WEARCON: wearable home monitoring in children with asthma reveals a strong association with hospital based assessment of asthma control.

BACKGROUND: Asthma is one of the most common chronic diseases in childhood. Regular follow-up of physiological parameters in the home setting, in relation to asthma symptoms, can provide complementary quantitative insights into the dynamics of the asthma status. Despite considerable interest in asthma home-monitoring in children, there is a paucity of scientific evidence, especially on multi-parameter monitoring approaches. Therefore, the aim of this study is to investigate whether asthma control can be accurately assessed in the home situation by combining parameters from respiratory physiology sensors. METHODS: Sixty asthmatic and thirty non-asthmatic children were enrolled in the observational WEARCON-study. Asthma control was assessed according to GINA guidelines by the paediatrician. All children were also evaluated during a 2-week home-monitoring period with wearable devices; a physical activity tracker, a handheld spirometer, smart inhalers, and an ambulatory electrocardiography device to monitor heart and respiratory rate. Multiple logistic regression analysis was used to determine which diagnostic measures were associated with asthma control. RESULTS: 24 of the 27 uncontrolled asthmatic children and 29 of the 32 controlled asthmatic children could be accurately identified with this model. The final model showed that a larger variation in pre-exercise lung function (OR = 1.34 95%-CI 1.07-1.68), an earlier wake-up-time (OR = 1.05 95%-CI 1.01-1.10), more reliever use (OR = 1.11 95%-CI 1.03-1.19) and a longer respiratory rate recovery time (OR = 1.12 95%-CI 1.05-1.20) were significant contributors to the probability of having uncontrolled asthma. CONCLUSIONS: Home-monitoring of physiological parameters correlates with paediatrician assessed asthma control. The constructed multivariate model identifies 88.9% of all uncontrolled asthmatic children, indicating a high potential for monitoring of asthma control. This may allow healthcare professionals to assess asthma control at home. TRIAL REGISTRATION: Netherlands Trail Register, NL6087 . Registered 14 February 2017.

Factors influencing the use of an artificial intelligence-based app (selfBACK) for tailored self-management support among adults with neck and/or low back pain.

PURPOSE: Tailored self-management support is recommended as first-line treatment for neck and low back pain, for which mHealth applications could be promising. However, there is limited knowledge about factors influencing the engagement with such apps. The aim of this study was to assess barriers and facilitators for engaging with a self-management mHealth app among adults suffering from neck and/or low back pain. MATERIALS AND METHODS: We carried out a qualitative descriptive study among adults with neck and/or low back pain. The artificial intelligence-based selfBACK app supports tailored self-management of neck and low back pain and was used for 6 weeks. After these 6 weeks, participants were interviewed by phone. RESULTS: Thirty-two adults (17 males) with neck and/or low back pain participated (mean age = 54.9 (SD = 15.8)). Our results show that the mode of delivery and the novelty of the selfBACK app were perceived most often as a barrier to use the app. The action plans of the app and health-related factors were perceived most often as facilitating factors. CONCLUSIONS: This study provides insight into possible strategies to improve an mHealth service. Furthermore, it shows that adults with neck and/or low back pain are willing and ready to receive blended treatment.

Adults with neck and/or low back pain are willing to receive blended care (combination of face-to-face contact with healthcare professional and use of eHealth service)When implementing eHealth services in rehabilitation treatment of adults with neck and/or low back pain, rehabilitation professionals need to choose an eHealth service which includes individual action plans, evidence-based content with health benefits, goal setting and rewards and incentives.When implementing eHealth services in rehabilitation treatment of adults with neck and/or low back pain, rehabilitation professionals need to choose an eHealth service which can be used on someone's own smartphone.When implementing eHealth services in rehabilitation treatment of adults with neck and/or low back pain, rehabilitation professionals need to educate their patients about the importance and possible long-term benefits of self-managing their pain.

Comparing VO2max determined by using the relation between heart rate and accelerometry with submaximal estimated VO2max.

