Patrick Boissy

Maximal grip force in chronic stroke subjects and its relationship to global upper extremity function

Objectives: Previous studies have shown that recovery of recordable grip strength in acute stroke subjects is one of the most sensitive assessments of initial upper limb recovery and a good prognostic factor for latter recovery. The objectives of this study were to test the reliability of maximal voluntary grip force (MVGF) measures and evaluate the relationship between paretic grip strength deficit and paretic upper extremity function in chronic stroke subjects. Design: Over a three-week period, bilateral MVGF was assessed three times with a modified strain gauge dynamometer in 15 chronic stroke subjects and 10 control subjects. The paretic MVGF deficit was expressed in relation to the MVGF of the nonaffected hand. Outcome measures: Upper extremity function in stroke subjects was measured using the Fugl-Meyer, the upper extremity performance test for the elderly (TEMPA), Box and Block and finger-to-nose tests. Results: MVGF measures in both groups of subjects demonstrated good reliability (intraclass correlation, ICC >0.86) and low standard error measurements (SEM). The paretic MVGF of the stroke subjects was greatly impaired in comparison to the control subjects. Results of linear and quadratic regressions analyses show that this impairment was significantly correlated (p <0.01) with the performance of the stroke subjects on the four upper extremity function tests. The percentages of variances explained by the MVGF deficit on all four upper extremity tests varied from 62% to 78% for the linear regressions and from 72% to 93% for the quadratic regressions. Conclusions: These results suggest that the paretic maximal grip strength, normalized with the maximal grip strength on the nonaffected side, appears to be a valuable outcome measure of upper extremity function in chronic stroke subjects.

A randomized controlled trial of home telerehabilitation for post-knee arthroplasty

We compared the effectiveness of home telerehabilitation with conventional rehabilitation following knee replacement surgery (total knee arthroplasty, TKA). Forty-eight patients (mean age 66 years) who received TKA were recruited prior to discharge from hospital after surgery and were randomly assigned to telerehabilitation or usual care. Telerehabilitation sessions (16 per participant over two months) were conducted by trained physiotherapists using videoconferencing to the patients home via an Internet connection (512 kbit/s upload speed). Disability and function were measured using standardized outcome measures in face-to-face evaluations at three times (prior to and at the end of treatment, and four months after the end of treatment). Clinical outcomes improved significantly for all subjects in both groups between endpoints. Some variables showed larger improvements in the usual care group two months post-discharge from therapy than in the telerehabilitation group. Home telerehabilitation is at least as effective as usual care, and has the potential to increase access to therapy in areas with high speed Internet services.

Changes in the surface EMG signal and the biomechanics of motion during a repetitive lifting task

The analysis of surface electromyographic (EMG) data recorded from the muscles of the back during isometric constant-force contractions has been a useful tool for assessing muscle deficits in patients with lower back pain (LBP). Until recently, extending the technique to dynamic tasks, such as lifting, has not been possible due to the nonstationarity of the EMG signals. Recent developments in time-frequency analysis procedures to compute the instantaneous median frequency (IMDF) were utilized in this study to overcome these limitations. Healthy control subjects with no history of LBP (n=9; mean age 26.3/spl plusmn/6.7) were instrumented for acquisition of surface EMG data from six electrodes on the thoraco-lumbar region and whole-body kinematic data from a stereo-photogrammetric system. Data were recorded during a standardized repetitive lifting task (load=15% body mass; 12 lifts/min; 5-min duration). The task resulted in significant decreases in IMDF for six of the nine subjects, with a symmetrical pattern of fatigue among contralateral muscles and greater decrements in the lower lumbar region. For those subjects with a significant decrease in IMDF, a lower limb and/or upper limb biomechanical adaptation to fatigue was observed during the task. Increases in the peak box acceleration were documented. In two subjects, the acceleration doubled its value from the beginning to the end of the exercise, which lead to a significant increase in the torque at L4/L5. This observation suggests an association between muscle fatigue at the lumbar region and the way the subject manipulates the box during the exercise. Fatigue-related biomechanical adaptations are discussed as a possible supplement to functional capacity assessments among patients with LBP.

A qualitative study of in-home robotic telepresence for home care of community-living elderly subjects.

