Home-based Reach-to-Grasp training for people after stroke is feasible: a pilot randomised controlled trial

Objective:

To determine feasibility of a randomised controlled trial (RCT) of home-based Reach-to-Grasp training after stroke.

Design:

single-blind parallel group RCT.

Participants:

Residual arm deficit less than 12 months post-stroke.

Interventions:

Reach-to-Grasp training in 14 one-hour therapist’s visits over 6 weeks, plus one hour self-practice per day (total 56 hours). Control: Usual care.

Main Measures:

Action Research Arm Test (ARAT), Wolf Motor Function Test (WMFT), pre-randomisation, 7, 12, 24 weeks post-randomisation.

Results:

Forty-seven participants (Reach-to-Grasp=24, usual care=23) were randomised over 17 months. Reach-to-Grasp participants received a median (IQR) 14 (13,14) visits, and performed 157 (96,211) repetitions per visit; plus 30 minutes (22,45) self-practice per day. Usual care participants received 10.5 (5,14) therapist visits, comprising 38.6 (30,45) minutes of arm therapy with 16 (6,24) repetitions of functional tasks per visit. Median ARAT scores in the reach-to-grasp group were 8.5 (3.0,24.0) at baseline and 14.5 (3.5,26.0) at 24 weeks compared to median of 4 at both time points (IQR: baseline (3.0,14.0), 24 weeks (3.0,30.0)) in the usual-care group. Median WMFT tasks completed at baseline and 24 weeks were 6 (3.0,11.5) and 8.5 (4.5,13.5) respectively in the reach-to-grasp group and 4 (3.0,10.0), 6 (3.0,14.0) in the usual care group. Incidence of arm pain was similar between groups. The study was stopped before 11 patients reached the 24 weeks assessment.

Conclusions:

An RCT of home-based Reach-to-Grasp training after stroke is feasible and safe. With ARAT being our preferred measure it is estimated that 240 participants will be needed for a future two armed trial.

Experimental challenge of bovine mammary glands with Enterococcus faecium during early and late lactation

Mammary glands of early and late lactation cows were challenged with Enterococcus faecium of bovine origin to determine in vivo pathogenicity and milk somatic cell count (SCC) responses. A total of 20 early lactation and 18 late lactation mammary glands were challenged. Two isolates highly adaptive and 2 isolates poorly adaptive for in vitro growth in mammary secretion were used as challenge strains of bacteria. Challenged quarters of early lactation cows were more susceptible to intramammary infection caused by E. faecium than those of late lactation cows. Intramammary challenge with isolates poorly adaptive for in vitro growth in mammary secretions resulted in 94.7% of quarters infected compared with 36.8% of the quarters infused with the isolates highly adaptive for in vitro growth in mammary secretions. Milk from quarters infused with the isolates poorly adaptive for in vitro growth had higher SCC and bacterial counts compared with quarters challenged with the isolates highly adaptive for in vitro growth. A stage of lactation effect within treatment groups was measured when milk SCC were compared between early and late lactation cows. Milk SCC in uninfused (negative control) quarters were lower in early lactation cows compared with late lactation cows. Conversely, in quarters infused with isolates poorly adaptive for in vitro growth, SCC were higher in early lactation cows compared with late lactation cows on d 2, 3, 4, 15, 16, and 17 postchallenge. In quarters infused with isolates highly adaptive for in vitro growth, SCC response did not differ between early and late lactation cows. In vitro growth of E. faecium in mammary secretion was inversely related to in vivo pathogenicity in the mammary glands of early and late lactation cows.

Relationship of sensory symptoms and motor function in patients with chemotherapy-induced peripheral neuropathy (CIPN) utilizing the EORTC QLQ CIPN20: NCCTG study N06CA

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Background: CIPN is characterized by adjectives not covered directly by most common measures of pain and functional limitations. Possible descriptors include numbness, tingling and shooting/burning pain. A prospective neuropathy treatment trial provided data to explore the relationship between self-reported aspects of this symptom. Methods: Baseline EORTC QLQ CIPN20 data and NCI CTCAE V3.0 (CTC)neuropathy grade (I-IV) were provided for all patients on trial. Spearman correlation coefficients and Kappa's coefficients of agreement were calculated between individual items and subscales of the CIPN20 as well as the CTC neuropathy scale. Simple regression models were applied to examine the association between the sensory symptoms and motor function in the fingers/hands (F/H). 200 patients provided 80% power to detect a correlation coefficient of 0.20 with a 5% Type I error. Results: A majority of patients reported “quite a bit” to “very much” numbness (57%) or tingling (62%) in F/H compared to “a little” or “not at all” (numbness (43%), tingling (38%)) by the CIPN20. In contrast, only 13% of the participants had grade III/IV neuropathy determined by the CTC scale. Fewer patients reported the higher two levels of CIPN20-measured shooting/burning pain in F/H (20% “quite a bit” to “very much”). Numbness and tingling were highly correlated (kappa=0.56), while neither were in high agreement with shooting/burning pain (kappa= 0.05 (tingling) and 0.14 (numbness)). The CIPN20 sensory and motor subscales were significantly associated with each other (p<.0001) but were not or only weakly associated with the CTC. Specifically, tingling, numbness, and shooting/burning pain were not associated with the CTC (R=0.16, 0.18 and 0 .11, respectively). Using the CIPN20, all three sensations; numbness, tingling and shooting or burning pain were strongly associated with motor function. Conclusions: The most common moderate to severe CIPN symptoms were numbness and tingling with shooting/burning pain being less common. Shooting/ burning pain appears to be a separate symptom experience from numbness and tingling. The CTC neuropathy grading scale appears to be less sensitive than the CIPN20 in picking up sensory symptoms.

No significant financial relationships to disclose.

Very Early Constraint-Induced Movement during Stroke Rehabilitation (VECTORS): A single-center RCT

BACKGROUND

Constraint-induced movement therapy (CIMT) is among the most developed training approaches for motor restoration of the upper extremity (UE).

METHODS

Very Early Constraint-Induced Movement during Stroke Rehabilitation (VECTORS) was a single-blind phase II trial of CIMT during acute inpatient rehabilitation comparing traditional UE therapy with dose-matched and high-intensity CIMT protocols. Participants were adaptively randomized on rehabilitation admission, and received 2 weeks of study-related treatments. The primary endpoint was the total Action Research Arm Test (ARAT) score on the more affected side at 90 days after stroke onset. A mixed model analysis was performed.