AIM: An exploratory study to identify parameters that can be used for estimating a subject's cardio-respiratory physical fitness level, expressed as VO2max, from a combination of heart rate and 3D accelerometer data. METHODS: Data were gathered from 41 healthy subjects (23 male, 18 female) aged between 20 and 29 years. The measurement protocol consisted of a sub-maximal single stage treadmill walking test for VO2max estimation followed by a walking test at two different speeds (4 and 5.5 kmh-1) for parameter determination. The relation between measured heart rate and accelerometer output at different walking speeds was used to get an indication of exercise intensity and the corresponding heart rate at that intensity. Regression analysis was performed using general subject measures (age, gender, weight, length, BMI) and intercept and slope of the relation between heart rate and accelerometer output during walking as independent variables to estimate the VO2max. RESULTS: A linear regression model using a combination of the slope and intercept parameters, together with gender revealed the highest percentage of explained variance (R2 = 0.90) and had a standard error of the estimate (SEE) of 2.052 mL O2kg-1min-1 with VO2max. Results are comparable with current commonly used sub-maximal laboratory tests to estimate VO2max. CONCLUSION: The combination of heart rate and accelerometer data seems promising for ambulant estimation of VO2max-.

Spasticity and contractures at the wrist after stroke: time course of development and their association with functional recovery of the upper limb.

OBJECTIVE: To investigate the time course of development of spasticity and contractures at the wrist after stroke and to explore if these are associated with upper limb functional recovery. DESIGN: Longitudinal observational study using secondary data from the control group of a randomized controlled trial. SETTING: The Acute Stroke Unit at the University Hospital of North Staffordshire. SUBJECTS: Patients without useful arm function (Action Research Arm Test - ARAT) score of 0 within 6 weeks of a first stroke. MAIN MEASURES: Spasticity was measured by quantifying muscle activity during passively imposed stretches at two velocities. Contractures were measured by quantifying passive range of movement and stiffness. Upper limb functional movement was assessed using the ARAT. All assessments were conducted at baseline, and at 6, 12, 24 and 36 weeks after recruitment. RESULTS: Thirty patients (43% male, median age 70 (range 52-90) years, median time since stroke onset 3 (range 1-5) weeks) were included. Twenty-eight (92%) demonstrated signs of spasticity throughout the study period. Participants who recovered arm function (n = 5) showed signs of spasticity at all assessment points but did not develop contractures. Patients who did not recover useful arm function (n = 25) had signs of spasticity and changes associated with contracture formation at all time points tested. CONCLUSION: In this group of patients who had no arm function within the first 6 weeks of stroke, spasticity was seen early, but did not necessarily hinder functional recovery. Contractures were more likely to develop in patients who did not recover arm function.

The relationship between objectively and subjectively measured activity levels in people with chronic low back pain.

OBJECTIVE: To compare self-report measures of daily activities with objective activity data to determine whether patients with chronic lower back pain report their activity levels as accurately as controls do. DESIGN: A cross-sectional study was performed in patients and controls. SETTING: The study was carried out in the daily environment of the subjects. SUBJECTS: Thirty-two chronic lower back pain patients with symptoms more than three months and 20 healthy controls from the Netherlands, aged 18-65 years. MAIN MEASURES: A tri-axial accelerometer was worn for five weekdays and the Baecke Physical Activity Questionnaire was filled in. Pearson's correlation was calculated to get insight in the awareness of patients and controls. Comparisons of the relationship between the objective and subjective scores of each individual patient with those of the group of controls were used to allocate each patient into subgroups: overestimators, underestimators and aware patients. Physical and psychological characteristics of these groups were explored. RESULTS: Patients showed weak correlations between the objective and subjective scores of physical activity and appear to have problems in estimating their activity levels (r = -0.27), in contrast to controls who showed strong correlations between the objective and subjective scores (r = 0.66). Comparison of the individual relationships of patients with those of controls showed that 44% of the patients were not aware of their activity level. There were relatively more underestimators (30%) than overestimators (14%). Physical characteristics between the three groups tended to be different. CONCLUSIONS: Patient self-reports about their activity level are relatively inaccurate when compared to objective measurements.

Chronic fatigue syndrome: Abnormally fast muscle fiber conduction in the membranes of motor units at low static force load.

