The utility of electromyographic biofeedback in the treatment of conversion paralysis.

Conversion paralysis has a poor prognosis when there is evidence of nonresponse to previous treatment, long duration, and secondary atrophy of the "paralyzed" muscles. The authors present four such cases in which conversion paralysis was treated successfully by means of electromyographic (EMG) biofeedback. Each of the four patients also suffered from a chronic pain condition. Results from statistical analyses indicated that the four patients demonstrated significant improvement in the functional capacity of the "paralyzed" muscles as measured by isometric maximum voluntary contraction and EMG activity. The improvements occurred without explicit psychotherapy and suggest that behavioral modification techniques alone may be helpful in such cases.

Functional capacity and residual functional capacity and their utility in measuring work capacity.

OBJECTIVE: The pain physician is often asked to establish the medical impairment of the chronic pain patient (CPP) and from that determination ascertain the work capacity of the CPP. Functional capacity (FC) testing has recently been introduced as a more objective and accurate way of facilitating the determination of work capacity. However, there are conceptual problems with the measurement of FC. These will be reviewed and the relationship of FC to residual functional capacity (RFC) will be determined. Finally, a method for measuring RFC in a job-specific manner will be suggested. DATA SOURCES: The literature in reference to the measurement of medical impairment, FC, and RFC was reviewed. STUDY SELECTION: Studies appropriate to the objective of this review were selected for inclusion. CONCLUSIONS: The FC and RFC are poorly defined. Lack of definition has interfered with design of appropriate test batteries specific to work capacity. To circumvent this problem a job-specific RFC measurement method is suggested. This method is based on the Dictionary of Occupational Titles.

The prediction of return to the workplace after Multidisciplinary Pain Center treatment.

The prediction of return to the workplace after Multidisciplinary Pain Center (MPC) treatment has become a major research area. To delineate the variables that predict this outcome, the authors reviewed 164 multidisciplinary variables studies. Of these, 79 addressed work as an outcome variable. Twenty-six studies attempted to identify patient variables predicting return to the workplace. These latter studies were critically inspected for eight methodological criteria: pain location, follow-up time interval, response percentage and follow-up method, return to work subcategorization, vocational movement, univariate vs. multivariate statistics, multi-colinearity and variance, and statistical treatment of dropouts. In addition, other disability studies besides those in the chronic pain area were reviewed for return to the workplace predictor variables. Of these 26 studies, only a few appeared to satisfy the criteria examined. In addition, many studies were in conflict with one another on whether a variable was predictive. The review of the nonchronic pain/disability prediction literature yielded a large number of potential predictors that related to the work area. It is unclear which variables or set of variables predict return to the workplace after MPC treatment. Chronic pain studies may be neglecting the work area as an important source of return to the workplace predictor variables.

Biofeedback in back muscle strengthening.

This study was undertaken to investigate the use of electromyography (EMG) biofeedback as an add-on therapy to standard exercise in the restoration of the functional abilities of the trunk extensor muscles in patients suffering from chronic low-back pain (CLBP). A controlled experimental investigation was conducted to study the effectiveness of using the proposed treatment modality in the management of the low-back pain problem. The results obtained indicate that the proposed methodology was an effective tool to achieve a significant improvement in the strength of lumbar paraspinal muscles of chronic low-back pain patients.

Stretching in the rehabilitation of low-back pain patients.

The major objective of this investigation was to study the effectiveness of the physical conditioning program used at the University of Miami Comprehensive Pain and Rehabilitation Center in restoring certain elements of the functional abilities of individuals suffering from chronic low-back pain and to evaluate the effectiveness of using a systematically applied, aggressive stretching maneuver as an add-on therapy in the treatment of chronic low-back pain patients. The effect(s) of the proposed stretching maneuver was evaluated. Twenty-eight chronic low-back pain patients were randomly assigned to one of two groups. The control group underwent a multimodal rehabilitation program, and the experimental group underwent the same rehabilitation program in addition to the systematic stretching maneuver under investigation. The results obtained showed that patients undergoing the multimodal rehabilitation program with and without the proposed systematic stretching maneuver showed a significant improvement in their functional abilities as seen from the significant increase in the static strength of the back extensors, with corresponding significant increase in back muscle myoelectric signals. Also, a significant decrease in their pain level was reported after 2 weeks of continuous treatment. The use of the systematic stretching maneuver enhanced the functional gains of chronic low-back pain patients compared to the control group.