RESULTS

A total of 52 participants (mean age 63.9 +/- 14 years) were randomized 9.65 +/- 4.5 days after onset. Mean NIHSS was 5.3 +/- 1.8; mean total ARAT score was 22.5 +/- 15.6; 77% had ischemic stroke. Groups were equivalent at baseline on all randomization variables. As expected, all groups improved with time on the total ARAT score. There was a significant time x group interaction (F = 3.1, p < 0.01), such that the high intensity CIT group had significantly less improvement at day 90. No significant differences were found between the dose-matched CIMT and control groups at day 90. MRI of a subsample showed no evidence of activity-dependent lesion enlargement.

CONCLUSION

Constraint-induced movement therapy (CIMT) was equally as effective but not superior to an equal dose of traditional therapy during inpatient stroke rehabilitation. Higher intensity CIMT resulted in less motor improvement at 90 days, indicating an inverse dose-response relationship. Motor intervention trials should control for dose, and higher doses of motor training cannot be assumed to be more beneficial, particularly early after stroke.

Genomic typing of enterococci isolated from bovine mammary glands and environmental sources

Enterococcal isolates (n = 102) from various sources of bovine origin on 1 farm were characterized using pulsed field gel electrophoresis analysis of SmaI restriction patterns. Isolates originated from feed samples (n = 6), bedding samples (n = 15), and bovine quarter-milk samples (n = 81). Isolates collected from milk samples included those from high-somatic cell count cows (n = 42), postpartum milk samples (n = 16), and clinical mastitis samples (n = 23). Species evaluated included Enterococcus faecium (n = 68), Enterococcus casseliflavus (n = 29), and Enterococcus faecalis (n = 5). A total of 20 clusters representing 44 isolates were detected when a similarity cut-off level of 75% was applied to interpret the pulsed field gel electrophoresis results. Fifteen of the clusters contained only isolates from milk samples. Four clusters contained isolates from bedding and milk samples. One cluster contained only isolates from feed samples. Clusters comprised of a single species represented 17 of the 20 total clusters. These results suggest enterococci from bovine origin were genetically diverse, whereas a limited number of isolates from various sources appeared to cluster together.

Xenorhabdus antibiotics: a comparative analysis and potential utility for controlling mastitis caused by bacteria

AIMS

The role of antibiotics produced by bacterial symbionts of entomopathogenic nematodes is to suppress growth of microbes in the soil environment. These antibiotics are active against Gram-positive and Gram-negative bacteria, and were tested against mastitis isolates from dairy cows.

METHODS AND RESULTS

Two bioassays were adapted for Xenorhabdus antibiotics; an overlay method on agar plates, and serially diluted, cell-free, Xenorhabdus cultures. The antimicrobial activities of the liquid cultures of 13 strains from five Xenorhabdus species were further evaluated. Antimicrobial activities of the type strains of X. nematophila, X. budapestensis and X. szentirmaii were tested on mastitis isolates of Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae with both bioassays. A previously reported antibiotic from X. nematophila, nematophin, was synthesized in three steps from tryptamine and 4-methyl-2-oxovaleric acid sodium salt.

CONCLUSIONS

The antibiotics of all three Xenorhabdus strains were powerful in either bioassay, but the sensitivity of the isolates differed from each other. While Kl. pneumoniae was the least susceptible, Staph. aureus had the highest sensitivity to each Xenorhabdus strain. Xenorhabdus szentirmaii and X. budapestensis were more potent antibiotic producers than X. nematophila, and raceme nematophin was ineffective against all mastitis isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results indicate that Xenorhabdus antibiotics are effective against mastitis isolates and should be further evaluated for their potential in mastitis control or prevention.

In Vitro Growth of Enterococci of Bovine Origin in Bovine Mammary Secretions from Various Stages of Lactation

In vitro growth responses of Enterococcus faecium and Enterococcus faecalis were tested in cell-free, fat-free bovine mammary secretions. Mammary secretions were collected during the dry period, and during early, late, and extended lactation. Sixty-three enterococcal isolates from aseptically collected bovine quarter milk samples and bedding samples from a commercial dairy herd were tested. Isolates from bovine quarter milk samples originated from mammary glands with clinical mastitis, cows with composite somatic cell score >4, postpartum milk samples, or from routine milk samples submitted to a mastitis diagnostic laboratory. Source of enterococcal isolates and the species significantly contribute to the ability of organisms to multiply in mammary secretions from various stages of lactation. Isolates collected from milk samples of the commercial herd and isolates from milk submitted to a mastitis diagnostic lab did not display enhanced growth in mammary secretions compared with isolates from bedding. Growth responses of E. faecalis were greater than those for E. faecium in secretions collected during the dry period, late lactation, and extended lactation. Bacterial growth did not differ between enterococcal species in mammary secretion collected from cows in early lactation. Differences in bacterial growth between E. faecalis and E. faecium in mammary secretions may indicate differences between species in susceptibility of mammary glands during the lactation cycle.

Defining the pathophysiology of the paclitaxel-acute pain syndrome

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Background: Paclitaxel therapy often results in a unique sub-acute pain syndrome, whose pathophysiology is unknown. While this syndrome is often termed as a ‘myalgia’ or ‘arthralgia’, it has not been demonstrated to be associated with any structural injury of muscles or joints. Identifying the pathophysiology mechanisms that result in the paclitaxel-acute pain syndrome might be a positive step in the development of effective prevention and/or treatment strategies. With the hypothesis that the paclitaxel-acute pain syndrome occurs as a result of nerve injury, an observational study to clarify the clinical characteristics of this syndrome was initiated. Methods: Oncology patients who were treated with at least one dose of paclitaxel and reported developing sub-acute pain were questioned using a detailed structured interview. Various aspects of the pain, including the time of onset, duration, location, severity, and exacerbating factors were evaluated. Data were tabulated descriptively. Results: Eighteen patients were interviewed. The onset of pain typically occurred 1–2 days after therapy and lasted for a median of 4–5 days. Pain was most commonly located in the back, hips, shoulders, thighs, legs and feet, with the most common descriptors used being ‘aching’ or ‘deep pain’. Commonly used adjectives to describe the pain were: ‘radiating’, ‘shooting’, ‘aching’, ‘stabbing’ and ‘pulsating’. Some patients described increased pain with weight bearing or walking. Fifteen of 18 patients specifically denied localization of pain to either joints or muscles. Conclusions: The nature of the pain, i.e. , generalized, deep aching pain, the notation of increased sensitivity with weight bearing (mechanical hyperalgesia) and the lack of localization to joints or muscles, support the hypothesis that the paclitaxel-acute pain syndrome results from a hyperalgesic dysfunction of nociceptive receptors, their fibers, or the spinothalamic system. These clinical conclusions are supported by the recent findings that markers of cellular injury can be identified in peripheral nerve tissues shortly following paclitaxel administration in an animal model (Peters CM, et al., Exp Neurol. 2007 Jan;203(1):42- 54).

