error. RESULTS: Change scores on the DASH and UEFI and correlations between change scores and global ratings were similar. Areas under the ROC curves for the DASH and UEFI were 67% and 65%, respectively. CONCLUSIONS: Neither assessment has a clear advantage over the other when measuring clinical change. LEVEL OF EVIDENCE: Not applicable.

Comparison of driving errors between on-the-road and simulated driving assessment: a validation study.

OBJECTIVE: Driving simulation provides a convenient and safe method for assessing driving behaviors. Many authors, however, agree that validation is a key component of any study that utilizes simulators to assess driving performance. The purpose of this study was to test driver response validity by discerning whether behavioral responses of drivers, as expressed by type and number of errors, are similar on the road and in the simulator. METHODS: We replicated real-world intersections in our driving simulator (STISIM M500W; Systems Technology Inc.) and assessed the number and type of driving errors committed by the same 39 participants while negotiating a right and a left turn both on the road and in the simulator. RESULTS: We found no significant interactions between the type of vehicle (road vs. simulator) and the type of turn (right versus left) for any of the driving errors, indicating that the same trends exist between driving errors made on the road and in the simulator and thus suggesting relative validity of the simulator. We also found no significant differences between the road and the simulator for lane maintenance, adjustment to stimuli, and visual scanning errors, indicating absolute validity for these types of errors. CONCLUSIONS: The findings suggest early support for external validity for our driving simulator, indicating that the results of assessing driving errors when negotiating turns in the simulator can be generalized or transferred to the road under the same testing conditions. A follow-up study with larger sample size is needed to establish whether driving performance in the simulator is predictive of driving performance on the road.

The administration and interpretation of the rapid exchange grip test: a national survey.

The purpose of the present study was to determine if the administration and interpretation of the rapid exchange grip (REG) test vary among hand therapists nationally. The REG is used to determine sincerity of effort of grip strength. There are inconsistencies in the literature regarding the administration and interpretation of the REG, as various studies use different testing protocols and diverse interpretation criteria for what constitutes a sincere effort. As a result, we expected to find a lack of standardization in the administration and interpretation of the REG in clinical practice. We conducted a random nationwide survey of 200 hand therapists. The questionnaire items regarding the administration of the REG included patient position, test instructions, handle settings, handling of the dynamometer, hand switch rate, number of repetitions, and techniques used to record the score. The items for the interpretation of the REG involved questions regarding comparative tests. We found that the REG test lacks standardized administration protocols and interpretation criteria among therapists nationwide. The lack of standardization is likely to affect the reliability and validity of the REG and to hinder the therapist's ability to accurately report its outcomes. The implications of lack of standardization in assessment techniques to the profession are discussed.

Clinical predictors of older driver performance on a standardized road test.

OBJECTIVES: To determine the relationship between clinical variables (demographics, cognitive testing, comorbidities, and medications) and failing a standardized road test in older adults. METHODS: Analysis of on-the road studies performed in optimal weather conditions, between January 1, 2005, and May 1, 2007. The standardized testing was held at the National Older Driver Research and Training Center (NODRTC), Florida, and included 127 adults aged 65 and older with current driver licenses, recruited by advertisement from the Gainesville, Florida, community. Measurements consist of demographics, self-reported medications and medical conditions, cognitive testing including Trail Making Part B, global rating score (pass/fail), and driver maneuver score (0-273, with 273 indicating perfect driving or zero errors). RESULTS: A total of 127 older adults completed the protocol. Mean age was 74.8 years (SD = 6.3); 46.5% females. Mean time for Trail Making Part B was 114.3 seconds (SD of 83). Among the 127 drivers, the mean Sum of Maneuvers Score was 238.9 (SD of 25.0) and 24 (19%) failed the driver test. Odds ratio estimates for failing the test included advanced age (6.7, 95% CI 2.2 to 19.8), presence of a neurological disease (2.8, 95% CI 1.2 to 6.5), and prolonged time to complete the Trail Making Part B cognitive test (2.5, 95% CI 1.0 to 5.9). Conversely, odds ratio estimates lowering the risk of failure included taking a non-diabetic hormonal medications (e.g., thyroid and estrogen drugs; 0.3, 95% CI .09 to 0.7) and having a musculoskeletal diagnosis (0.3, 95% CI .1 to 0.7). CONCLUSIONS: To our knowledge, this is the first study to examine the medical predictors of failing a standardized road test. Advanced age and prolonged time on Trail Making Part B were the two major predictors of test failure and a lower Sum of Maneuvers Score. Our study also found that having a neurological diagnosis (primarily cerebrovascular and Parkinson's disease) predicted test failure. Medications from neurological class also predicted a lower Sum of Maneuvers Score. Further study needs to be done to explain the apparent protective effect of musculoskeletal conditions and hormonal medications.