Upper Extremity Function Assessment Using a Glove Orthosis and Virtual Reality System

Hand motor control deficits following stroke can diminish the ability of patients to participate in daily activities. This study investigated the criterion validity of upper extremity (UE) performance measures automatically derived from sensor data during manual practice of simulated instrumental activities of daily living (IADLs) within a virtual environment. A commercial glove orthosis was specially instrumented with motion tracking sensors to enable patients to interact, through functional UE movements, with a computer-generated virtual world using the SaeboVR software system. Fifteen stroke patients completed four virtual IADL practice sessions, as well as a battery of gold-standard assessments of UE motor and hand function. Statistical analysis using the nonparametric Spearman rank correlation reveals high and significant correlation between virtual world-derived measures and the gold-standard assessments. The results provide evidence that performance measures generated during manual interactions with a virtual environment can provide a valid indicator of UE motor status.

Altered visual strategies and attention are related to increased force fluctuations during a pinch grip task in older adults

The purpose of the study was to determine the visual strategies used by older adults during a pinch grip task and to assess the relations between visual strategy, deficits in attention, and increased force fluctuations in older adults. Eye movements of 23 older adults (>65 yr) were monitored during a low-force pinch grip task while subjects viewed three common visual feedback displays. Performance on the Grooved Pegboard test and an attention task (which required no concurrent hand movements) was also measured. Visual strategies varied across subjects and depended on the type of visual feedback provided to the subjects. First, while viewing a high-gain compensatory feedback display (horizontal bar moving up and down with force), 9 of 23 older subjects adopted a strategy of performing saccades during the task, which resulted in 2.5 times greater force fluctuations in those that exhibited saccades compared with those who maintained fixation near the target line. Second, during pursuit feedback displays (force trace moving left to right across screen and up and down with force), all subjects exhibited multiple saccades, and increased force fluctuations were associated ( rs = 0.6; P = 0.002) with fewer saccades during the pursuit task. Also, decreased low-frequency (<4 Hz) force fluctuations and Grooved Pegboard times were significantly related ( P = 0.033 and P = 0.005, respectively) with higher (i.e., better) attention z scores. Comparison of these results with our previously published results in young subjects indicates that saccadic eye movements and attention are related to force control in older adults. NEW & NOTEWORTHY The significant contributions of the study are the addition of eye movement data and an attention task to explain differences in hand motor control across different visual displays in older adults. Older participants used different visual strategies across varying feedback displays, and saccadic eye movements were related with motor performance. In addition, those older individuals with deficits in attention had impaired motor performance on two different hand motor control tasks, including the Grooved Pegboard test.

A method of hand motor control assessment in patients with post-stroke spasticity

Introduction: In order to assess hand spasticity in post-stroke patients, it is necessary to apply an objective and sensitive method which allows for characterising motor control. It is significant due to the necessity to monitor the effects of the therapeutic process according to the requirements of Evidence-Based Medicine (EBM). The aim of the study was to assess the usefulness of the measurement of pressure generated during a maximal palmar grasp and after its release for evaluating the level of hand motor control in poststroke patients compared to subjective scales. Material and methods: In order to characterise motor control, a numerical indicator calculated on the basis of the measurements of pressure generated during a maximal palmar grasp and after its release was suggested. To perform the measurements, 12 poststroke patients with hemiparesis were included in the study. In the research, the level of hand paresis was assessed with Brunnström Approach, the intensity of spasticity was graded with Modified Ashworth Scale, while hand motor function was classified with Fugl-Meyer Assessment (FMA). Pressure generated during a palmar grasp and after its release as well as palm area were measured with the use of a photometric method. The assessment was made twice, i.e. on the day of admission to the in-patient rehabilitation ward and after a three-week hospital treatment. Results: In the second measurement, a slight decrease in paresis intensity according to Brunnström Approach and lower intensity of spasticity according to Ashworth Scale were noted. A higher number of points in the FMA scale was observed. The values of the suggested indicator changed; however, in no case were these changes statistically significant. Conclusions: 1. Compared to other subjective scales, the usefulness of the measurement of pressure generated during a maximal palmar grasp and after its release for assessing the level of hand motor control in post-stroke patients was not confirmed. 2. The usefulness of the recommended method of spastic hand motor control assessment needs to be verified in further research carried out according to EBM requirements.

Comparative studies on standard and new test methods for evaluating the effects of structural firefighting gloves on hand dexterity

This research identifies laboratory test methods designed to advance assessment of the effects of structural firefighter gloves on a firefighter’s ability to perform tasks with their hands. Two new hand dexterity test methods are discussed: a modified tool test for measuring glove effects on gross or whole hand motor control, and a novel cylinder lift method for evaluating glove effects on fine or fingertip hand dexterity. Data generated by testing a representative group of structural firefighter and other responder gloves are used to show that these new test methods provide less variable data and a more useful and informative assessment of the effects of glove construction on hand dexterity than that provided by standard small pin pegboard tests. Based on these comparisons, a combination of the newly developed tool and cylinder lift test methods are recommended for evaluating the effects of structural firefighter gloves on hand dexterity in standards used as the basis of certifying the performance of structural firefighter clothing.

Hand Motor Control: Maturing an Immature Science

In the target article Mark Latash has argued that there is but a single bona-fide theory for hand motor control (referent configuration theory). If this is true, and research is often phenomenological, then we must admit that the science of hand motor control is immature. While describing observations under varying conditions is a crucial (but early) stage of the science of any field, it is also true that the key to maturing any science is to vigorously subject extant theories and budding laws to critical experimentation. If competing theories are absent at the present time is it time for scientists to focus their efforts on maturing the science of hand motor control through critical testing of this long-standing theory (and related collections of knowledge such as the uncontrolled manifold)?