No significant financial relationships to disclose.

A pneumatic muscle hand therapy device

Intensive repetitive therapy improves function and quality of life for stroke patients. Intense therapies to overcome upper extremity impairment are beneficial, however, they are expensive because, in part, they rely on individualized interaction between the patient and rehabilitation specialist. The development of a pneumatic muscle driven hand therapy device, the Mentortrade mark, reinforces the need for volitional activation of joint movement while concurrently offering knowledge of results about range of motion, muscle activity or resistance to movement. The device is well tolerated and has received favorable comments from stroke survivors, their caregivers, and therapists.

Bacterial Counts in Organic Materials Used as Free-Stall Bedding Following Treatment with a Commercial Conditioner

An acidic conditioner was tested in recycled manure and sawdust used as free-stall bedding to determine the effect on bacterial counts of common environmental mastitis pathogens. Free stalls were bedded with 10 kg of either kiln-dried sawdust or recycled manure per stall. All bedding was removed and fresh bedding was applied every 7 d. Approximately 1 kg of commercial bedding conditioner containing 93% sodium hydrosulfate (wt/wt) was spread evenly over bedding in the back one-third of each treated stall. Control bedding received no treatment. Cows were bedded on the same material for 3 consecutive weeks. After 3 wk on a bedding treatment, cows remained in the same pens and bedding treatments were changed between rows within pens in a switchback design. The addition of bedding conditioner to sawdust reduced gram-negative bacterial, coliform, Klebsiella spp., and streptococcal counts immediately after application and 1 d after application. Bacterial counts did not differ between treated and untreated sawdust on d 2 and 6 after the conditioner treatment. Each bacterial count measured was reduced in recycled manure immediately after application. Gram-negative bacterial and streptococcal counts were reduced in treated recycled manure compared with untreated recycled manure on d 1 after conditioner was applied. Bacterial counts did not differ between treated and untreated recycled manure bedding on d 2 and 6 after application in free stalls. The antibacterial activity of the conditioner was related to the pH of the bedding and was diminished by d 2 after application in both bedding types.

Iron uptake by Escherichia coli cultured with antibodies from cows immunized with high-affinity ferric receptors

The synergistic effects of immunoglobulin G (IgG) from cows vaccinated with ferric citrate receptor (FecA) and IgG from cows vaccinated with ferric enterobactin receptor (FepA) were measured in an in vitro iron uptake assay. Serum was isolated and pooled within treatment from five cows each vaccinated with FepA or FecA or not vaccinated. Immunoglobulin G was isolated by ammonium sulfate precipitation and protein G affinity chromatography. Six Escherichia coli isolates from bovine intramammary infections were cultured in an iron-depleted medium to induce high-affinity iron acquisition systems and, in iron-depleted conditions, to specifically induce the expression of FecA. The bacterial cells were mixed with either 3 or 6 mg/mL of purified IgG and 55Fe. The radioactivity of 55Fe taken up by the bacterial cells was measured by a liquid scintillation counter after 5-, 10-, and 15-min incubations at 37 degrees C. The combination of anti-FecA IgG and anti-FepA IgG reduced 55Fe uptake compared with either anti-FecA or anti-FepA alone. Iron uptake was reduced more by anti-FecA IgG than by anti-FepA IgG when the ferric citrate system was induced. Reduction of iron uptake did not differ between anti-FepA alone and anti-FecA alone when citrate was absent from the medium.

A study design to investigate the effect of intense Tai Chi in reducing falls among older adults transitioning to frailty

This paper describes the study design, methodological considerations, and baseline characteristics of a clinical trial to determine if intense (48 weeks, twice per week) Tai Chi practice can reduce the frequency of falls among older adults transitioning to frailty compared to a wellness education program. Twenty facilities will be stratified on socioeconomic status and facility type and randomly assigned to one of the two interventions. Secondary outcome measurements include variables related to function, behavior, and the biomechanics of movement. This study is unique because it represents an effort to offer a novel physical intervention to a large sample of transitional frail adults, a population that has received few formal exercise interventions. In addition to bringing the interventions into facilities, a 1-year follow-up is also included to assess rates of change in outcome measurements.

Associations of demographic, functional, and behavioral characteristics with activity-related fear of falling among older adults transitioning to frailty

OBJECTIVES

To determine, in a cohort of older individuals transitioning to frailty (defined by Speechley and Tinetti, 1991) who have previously fallen, whether there are significant associations between demographic, functional, and behavioral characteristics and activity-related fear of falling, using both the Falls Efficacy Scale (FES) and the Activities-Specific Balance Confidence Scale (ABC).

DESIGN

Baseline cross-sectional analysis in a prospective cohort intervention study.

SETTING

Twenty independent senior living facilities in Atlanta.

PARTICIPANTS

Seventeen male and 270 female subjects (n = 287), age 70 and older (mean +/- standard deviation, 80.9 +/- 6.2), with Mini-Mental State Examination score > or = 24, transitioning to frailty, ambulatory (with or without assistive device), medically stable, and having fallen in the past year.

MEASUREMENTS

Activity-related fear of falling was evaluated with the FES and ABC Scale. Because of the comparable data derived from each scale, associations with functional measures-related analyses were expressed using the latter. Depression was measured by Center for Epidemiological Studies Depression Scale. Functional measurements included timed 360 degrees turn, functional reach test, timed 10-meter walk test, single limb stands, picking up an object, and three chair stands.

RESULTS

No statistically significant association was found between activity-related fear of falling and age. For the proposed activities, about half (ABC, 48.1%; FES, 50.1%) of the subjects were concerned about falling or showed lack of confidence in controlling their balance. A statistically significant inverse correlation was found between FES and ABC (r = -0.65; P < .001). African-American subjects showed more activity-related fear of falling than did Caucasians (odds ratio (OR): 2.7 for ABC; 2.1 for FES). Fearful individuals were more likely to be depressed and more likely to report the use of a walking aid than were nonfearful individuals. Fear of falling was significantly correlated to all of the functional measurements (P < .05). In a multivariable logistic regression model, depression, using a walking-aid, slow gait speed, and being an African-American were directly related to being more fearful of falling.

CONCLUSIONS

Activity-related fear of falling was present in almost half of this sample of older adults transitioning to frailty. The significant association of activity-related fear of falling with demographic, functional, and behavioral characteristics emphasizes the need for multidimensional intervention strategies to lessen activity-related fear of falling in this population.

Assessing Wolf motor function test as outcome measure for research in patients after stroke

BACKGROUND AND PURPOSE

The Wolf Motor Function Test (WMFT) is a new time-based method to evaluate upper extremity performance while providing insight into joint-specific and total limb movements. This study addresses selected psychometric attributes of the WMFT applied to a chronic stroke population.