We examined the requirements for robots in home telecare using two focus groups. The first comprised six healthcare professionals involved in geriatric care and the second comprised six elderly people with disabilities living in the community. The concept of an in-home telepresence robot was illustrated using a photograph of a mobile robot, and participants were then asked to suggest potential health care applications. Interview data derived from the transcript of each group discussion were analyzed using qualitative induction based on content analysis. The analyses yielded statements that were categorized under three themes: potential applications, usability issues and user requirements. Teleoperated mobile robotic systems in the home were thought to be useful in assisting multidisciplinary patient care through improved communication between patients and healthcare professionals, and offering respite and support to caregivers under certain conditions. The shift from a traditional hospital-centred model of care in geriatrics to a home-based model creates opportunities for using telepresence with mobile robotic systems in home telecare.

Inertial Measures of Motion for Clinical Biomechanics: Comparative Assessment of Accuracy under Controlled Conditions - Effect of Velocity

Background Inertial measurement of motion with Attitude and Heading Reference Systems (AHRS) is emerging as an alternative to 3D motion capture systems in biomechanics. The objectives of this study are: 1) to describe the absolute and relative accuracy of multiple units of commercially available AHRS under various types of motion; and 2) to evaluate the effect of motion velocity on the accuracy of these measurements. Methods The criterion validity of accuracy was established under controlled conditions using an instrumented Gimbal table. AHRS modules were carefully attached to the center plate of the Gimbal table and put through experimental static and dynamic conditions. Static and absolute accuracy was assessed by comparing the AHRS orientation measurement to those obtained using an optical gold standard. Relative accuracy was assessed by measuring the variation in relative orientation between modules during trials. Findings Evaluated AHRS systems demonstrated good absolute static accuracy (mean error < 0.5o) and clinically acceptable absolute accuracy under condition of slow motions (mean error between 0.5o and 3.1o). In slow motions, relative accuracy varied from 2o to 7o depending on the type of AHRS and the type of rotation. Absolute and relative accuracy were significantly affected (p<0.05) by velocity during sustained motions. The extent of that effect varied across AHRS. Interpretation Absolute and relative accuracy of AHRS are affected by environmental magnetic perturbations and conditions of motions. Relative accuracy of AHRS is mostly affected by the ability of all modules to locate the same global reference coordinate system at all time. Conclusions Existing AHRS systems can be considered for use in clinical biomechanics under constrained conditions of use. While their individual capacity to track absolute motion is relatively consistent, the use of multiple AHRS modules to compute relative motion between rigid bodies needs to be optimized according to the conditions of operation.

In home telerehabilitation for older adults after discharge from an acute hospital or rehabilitation unit: A proof-of-concept study and costs estimation

Purpose.The purpose of this study is to investigate rehabilitation through teletreatment as an alternative to a physical home-care visit to deliver services to individuals at home following discharge from an acute hospital or rehabilitation unit. Method.Four community-living elderly people were recruited for telerehabilitation services prior being discharged from an acute-care hospital and a geriatric rehabilitation unit. Once the patient returned home, an appointment was made for the assessing therapist to take the clinical measurements (T1) in a face-to-face session. Four clinical variables were used (functional autonomy, balance, locomotor performance in walking and lower-body strength). Telerehabilitation sessions with the participants were conducted with trained personnel in the individuals home. The system used to support telerehabilitation services for this proof of concept was built around network-attached remotely-controlled pan/tilt/zoom cameras with MJPEG compression, media displays and hands-free phones. Before the patient was discharged from the physiotherapy program, the same assessing therapist visited the subject again to take the T2 measurements in a face-to-face session. The satisfaction of the health-care professional was determined for each session with the homemade questionnaire. Costs related to telerehabilitation were compared to theoretically home visits. Results.All four subjects improved on the four clinical variables. Mean costs for the telerehabilitation program, comprising 12 sessions over 4 weeks was

Comparative Analysis of 3-D Robot Teleoperation Interfaces With Novice Users

487. Conclusion.Telerehabilitation seems to be a practical alternative for dispensing rehabilitation services after patients are discharged from an acute hospital or rehabilitation unit.

In-Home Telerehabilitation Compared with Face-to-Face Rehabilitation After Total Knee Arthroplasty: A Noninferiority Randomized Controlled Trial.

Being able to act remotely in our homes could be very useful in providing various services such as surveillance and remote interventions, which are key features for telehomecare applications. In addition to navigation and environmental challenges that a telepresence robot would face in home settings, the system requires an appropriate teleoperation interface for safe and efficient usage by novice users. This paper describes the design criteria and characterizes visualization and control modalities of user interfaces with a real robot. By considering the users needs along with the current state of the art in teleoperation interfaces, two novel mixed-reality visualization modalities are compared with standard video-centric and map-centric perspectives. We report teleoperation trials under six different task scenarios with a sample of 37 novice operators in homelike conditions. The results based on three quantitative metrics and one qualitative metric outline under which conditions the novel mixed-reality visualization modalities significantly improve the performance of novice users.