OBJECTIVE: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of - especially muscular -fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities. METHODS: Females with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured. RESULTS: The CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed. CONCLUSION: Our results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance. SIGNIFICANCE: These findings help to detangle the underlying mechanisms of CFS.

Stop using the Ashworth Scale for the assessment of spasticity.

AIM: Many studies have been performed on the methodological qualities of the (modified) Ashworth Scale but overall these studies seem inconclusive. The aim of this study was to investigate the construct validity and inter-rater reliability of the Ashworth Scale (AS) for the assessment of spasticity in the upper and lower extremities. METHOD: A cross-sectional study on spasticity in the elbow flexors (part 1) and knee extensors (part 2) was carried out. In both parts AS was assessed while muscle activity and resistance were recorded simultaneously in patients with upper motor neuron syndrome. Each patient was measured by three raters. RESULTS: 30 patients participated, 19 in each part of the study. For elbow flexor muscles, AS was not significantly associated with electromyographic parameters, except for rater 2 (rho = 0.66, p<0.01). A significant moderate association was found with resistance (0.54< or = rho < or =0.61, p<0.05). For knee extensors, AS scores were moderately associated with muscle activity (0.56< or = rho < or =0.66, p<0.05) and also with resistance (0.55< or = rho < or =0.87, p<0.05). The intraclass correlation coefficient for absolute agreement was 0.58 for elbow flexors and 0.63 for knee extensors. In linear mixed model analysis, the factor rater appeared to be highly associated with AS. CONCLUSION: The validity and reliability of the AS is insufficient to be used as a measure of spasticity.

Does exercise-induced bronchoconstriction affect physical activity patterns in asthmatic children?

Exercise-induced bronchoconstriction (EIB) is a sign of uncontrolled childhood asthma and classically occurs after exercise. Recent research shows that EIB frequently starts during exercise, called breakthrough-EIB (BT-EIB). It is unknown whether this more severe type of EIB forces children to adapt their physical activity (PA) pattern in daily life. Therefore, this pilot study aims to investigate daily life PA (amount, intensity, duration, and distribution) in children with BT-EIB, 'classic' EIB, and without EIB. A Fitbit Zip activity tracker was used for one week to objectively measure daily life PA at one-minute intervals. Thirty asthmatic children participated. Children with BT-EIB were less physically active compared to children without EIB (respectively 7994 and 11,444 steps/day, p = .02). Children with BT-EIB showed less moderate-to-vigorous PA compared to the children without (respectively 117 and 170 minutes/day, p = .02). Children with EIB (both BT and classic) had significant shorter bouts of activity and a less stretched distribution of bout lengths compared to the non-EIB group (all p < .05). These results emphasize a marked association between EIB severity and PA patterns in daily life, stressing the need for a thorough clinical evaluation of exercise-induced symptoms in childhood asthma.

Patient ratings of spasticity during daily activities are only marginally associated with long-term surface electromyography.

AIM: To investigate the association between subjective spasticity ratings and objective spasticity measurement using a new tool for spasticity assessment, that is long-term surface electromyography (sEMG) recordings during daily activities. For monitoring, processing and analysis of this long-term sEMG data, a muscle activity detection algorithm was developed. METHOD: sEMG of the rectus femoris, vastus lateralis, adductor group and semitendinosus of 14 complete spinal-cord-injured patients, in whom voluntary muscle contraction was absent, was recorded continuously during daily activities. Synchronously, subjects stored their activities in a diary and scored their experienced level of spasticity on the Visual Analogue Scale (VAS) for that particular activity. sEMG data were analysed using a high-quality burst-detection algorithm that was developed and validated within this study. Derived sEMG parameters were clustered using principal-component analysis (PCA) and used in a linear mixed model analysis to study their association with VAS. RESULTS: VAS scores appeared significantly associated with the PCA components representing the number and the duration of bursts, but not burst amplitude. Furthermore, VAS scores were associated with the activity performed. The percentage explained variance was, however, low, that is 27-35%. CONCLUSIONS: Patient ratings of the level of spasticity appear poorly associated with spasticity in terms of involuntary muscle activity assessed with long-term sEMG recordings. It is likely that other factors such as pain and cognitions are also incorporated in these patient ratings. Clinicians are therefore strongly advised to perform complementary objective assessments using long-term sEMG recordings.