METHODS

Nineteen individuals after stroke and with intact cognition and sitting balance were age- and sex-matched with 19 individuals without impairment. Subjects performed the WMFT and the upper extremity portion of the Fugl-Meyer Motor Assessment (FMA) on 2 occasions (12 to 16 days apart), with scoring performed independently by 2 random raters.

RESULTS

The WMFT and FMA demonstrated agreement (P<0.0001) between raters at each session. WMFT scores for the dominant and nondominant extremities of individuals without impairment were different (P</=0.05) from the more and less affected extremities of subjects after stroke. The FMA score for the more affected extremity of subjects after stroke was different (P</=0.05) from the dominant and nondominant extremities. However, the FMA score for the less affected upper extremity of individuals after stroke was not different (P>0.05) from the dominant and nondominant extremities of individuals without impairment. The WMFT and FMA scores were related (P<0.02) for the more affected extremity in individuals after stroke.

CONCLUSIONS

The interrater reliability, construct validity, and criterion validity of the WMFT, as used in these subject samples, are supported.

From tibialis anterior to Tai Chi: biofeedback and beyond

This keynote presentation highlights events that have contributed to scientific explorations of one research clinician. Steve Wolf traces his scientific roots to early studies in single motor unit control under the guidance of his primary mentor, John Basmajian, MD. This work led to subsequent studies on the role of EMG feedback in predicting successful outcomes in upper extremity use and in ambulatory capabilities among patients with chronic stroke. These findings are contrasted to further efforts to condition entire reflexes rather than individual muscles through use of operant-conditioning paradigms. The findings from applications of EMG biofeedback to stroke patients became the basis for minimal motor criteria in the treatment of the impaired upper extremities of patients with chronic stroke, using "forced use" or "constraint-induced movement therapy." Last, investigations into center of pressure feedback using computerized balance machines resulted in a series of experiments that ultimately led to the finding that Tai Chi as an exercise form for older adults can have a substantially favorable effect in delaying the onset of fall events.

Doing it with mirrors: a case study of a novel approach to neurorehabilitation

Arm amputees can experience the perception of movement of a phantom limb while looking at a mirror reflection of the moving, intact arm superimposed on the perceived phantom. Such use of a mirror to provide illusory visual feedback of movement can be useful in rehabilitation of hemiparetic patients. In this case report, we describe the successful application of "mirror therapy" to the post-stroke rehabilitation of a patient with poor functional use of an upper extremity, due mainly to somatosensory deficits. Mirror therapy facilitated employment of a motor copy strategy (bimanual movements) and later progression to "forced use" of the affected arm. The end result was increased functional use of the affected upper limb.

Modified emory functional ambulation profile: an outcome measure for the rehabilitation of poststroke gait dysfunction

BACKGROUND AND PURPOSE

The modified Emory Functional Ambulation Profile (mEFAP) is an easily administered test that measures the time to ambulate through 5 common environmental terrains with or without an assistive device or manual assistance. The mEFAP was evaluated for its interrater reliability, test-retest reliability, concurrent validity, and sensitivity to change during outpatient rehabilitation for poststroke gait dysfunction.

METHODS

Twenty-six poststroke patients were followed up prospectively in a rehabilitation day-treatment program. The mEFAP, Berg Balance Test (BBT), and 7-item mobility subsection of the Functional Independence Measure + Functional Assessment Measure (FAMm) were completed at admission and discharge.

RESULTS

mEFAP interrater reliability (intraclass coefficient [ICC] 0.999) and test-retest reliability (ICC 0.998) were high. The BBT demonstrated high interrater (ICC 0.992) but poor test-retest (ICC 0.605) reliability. Initial and final scores comparing the mEFAP with the BBT (r=-0.735, r=-0.703) and the mEFAP with the FAMm (r=0.685, r=-0.775) were strongly correlated. Improvement on the mEFAP correlated with improved BBT performance (r=-0.524). There was no correlation between overall change observed on the FAMm and change on the mEFAP (r=-0.145). Total mEFAP and all mEFAP subtask scores improved over time (P:<0.0001).

CONCLUSIONS

The mEFAP is a reliable gait-assessment tool for patients with stroke and is sensitive to change in ambulation speed.

Establishing the reliability and validity of measurements of walking time using the Emory Functional Ambulation Profile

BACKGROUND AND PURPOSE

The Emory Functional Ambulation Profile (E-FAP) measures time to walk in different environments and accounts for use of assistive devices. This study assessed the reliability and validity of walking time measurements using these components.

SUBJECTS

Twenty-eight subjects who had strokes and 28 subjects without impairment were recruited.

METHODS

The E-FAP, Berg Balance Test, Functional Reach Test, and Timed 10-Meter Walk Test were administered in random order during a single data collection session.

RESULTS

Interrater reliability for the total E-FAP was > or = .997. Subjects without impairment performed better on all 4 tests than did subjects who had strokes. Increased times on the E-FAP correlated with poor performance on the Berg Balance Test and slow gait speeds on the Timed 10-Meter Walk Test in the subjects who had strokes. The E-FAP scores and the Functional Reach Test scores were not correlated.

CONCLUSION AND DISCUSSION

The E-FAP can be administered easily and inexpensively. Because the E-FAP scores differentiated subject groups and correlated with known measures of function, the E-FAP may be a clinically useful measure of ambulation.

An application of upper-extremity constraint-induced movement therapy in a patient with subacute stroke

BACKGROUND AND PURPOSE

The purpose of this case report is to demonstrate the application of constraint-induced movement therapy with an individual with upper-extremity hemiparesis within 4 months after sustaining a cerebrovascular accident (stroke). Such patients often fail to develop full potential use of their affected upper extremity, perhaps due to a "learned nonuse phenomenon."

CASE DESCRIPTION

The patient was a 61-year-old woman with right-sided hemiparesis resulting from an ischemic lacunar infarct in the posterior limb of the left internal capsule. The patient's less-involved hand was constrained in a mitten so that she could not use the hand during waking hours, except for bathing and toileting. On each weekday of the 14-day intervention period, the patient spent 6 hours being supervised while performing tasks using the paretic upper extremity. Pretreatment, posttreatment, and 3-month follow-up outcome measures included the Wolf Motor Function Test and the Motor Activity Log (MAL).

OUTCOMES

For the Wolf Motor Function Test, both the mean and median times to complete 16 tasks improved from pretreatment to posttreatment and from posttreatment to follow-up. Results of the MAL indicated an improved self-report of both "how well" and "how much" the patient used her affected limb in 30 specified daily tasks. These improvements persisted to the follow-up.