Acceptable maximum effort (AME). A psychophysical measure of strength in back pain patients.

A new quantitative method for measuring functional abilities of chronic low-back pain patients is introduced. The method is based upon a psychophysical model referred to as acceptable maximum effort (AME). AME is the highest level of voluntary effort that a person can achieve without inducing unacceptable pain. In the current study, the AME method was applied to strength measurement. By use of a static strength measurement procedure, arm, leg, shoulder, back, and composite strengths were assessed upon admission to and discharge from a 4-week, nonsurgical comprehensive pain treatment program. The reliability of the AME method for each strength measure was assessed. In addition, the method was used to evaluate pre- to post-treatment changes in strength. Results indicate the AME method to be highly reliable and useful in determining treatment outcome. Reliability coefficients for all strength measures were above .90. The results are discussed in terms of their implications for standardized functional ability measurement in the area of chronic pain.

Does nonsurgical pain center treatment of chronic pain return patients to work? A review and meta-analysis of the literature.

Evidence in the literature relating to return to work as an outcome variable for nonsurgical treatment for chronic pain was examined. Study selection criteria were as follows: a detailed definition of patient work status, delineation of work status pre-treatment and at follow-up, and documentation of the proportion of patients employed at follow-up. Of 171 studies reviewed, 37 fulfilled these selection criteria. Because the data were objective in nature, they were abstracted by the senior author only. For the coded variables of time to follow-up, proportion of patients working pre-treatment and at follow-up and number of patients, descriptive statistics and correlations were calculated. Change in employment status at follow-up was significant (P < .005) for all groups examined. In addition, comparisons for work outcome between treated patients versus patients rejected due to lack of insurance, and between treated patients versus patients who dropped out of treatment were both significant (P < .001). The mean difference in employment at follow-up for treated patients versus those not treated was approximately 50%. The proportion of patients working increased from 20% to 54% post chronic pain nonsurgical treatment. Correlation analyses did not find a significant trend in percent employed with time to follow-up. These results indicate that (1) chronic pain nonsurgical treatment does return patients to work; (2) increased rates of return to work are due to treatment, and (3) benefits of treatment are not temporary.

Measuring residual functional capacity in chronic low back pain patients based on the Dictionary of Occupational Titles.

STUDY DESIGN: This study designed and tested a functional battery based on the Dictionary of Occupational Titles (DOT). OBJECTIVES: Such a battery can be used to measure residual functional capacity (RFC) in chronic pain patients (CPP) and results can be matched against the demand minimum functional capacities (DMFC) of DOT jobs. SUMMARY OF BACKGROUND DATA: Physicians have difficulty translating medical impairment into functional limitation and thereby establishing the RFC of CPPs. METHODS: The DOT, a USA government publication, provides information about physical demands of every USA job according to 36 factors and subfactors. The authors defined and developed a functional battery based on these factors/subfactors. This battery was tested on 67 consecutive CPPs to determine the percentage of CPPs able to pass specific job factors and the full battery and return to some DOT job, and evaluated the effects of pain on battery performance. The data were factor analyzed. RESULTS: The battery determined if CPPs could perform DOT job factors and had the necessary RFC to be placed in a DOT job. The vast majority of CPPs could not pass the full battery and the presence of pain and original job classification predicted whether a CPP could perform a job factor. Factor analyses grouped the factors into four independent categories supporting the design of the battery. CONCLUSION: The battery can assess whether CPPs are able to return to work.