Influence of gravity compensation on muscle activation patterns during different temporal phases of arm movements of stroke patients.

BACKGROUND: Arm support to help compensate for the effects of gravity may improve functional use of the shoulder and elbow during therapy after stroke, but gravity compensation may alter motor control. OBJECTIVE: To obtain quantitative information on how gravity compensation influences muscle activation patterns during functional, 3-dimensional reaching movements. METHODS: Eight patients with mild hemiparesis performed 2 sets of repeated reach and retrieval movements, with and without unloading the arm, using a device that acted at the elbow and forearm to compensate for gravity. Electromyographic (EMG) patterns of 6 upper extremity muscles were compared during elbow and shoulder joint excursions with and without gravity compensation. RESULTS: Movement performance was similar with and without gravity compensation. Smooth rectified EMG (SRE) values were decreased from 25% to 50% during movements with gravity compensation in 5 out of 6 muscles. The variation of SRE values across movement phases did not differ across conditions. CONCLUSIONS: Gravity compensation did not affect general patterns of muscle activation in this sample of stroke patients, probably since they had adequate function to complete the task without arm support. Gravity compensation did facilitate active arm movement excursions without impairing motor control. Gravity compensation may be a valuable modality in conventional or robot-aided therapy to increase the intensity of training for mildly impaired patients.

Spasticity, an impairment that is poorly defined and poorly measured.

OBJECTIVE: To explore, following a literature review, whether there is a consistent definition and a unified assessment framework for the term 'spasticity'. The congruence between the definitions of spasticity and the corresponding methods of measurement were also explored. DATA SOURCES: The search was performed on the electronic databases Web of Science, Science Direct and MEDLINE. REVIEW METHODS: A systematic literature search of publications written in English between the years 1980 and 2006 was performed with the following keywords: spasticity and tone. The search was limited to the following keywords: stroke, hemiplegia, upper, hand and arm. RESULTS: Two hundred and fifty references contributed to this review (190 clinical trials, 46 literature reviews, and 14 case reports). Seventy-eight used the Lance definition; 88 equated spasticity with increased muscle tone; 78 provided no definition; and six others used their own definitions for spasticity. Most papers used a single measure and some used more than one. Forty-seven papers used neurophysiological methods of testing, 228 used biomechanical methods of measurement or assessment, 25 used miscellaneous clinical measures (e.g. spasm frequency scales) and 19 did not explicitly describe a measure. CONCLUSION: The term spasticity is inconsistently defined and this inconsistency will need to be resolved. Often, the measures used did not correspond to the clinical features of spasticity that were defined within a paper (i.e. internal validity was compromised). There is need to ensure that this lack of congruence is addressed in future research.

Behaviour of a surface EMG based measure for motor control: motor unit action potential rate in relation to force and muscle fatigue.

Surface electromyography parameters such as root-mean-square value (RMS) and median power frequency (FMED) are commonly used to assess the input of the central nervous system (CNS) to a muscle. However, RMS and FMED are influenced not only by CNS input, but also by peripheral muscle properties. The number of motor unit action potentials (MUAPs) per second, or MUAP Rate (MR), being the sum of the firing rates of the active motor units, would reflect CNS input solely. This study explored MR behaviour in relation to force and during a fatiguing contraction in comparison to RMS and FMED. In the first experiment (n=10) a step contraction of shoulder elevation force (20-100 N) was performed while multi-channel array EMG was recorded from the upper trapezius muscle. The sensitivity of MR for changes in force (1.8%/N) was almost twice as high as that of RMS (0.97%/N), indicating that MR may be more suitable for monitoring muscle force. The second experiment (n=6) consisted of a 15-min isometric contraction of the biceps brachii. MR increased considerably less than RMS (0.9% vs. 4.1%), suggesting that MR selectively reflects central motor control whereas RMS also reflects peripheral changes. These results support that, at relatively low force levels, MR is a suitable parameter for non-invasive assessment of the input of the CNS to the muscle.

