Biomedical subjects

Patrick Loisel

Publications and source records attributed to Patrick Loisel.

12 recordsLinked to original sources

PubMed2004

Treatment of lateral epicondylitis: where is the evidence?

Lateral epicondylitis is the most commonly diagnosed elbow condition and affects about 1-3% of the population at large. It produces a heavy burden of workdays lost and residual impairments. Although many treatment modalities are used, few of them rest on scientific evidence and none has been proven more effective than the others. This paucity of evidence on treatments for lateral epicondylitis may stem from several sources, including the possible self-limiting nature of the condition, the lack of pathophysiological data, the methodological shortcomings of available studies, and the existence of numerous factors influencing the outcome.

Evidence-Based Medicine↗

PubMed2004

The interrater reliability of a functional capacity evaluation: the physical work performance evaluation.

The purpose was to evaluate the interrater reliability of the Dynamic Strength, Position Tolerance, and Mobility tasks of the Physical Work Performance Evaluation (PWPE), a Functional Capacity Evaluation often used with workers disabled due to back pain. For each worker's evaluation, two raters were preselected among five trained raters. One of the raters administered the PWPE while the other functioned as a silent rater. A convenience sample of 40 workers disabled due to back pain and referred to an occupational rehabilitation center was used. In general, the reliability was "substantial" (0.61 < or = kappa < or = 0.80) to "almost perfect" (0.81 < or = kappa < or = 1.00) for most of the 21 tasks and three sections of the PWPE evaluated with the exception of three tasks in the Mobility section (ladder climbing (kappa = 0.47), repetitive trunk rotation--standing (kappa = 0.54), and repetitive trunk rotation--sitting (kappa = 0.37)) task and the Mobility section itself (kappa = 0.54). Several reasons could explain the lower agreement on the observation of the physical signs associated with these tasks. Since these tasks involve rotation movements or complex neuromuscular integration, it seemed difficult for the raters to define what are the normal physical signs and when physical signs of maximal functional capacity are present. The criteria for establishing the presence of the physical signs in the PWPE should be improved.

Adolescent↗

PubMed2003

Muscle recovery from a short fatigue test and consequence on the reliability of EMG indices of fatigue.

The purpose of the present study was to evaluate if rest intervals of 10 or 15 min allow the back muscles to recover completely, from an electromyographic (EMG) point of view, after performing a fatiguing contraction. Twelve healthy males stood in a dynamometer with the trunk in a vertical position and performed three trunk extension fatiguing trials (30 s contractions sustained at 75% of the maximal voluntary contraction) separated successively by a 15 min (between trial 1 and 2) and a 10 min (between trial 2 and 3) rest period. The EMG signals from four pairs of back muscles were collected at 2,048 Hz with active surface electrodes. Different EMG indices computed from the temporal and frequency domains of the EMG signal were considered to evaluate muscular fatigue and recovery from trial 1 to trial 2 and from trial 2 to trial 3. No significant differences (one-way ANOVAs between the three trials, alpha=0.05) were obtained for the different EMG indices computed. The percentage of variance explained by the inter-trial effect was none in most cases, corroborating that no systematic error was present between the trials and suggesting that complete muscle recovery was allowed with 10 or 15 min rest periods. These results support the use of rest periods of 10 to 15 min between multiple fatigue tests, at least for back muscles and for high intensity short duration fatigue tasks as the one used in the present study.

Adult↗

PubMed2003

Back strength cannot be predicted accurately from anthropometric measures in subjects with and without chronic low back pain.

