Posts Tagged outcome assessment

[ARTICLE] A modified standardized nine hole peg test for valid and reliable kinematic assessment of dexterity post-stroke – Full Text

Abstract

Background

Impairments in dexterity after stroke are commonly assessed by the Nine Hole Peg Test (NHPT), where the only outcome variable is the time taken to complete the test. We aimed to kinematically quantify and to compare the motor performance of the NHPT in persons post-stroke and controls (discriminant validity), to compare kinematics to clinical assessments of upper extremity function (convergent validity), and to establish the within-session reliability.

Methods

The NHPT was modified and standardized (S-NHPT) by 1) replacing the original peg container with an additional identical nine hole pegboard, 2) adding a specific order of which peg to pick, and 3) specifying to insert the peg taken from the original pegboard into the corresponding hole of the target pegboard. Eight optical cameras registered upper body kinematics of 30 persons post-stroke and 41 controls during the S-NHPT. Four sequential phases of the task were identified and analyzed for kinematic group differences. Clinical assessments were performed.

Results

The stroke group performed the S-NHPT slower (total movement time; mean diff 9.8 s, SE diff 1.4), less smoothly (number of movement units; mean diff 0.4, SE diff 0.1) and less efficiently (path ratio; mean diff 0.05, SE diff 0.02), and used increased scapular/trunk movements (acromion displacement; mean diff 15.7 mm, SE diff 3.5) than controls (P < 0.000, r ≥ 0.32), indicating discriminant validity. The stroke group also spent a significantly longer time grasping and releasing pegs relative to the transfer phases of the task compared to controls. Within the stroke group, kinematics correlated with time to complete the S-NHPT and the Fugl-Meyer Assessment (rs 0.38–0.70), suggesting convergent validity. Within-session reliability for the S-NHPT was generally high to very high for both groups (ICCs 0.71–0.94).

Conclusions

The S-NHPT shows adequate discriminant validity, convergent validity and within-session reliability. Standardization of the test facilitates kinematic analysis of movement performance, which in turn enables identification of differences in movement control between persons post-stroke and controls that may otherwise not be captured through the traditional time-based NHPT. Future research should ascertain further psychometric properties, e.g. sensitivity, of the S-NHPT.

Background

Impaired upper limb dexterity is evident as in many as 45–70% of the stroke victims one year post-stroke [12]. Such impairment is often evaluated in clinics by performance of the Nine Hole Peg Test (NHPT) [3], which is a frequently used dexterity task in many clinical populations [4567]. The NHPT equipment consists of a container with nine small pegs and a target pegboard with nine holes. Performance of the NHPT requires the pegs to be picked up from the container one-by-one unimanually and transferred and inserted into the holes of the pegboard until it is filled, upon which the pegs are returned unimanually to the container. The test is performed as quickly as possible and the only outcome variable is the total time to complete the task. Consequently, motor performance is currently not analyzed during the NHPT despite potentially providing valuable information relating to upper limb dexterity, especially among persons with a neurological dysfunction.

Among persons with stroke, the NHPT is considered reliable [8], valid [7910], and sensitive to change [71011]. Nevertheless, and despite overall good test-retest reliability post-stroke, low test-retest reliability has been found in persons post-stroke who have spasticity in the affected hand [8]. Further, the measurement errors are large; the minimal detectable change of the NHPT is estimated to 33 s for an individual post-stroke, and even doubled in the presence of spasticity [8]. The measurement properties of computer-assisted assessments of NHPT in virtual environments have been investigated with promising results [1213]. However, high intra-subject variation indicates that haptic and virtual reality technologies are more demanding for a stroke population and for instance require more practice trials prior to the actual test than when performing a conventional NHPT.

