Showing papers in "Journal of Rehabilitation Research and Development in 2004"

The effect of walking speed on center of mass displacement.

Abstract: The movement of the center of mass (COM) during human walking has been hypothesized to follow a sinusoidal pattern in the vertical and mediolateral directions. The vertical COM displacement has been shown to increase with velocity, but little is known about the mediolateral movement of the COM. In our evaluation of the mediolateral COM displacement at several walking speeds, 10 normal subjects walked at their self-selected speed and then at 0.7, 1.0, 1.2, and 1.6 m/s in random order. We calculated COM location from a 15-segment, full-body kinematic model using segmental analysis. Mediolateral COM displacement was 6.99 +/- 1.34 cm at the slowest walking speed and decreased to 3.85 +/- 1.41 cm at the fastest speed (p < 0.05). Vertical COM excursion increased from 2.74 +/- 0.52 at the slowest speed to 4.83 +/- 0.92 at the fastest speed (p < 0.05). The data suggest that the relationship between the vertical and mediolateral COM excursions changes substantially with walking speed. Clinicians who use observational gait analysis to assess walking problems should be aware that even normal individuals show significant mediolateral COM displacement at slow speeds. Excessive vertical COM displacement that is obvious at moderate walking speeds may be masked at slow walking speeds.

Weakness and strength training in persons with poststroke hemiplegia: rationale, method, and efficacy.

Abstract: Several converging lines of contemporary evidence suggest that weakness presents a more serious compromise to movement function in poststroke hemiplegia than spasticity. This review exami ...

Quality of life of individuals with spinal cord injury: a review of conceptualization, measurement, and research findings.

Abstract: Quality of life (QoL) is increasingly becoming a key concept in research and clinical services. However, no agreement exists on what QoL is and how it is to be measured. This paper reviews three different yet linked approaches to QoL conceptualization: QoL as subjective well-being; QoL as achievement; and QoL as utility. People with spinal cord injury (SCI) tend to report fewer feelings of well-being, on average, than nondisabled persons; score lower on physical, mental, and social health and in other domains of life that people consider important to life quality; and have a health state that is preferred much less than that of the average person. Many QoL instruments used in SCI research have not been validated for this group, or have questionable assumptions, and clinical applications of QoL measures still have many problems. Much SCI QoL research tends to be atheoretical.

Stepping over obstacles to improve walking in individuals with poststroke hemiplegia.

Abstract: For this study, we evaluated two training interventions for improving gait parameters in individuals with poststroke hemiplegia using a training methodology that required them to step over objects. Gait velocity, step length, ability to step over obstacles, and walking endurance were compared before and after 2 weeks of training and 2 weeks after cessation of training. Twenty subjects with poststroke hemiplegia completed six intervention sessions in which they were asked to step over either virtual objects while walking on a motorized treadmill or real foam objects on a 10 m walkway. With the virtual object training, if either foot collided with the virtual object, a tone sounded and a vibrotactile stimulus was applied to the colliding foot. All subjects tolerated the training sessions well, and no incidences of falling or undue cardiovascular responses occurred. The virtual obstacle training generated greater improvements in gait velocity compared with real training (20.5% vs. 12.2% improvement) during the fast walk test (p < 0.01). Improvements in gait velocity for both training methods were similar in the self-selected walk test (33.3% vs. 34.7% improvement). Overall, subjects showed clinically meaningful changes in gait velocity, stride length, walking endurance, and obstacle clearance capacity as a result of either training method. These changes persisted for 2 weeks posttraining. The inclusion of enhanced safety and visual augmentation may be responsible for the effectiveness of the virtual object intervention. These results demonstrate preliminary evidence for clinical effectiveness of obstacle training for improving gait velocity poststroke. In addition, these results provide evidence for enhanced clinical performance with virtual obstacle training.

Comparison of the 2-, 6-, and 12-minute walk tests in patients with stroke.