OBJECTIVES: (1) To develop a multiple regression equation using anthropometric measurements to predict back strength and (2) to estimate the effect of practice on the back strength results and back strength predictions. DESIGN: Comparative study with repeated measures performed on three days. BACKGROUND: The assessment of back muscle relative endurance (% maximal strength) requires the measurement of maximal back strength which is problematic with low back pain patients. METHODS: The back strength (L5/S1 static extension moment), age and 26 anthropometric parameters were obtained from 83 male volunteers [42 healthy subjects and 41 chronic low back pain patients] aged between 20 and 60 years. A subsample of 20 healthy subjects and 20 patients were assessed through three days of testing to evaluate the variations of back strength with practice. RESULTS: The final regression model (n=42 healthy subjects) explained 39% of the variance in back strength. Back strength increased with practice (Day1<Day2 & 3) for both healthy and patients groups. However, the error of prediction of back strength derived from the regression model showed a significant improvement with practice for the patients only. CONCLUSIONS: Back strength cannot be predicted from simple anthropometric measures without important errors. The decrease of the error of prediction obtained for the patient group is indicative of a decreasing influence of psychological factors that are independent of motor learning because the effect of motor learning would have occurred on both groups if present. RELEVANCE: The prediction of back strength would be useful to determine (1) the relative force level of a given exercise or (2) the preinjury back strength. Unfortunately, anthropometric measurements are not enough good predictors of back strength.

Adult↗

PubMed2003

Surface electromyography assessment of back muscle intrinsic properties.

The purpose of this study was to assess (1) the reliability and (2) the sensitivity to low back pain status and gender of different EMG indices developed for the assessment of back muscle weakness, muscle fiber composition and fatigability. Healthy subjects (men and women) and chronic low back pain patients (men only) performed, in a static dynamometer, maximal and submaximal static trunk extension tasks (short and long duration) to assess weakness, fiber composition and fatigue. Surface EMG signals were recorded from four (bilateral) pairs of back muscles and three pairs of abdominal muscles. To assess reliability of the different EMG parameters, 40 male volunteers (20 controls and 20 chronic low back pain patients) were assessed on three occasions. Reliable EMG indices were achieved for both healthy and chronic low back pain subjects when specific measurement strategies were applied. The EMG parameters used to quantify weakness and fiber composition were insensitive to low back status and gender. The EMG fatigue parameters did not detect differences between genders but unexpectedly, healthy men showed higher fatigability than back pain patients. This result was attributed to the smaller absolute load that was attributed to the patients, a load that was defined relative to their maximal strength, a problematic measure with this population. An attempt was made to predict maximal back strength from anthropometric measurements but this prediction was prone to errors. The main difficulties and some potential solutions related to the assessment of back muscle intrinsic properties were discussed.

Abdominal Wall↗

PubMed2003

Constructing the program impact theory for an evidence-based work rehabilitation program for workers with low back pain.

PURPOSE: Several low back pain work rehabilitation programs have been developed and evaluated for their outcomes. Unfortunately, the program impact theory for these programs is not described, and consequently, the exact mechanisms of action by which these programs intend to increase the probability of return to work remain unknown. This lack of knowledge jeopardizes the implementation of effective programs by health professionals and managers. The objective of this paper is to present the results of an exploratory study aimed at building the program impact theory for the PREVICAP work rehabilitation program. METHODS: The program impact theory was develop by conducting: unpublished documents and scientific literature analyses, individual and group discussions with multiple stakeholders and observation of program reality by reviewing the files of workers who completed the program. RESULTS: The PREVICAP program's impact theory was elaborated based on an ecological approach to work rehabilitation. Program goals and objectives were defined for the three dimensions of the model: the worker, the work environment and the interaction between the worker and his work environment. Two program action mechanisms were defined and describe how the program was intended to achieve its expected outcomes. CONCLUSIONS: This study made explicit the PREVICAP program impact theory and can help rehabilitation practitioners to address work disability according to an ecological model.

Canada↗

PubMed2002

Discriminative and predictive validity assessment of the quebec task force classification.