Advantages of the NHPT include the simple, cheap and easily portable equipment as well as the test being easy to administer and time-efficient [710]. There are, however, some drawbacks when testing persons post-stroke. First, the outcome score of the test is based solely on the time for task accomplishment [14]. Hence, a time reduction of the NHPT in rehabilitation of a person post-stroke may represent either a true motor recovery (i.e. performing movement patterns in a similar way as before the stroke) or compensation (performing different movement patterns than prior to the stroke) [15]. Compensatory strategies are common during upper limb tasks post-stroke, and thus plausible in a fine manipulative task like the NHPT. Secondly, the current NHPT test procedure may provide unreliable results for repeated measures or group comparisons as there is no standardized procedure with regard to the order in which the pegs are inserted into the target holes. To increase the stringency of the NHPT, we modified and standardized the test, which we henceforth refer to as the Standardized Nine Hole Peg test (S-NHPT). The experimental setup with two pegboards was in analogy with that of a study exploring three different methods of completing the NHPT, focusing on comparisons to tests in a virtual setting [12]. However, we have standardized the experimental setup even further by stipulating the order in which the pegs should be transferred.

Kinematic assessments may detect changes in movement performance that are not captured by only considering the time taken to complete the NHPT [14], and provide objective measures that may be more sensitive and not vulnerable to ceiling effects [16]. Recent research calls for parameters indicating quality of movements in persons post-stroke by means of kinematic analysis in order to better understand motor recovery [141517]. However, a test of fine upper limb fine dexterity like the NHPT has not been investigated. Our modifications and standardization enabled our first aim to kinematically characterize S-NHPT performance in a group of persons post-stroke and compare it to that of a non-disabled control group (discriminant validity). A second aim was to determine the convergent validity of the S-NHPT by comparing kinematics (movement time, peak speed, number of movement units, reach-grasp ratio, path ratio, acromion vertical displacement and trunk displacement) to the total movement time and to other clinical assessments (the Fugl-Meyer Assessment, the Stroke Impact Scale and grip strength). A third aim was to establish the within-session reliability of the S-NHPT, i.e., the consistency of the hand trajectories during the nine pick-up and transfer movements of the test.[…]

 

Continue —-> A modified standardized nine hole peg test for valid and reliable kinematic assessment of dexterity post-stroke | Journal of NeuroEngineering and Rehabilitation | Full Text

 

Fig. 1Experimental setup and movement phases. a) Marker positions used for the calculations of the kinematic variables. Markers displayed with a dot in the center of the marker were positioned on the trunk. The enlarged pegboard shows the standardized order of which peg to pick and which hole to fill, referred to as the “vertical row strategy”. The S-NHPT consists of 9 pegs (3.8 cm long, 0.64 cm wide) and two pegboards (12.7 cm × 12.7 cm) with 9 holes (0.70 cm wide) spaced 3.2 cm apart. The two pegboards were attached to a wooden panel with a distance of 18 cm between the center holes of the pegboards. The arrow indicates the direction of the movement. b) The velocity of the index finger marker in the medial direction displays the events defining the transfer phases Peg Transfer (positive curve) and Hand Return (negative curve). The manipulative phases Peg Grip and Peg In Hole are between those transfer movements (see Methods)

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[ARTICLE] Upper Limb Kinematics in Stroke and Healthy Controls Using Target-to-Target Task in Virtual Reality – Full Text

Background: Kinematic analysis using virtual reality (VR) environment provides quantitative assessment of upper limb movements. This technique has rarely been used in evaluating motor function in stroke despite its availability in stroke rehabilitation.

Objective: To determine the discriminative validity of VR-based kinematics during target-to-target pointing task in individuals with mild or moderate arm impairment following stroke and in healthy controls.

Methods: Sixty-seven participants with moderate (32–57 points) or mild (58–65 points) stroke impairment as assessed with Fugl-Meyer Assessment for Upper Extremity were included from the Stroke Arm Longitudinal study at the University of Gothenburg—SALGOT cohort of non-selected individuals within the first year of stroke. The stroke groups and 43 healthy controls performed the target-to-target pointing task, where 32 circular targets appear one after the other and disappear when pointed at by the haptic handheld stylus in a three-dimensional VR environment. The kinematic parameters captured by the stylus included movement time, velocities, and smoothness of movement.

Results: The movement time, mean velocity, and peak velocity were discriminative between groups with moderate and mild stroke impairment and healthy controls. The movement time was longer and mean and peak velocity were lower for individuals with stroke. The number of velocity peaks, representing smoothness, was also discriminative and significantly higher in both stroke groups (mild, moderate) compared to controls. Movement trajectories in stroke more frequently showed clustering (spider’s web) close to the target indicating deficits in movement precision.