Abstract: This study assessed inter- and intrarater reliability and sensitivity to change of the 2-, 6-, and 12-minute walk tests following stroke. A convenience sample of patients enrolled in an inpatient stroke rehabilitation program participated in the standardization protocol. The 2-, 6-, and 12-minute walk tests were performed and inter- and intrarater reliability and responsiveness to change assessed. The interrater intraclass correlation coefficients (ICCs) for the 2-, 6-, and 12-minute walk tests were, respectively, 0.85, 0.78, and 0.68 (p < 0.0007 for each). The intrarater ICCs were 0.85, 0.74, and 0.71 (p < 0.0003 for each). Responsiveness to change as measured by standardized response mean (SRM) scores was, respectively, 1.34, 1.52, and 1.90 (F = 24.24, p < 0.001). Pearson correlations for the 2-, 6-, and 12-minute walk tests by the same rater on the same day were 2 versus 6 minutes, r = 0.997; 2 versus 12 minutes, r = 0.993; and 6 versus 12 minutes, r = 0.994 (p < 0.0001 for each). The 2-, 6-, and 12-minute walk tests show acceptable inter- and intrarater reliability and high intertest correlations when they are used for the assessment of walking following stroke. The SRM statistic indicates that the 12-minute walk test is the most responsive to change.

Pushrim biomechanics and injury prevention in spinal cord injury: recommendations based on CULP-SCI investigations.

Abstract: Over 50 percent of manual wheelchair users with spinal cord injury (SCI) are likely to develop upper-limb pain and injury. The majority of studies related to pain have implicated wheelchair propulsion as a cause. This paper draws from a large multisite trial and a long-standing research program to make specific recommendations related to wheelchair propulsion that may decrease the risk of upper-limb injury. The studies include over 60 subjects over 1 yr after a traumatic SCI below the second thoracic level. Specific aspects of the propulsive stroke that may relate to injury include cadence, magnitude of force, and the pattern of the hand during the nonpropulsive part of the stroke. Lower peak forces, slower cadence, and a circular propulsive stroke in which the hand falls below the pushrim during recovery may help prevent injury. In addition, wheelchair users should use the lightest weight adjustable wheelchair possible. Future work should include interventional trials and larger studies that allow for more complex statistical models that can further detail the relationship between wheelchair propulsion, user characteristics, and upper-limb injuries.

A systematic literature review of the effect of different prosthetic components on human functioning with a lower-limb prosthesis

Abstract: A correct prosthetic prescription can be derived from adapting the functional benefits of a prosthesis to the functional needs of the prosthetic user. For adequate matching, the functional abilities of the amputees are of value, as well as the technical and functional aspects of the various prosthetic components. No clear clinical consensus seems to be given on the precise prescription criteria. To obtain information about different prosthetic components and daily functioning of amputees with a prosthesis, we performed a systematic literature search. The quality of the studies was assessed with the use of predetermined methodological criteria. Out of 356 potentially relevant studies, 40 studies eventually qualified for final methodological analysis and review. Four satisfied all the criteria and were classified as A-level studies, 26 as B-level, and 10 studies as C-level studies. Despite a huge amount of literature, our formal clinical knowledge had considerable gaps concerning the effects of different prosthetic components and their mechanical characteristics on human functioning with a lower-limb prosthesis. Therefore, with regard to prosthetic guideline development, we must still largely rely on clinical consensus among experts. The integration of knowledge from research with the expert opinion of clinical professionals and the opinions and wishes of consumers can form a solid base for a procedure on guideline development for prosthetic prescription.

The smart wheelchair component system.

Abstract: While the needs of many individuals with disabilities can be satisfied with power wheelchairs, some members of the disabled community find it difficult or impossible to operate a standard power wheelchair. To accommodate this population, several researchers have used technologies originally developed for mobile robots to create "smart wheelchairs" that reduce the physical, perceptual, and cognitive skills necessary to operate a power wheelchair. We are developing a Smart Wheelchair Component System (SWCS) that can be added to a variety of commercial power wheelchairs with minimal modification. This paper describes the design of a prototype of the SWCS, which has been evaluated on wheelchairs from four different manufacturers.