DISCUSSION

Two weeks of constraining the unaffected limb, coupled with practice of functional movements of the impaired limb, may be an effective method for restoring motor function within a few months after cerebral insult. Encouraging improvements such as these strongly suggest the need for a group design that would explore this type of intervention in more detail.

An alternative perspective

The need for a revised definition is discussed and a more simplified alternative is suggested.

Organization of responses in human lateral gastrocnemius muscle to specified body perturbations

There is mounting evidence that human muscles have discrete partitions. In an effort to accurately assess how the control to each of the three heads (designated as A-C) of the lateral gastrocnemius (LG) muscle might be organized, we performed exploratory studies in five subjects each of whom was provided 30 random angular and linear perturbations while standing on a balance platform in each of three experiments. The responses from each LG head were recorded with strategically-placed fine-wire electrodes and, after correction for variation in distance to each recording site, latency to activation and the sequence of recruitment for each LG head were determined. Within individual subjects, the same LG head was first recruited. The C-head was recruited first during linear perturbations between subjects and across sessions, but the overall recruitment pattern was different between subjects. The fact that a consistent, selective response was seen during dynamic linear but not angular perturbations suggests that a more consistent strategy of inter-partition response may be engaged for the former perturbation. This behaviour may be caused by use of the LG C-head to assist the medial gastrocnemius to control ankle plantar flexion and pronation during the shearing forces generated with linear translations. Further exploration into the relationship between selective activation of muscle partitions in the presence of defined movement conditions appears justified.

Morphological analysis of the human tibialis anterior and medial gastrocnemius muscles

The morphology and nerve innervation patterns of eight tibialis anterior (TA) and medial gastrocnemius (MG) muscles from human cadavers were examined. TA has three distinct partitions, two of which lie posteriorly. The anterior aspect of the muscle has one partition (head A) whose fibers are oriented longitudinally. The posterior partitions possess fibers that course longitudinally (B head) and obliquely (C head). The posterior longitudinal fibers and the anterior longitudinal fibers are divided by an aponeurosis that is continuous with the tendon of insertion. The proximal muscle fibers insert into this aponeurosis and the distal fibers insert into the tendon. The MG is a unipennate muscle. Both TA and MG muscles show variations in innervation patterns among specimens. In light of these findings, partitioning of TA may be based on its architecture.

Electrokinesiologic measurement of trunk sagittal mobility and lumbar erector spinae muscle activity

Additional studies to determine intratester reliability of electrokinesiologic (EK) measures related to trunk movement and low back muscle activity are needed. EMG activity and EK records of repetitive movements at both natural and maximal speeds were computer sampled and quantified among 22 nonimpaired subjects. Significant differences were observed between group means at different speeds and trials for both kinematic and EMG measures. Predictably, maximal speed testing resulted in higher levels of EMG activity when compared to natural speed testing. Intratester reliability of measures was high at both speeds. Range of motion data correlated well between two trials for both natural and maximal speed movements, ranging from 0.81 to 0.97. Correlation of speed of movement measures ranged from 0.41 to 0.76. These data suggest that computer-analyzed EMG activity and EK signals are reliable assessment tools for trunk mobility. The application of this procedure to persons with low back pain to acquire EMG activity and mobility data appears justified.

Self-report benefits of Tai Chi practice by older adults

Older persons who are willing to begin exercise programs are often not willing to continue them. At the Atlanta FICSIT (Frailty and Injuries: Cooperative Studies of Intervention Techniques) site, individuals aged 70+ were randomized to Tai Chi (TC), individualized balance training (BT), and exercise control education (ED) groups for 15 weeks. In a follow-up assessment 4 months post-intervention, 130 subjects responded to exit interview questions asking about perceived benefits of participation. Both TC and BT subjects reported increased confidence in balance and movement, but only TC subjects reported that their daily activities and their overall life had been affected; many of these subjects had changed their normal physical activity to incorporate ongoing TC practice. The data suggest that when mental as well as physical control is perceived to be enhanced, with a generalized sense of improvement in overall well-being, older persons' motivation to continue exercising also increases.

Exploring the basis for Tai Chi Chuan as a therapeutic exercise approach

For many centuries Tai Chi has been a martial art form, practiced primarily in Oriental cultures. For the past 300 years this movement approach has been used as an exercise form, practiced by millions of Chinese elderly people. To date, virtually no information exists about the therapeutic elements of this intriguing movement sequence. This article provides a historical review of existing documentation of reputed Tai Chi benefits. The 108 "forms" of Tai Chi Chuan are reduced to 10 composite forms for ease of application of these forms to older individuals within a reasonable time frame. An effort is set forth to identify the potential therapeutic elements within these forms.

The effect of Tai Chi Quan and computerized balance training on postural stability in older subjects. Atlanta FICSIT Group. Frailty and Injuries: Cooperative Studies on Intervention Techniques

BACKGROUND AND PURPOSE

This study explored whether two exercise programs would affect the ability to minimize postural sway of 72 relatively inactive, older subjects who participated in the Atlanta FICSIT trial.

SUBJECTS

Subjects were randomly assigned to (1) a computerized balance training group, (2) a tai chi group, or (3) an educational group serving as a control for exercise. Each group consisted of 24 members.

METHODS

All subjects were evaluated under four postural conditions before, immediately after, and 4 months following their respective interventions, each of which was given over 15 weeks.

RESULTS

Platform balance measures revealed greater stability after training among subjects in the balance training group but little change in stability among subjects in the tai chi and educational group. Subjects in the tai chi group were less afraid of falling after training compared with subjects in other groups with similar covariates.

CONCLUSION AND DISCUSSION

Unlike computerized balance training, tai chi does not improve measures of postural stability. Because tai chi delayed onset to first or multiple falls in older individuals, this effect does not appear to be associated with measures of enhanced postural stability. Tai chi may gain its success, in part, from promoting confidence without reducing sway rather than primarily facilitating a reduction in sway-based measures.

Environmental and behavioral circumstances associated with falls at home among healthy elderly individuals. Atlanta FICSIT Group

OBJECTIVE

To conduct an in-depth examination of the environmental and behavioral circumstances associated with falls and near-falls experienced by elderly individuals and to evaluate the usefulness of reenactment as a method for studying falls.

DESIGN

Observational and self-report data of incidents were obtained through a reenactment procedure. Environmental characteristics were documented with physical measurements, visual inspection, and photography.

SETTING

Incidents occurred inside participants' homes, and reenactments were conducted at incident sites.

PARTICIPANTS

Subjects were 15 community-dwelling, relatively healthy individuals, age 70 to 81 years.

MAIN OUTCOME MEASURES

Incidents were analyzed to determine patterns of interaction of individuals' personal characteristics, environmental use behaviors, and environmental characteristics.