Conclusion: The target-to-target pointing task can provide valuable and specific information about sensorimotor impairment of the upper limb following stroke that might not be captured using traditional clinical scale.

Introduction

In stroke, the prevalence of upper limb impairment is approximately 50–80% in the acute phase (13) and 40–50% in the chronic phase (24). The frequently observed upper limb impairments after stroke are paresis, abnormal muscle tone, decreased somatosensation, and coordination. As a consequence of these impairments, individuals with stroke may experience reduced ability to perform everyday activities such as opening a door, handling a key, or working with a computer. Therefore, assessment of upper limb motor function is critical for determining the prognosis and evaluating the treatment effects following stroke (56).

The assessment of motor functions in stroke is usually performed using standardized clinical scales. Some of the most frequently used clinical instruments for assessing upper extremity impairment and activity capacity in stroke are Fugl-Meyer Assessment of Upper Extremity (FMA-UE) and Action Research Arm Test (ARAT) (79). These scales are reliable (1012) and responsive to change (1314) for measuring gross changes in motor function. They have also been recommended as core measures to be included in every stroke recovery trial (6). However, observer-based ordinal instruments like FMA-UE and ARAT lack the sensitivity to assess subtle, yet, potentially important changes in movement performance (15). These clinical scales tend to have ceiling effect since they rely on scoring criteria rather than a continuous measurement construct (16).

Kinematic assessment is one solution for the need for a more objective, accurate, and sensitive measurement method (6). Kinematic assessment is being increasingly used in upper limb evaluation after stroke, out of which motion capture systems (17), robotic devices, and virtual reality (VR) systems with haptic devices (18) have become popular in the last decade. Kinematic assessment has revealed that the arm movements in subjects with stroke are slower, less accurate, less smooth, and more segmented than healthy subjects (1926).

Kinematic assessment involving the use of VR with haptic device has shown to be a promising tool for upper limb stroke rehabilitation (2728). Despite the availability of the VR system for stroke rehabilitation, it has been rarely used in assessment of upper limb movements after stroke. Individuals with stroke use similar strategies for reaching objects in both real and virtual environments (29). Previous studies using the target-to-target pointing task have shown that the movement time, velocity, and trajectory straightness were improved after a 5-week computer gaming practice in individuals with stroke (30). Movement time, mean velocity, and trajectory straightness were also stable in a test–retest study in healthy subjects (31). A clear advantage with VR systems as a measurement tool is its standardized instructions, adaptation of tasks according to patients’ functioning level, and availability of quick feedback (32). The VR assessment and training are often described as enjoyable and challenging by the users (3334).

The target-to-target pointing task is similar to routinely used tasks in everyday life, such as interacting with touch screens, using electrical switches, and pushing buttons on various devices. The choice of a regularly performed, purposeful task for this study increases its ecological validity. With VR technologies becoming more available, it opens up an opportunity to use the VR interface to acquire accurate and detailed kinematic data of upper limb movements after stroke (35). The novelty of this study is in evaluating a compact and easy-to-use haptic device coupled with VR in 3D space in order to measure movement performance during a common upper limb task.

The aim of this study was to identify the end-point kinematic variables obtained during the VR-based target-to-target pointing task that discriminate among individuals with mild and moderate upper limb impairment after stroke and healthy controls.[…]

 

Continue —>  Frontiers | Upper Limb Kinematics in Stroke and Healthy Controls Using Target-to-Target Task in Virtual Reality | Neurology

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[DOCTORAL DISSERTATION] Upper extremity disability after stroke. Psychometric properties of outcome measures and perceived ability to perform daily hand activities – Full Text

LUND UNIVERSITY

Department of Health Sciences, Physiotherapy, Lund University

DOCTORAL DISSERTATION

Date of issue 2016-10-08

Author(s) Elisabeth Ekstrand

Abstract

Disability of the upper extremity is common after stroke. To be able to evaluate recovery and effects of interventions there is a need for stable and precise outcome measures. In order to design and target efficient rehabilitation interventions it is important to know which factors that affect the ability to perform daily hand activities. At the time when the studies in this thesis were planned there was limited knowledge of the psychometric properties of outcome measures for persons with mild to moderate impairments of the upper extremity after stroke. There was also a lack of knowledge of which daily hand activities these persons perceive difficult to perform and which factors are associated with the performance.