Prevalence and identification of shoulder pathology in athletic and nonathletic wheelchair users with shoulder pain: A pilot study.

Abstract: Although many wheelchair users report shoulder pain, the prevalence of specific pathologies remains controversial. Rotator cuff impingement, glenohumeral instability, and biceps tendonitis have been stated as the most commonly found pathology. This study investigated the prevalence and identity of shoulder pathology in athletic and nonathletic manual wheelchair users (MWCUs). Fifty-two MWCUs (26 athletes, 26 nonathletes) completed a survey regarding the nature of their injury, sports involvement, history, and presence of current and/or past shoulder pathology. Subjects currently experiencing shoulder pain underwent a clinical examination of both shoulders. Analysis of variance (p

Effectiveness of insoles on plantar pressure redistribution.

Abstract: For this study, we compared the effectiveness of different design insoles for redistributing pressure during walking for diabetic patients and for normal control subjects. Comparisons of dynamic plantar foot pressure patterns were made with different support, including shoe-only, flat insole, and three contoured insoles. We custom-molded the three contoured insoles by casting the plantar surface of the foot under the conditions of non-weight-bearing, semi-weight-bearing, and full-weight-bearing. With the F-Scan in-shoe system, the interfacial pressure distribution during walking with different plantar supports was measured at 50 Hz for 10 s. The use of insoles could significantly reduce local peak pressure and pressure-time integral and increase the contact area. Contoured insoles were significantly better than flat insoles with regard to the insole functions in reducing local peak pressures. The insole with the semi-weight-bearing foot shape can offer the greatest peak pressure reduction compared to other insole designs, especially for patients with peak pressure located at the second to third metatarsal heads.

Questionnaire for Persons with a Transfemoral Amputation (Q-TFA): initial validity and reliability of a new outcome measure.

Abstract: The Questionnaire for Persons with a Transfemoral Amputation (Q-TFA) is a new self-report measure developed for nonelderly transfemoral amputees using a socket- or osseointegrated prosthesis to reflect use, mobility, problems, and global health, each in a separate score (0-100). This paper describes the initial measurement properties of the Q-TFA as completed by 156 persons with a transfemoral amputation using a socket prosthesis (67% male, 92% nonvascular cases, mean age 51 years). Criterion validity was determined by associations between scores of the Q-TFA and the Short-Form 36 (SF-36)-Item Health Survey. Reliability was assessed by retest (n = 48) and by determination of the internal consistency. Correlations between Q-TFA and SF-36-Item Health Survey scales matched hypothesized patterns. Intraclass correlations were between 0.89 and 0.97, and measurement error ranged from 10 to 19 points. Cronbach's alpha revealed good internal consistency, with no values less than 0.7. This study shows that the Q-TFA, applied to persons using a transfemoral socket prosthesis, has adequate initial validity and reliability.

Identification of key pinch forces required to complete functional tasks.

Abstract: Reconstructive hand surgeries restore key pinch to individuals with pinch force deficits caused by tetraplegia. Data that define the magnitudes of force necessary to complete functional key pinch tasks are limited. This study aims to establish target pinch forces for completing selected tasks that represent a range of useful functional activities. A robot arm instrumented with a force sensor completed the tasks and simultaneously measured the forces applied to the task objects. Lateral pinch force requirements were calculated from these measured object forces. Pinch force requirements ranged from 1.4 N to push a button on a remote to 31.4 N to insert a plug into an outlet. Of the tasks studied, 9 of 12 required less than 10.5 N. These pinch force requirements, when compared to pinch forces produced by 14 individuals with spinal cord injuries (with and without surgical reconstruction of pinch), accurately predicted success or failure in 81% of subject trials. The prediction errors indicate a need to measure other factors such as pinch opening, force location, force direction, and proximal joint control.

Cerebral and cerebellar sensorimotor plasticity following motor imagery-based mental practice of a sequential movement.