Process analysis of functional capacity assessment.

Researchers and practitioners, as well as vendors, have placed much emphasis on what constitutes a functional capacity testing battery. Statistical, procedural, behavioral, technological, as well as legal issues surrounding this type of human performance evaluation are also continuously being addressed in the literature. In addition, several methods, batteries, equipment, and protocols have been developed for the purpose of evaluating what an injured person can or cannot do. It is a fact that 'testing' of individuals is but one component of an intricate process consisting of: identification of an evaluee, researching a market, referring the evaluee to a facility, evaluating a set of abilities, making inference about the evaluee's performance, reporting the findings, following up on the case, and possibly a legal involvement due to litigation. These components comprise the process of functional capacity testing. The purpose of this paper is to describe and analyze the various components of the process of quantitative testing of functional capacity. It is believed that each component of the FCA process is as important as the actual testing.

Physician limitations when assessing work capacity: a review.

Literature evidence indicates that physicians have great difficulty in translating medical impairment into functional limitation and thereby establishing the work capacity or the residual functional capacity (RFC) of the injured worker. This is especially true for the chronic pain patient (CPP). Development of quantitative methods for the measurement of functional capacity (FC), have not improved the problems involved in the measurement of RFC and the translation of RFC into the demand minimum functional capacity (DMFC) of some job or jobs. The relationship between FC, RFC, work capacity and DMFC is reviewed. We have developed a method/battery for measuring RFC in CPPs utilizing the Dictionary of Occupational Titles (DOT) which is readily translatable into DMFC of some job or jobs. Suggestions are made for future directions in the measurement of work capacity.

Computer-aided design and analysis of the sitting workplace for the disabled.

This paper describes a personal microcomputer model to match the need of the ambulatory disabled to the physical workplace. It is noted that back pain resulting from working from wheelchairs is the most common complaint of many who continue or return to work. The use of computer-aided design in matching the person to his/her workstation is described.

Work scheduling under normal and prolonged-vibration environments.

This paper summarizes the research conducted to study human performance and recovery under prolonged, whole-body, vertical vibration. The results showed that performance under vibratory environment is inferior to that under normal environment. Interaction between work-rest schedules and the vibratory environment was detected. Parameters affecting selection of optimum work-rest schedules are discussed.

Determination of lifting abilities: a comparative study of four techniques.

The main objective of this study was to test the differences among four techniques for the determination of lifting abilities. This study introduced a new submaximal isometric strength testing technique. The proposed test was based on the concept of acceptable maximum effort (AME) which is the level of static exertion the individual is willing to perform voluntarily and comfortably without over-exertion (as opposed to the maximum ability of performance). Twelve male and five female subjects underwent the protocol of the four strength testing techniques investigated: isometric maximum voluntary contraction (MVC); maximum acceptable weight (MAW); maximum dynamic lifting (MDL); and acceptable maximum effort (AME). The results showed that MAW recorded the lowest values followed by AME, then MDL, then MVC. The correlation between AME and MAW was higher than that found between MVC and MAW. Also, it was found that AME is a reproducible measure of muscular functional abilities. On the average, the coefficient of variation was less than 15% for data for both males and females. The implications of these results in determining lifting abilities are discussed.

Physiological limits in lifting.

Two different experiments were conducted to study the effects of frequency, height and load of lift on computed maximal oxygen uptake and to compare the data obtained to a standard bicycle ergometer. A progressive submaximal technique was used to predict maximal oxygen uptake. The results of the present study revealed that across all heights, an increase in either the frequency of lift or load of lift was accompanied by an increase in computed maximal oxygen uptake; however, all maximal oxygen uptake values reported showed a tendency to level off beyond the frequency of five lifts/min. The results also showed that combined arm and leg lifting recorded the highest maximal oxygen uptake followed by leg lifting then arm lifting, respectively. Maximal oxygen uptake values obtained for lifting tasks were much lower than those obtained for a bicycle ergometer. It is therefore recommended that limits for continuous work for a lifting task be based on the attainable maximal oxygen uptake for that particular task and not on a maximal oxygen uptake obtained from another task such as a bicycle ergometer test.