The overall aim of this thesis was to evaluate the psychometric properties of outcome measures for upper extremity after stroke, and to describe which daily hand activities persons with mild to moderate impairments in upper extremity after stroke perceive difficult to perform and identify associated factors with their performance.

In paper I – IV, between 43 and 45 participants were included. Muscle strength in the upper extremity, somatosensation (active touch), dexterity and self-perceived ability to perform daily hand activities were assessed twice, one to two weeks apart. In paper V, 75 participants were included and the evaluated measures of the upper extremity were used together with other stroke specific outcomes to cover important aspects of functioning and disability according to the International Classification of Functioning, Disability and Health (ICF). Test-retest analyses for continuous data were made with the Intraclass Correlation Coefficient (ICC), the Change in Mean, the Standard Error of Measurement (SEM) and the Smallest Real Difference (SRD) (Paper I, III and IV). For ordinal data the Kappa coefficient and the Elisabeth Svensson rank-invariant method were used (Paper II and III). For analyses of convergent validity the Spearman’s correlation coefficient (rho) was calculated (Paper III). The ability to perform daily hand activities and the associations with potential factors were evaluated by univariate and multivariate linear regression models (Study V).

The results showed that outcome measures for isometric and isokinetic muscle strength, active touch, dexterity and self-perceived daily hand activities have high test-retest agreements and can be recommended for persons with mild to moderate impairments in the upper extremity after stroke (Paper I to IV). Isometric strength measurements had lower measurement errors than isokinetic measurements and might be preferred (Paper I). The outcomes of dexterity showed learning effects (Paper III) and the ratings of perceived daily hand activities (Paper IV) had relatively high random measurement errors which must be taken into account when recovery and effects of interventions are evaluated. The three evaluated dexterity measures were partly related and can complement each other (Paper IV). Daily hand activities that require bimanual dexterity were perceived most difficult to perform, and dexterity and participation were the strongest contributing factors for performing daily hand activities after stroke (Paper V).

In conclusion, this thesis has shown that outcome measures assessing functioning and disability of upper extremity after stroke are reliable and can be used in clinical settings and research. To increase the ability to perform daily hand activities, dexterity and perceived participation, in particular, should be considered in the assessments, goal-settings and rehabilitation after stroke.

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[Abstract] Clinically Important Difference of the Arm Motor Ability Test in Stroke Survivors

Abstract

Background. The Arm Motor Ability Test (AMAT) is used to assess and quantify upper-extremity (UE) functional limitation in stroke and other conditions. However, the AMAT score change indicative of important and clinically meaningful change has not been determined.

Objective. To determine the clinically important difference (CID) for the AMAT for individuals with stroke exhibiting mild to moderate hemiparesis.

Methods. A total of 146 chronic stroke survivors exhibiting stable, mild to moderate UE hemiparesis were administered the AMAT before and after interventions targeting their affected UEs. Patients and treating therapists rated perceived amount of UE motor recovery for each participant on a global rating of change (GROC) scale evaluating several facets of UE movement (grasp, release, move the affected UE, perform 5 important functional tasks, overall UE function). Estimated CID of the Functional Ability Scale of the AMAT was calculated using the receiver operating characteristics curve with the GROC scale as the anchor. Distribution-based methods were also used to estimate the CID.

Results. Mean baseline, postintervention, and change in AMAT values for all participants were 3.0 (0.68), 3.3 (0.73), and 0.33 (0.43) respectively. The CID was estimated as an improvement of 0.32 to 0.42 when anchored by the therapist’s perception of improvement and 0.29 to 0.40 when anchored by the patient’s perception of improvement. The CID using distribution-based methods ranged from 0.40 to 0.44.

Conclusions. A change of 0.44 or greater on the AMAT indicates a clinically meaningful improvement in UE functional movements. Clinicians should use this value to determine goals and interpret change scores.