Abstract: Motor behavior and sensorimotor activation of the cerebrum and cerebellum were measured before and after motor imagery-based mental practice (MP) and physical practice (PP) of a sequential motor task. Two-button-press sequences (A, B) were performed outside a magnetic resonance imaging scanner and at 2 Hz inside the scanner during a pretest. Participants (n = 39) completed PP, MP, or no practice (NP) of Sequence A for 1 week and were posttested. Sequence A performance improved 121%, 86%, and 4% for the PP, MP, and NP groups, respectively (p 0.05). PP improvements were accompanied by increased striatal and decreased cerebellar activation, while MP improvements were accompanied by increased cerebellar, premotor, and striatal activation. The efficacy of MP for activating cerebral and cerebellar sensorimotor networks suggests that MP might be an effective substitute or complement to PP to activate compensatory networks for motor rehabilitation.

The Influence of Voluntary Tonic Emg Level on the Vestibular-Evoked Myogenic Potential

Abstract: Vestibular-evoked myogenic potentials (VEMPs) are proposed as a reliable test to supplement the current vestibular test battery by providing diagnostic information about saccular and/or inferior vestibular nerve function. VEMPs are short-latency electromyograms (EMGs) evoked by high-level acoustic stimuli and recorded from surface electrodes over the tonically contracted sternocleidomastoid muscle. VEMP amplitude is influenced by the EMG level, which must be controlled. This study examined the ability of subjects to achieve the EMG target levels over a range of target levels typically used during VEMP recordings. In addition, the influence of target EMG level on the latency and amplitude of the click- and tone-evoked VEMP was examined. The VEMP amplitude increased as a function of EMG target level, and the latency remained constant. EMG target levels ranging from 30 microV to 50 microV are suggested for clinical application of the VEMP.

Effects of shoe heel height on biologic rollover characteristics during walking.

Abstract: This study investigated the effects of shoe heel height on the rollover characteristics of the biologic ankle-foot system. Ten nondisabled adult female volunteers walked using three pairs of shoes with varying heel heights and at three walking speeds with each pair of shoes. Kinematic and kinetic data needed to calculate the rollover shapes of the ankle-foot systems of the participants were collected. Rollover shapes are the effective rocker geometries that ankle-foot systems conform to between heel contact and opposite heel contact. Parameters of the best-fit circular arcs to the rollover shapes were used in an examination of the effects of shoe heel height on the ankle-foot system. The results support the notion that nondisabled humans automatically adapt their ankle-foot systems to accommodate a range of shoe heel heights, resulting in rollover shapes that do not change appreciably. Given physiologic constraints, this adaptation may not be possible for very high heels.

Relationship between manual wheelchair skill performance and participation of persons with spinal cord injuries 1 year after discharge from inpatient rehabilitation

Abstract: This cross-sectional study describes the level of manual wheelchair skill performance and participation of persons with spinal cord injuries (SCIs) 1 year after discharge from inpatient rehabilitation and tests the hypothesis that wheelchair skill performance is positively related to participation. Participants included 81 persons with SCI from eight rehabilitation centers in the Netherlands. The Wheelchair Circuit consists of eight wheelchair skills and results in three test scores: ability, performance time, and physical strain. Participation was assessed with the sum of the subscales Mobility Range and Social Behavior of the 68-Item Sickness Impact Profile (SIPSOC). SIPSOC was moderately related to the ability score (the Spearman rank correlation [rS] = -0.49), the performance time score (rS = 0.54), and the physical strain score (rS = 0.38). The regression analyses showed that, after controlling for lesion and personal characteristics, manual wheelchair skill performance is positively related to participation, with the strongest association for the performance time score. In persons with SCI who are manual wheelchair users, wheelchair skill performance is moderately associated to participation. Training of wheelchair skills has to be an important goal of rehabilitation, and persons should be stimulated to maintain their wheelchair skills after discharge from rehabilitation.

Accelerometer output and its association with energy expenditure in persons with multiple sclerosis.