Trapezius muscle rest time during standardised computer work--a comparison of female computer users with and without self-reported neck/shoulder complaints.

Work related musculoskeletal disorders (WMSDs) in the shoulder/neck area are a common and increasing problem among European computer workers, especially women. Long-term low-level workloads with low degree of muscle rest are a potential risk factor for developing WMSDs. The purpose of the present study of female computer users (age 45-65 years) in Denmark and Sweden was to investigate if subjects with self-reported neck/shoulder complaints (cases, N=35) show less trapezius muscle relative rest time (RRT) than controls (N=44) when performing standardised short-term computer work tasks in controlled laboratory conditions. Surface electromyography (EMG) signals were recorded bilaterally from the upper trapezius muscles during a type, edit, precision and colour word stress task. Besides RRT, 10th percentile RMS values were calculated. On the average, 15 of the cases and 18 of the controls showed analysable EMG files per task. For the colour word stress task, the results showed lower RRT values and higher 10th percentile RMS amplitude levels among cases compared to controls. No such signs could be found for the other tasks performed. The present results indicate an increased motor response to a psychological stressor among subjects with self-reported neck/shoulder complaints.

Upper trapezius muscle activation patterns in neck-shoulder pain patients and healthy controls.

This study aimed at investigating whether patients with neck-shoulder complaints from different aetiologies (work-related musculo-skeletal disorders, WMSD; whiplash associated disorders, WAD) show comparable muscle activation patterns, characterised by higher activation and lower relaxation levels of the trapezius muscles compared to healthy controls. Twenty healthy controls, 21 WMSD and 20 WAD patients with non-acute neck-shoulder pain were recruited for this cross-sectional study. Surface electromyography (sEMG) recordings were performed at the upper trapezius muscles during reference contractions, standardised computer tasks (typing and unilateral stress task), and rest measurements. sEMG was continuously recorded during these measurements. Outcome measures were root mean square (RMS) to study muscle activity, and relative rest time (RRT) to study muscle relaxation. Statistical analysis comprised the bootstrap technique and Kruskall-Wallis tests. Results showed no clear evidence for abnormal muscle activation patterns in WMSD and WAD patients compared to healthy controls. However, a tendency was observed for higher RMS levels during the reference contractions and computer tasks in both patient groups compared to healthy controls, and lower RRT levels at the non-dominant side during stress. Both patient groups also showed larger variability in RMS and RRT values. This variability has more often been reported in literature and may suggest the existence of subgroups of pain patients with corresponding different muscle activation patterns not related to aetiology. Future research may focus on identifying these subgroups of patients with neck-shoulder pain.

Clinometric properties of a clinical spasticity measurement tool.

PURPOSE: To investigate clinometric properties of an Anglo-Dutch spasticity measurement tool (ADSMT), an objective tool providing information about both neurophysiological and biomechanical aspects of spasticity about the wrist joint in the clinical setting. METHOD: ADSMT measurements were performed with 12 healthy and 11 participants with post-stroke spasticity, and consisted of assessing the maximum range of passive wrist movement (pROM) and passive wrist extension at different cycle rates. Outcome measures were wrist angle, flexor and extensor activation, and resistance to movement. Intra-class Correlation Coefficients (ICCs) were calculated for inter-rater and test-retest reliability. Validity was investigated by calculating Spearman's rho between ADSMT outcome measures and the Modified Ashworth Scale (n=12), the Action Research Arm Test (n=6), and a validated wrist rig (n=6). RESULTS: Impaired participants had higher flexor activity and higher resistance to movement during passive wrist extension compared to unimpaired participants. For all outcome measures inter-rater and test-retest reliability were satisfactory to good and concurrent validity was sufficient. CONCLUSIONS: Outcome measures related to wrist flexor activity and resistance to movement during extension are promising for spasticity assessment using the ADSMT. Further knowledge on reference values and practicality is necessary for this tool to become incorporated in the clinical setting.