Accelerometer-based wireless body area network to estimate intensity of therapy in post-acute rehabilitation

BACKGROUND The availability of less resource-intensive alternatives to home visits for rehabilitation following orthopaedic surgeries is important, given the increasing need for home care services and the shortage of health resources. The goal of this trial was to determine whether an in-home telerehabilitation program is not clinically inferior to a face-to-face home visit approach (standard care) after hospital discharge of patients following a total knee arthroplasty. METHODS Two hundred and five patients who had a total knee arthroplasty were randomized before hospital discharge to the telerehabilitation group or the face-to-face home visit group. Both groups received the same rehabilitation intervention for two months after hospital discharge. Patients were evaluated at baseline (before total knee arthroplasty), immediately after the rehabilitation intervention (two months after discharge), and two months later (four months after discharge). The primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire at the last follow-up evaluation. Secondary outcome measures included the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, functional and strength tests, and knee range of motion. The noninferiority margin was set at 9% for the WOMAC. RESULTS The demographic and clinical characteristics of the two groups of patients were similar at baseline. At the last follow-up evaluation, the mean differences between the groups with regard to the WOMAC gains, adjusted for baseline values, were near zero (for 182 patients in the per-protocol analysis): -1.6% (95% confidence interval [CI]: -5.6%, 2.3%) for the total score, -1.6% (95% CI: -5.9%, 2.8%) for pain, -0.7% (95% CI: -6.8%, 5.4%) for stiffness, and -1.8% (95% CI: -5.9%, 2.3%) for function. The confidence intervals were all within the predetermined zone of noninferiority. The secondary outcomes had similar results, as did the intention-to-treat analysis, which was conducted afterward for 198 patients. CONCLUSIONS Our results demonstrated the noninferiority of in-home telerehabilitation and support its use as an effective alternative to face-to-face service delivery after hospital discharge of patients following a total knee arthroplasty. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Effects of orthopaedic immobilization of the right lower limb on driving performance: an experimental study during simulated driving by healthy volunteers.

BackgroundIt has been suggested that there is a dose-response relationship between the amount of therapy and functional recovery in post-acute rehabilitation care. To this day, only the total time of therapy has been investigated as a potential determinant of this dose-response relationship because of methodological and measurement challenges. The primary objective of this study was to compare time and motion measures during real life physical therapy with estimates of active time (i.e. the time during which a patient is active physically) obtained with a wireless body area network (WBAN) of 3D accelerometer modules positioned at the hip, wrist and ankle. The secondary objective was to assess the differences in estimates of active time when using a single accelerometer module positioned at the hip.MethodsFive patients (77.4 ± 5.2 y) with 4 different admission diagnoses (stroke, lower limb fracture, amputation and immobilization syndrome) were recruited in a post-acute rehabilitation center and observed during their physical therapy sessions throughout their stay. Active time was recorded by a trained observer using a continuous time and motion analysis program running on a Tablet-PC. Two WBAN configurations were used: 1) three accelerometer modules located at the hip, wrist and ankle (M3) and 2) one accelerometer located at the hip (M1). Acceleration signals from the WBANs were synchronized with the observations. Estimates of active time were computed based on the temporal density of the acceleration signals.ResultsA total of 62 physical therapy sessions were observed. Strong associations were found between WBANs estimates of active time and time and motion measures of active time. For the combined sessions, the intraclass correlation coefficient (ICC) was 0.93 (P ≤ 0.001) for M3 and 0.79 (P ≤ 0.001) for M1. The mean percentage of differences between observation measures and estimates from the WBAN of active time was -8.7% ± 2.0% using data from M3 and -16.4% ± 10.4% using data from M1.ConclusionWBANs estimates of active time compare favorably with results from observation-based time and motion measures. While the investigation on the association between active time and outcomes of rehabilitation needs to be studied in a larger scale study, the use of an accelerometer-based WBAN to measure active time is a promising approach that offers a better overall precision than methods relying on work sampling. Depending on the accuracy needed, the use of a single accelerometer module positioned on the hip may still be an interesting alternative to using multiple modules.