Abstract: Limited data support the strong association between rates of accelerometer activity counts and energy expenditure during dynamic activity in persons with multiple sclerosis (MS). This study examined the association between rates of activity counts and energy expenditure during walking by using two models of accelerometers and generated cut-points representing moderate-to-vigorous physical activity (MVPA) in persons with MS. Participants were 43 persons with MS and 43 controls who undertook 5 min of seated rest and up to five 6 min periods of walking at five different speeds on a treadmill. While walking, participants wore two models of accelerometers and a mouth- piece in-line with an open-circuit spirometry system for meas- uring energy expenditure (rate of oxygen consumption). Strong linear associations were found between accelerometer activity counts and energy expenditure, and the magnitude did not differ between MS and controls for both accelerometer models. The mean slopes of the linear relationships were steeper in persons with MS than controls and resulted in distinct cut-points for MVPA based on accelerometer counts for persons with MS and controls. The strong linear relationship between activity counts and energy expenditure and cut-points for quantifying time spent in MVPA should allow for better understanding of physical activity and examination of its predictors and consequences when using accelerometers in MS.

The effect of seat position on wheelchair propulsion biomechanics.

Abstract: This study examined the effect of seat position on handrim biomechanics. Thirteen experienced users propelled a wheelchair over a smooth level floor at a self-selected speed. Kinetic and temporal-distance data were collected with the use of an instrumented rim and a motion analysis system. A custom-designed axle was used to change the seat position. We used repeated measures analysis of variance to evaluate if differences existed in the temporal-distance and kinetic data with change in seat position. Results showed that a shorter distance between the axle and shoulder (low seat height) improved the push time and push angle temporal variables (p < 0.0001). Tangential force output did not change with seat position. Axial and radial forces were highest in the lowest seat position (p < 0.001). Propulsion efficiency as measured by the fraction of effective force did not significantly change with seat position.

Automated Constraint-Induced Therapy Extension (AutoCITE) for movement deficits after stroke.

Abstract: We report progress in the development of AutoCITE, a workstation that delivers the task practice component of upper-limb Constraint-Induced Movement therapy and that can potentially be used in the clinic or the home without the need for one-on-one supervision from a therapist. AutoCITE incorporates a computer and eight task devices arranged on a modified cabinet. Task performance is automatically recorded, and several types of feedback are provided. In preliminary testing, nine chronic stroke subjects with mild to moderate motor deficits practiced with AutoCITE for 3 h each weekday for 2 weeks. Subjects wore a padded mitt on the less-affected hand for a target of 90% of their waking hours. In terms of effect sizes, gains were large and significant on the Motor Activity Log, and moderate to large on the Wolf Motor Function Test. These gains were comparable to the gains of a matched group of 12 subjects who received standard Constraint-Induced Movement therapy.

Effect of an exercise program on functional performance of institutionalized elderly.

Abstract: This study determined the effectiveness of a 6-month program of regular exercises for the improvement of functional performance of the elderly living in a nursing home. The 40 subjects aged 60 to 99 who took part in this trial were assigned either to a comparative group or an exercise group. The following variables were measured: functional performance with the use of an obstacle course, a lower-limb function test, and a 6-minute walk test (gait velocity); isometric strength of the knee extensors; proprioception of the lower limbs; mental status through the Mini-Mental State Examination (MMSE); and depression symptoms with the use of the Geriatric Depression Scale (GDS). In the exercise group, 19 subjects completed the program and attended an average of 32 (68%) sessions. At the end of the trial, the exercise subjects showed significant performance improvement in quantitative and qualitative obstacle course scores, lower-limb function test, gait velocity test, knee extensors strength, and the GDS, while the nonexercise subjects showed significant decrease in qualitative obstacle course score, lower-limb function, gait velocity, MMSE, and the GDS.

Measures of postural stability.