Ambulant monitoring and web-accessible home-based exercise program during outpatient follow-up for resected lung cancer survivors: actual use and feasibility in clinical practice.

PURPOSE: The aim of this study is to evaluate the feasibility of a telehealthcare application for operable lung cancer (OLC) patients, consisting of ambulant symptom and physical activity monitoring (S&PAM) and a web-accessible home-based exercise program (WEP), and identify possible barriers for successful adoption and implementation. METHODS: A two-stage mixed methods design was used, in which 22 OLC patients and their treating healthcare professionals (HCPs) participated from pre-surgery to three (stage 1; n = 10) or six (stage 2; n = 12) months post-surgery. Actual use and acceptability (usability, usefulness, and satisfaction) were evaluated. RESULTS: Seventeen OLC patients (age (SD): 59 (8) years; 8 female) actively used the modules. S&PAM use varied from 1 to 11 monitoring days prior to outpatient consultations. Patients used WEP most frequently during the first 5 weeks, with an average of four logins a week. Fifty-eight percent used WEP beyond 7 weeks. No adverse situations occurred, and patients felt confident using the applications. Perceived added value included active lifestyle promotion, decreased anxiety, and accessibility to specialized HCPs. Physiotherapists used WEP as intended. Contrarily, physicians scarcely used information from S&PAM. To promote future adoption, strategies should focus on high-level patient tailoring of the technology, and formalization of including the applications in the clinical workflow. CONCLUSIONS: Ambulant monitoring and web-accessible home exercise is clinically feasible for OLC patients. However, low level of adoption by referring physicians may hamper successful implementation. IMPLICATIONS FOR CANCER SURVIVORS: Patients perceived both ambulant monitoring and web-accessible exercise as an added value to regular care and feasible to use in the period before and after lung resection.

A systematic review of the methodology of telemedicine evaluation in patients with postural and movement disorders.

We reviewed the methodology used in telemedicine research concerning patients with postural and movement disorders. Literature searches were performed using various computerized databases through to October 2005. Twenty-two studies met the criteria for review. Two broad models of telemedicine delivery were represented in the literature: (1) telemedicine between health-care professionals at each telemedicine site (n=16) and (2) telemedicine between health-care professionals and a patient at a remote site (n=6). Disparate research methodologies were used to investigate these two models. Most studies were limited to investigating the technical feasibility and acceptability of a telemedicine service rather than focusing on the overall effect of introducing the telemedicine service into routine health care. Nonetheless, it is possible to conclude that telemedicine is acceptable for both patients and professionals when used in rehabilitation. Since the two models of telemedicine evaluation tend to explore different outcomes (diagnostic accuracy versus health status), it is recommended that separate methodologies should be used. In contrast to evaluations of telemedicine model 2, randomized controlled trials appear to be less valuable for telemedicine model 1.

Usability in telemedicine systems-A literature survey.

INTRODUCTION: The rapid development of sensors and communication technologies enable the growth of new innovative services in healthcare, such as Telemedicine. An essential ingredient in the development of a telemedicine system and its final acceptance by end users are usability studies. The principles of usability engineering, evaluations and telemedicine are well established, and it may contribute to the adoption and eventually deployment of such systems and services. An in-depth usability analysis, including performance and attitude measures, requires knowledge about available usability techniques, and is depending on the amount of resources. Therefore it is worth investigating how usability methods are applied in developing telemedicine systems. Our hypothesis is: with increasing research and development of telemedicine systems, we expect that various usability methods are more equally employed for different end-user groups and applications. METHOD: A literature survey was conducted to find telemedicine systems that have been evaluated for usability or ease of use. The elements of the PICO framework were used as a basis for the selection criteria in the literature search. The search was not limited by year. Two independent reviewers screened all search results first by title, and then by abstract for inclusion. Articles were included up to May 2015. RESULTS: In total, 127 publications were included in this survey. The number of publications on telemedicine systems significantly increased after 2008. Older adults and end-users with cardiovascular conditions were among largest target end-user groups. Remote monitoring systems were found the most, in 90 publications. Questionnaires are the most common means for evaluating telemedicine systems, and were found in 88 publications. Questionnaires are used frequently in studies focusing on cardiovascular diseases, Parkinson's disease and older adult conditions. Interviews are found the most in publications related to stroke. In total 71% of the publications were trial-orientated and the remaining process orientated. An increase in telemedicine research, development and applications is found worldwide, with the majority of publications conducted in America. DISCUSSION AND CONCLUSION: Monitoring patients in their homes can lead to better healthcare at lower costs which implies an increased demand of new healthcare strategies like telemedicine. We expected that with the increase in telemedicine research and development, a greater range of usability methods would also be employed in the included publications. This is not the case. Researchers employed questionnaires as a preferred usability method for each type of telemedicine system and most end-users. However, in process-orientated studies a greater range of usability evaluations were applied, with fewer differences found in the amount of publications for each evaluation method. Questionnaires enable researchers to evaluate a system quickly on end users, as it requires less expertise on the evaluation method compared to the other methods. They are easily distributed and are customizable. The use of questionnaires is therefore an evaluation method of choice for a variety of telemedicine systems and end-users.