Physiologic responses to static, dynamic and combined work.

The main objective of the present study was to determine the effects on cardiovascular stress of tasks that have varying degrees of static and dynamic components (weight holding, manual lifting and stepping). Heart rate, oxygen consumption and blood pressure were used as indices of cardiovascular stress. The results showed that oxygen consumption and heart rate responses to manual lifting are significantly lower than those of stepping and higher than those of weight holding. A low frequency lifting task evoked significantly lower systolic blood pressure than a high frequency lifting task. This study supported the idea that a physiologic fatigue criterion (PFC) based on stepping should not be applied directly to tasks such as manual lifting. In addition, a PFC for manual lifting should not be based only on oxygen consumption or heart rate; it also should incorporate systolic blood pressure as one of the monitored stress factors in setting lifting standards.

Spinal compression tolerance limits for the design of manual material handling operations in the workplace.

Spinal compression tolerance limits (SCTL) have been widely used by ergonomists in setting work tolerance limits for manual materials handling (MMH) operations. Thus, the effect of personal and experimental factors on spinal compression tolerance limits (SCTL) is reviewed with the aid of regression and correlation analyses performed on data compiled from the published literature. Tables of SCTL from various sources utilizing large number of specimens and personal factors are presented so that they can be accessed by ergonomists easily. Integrated biomechanical guidelines based on SCTL are provided for the design of MMH operations in the workplace. It is suggested that, in order to reduce the probability of MMH injuries, biomechanical tolerance limits should be set at the damage load instead of the load at fracture. The damage load is the weight which causes the first gross signs of damage such as tissue fluid and blood. An algorithm is described to demonstrate the use of a biomechanics approach to the design of MMH operations.

Functional electric stimulation in the reversal of conversion disorder paralysis.

Numerous reports have documented the usefulness of functional electric stimulation (FES) in restoring and/or improving the function of organically diseased or paralyzed muscles. There are few reports related to the use of FES in the treatment of conversion disorder paralysis of the hysterical type. This paper presents a case of hysterically paralyzed muscles where the patient received daily treatment with FES for two weeks. Electric current was applied to a weak quadriceps and to paralyzed tibialis anterior muscles. This electrotherapeutic modality was effective in improving the function of the quadriceps and in reversing the paralysis of the tibialis anterior muscles. The improvement in the muscles' functional abilities was documented through the use of quantitative measures of muscle strength as well as computerized analysis of EMG signals. The results showed that the administration of FES resulted in a dramatic increase in motor units recruitment, increased muscle strength, and improved voluntary muscle control.

Efficacy of physical restoration in the elderly.

Studies of the effects of physical exercise programs have shown that such programs can improve older persons' functional capacity. Research was conducted to determine the efficacy of two different types of physical restoration regimens--active and passive--in improving the performance of elderly persons with chronic pain conditions. Data from elderly persons admitted for back and pain rehabilitation to the Comprehensive Pain and Rehabilitation Center (CPRC) at the University of Miami are presented. The active approach consisted of the aggressive rehabilitation program at the CPRC, a 4-week program of daily physical therapy, occupational therapy, behavioral modification, and counseling. Treatment goals were improved strength, flexibility, posture, balance, gait, and overall well-being. The passive approach was based on the use of functional electric stimulation (FES) as an adjunct treatment to strengthen lower extremity muscles weakened by disuse. To evaluate the effectiveness of these approaches to physical restoration, we performed ergonomic assessment of subjects' functional abilities, including static strength and range of motion. Findings indicated that both methods were valuable in physical restoration in the elderly. Specifically FES proved effective in strengthening weak muscles in the lower extremities and shows great potential for neuromuscular conditioning in older cohorts.