STUDY DESIGN: A prospective cohort study of workers with low back pain who had been absent from work for more than 4 weeks was conducted. OBJECTIVE: To assess the discriminative and predictive validity of the Quebec Task Force Classification for workers during the subacute phase of disability from back pain. SUMMARY OF BACKGROUND DATA: The Quebec Task Force Classification was designed for clinical decision making, prognosis establishment, quality of care evaluation, and scientific research in low back pain. METHODS: For this study, 104 workers absent from work because of back pain were classified according to the first four categories of the Quebec Task Force Classification 4 weeks after their first day of work absence. They then were randomized into four treatment groups: standard care (control), clinical-rehabilitation intervention, occupational intervention, and the Sherbrooke model (a combination of the clinical-rehabilitation and occupational interventions). Functional status, pain level, and work status were assessed at baseline and after 1 year. Duration of full compensation and back-related costs were calculated over a mean follow-up period of 6.5 years. The discriminative validity of the Quebec Task Force Classification was evaluated using Kendall tau correlation coefficients. Predictive validity was evaluated using logistic regression analyses. Age, gender, comorbidities, body mass index, and treatment group were considered as potential confounders. RESULTS: Significant but low correlation coefficients were found between Quebec Task Force Classification categories and functional status scores at baseline. Subjects classified as having distal radiating pain (categories 3 and 4) at baseline were more likely to have a lower functional status, higher pain level, and no return to regular work at the 1-year follow-up evaluation. They also were more likely to accumulate more days of full compensation and to cost more after a mean follow-up period of 6.5 years. CONCLUSION: The Quebec Task Force Classification demonstrated good predictive ability by discriminating between subjects with and those without distal radiating pain.

Adult↗

PubMed2002

A biomechanical comparison of lifting techniques between subjects with and without chronic low back pain during freestyle lifting and lowering tasks.

OBJECTIVE: To evaluate if chronic low back pain patients perform manual material handling tasks differently from control subjects. DESIGN: Comparative study using a repeated measures design. BACKGROUND: No study evaluated the lifting technique of back pain patients relative to control subjects during free style lifting and lowering tasks. Previous findings suggest that lowering would be more hazardous than lifting to the low back. It would be interesting to evaluate if chronic low back pain patients behave differently than controls when lifting and lowering. METHODS: Thirty-three male subjects (18 controls, 15 suffering from non-specific chronic low back pain) participated. A 12-kg box was lifted (freestyle) from the floor to the hips (1) in front (symmetric task) or (2) to a shelf located at 90 degree on the right (asymmetric task) and was lowered back to the floor. A 3D biomechanical analysis involving the assessment of L5/S1 loading, posture of segments, inertial parameters, and EMG was performed. RESULTS: There was no difference between the groups for postural (trunk and lower limb angles), inertial (trunk velocity and acceleration), and L5/S1 loading (moments and compression) variables. The patients showed abnormally low left lumbar erector spinae (symmetric task, lowering) or high left thoracic erector spinae (all tasks) EMG activation. Significant Group x Action (lifting vs. lowering) interactions were also observed for some inertial and L5/S1 loading variables suggesting that the biomechanical differences detected between lifting and lowering may have a differential influence on the technique used by back pain patients and control subjects. CONCLUSIONS: The gross lifting technique of back pain patients was unaltered relative to controls but the activation of paraspinal muscles differed, suggesting that a more detailed biomechanical analysis, such as the use of EMG driven models, might be required to reveal lumbar impairments during lifting. RELEVANCE: To evaluate if chronic low back pain patients use naturally different lifting techniques to prevent pain exacerbation and damaged lumbar tissue overloading.

Adult↗

PubMed2002

Helping clinicians in work disability prevention: the work disability diagnosis interview.