The effect of walking aids on muscle activation patterns during walking in stroke patients.

The purpose of this study was to investigate changes in muscle activation patterns with respect to timing and amplitude that occur when subjects with stroke walk with and without a walking aid. This knowledge could help therapists in deciding whether or not patients should use a cane or quad stick while walking. Thirteen patients suffering from a first unilateral ischemic stroke participated in the study. Surface electromyography (SEMG) of the erector spinae, gluteus maximus, gluteus medius, vastus lateralis, semitendinosus, gastrocnemius and tibialis anterior of the affected side were measured during three different conditions: (1) walking without a walking aid, (2) walking with a cane and (3) walking with a quad stick. Timing and amplitude parameters of the activation patterns were quantified using an objective burst detection algorithm and statistically evaluated. Results showed a statistically significant and clinically relevant decrease in burst duration of both erector spinae and tibialis anterior when walking with a cane. The amplitude of the vastus lateralis and tibialis anterior dropped when patients walked with a cane and quad stick. The use of a cane should be considered when therapy is given to stroke patients to achieve normal muscle activation patterns.

Rectus femoris surface myoelectric signal cross-talk during static contractions.

The clinical application of EMG requires that the recorded signal is representative of the muscle of interest and is not contaminated with signals from adjacent muscles. Some authors report that surface EMG is not suitable for obtaining information on a single muscle but rather reflects muscle group function [J. Perry, C.S. Easterday, D.J. Antonelli, Surface versus intramuscular electrodes for electromyography of superficial and deep muscles. Physical Therapy 61 (1981) 7-15]. Other authors report however, that surface EMG is adequate to determine individual muscle function, once guidelines pertaining to data acquisition are followed [D.A. Winter, A.J. Fuglevand, S.E. Archer. Cross-talk in surface electromyography: theoretical and practical estimates. Journal of Electromyography and Kinesiology 4 (1994) 15-26]. The aim of this study was to determine whether surface EMG was suitable for monitoring rectus femoris (RF) activity during static contractions. Five healthy subjects, having given written informed consent, participated in this trial. Surface and fine wire EMG from the rectus femoris and the vastus lateralis (VL) muscles were recorded simultaneously during a protocol of static contractions consisting of knee extensions and hip flexions. Ratios were used to quantify the relationship between the surface EMG amplitude value and the fine wire EMG amplitude value for the same contraction. The results showed that hip flexion contractions elicited RF activation only and that knee extension contractions elicited fine wire activity in VL only. When the relationship between RF surface and RF fine wire electrodes was compared for hip flexion and knee extension contractions, it was observed that for all subjects, there was a tendency for increased RF surface activity in the absence of RF fine wire activity during knee extensions. It was concluded that the activity recorded by the RF surface electrode arrangement during knee extension consisted of EMG from the vastii, i.e., cross-talk and that vastus intermedius was the most likely origin of the erroneous signal. Therefore it is concluded that for accurate EMG information from RF, fine wire electrodes are necessary during a range of static contractions.