Abstract: Dynamic posturography has become an important tool for understanding standing balance in clinical settings. A key test in the NeuroCom International (Clackamas, Oregon) dynamic posturography system, the Sensory Organization Test (SOT), provides information about the integration of multiple components of balance. The SOT test leads to an outcome measure called the "equilibrium score" (ES), which reflects the overall coordination of the visual, proprioceptive, and vestibular systems for maintaining standing posture. Researchers, therapists, and physicians often use the ES from the SOT as a clinically relevant measure of standing balance. We discuss here the formula used for evaluating the ES and propose an additional measure of postural stability, called the Postural Stability Index (PSI), that accounts for shear force and individual anthropomorphic measures. We propose that this new measure provides a clinically important adjunct to the current SOT and can be calculated from data already collected by the NeuroCom forceplate during the SOT.

A comparative study of the effects of electrical stimulation and laser treatment on experimental wound healing in rats.

Abstract: We investigated the effects of electrical stimulation (ES) and laser treatment on wound healing in rats. A randomized-controlled trial, conducted at the Experimental and Clinical Research Centre of Erciyes University (Kayseri, Turkey), divided 124 healthy female Swiss-Albino rats into four groups. A 6 cm linear incision was made at the dorsal skin of all rats. Group 1 was given a constant direct current of 300 microA for 30 min per day. The current was applied in negative polarity for the first 3 days and in positive polarity for the next 7 days. Group 3 received a full-contact, continuous gallium-arsenide (GaAs) laser therapy, with a wavelength of 904 nm, an energy density of 1 J/cm2, and an average power of 6 mW for 10 min per day. The remaining two groups (Groups 2 and 4) were considered the control groups and received sham treatment. All groups were treated for 10 days. Histopathologic and biochemical evaluations were conducted on 10 rats from each group on the 4th and 10th days, and wound breaking strength was measured for biomechanical evaluation on the 25th day of the study. Both ES and laser treatment proved significantly effective in the inflammatory phase compared with control groups (p 0.05). Although ES and laser treatment both were effective in the maturation phase, increasing wound breaking strength compared with their control groups (p 0.05). We conclude that ES and laser treatment both have beneficial effects during the inflammatory, proliferation, and maturation phases of a wound. Both ES and laser treatment can be used successfully in decubitis ulcers and chronic wounds, in combination with conventional therapies such as daily care and debridement of wounds; however, ES has more beneficial effects during the inflammatory phase in some parameters than laser treatment.

The relationship between energy expenditure and lean tissue in monozygotic twins discordant for spinal cord injury.

Abstract: Energy expenditure and fat-free mass (FFM), as well as the relationships between these parameters, were investigated in thirteen pairs of monozygotic twins discordant for SCI. Basal energy expenditure (BEE) and resting energy expenditure (REE) were determined by indirect calorimetry. Measurements for FFM and fat mass were obtained by dual-energy x-ray absorptiometry. Total body potassium was determined by a 4-Pi whole-body counting chamber. Values are expressed as mean standard deviation. BEE and REE of the twins with SCI were significantly less than those of the able-bodied co-twins (1387 268 vs. 1660 324 kcal/d, p < 0.005, and 1682 388 vs. 1854 376 kcal/d, p < 0.05, respectively). Regardless of the group, direct and highly significant relationships were evident between BEE or REE and FFM or TBK. In summary, twins with SCI had lower energy expenditure than their able-bodied co-twins. Regardless of paralysis, direct linear relationships existed between energy expenditure and measures of lean mass.

Use of Rasch person-item map in exploratory data analysis: a clinical perspective.

Abstract: The National Institutes of Health (NIH) includes visual impairment in the 10 most prevalent causes of disability in America. As rehabilitation programs have the potential to restore independence and improve the quality of life for affected persons, NIH research priorities include evaluating their effectiveness. This paper demonstrates a clinical perspective on the use of the Rasch person-item map to evaluate the range and precision of a new vision function questionnaire in early analysis (prior to full sample). A self-report questionnaire was developed to measure the difficulty that persons with different levels of vision loss have performing daily activities. This 48-item Veterans Affairs Low-Vision Visual Functioning Questionnaire (VA LV VFQ-48) was administered to 117 low-vision patients. Preliminary analysis indicates that the questionnaire items are applicable to persons of differing abilities. The Rasch person-item map demonstrates that the field-test version of the VA LV VFQ-48 has good range and is well centered with respect to the person measure distribution. Construct validity and reliability are also demonstrated.