RESULTS

Seven patterns were identified: collisions in the dark, failing to avoid temporary hazards, preoccupation with temporary conditions, frictional variations between shoes and floor coverings, excessive environmental demands, habitual environmental use, and inappropriate environmental use.

CONCLUSIONS

There is a dynamic interaction between environmental conditions and behavior involving use of the environment and its implications for falls in older people. Although some incidents involved familiar environmental and behavioral risk factors, less familiar factors also were critical contributors to the incidents. Successful elimination of these factors is likely to be closely related to an individual's perception that an environmental or environmental use problem is correctable, motivation to undertake changes in the environment, and a desire to integrate changes into daily activities.

Long latency ankle responses to dynamic perturbation in older fallers and non-fallers

OBJECTIVE

The purpose of this study was to examine the effects of falling history and aging on the latency and magnitude of long latency responses in the lateral gastrocnemius (LG) and tibialis anterior (TA) muscles of older adults.

DESIGN

Single observation study.

SETTING

Emory University School of Medicine, Center for Rehabilitation Medicine, serving the greater Atlanta, Georgia, area.

PARTICIPANTS

There were 62 community-dwelling adults aged 60 or older, 32 with a history of two or more unexplained falls in the past year and 30 with no history of falls in the past year.

MEASUREMENTS

The electromyographic activity of the gastrocnemius and tibialis anterior muscles was recorded bilaterally during repeated 10 degree dorsiflexion perturbations to standing subjects at the acceleration of gravity and a velocity of approximately 100 deg/sec. The latency and magnitude of the long latency EMG responses (LLR) of both muscles were determined and compared between individuals by falls history and by decades of age.

MAIN RESULTS

No significant differences between falls status groups existed for mean LLR latencies or magnitudes of either LG or TA. Attenuation of the LLR throughout the trials was significantly different between groups. Non-fallers demonstrated attenuation of the LG magnitude over the first five stretches. Fallers showed maladaptation of the LG response, with the latency becoming shorter over 25 trials. More than half of the subjects in both groups had one or more instances of temporal reversal of the response latencies, with the TA response occurring earlier than the LG response during the first five stretches. No differences existed in the LLR between age decades within faller or non-faller groups. A timed measure of mobility (Up & Go) showed a significant difference between falls status, but not between age decades in either group.

CONCLUSIONS

Lack of differences between falls status and age decade groups over all trials suggests that LLRs remain intact between older fallers and non-fallers and between older age groups. The mechanism of perturbation is a distinguishing feature of this study and probably contributes to our findings. The appearance of an atypical response strategy in both groups, where the TA response often occurs before the LG response, has raised the question of whether there is always a stereotypical pattern of LLRs during postural perturbations outside the experimental setting.

The Adolescents Training and Learning to Avoid Steroids (ATLAS) prevention program. Background and results of a model intervention

OBJECTIVE

To develop and test a school-based intervention to prevent anabolic androgenic steroid use among high-risk adolescent athletes.

DESIGN

Nonrandom controlled trial.

SETTING

Two urban high schools.

PARTICIPANTS

Fifty-six adolescent football players at the experimental school and 24 players at the control school.

INTERVENTION

Eight weekly, 1-hour classroom sessions delivered by the coach and adolescent team leaders, and eight weight-room sessions delivered by research staff. The intervention addressed sports nutrition and strength training as alternatives to steroid use, drug refusal role play, and antisteroid media campaigns.

OUTCOME MEASURES

A preintervention and postintervention questionnaire that assessed attitudes toward and intent to use steroids and other drugs; knowledge of drug effects; and diet, exercise, and related constructs.

RESULTS

Compared with controls, experimental subjects were significantly less interested in trying steroids after the intervention, were less likely to want to use them even if their friends used them, were less likely to believe steroid use was a good idea, believed steroids were more dangerous, had better knowledge of alternatives to steroid use, had improved body image, increased their knowledge of diet supplements, and had less belief in these supplements as beneficial.

CONCLUSIONS

Significant beneficial effects were found despite the sample size, suggesting that the effects of the intervention was large. This outcome trial demonstrates an effective anabolic androgenic steroid prevention program for adolescent athletes, and the potential of team-based interventions to enhance adolescents' health.

Determining consistency of elbow joint threshold angle in elbow flexor muscles with spastic hypertonia

BACKGROUND AND PURPOSE

Threshold angle, the point in passive range of motion where a muscle response or torque change is elicited, may be a potentially valid measure of hypertonus. Because the relationship of initial muscle length to threshold angle has not been addressed previously, this preliminary study examined whether starting elbow joint position and speed of stretch to elbow flexor muscles affect threshold angle.

SUBJECTS

Five subjects with stroke-induced hypertonia of the elbow flexor muscles participated.

METHODS

Two starting angles and two designated stretch speeds were applied randomly by a torque motor at each of three testing sessions.

RESULTS

Starting angle, subject, and session affected threshold angle. A 90-degree starting angle at a stretch speed of approximately 1.0 radian/s produced the most consistent threshold angles between sessions within subjects, and threshold angle was relatively consistent for some subjects, irrespective of speed.

CONCLUSION AND DISCUSSION

If future research indicates that these data can be generalized, the use of threshold angle as a consistent measure of hypertonia will require comparison within individuals, use of a consistent starting angle, and a movement condition of a 90-degree starting angle and an approximate movement speed of 1.0 radian/s across sessions.

Theoretical basis for patterning EMG amplitudes to assess muscle dysfunction

A theoretical basis for assessing muscle dysfunction due to sprain/strain injuries is presented. We propose that muscle tissue trauma results in an alteration in the patterns of neural recruitment, a reduction in the force-generating capability of the injured muscle, and/or pain sensations. Furthermore, a lower than normal recruitment of motoneuron pools in the injured area can result in elevated recruitment levels from compensating motoneuron pools for a given motor task. It is proposed that these changes in motoneuron recruitment can be readily apparent in the ratios of EMG amplitudes among multiple pairs of muscles associated kinoffologically with the affected muscle. Chronic compensating actions, such as those resulting from faulty neural feedback of the force-length-velocity relationships for a stretched tendon or muscle unit, could cause further injuries. It is proposed that consistent and valid measures of ratios of EMG amplitudes between many muscle pairs acquired for well-defined motor tasks can be used to facilitate diagnoses and direct treatment strategies for sprain/strain injuries and pain.

Reducing frailty and falls in older persons: an investigation of Tai Chi and computerized balance training. Atlanta FICSIT Group. Frailty and Injuries: Cooperative Studies of Intervention Techniques

OBJECTIVE

To evaluate the effects of two exercise approaches, Tai Chi (TC) and computerized balance training (BT), on specified primary outcomes (biomedical, functional, and psychosocial indicators of frailty) and secondary outcomes (occurrence of falls).