Source: Clinically Important Difference of the Arm Motor Ability Test in Stroke Survivors

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[ARTICLE] Grip strength is a representative measure of muscle weakness in the upper extremity after stroke – Full Text

Abstract

Background: Muscle weakness is the most common impairment in the upper extremity after stroke, leading to a reduced ability to use the arm and the hand in daily activities. Grip strength is easier to measure than precise, but more time-consuming, isokinetic and isometric arm muscle strength measurements. It would therefore be advantageous in a clinical setting if grip strength could be used as a proxy for muscle strength in the entire upper extremity.
Objective: To investigate the association between grip strength and isometric and isokinetic arm muscle strength in persons with chronic stroke.
Methods: Forty-five persons with mild-to-moderate paresis in the upper extremity, at least 6 months post-stroke participated. Isometric grip strength was measured with a computerized grip dynamometer and arm strength (isometric shoulder abduction and elbow flexion as well as isokinetic elbow extension and flexion) with an isokinetic dynamometer. Pearson’s correlation coefficient was used to determine the association between the muscle strength measurements.
Results: There were significant correlations (p < .0001) between grip strength and all arm strength measurements in both the more affected (r = 0.77–0.82) and the less affected upper extremity (r = 0.65–0.82).
Conclusion: This cross-sectional study showed that grip strength is strongly associated with muscle strength in the arm in persons in the chronic phase after stroke. As grip strength is easy to measure and less time-consuming than arm muscle strength measurements, this implies that grip strength can be a representative measure of muscle weakness of the entire upper extremity in the chronic phase after stroke.

Continue —>  Grip strength is a representative measure of muscle weakness in the upper extremity after stroke – Topics in Stroke Rehabilitation –

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[ARTICLE] A cohort study investigating a simple, early assessment to predict upper extremity function after stroke – a part of the SALGOT study – Full Text HTML

Abstract

Background: For early prediction of upper extremity function, there is a need for short clinical measurements suitable for acute settings. Previous studies demonstrate correct prediction of function, but have ether included a complex assessment procedure or have an outcome that does not automatically correspond to motor function required to be useful in daily activity. The purpose of this study was to investigate whether a sub-set of items from the Action Research Arm Test (ARAT) at 3 days and 1 month post-stroke could predict the level of upper extremity motor function required for a drinking task at three later stages during the first year post-stroke.

Methods: The level of motor function required for a drinking task was identified with the Fugl-Meyer Assessment for Upper Extremity (FMA-UE). A structured process was used to select ARAT items not requiring special equipment and to find a cut-off level of the items’ sum score. The early prognostic values of the selected items, aimed to determine the level of motor function required for a drinking task at 10 days and 1 and 12 months, were investigated in a cohort of 112 patients. The patients had a first time stroke and impaired upper extremity function at day 3 after stroke onset, were ≥18 years and received care in a stroke unit.

Results: Two items, “Pour water from glass to glass” and “Place hand on top of head”, called ARAT-2, met the requirements to predict upper extremity motor function. ARAT-2 is a sum score (0-6) with a cut-off at 2 points, where >2 is considered an improvement. At the different time points, the sensitivity varied between 98 % and 100 %, specificity between 73 % and 94 %. Correctly classified patients varied between 81 % and 96 %.

Conclusions: Using ARAT-2, 3 days post-stroke could predict the level of motor function (assessed with FMA-UE) required for a drinking task during the first year after a stroke. ARAT-2 demonstrates high predictive values, is easily performed and has the potential to be clinically feasible.

Full Text HTML —>  BMC Neurology | Full text | A cohort study investigating a simple, early assessment to predict upper extremity function after stroke – a part of the SALGOT study.

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[ARTICLE] Factors Associated with Home versus Institutional Discharge Following Inpatient Stroke Rehabilitation

…One in five stroke patients were discharged to a SNF after inpatient rehabilitation. Several sociodemographic and clinical characteristics on admission were identified that could be considered as important factors in early discussions for discharge planning…

via Factors Associated with Home versus Institutional Discharge Following Inpatient Stroke Rehabilitation – Archives of Physical Medicine and Rehabilitation.

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ARTICLE: Corticospinal Tract Integrity and Lesion Volume Play Different Roles in Chronic Hemiparesis and Its Improvement Through Motor Practice

…CST integrity correlated best in this small trial with chronic long-term status but not treatment-induced improvements. The CST may play a different role in the mechanisms mediating long-term outcome compared to those underlying practice-induced gains after a chronic plateau in motor function…

via Corticospinal Tract Integrity and Lesion Volume Play Different Roles in Chronic Hemiparesis and Its Improvement Through Motor Practice.

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