Recent evidence has demonstrated that disability from musculoskeletal disorders is a multifactorial problem that is not only due to workers' characteristics but also closely related to environmental factors, such as the workplace, the health care system, the compensation system, and the interactions among all stakeholders regarding the disability problem. The Work Disability Diagnosis Interview (WoDDI) was developed following a systematic method in order to help clinicians detect possible disability prognostic factors in subacute or chronic musculoskeletal pain patients. A structured literature review, followed by expert input and a second round of revisions after 4-year's usage led to the current version. The WoDDI is composed of open-ended questions on physical, psychosocial, occupational, and administrative factors, collated into an interview form used at the first encounter with the disabled worker. It enables clinicians to develop a rehabilitation plan and focus on disability resolution in patients absent from work due to a musculoskeletal disorder. Initial application demonstrated a high prevalence of sociodemographic, work-related, and psychosocial factors that may contribute to prolonged work absence.

Absenteeism↗

PubMed2002

Electromyographic assessment of back muscle weakness and muscle composition: reliability and validity issues.

OBJECTIVE: To assess the reliability and construct validity of various electromyographic indices developed to assess back muscle weakness and muscle fiber composition. DESIGN: A prospective study with repeated measures performed on 3 days along with comparisons of groups presenting different back strength and/or back muscle fiber composition. SETTING: A biomechanics laboratory within a rehabilitation center. PARTICIPANTS: Forty male volunteers (20 healthy, 20 with chronic low back pain) were assessed on 3 different days to assess reliability and to make group comparisons. Thirteen healthy women were also assessed once to obtain a third group with known lower strength and different back muscle fiber composition. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Surface electromyography was recorded for 4 pairs of homologous back muscles while the subjects performed, on a dynamometer, static trunk extension efforts. Electromyographic parameters were computed to assess muscle weakness and muscle fiber composition. The reliability of the data collected across the 3 sessions and comparisons between groups were determined. RESULTS: Electromyographic parameters generally showed good to excellent reliability, but were insensitive to differences in back muscle strength and did not appear to be related to muscle composition. Some trends were observed in the electromyographic parameters across the force levels, but the large interindividual variability impeded statistical comparisons. CONCLUSIONS: The assessment of muscle weakness and muscle fiber composition through electromyographic analysis does not appear feasible, at least on an individual basis, for the muscles of the back.

Adult↗

PubMed2001

Therapeutic Return to Work: Rehabilitation in the workplace.

Therapeutic Return to Work is a work rehabilitation program linking graded work exposure with functional restoration therapy for chronic low back pain. This study evaluates the impact of the program on stable return to work (RTW) and compares it with the impact on RTW of three frequently used ways of management of back pain (normative comparison). At two year follow-up, 93% of participants of the Therapeutic Return to Work program were working. This rate was higher than in the comparison groups. Although limited by its norm-referenced evaluation design, the results of this study indicate the importance of placing the work site in the center of the of work rehabilitation process. In this program occupational therapists make full use of the client's natural environment.

Journal Article↗

PubMedDate not supplied

From evidence to community practice in work rehabilitation: the Quebec experience.

BACKGROUND: The causes of prolonged disability due to back pain are multiply determined, involving medical, social, and environmental factors. Possible solutions to the problem of prolonged back pain disability have emerged from recent research but few efforts have been made to transfer evidence-based programs to large community settings. OBJECTIVE: This article describes three phases of the process of transfer of evidence from rehabilitation research to community practice in the province of Quebec. METHODS AND RESULTS: Phase A: Based on literature review and expert knowledge, the Sherbrooke model was developed and assessed through a population-based, randomized clinical trial. Results at 1-year follow-up showed quicker return to regular work and improvement of quality of life; the 6-year follow-up showed the cost-effectiveness of the method. Phase B: Based on the Sherbrooke model experience and recent evidence, a new program addressing the disability paradigm was developed and implemented in the province of Quebec (Canada). Results at 1- and 3-year follow-ups showed that only 24% of workers were not working owing to their musculoskeletal disorder. The program is presently being tested through a population-based, randomized clinical trial in a population of construction workers. Phase C: To implement the program at a provincial level, a network for management, research and education in work rehabilitation was developed. An external assessment is presently planned to evaluate return to work and economic outcomes and quality of implementation of the program in various settings.

Adult↗