DESIGN

The Atlanta FICSIT (Frailty and Injuries: Cooperative Studies of Intervention Techniques), a prospective, randomized, controlled clinical trial with three arms (TC, BT, and education [ED]. Intervention length was 15 weeks, with primary outcomes measured before and after intervention and at 4-month follow-up. Falls were monitored continuously throughout the study.

SETTING

Persons aged 70 and older living in the community.

PARTICIPANTS

A total of 200 participants, 162 women and 38 men; mean age was 76.2.

MEASUREMENTS

Biomedical (strength, flexibility, cardiovascular endurance, body composition), functional (IADL), and psychosocial well-being (CES-D scale, fear of falling questionnaire, self-perception of present and future health, mastery index, perceived quality of sleep, and intrusiveness) variables.

RESULTS

Grip strength declined in all groups, and lower extremity range of motion showed limited but statistically significant changes. Lowered blood pressure before and after a 12-minute walk was seen following TC participation. Fear of falling responses and intrusiveness responses were reduced after the TC intervention compared with the ED group (P = .046 and P = .058, respectively). After adjusting for fall risk factors, TC was found to reduce the risk of multiple falls by 47.5%.

CONCLUSIONS

A moderate TC intervention can impact favorably on defined biomedical and psychosocial indices of frailty. This intervention can also have favorable effects upon the occurrence of falls. Tai Chi warrants further study as an exercise treatment to improve the health of older people.

Reducing human biceps brachii spinal stretch reflex magnitude

1. Nine subjects received 6 baseline and 24 training sessions, each consisting of 250 elbow joint stretch perturbations into extension. The training sessions were designed to reduce the subjects' biceps brachii spinal stretch reflexes (SSR). Changes in longer-latency responses and short-latency brachioradialis responses were also monitored. Background electromyogram activity was recorded from the lateral head of triceps brachii during the biceps sampling intervals. These data were compared with those form 12 control subjects who received equal numbers of stretches over an extended baseline (i.e., without application of a training paradigm). 2. Training subjects reduced their mean biceps SSR responses by 24%, whereas control subjects increased their responses by 12% When changes in activity were grouped by sets of six consecutive sessions following the baseline interval, group-by-time interaction was observed. Training subjects showed significant reductions from baseline after the first raining set. The increased magnitude of biceps SSR for control subjects was significantly larger than baseline in sets 2-5. After the first training interval, all subsequent differences between groups were statistically significant. 3. The brachioradialis showed greater response variability, but these responses paralleled those seen in biceps brachii. The training group reduced their brachioradialis responses by 18%, whereas the control group increased their responses by 12%. Background activity recorded over the lateral head of triceps brachii during the biceps brachii SSR window became smaller in both groups. 4. Comparison of data between control subjects and subjects who had undergone biceps SSR up-training in previous studies suggests that the small increase seen among the present control subjects was probably not the result of a direct training effect. 5. Baseline differences in longer-latency response onset time were seen between groups. Over extended baseline sessions, longer-latency responses showed only a 1% onset, representing a change of 0.3 ms, in the control group. A 1.3% later onset, equaling a change of 1.1 ms, was observed over conditioning sessions in the training group. When analyzed by sets following baseline, neither group showed significant within- or between-group changes over time. 6. The magnitude of the longer-latency biceps brachii response showed 7% and 37% reductions for the control and training groups, respectively. No difference in set averages was seen within groups, but a significant difference was measured over sets 2-4 between groups. Reductions in the magnitude of longer-latency responses in training subjects were more obvious in later training sessions. 7. These data suggest that 1) the biceps brachii SSR can be reduced in human subjects; 2) concurrent changes are often observed in the synergist brachioradialis; and 3) the reduced biceps SSR magnitude is not linked to a compensatory increase in antagonist muscle activity. Reductions in the magnitude of longer-latency biceps brachii activity seen in parallel with the decreased SSR may imply that some degree of supraspinal processing is required to achieve this task.

Efficacy of insulin and sulfonylurea combination therapy in type II diabetes. A meta-analysis of the randomized placebo-controlled trials

BACKGROUND

Numerous studies demonstrate the efficacy of the combination therapy of insulin and sulfonylurea in subjects with type II diabetes mellitus. However, two recent meta-analyses of randomized trials during the last decade provided inconsistent conclusions and failed to resolve the controversy.

OBJECTIVE

To assess the efficacy of insulin and sulfonylurea combination therapy in type II diabetes mellitus by performing meta-analysis of only the controlled studies selected according to specific strict criteria.

METHODS

A computerized literature survey was conducted using the MEDLINE database from January 1980 through March 1992 with the search headings of "sulfonylurea" and "insulin" and "combination therapy in diabetes mellitus. "A manual search was also performed using references from each retrieved report. Case reports, review articles, editorials, and citations reported in non-English-language journals without English translations were excluded. Forty-three citations were obtained. Four strict inclusion criteria were used to select studies: randomized, placebo-controlled trials (oral agent plus insulin vs placebo plus insulin); homogeneous target population (subjects with type II diabetes); intervention using the same sulfonylurea agent in a combination therapy; and uniform outcome measures to evaluate efficacy such as body weight; values for serum glucose, glycohemoglobin, and C peptide; daily insulin dosage; and lipid concentrations. More stringent qualitative subcriteria were then used to eliminate bias in the final unanimous selection by two blinded reviewers. Data were pooled and analyzed using Student's t test and Winer's combined test.

RESULTS

Sixteen studies satisfied the inclusion criteria. Metabolic control improved with the combination therapy as reflected by a significant lowering of fasting serum glucose values (P < .01) and glycohemoglobin concentrations (P < .025). Moreover, improved metabolic control was achieved with a significantly smaller daily insulin dose (P < .01) and without a significant change in body weight. Finally, the combination therapy enhanced the endogenous insulin secretion as expressed by an increase in fasting serum C peptide concentration (P < .05).

CONCLUSIONS

Combination therapy with insulin and sulfonylurea may be a more appropriate and a suitable option to insulin monotherapy in subjects with non-insulin-dependent diabetes in whom primary or secondary failure to sulfonylurea developed. It may also be a more cost-effective way of long-term management in this group of subjects, especially in the elderly.

A cross-sectional validation study of the FICSIT common data base static balance measures. Frailty and Injuries: Cooperative Studies of Intervention Techniques

BACKGROUND

Two simple balance scales comprising three or four familiar tests of static balance were developed, and their validity and reliability are described. The scales were such that the relative difficulties of the basic tests were taken into consideration.