Duration and functional outcome of spinal cord injury rehabilitation in the Netherlands.

Abstract: This study describes the length of stay (LOS) and functional outcome of spinal cord injury (SCI) in the Netherlands and its determinants. Data of 157 patients from eight rehabilitation centers were available. Mean age was 40.0 years and 76.4% were traumatic injuries, 39.8% had tetraplegia, and 69.9% had a motor complete SCI. Median LOS was 240 days (interquartile range 164-322). Median motor Functional Independence Measure (FIM) scores at discharge were 37.3 for persons with complete tetraplegia and 69.7 for persons with complete paraplegia. Level and completeness of injury, bed rest because of pressure sores, and LOS were predictors of motor FIM scores. Duration of SCI rehabilitation in the Netherlands is long compared with the literature. Functional outcome appears slightly better in persons with complete tetraplegia, but not in persons with complete paraplegia when compared with data from the United States. International studies are necessary to reveal strengths and weaknesses of SCI rehabilitation systems in different countries.

Shape and volume change in the transtibial residuum over the short term: preliminary investigation of six subjects.

Abstract: A preliminary investigation was conducted to characterize the magnitude and distribution of volume change in transtibial residua at two time intervals: upon prosthesis removal and at 2 week intervals. Six adult male unilateral transtibial amputee subjects, between 0.75 and 40.0 years since amputation, were imaged 10 times over a 35-minute interval with a custom residual limb optical scanner. Volume changes and shape changes over time were assessed. Measurements were repeated 2 weeks later. Volume increase on socket removal for the six subjects ranged from 2.4% to 10.9% (median 6.0% +/- standard deviation 3.6%). Rate of volume increase was highest immediately upon socket removal and decreased with time (five subjects). In four subjects, 95% of the volume increase was reached within 8 minutes. No consistent proximal-to-distal differences were detected in limb cross-sectional area change over time. Limb volume differences 2 weeks apart ranged from -2.0% to 12.6% (0.6% +/- 5.5%) and were less in magnitude than those within a session over the 35-minute interval (five subjects). Multiple mechanisms of fluid movement may be responsible for short-term volume changes, with different relative magnitudes and rates in different amputees.

The biomechanics of wheelchair propulsion in individuals with and without upper-limb impairment.

Abstract: We used an instrumented wheelchair ergometer and 3D motion analysis system to collect joint kinematic and temporal data, as well as hand rim and joint kinetics, in 47 manual wheelchair users (MWCUs) (15 with upper-limb impairment and 32 without upper-limb impairment). The group with upper-limb impairment propelled with a higher stroke frequency and reduced hand-rim contact time, and smaller peak joint angles and joint excursion of the wrist, elbow, and shoulder during the contact phase. They also propelled with a reduced power output and reduced hand-rim propulsive and resultant forces, moments, and joint compressive forces. We concluded that these kinematic and kinetic strategies might be a mechanism for allowing MWCUs with upper-limb impairment to remain independent. Additionally, the reduced joint excursion and reduced magnitude of forces may protect them from the development of secondary upper-limb pathologies.

Using wavelet analysis to characterize the thermoregulatory mechanisms of sacral skin blood flow

Abstract: Pressure-induced skin blood flow responses measured via laser Doppler flowmetry are commonly reported in the time domain. The usefulness of spectral analysis in examining blood flow control mechanisms has been demonstrated, but traditional Fourier analysis does not provide sufficient resolution to reveal characteristic low frequencies. Time-frequency (wavelet) analysis was performed on 10 subjects' sacral skin blood flow responses to heating (45 degrees C) with improved resolution. Five frequency bands were identified (0.008-0.02 Hz, 0.02-0.05 Hz, 0.05-0.15 Hz, 0.15-0.4 Hz, and 0.4-2.0 Hz) corresponding to metabolic, neurogenic, myogenic, respiratory, or cardiac origins. Significant differences were observed in the mean normalized power of the metabolic (p < 0.01) and myogenic frequency bands (p < 0.01) between preheating and maximal heating and preheating and postheating periods. Power increased for the metabolic frequency and decreased for the myogenic frequency. Wavelet analysis successfully characterized thermoregulatory control mechanisms by revealing the contributions of the physiological rhythms embedded in the blood flow signal.

The experience of time in the transition from hospital to home following stroke.

Abstract: This paper reports findings related to the transition from hospital to home during the first month after discharge following acute stroke. Qualitative data were obtained from in-depth, semistructured interviews with 51 male stroke survivors and their caregivers. Data were analyzed with the N6 software application, designed to assist with qualitative data analysis. Stroke survivors described experiences related to changes in the temporal order of life, disruptions in sense of self, and strategies used to manage time. Findings indicate that changes in the temporal order of life are related to functional impairments and disruption in the taken-for-granted body. At 1 month post-discharge, survivors are struggling with establishing routines in their day and coping with an increased amount of idle time. In conclusion, strategies for managing increased idle time are "passing time," "waiting on time," and "killing time."

The potential of virtual reality for rehabilitation.

Abstract: Today’s clinician is privileged to have access to a variety of technologies that provide tools for both research and clinical intervention. The papers in this issue illustrate some of the ways in which technology improves therapy and enhances evaluation. We learn how dynamic posturography can lead to a better understanding of standing balance in clinical settings, how a variety of innovative biomechanical techniques (e.g., polycentric knee mechanism, optical scanner imaging of the transtibial residua) may improve gait for people with amputations, how automatic speech recognition is being used as a computer input method, and how ultrasound and laser treatments may benefit wound healing. An equally innovative technology that has not yet been presented within these pages is virtual reality (VR), the use of interactive simulations created with computer hardware and software to present users with opportunities to engage in environments that appear and feel similar to real-world objects and events [1–3]. VR is considered one of the most innovative technologies and promises to have a considerable impact on neurorehabilitation over the next 10 years [4]. Virtual environments are usually experienced with the aid of special hardware and software for input (transfer of information from the user to the system) and output (transfer of information from the system to the user). The selection of appropriate hardware and software is important because their characteristics may greatly influence the way users respond to a virtual environment [5]. The output to the user can be delivered by different modalities including visual, auditory, haptic, vestibular, and olfactory stimuli, although, to date, most VR systems deliver primarily visual-auditory feedback. Visual information is commonly displayed by headmounted displays, projection systems, or flat screens of varying size. In addition to specialized hardware, application software is also necessary. In recent years, off-the-shelf, ready-for-clinical-use VR software has become available for purchase. However, more frequently, special software development tools are required for the design and coding of an interactive simulated environment that will achieve a desired rehabilitation goal. In many cases, innovative intervention ideas may entail customized programming for the construction of a virtual environment from scratch, with the use of traditional programming languages. VR technologies have now begun to be used as an assessment and treatment tool in rehabilitation [3,6]. Applications have been directed at a variety of clinical populations including those with cognitive [7–11] and metacognitive [12–14] deficits. Other applications are being directed at the rehabilitation of motor deficits [15–17] to help provide recreational opportunities for people with severe disabilities [18]. VR also shows promise for training in activities of daily living with different populations, including use of a virtual kitchen and vending machine, street crossing, and a hospital and university way-finding environment [11,19,20]. The rehabilitation of driving skills following traumatic brain injury is one example in which individuals may begin at a simple level (i.e., straight, Patrice L. (Tamar) Weiss, PhD; Noomi Katz, OTR, PhD Department of Occupational Therapy, University of Haifa, Haifa, Israel; School of Occupational Therapy, Hadassah-Hebrew University, Jerusalem, Israel