METHODS

Using FICSIT data, Fisher's method was used to construct scales combining ability to maintain balance in parallel, semi-tandem, tandem, and one-legged stances. Reliability was inferred from the stability of the measure over 3-4 months. Construct validity was assessed by cross-sectional correlations.

RESULTS

Test-retest reliability (over 3-4 months) was good (r = .66). Validity of the FICSIT-3 scale was suggested by its low correlation with age, its moderate to high correlations with physical function measures, and three balance assessment systems. The FICSIT-4 scale discriminated balance over a wide range of health status; the three-test scale had a substantial ceiling effect in community samples.

CONCLUSION

A balance scale was developed that appears to have acceptable reliability, validity, and discriminant ability.

Contralateral and long latency effects of human biceps brachii stretch reflex conditioning

Results from previous studies on monkeys and human subjects have demonstrated that the biceps brachii spinal stretch reflex (SSR) can be operantly conditioned. The extent to which conditioning paradigms influence contralateral SSRs or longer latency responses in the same limb has not been examined. Nine subjects were given 10 training sessions to either increase or decrease the size of their biceps brachii SSR. Group changes were compared to the mean of six baseline (control) sessions. Both groups showed progressive SSR changes over the training sessions. Up-trained subjects increased their SSR responses by an average of 135.3% above baseline, with the last three sessions showing a 237.5% increase, while down-trained subjects reduced their average SSR responses by 43.4%, with a 52.7% reduction over the last three sessions. ipsilateral longer latency responses showed average changes of 68.9% and -68.7% for up- and down-trainers, respectively. As in the case of SSRs, these responses changed progressively over sessions, with a 131.5% increase seen in the last three up-training sessions and an 82.4% reduction over the same period for down-trainers. Correlation coefficients between SSR and longer latency responses were high (R = 0.90, up-trainers; R = 0.87, down-trainers). Contralateral SSR and longer latency responses, measured in the absence of feedback and at least 10 min after ipsilateral conditioning, showed directional changes that were similar to the trained side, but their magnitudes were not as profound. Collectively, these data suggest that unilateral SSR conditioning affects spinal circuits controlling contralateral SSRs and influences longer latency responses.

The effects of exercise on falls in elderly patients. A preplanned meta-analysis of the FICSIT Trials. Frailty and Injuries: Cooperative Studies of Intervention Techniques

OBJECTIVE

To determine if short-term exercise reduces falls and fall-related injuries in the elderly.

DESIGN

A preplanned meta-analysis of the seven Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT)--independent, randomized, controlled clinical trials that assessed intervention efficacy in reducing falls and frailty in elderly patients. All included an exercise component for 10 to 36 weeks. Fall and injury follow-up was obtained for up to 2 to 4 years.

SETTING

Two nursing home and five community-dwelling (three health maintenance organizations) sites. Six were group and center based; one was conducted at home.

PARTICIPANTS

Numbers of participants ranged from 100 to 1323 per study. Subjects were mostly ambulatory and cognitively intact, with minimum ages of 60 to 75 years, although some studies required additional deficits, such as functionally dependent in two or more activities of daily living, balance deficits or lower extremity weakness, or high risk of falling.

INTERVENTIONS

Exercise components varied across studies in character, duration, frequency, and intensity. Training was performed in one area or more of endurance, flexibility, balance platform, Tai Chi (dynamic balance), and resistance. Several treatment arms included additional nonexercise components, such as behavioral components, medication changes, education, functional activity, or nutritional supplements.

MAIN OUTCOME MEASURES

Time to each fall (fall-related injury) by self-report and/or medical records.

RESULTS

Using the Andersen-Gill extension of the Cox model that allows multiple fall outcomes per patient, the adjusted fall incidence ratio for treatment arms including general exercise was 0.90 (95% confidence limits [CL], 0.81, 0.99) and for those including balance was 0.83 (95% CL, 0.70, 0.98). No exercise component was significant for injurious falls, but power was low to detect this outcome.

CONCLUSIONS

Treatments including exercise for elderly adults reduce the risk of falls.

Operant conditioning of spinal stretch reflexes in patients with spinal cord injuries

Hyperactive spinal stretch reflexes (SSRs) often occur with spinal cord injuries (SCI). These altered SSRs may impair movement. Recent studies in monkeys and human subjects have indicated that the magnitude of SSRs can be modulated using operant conditioning. The purpose of this study was to determine whether hyperactive biceps brachii SSRs could be operantly conditioned downward. Seventeen chronic (> 1 year postlesion) spinal cord-injured patients participated. Subjects were trained to keep biceps background (prestretch) electromyographic (EMG) activity and elbow angle at predetermined levels prior to having the elbow rapidly extended by a torque motor to elicit the biceps SSR. All subjects participated in six baseline sessions over a 2-week period. Then, subjects were randomly assigned to either control or training groups for the next 24 sessions over an 8-week period. By the end of the study, training subjects had significantly reduced biceps SSRs (t test, P < 0.001), while control subjects SSRs were not significantly reduced (t test, P > 0.05). The reduced SSRs persisted for up to 4 months following cessation of training. The results of this study support the hypothesis that hyperactive SSRs can be operantly conditioned downward in SCI patients.

Overcoming limitations in elbow movement in the presence of antagonist hyperactivity

BACKGROUND AND PURPOSE

A traditional perspective on rehabilitation of patients with abnormal muscular hyperactivity presumes that relaxation should be facilitated prior to recruitment of antagonists, if effective movement about a joint is to occur. The purpose of the study was to determine the effect of training weak triceps brachii muscles, with hyperactivity present in the opposing biceps brachii muscles, on elbow function in individuals at least 1 year poststroke.

SUBJECTS

Sixteen patients with chronic stroke were randomly assigned to receive electromyographic biofeedback to retrain the triceps muscle (n = 8) or to receive conventional movement training (n = 8).

METHODS

Both groups participated in 5 baseline and 10 training sessions involving tasks requiring elbow extension. Preintervention and postintervention measurements included elbow extension range of motion, triceps and biceps muscle electromyographic activity during performance of elbow extension, resisted elbow extension, and a reaching task.

RESULTS

Two-sample t-test results of between-group comparisons for each variable were not significant. One-sample t-test results of within-group comparisons showed significant increases in triceps muscle mean electromyographic activity during two of the three tasks for the feedback group, but not for the nonfeedback group. Passive and active range of motion in both groups increased significantly, although biceps muscle co-contraction persisted.

CONCLUSION AND DISCUSSION

These results suggest that functional improvements at the elbow may have been due to biomechanical (peripheral) rather than neuromuscular (central) changes about the joint. Furthermore, these preliminary data indicate that patients with stroke may be trained to increase movement without first being trained to specifically inhibit hyperactivity in muscles.