The inter-therapist reliability of the slump test

This study examined the inter-therapist reliability of the slump test. Six pairs of physiotherapists tested a total of 93 patients currently receiving treatment for lumbar and/or lower limb symptoms. Each pair performed two slump tests on patients during a normal clinical visit. The slump test was positive if the patients' symptoms were reproduced, and subsequently decreased with cervical extension. A second definition of positive slump required decreased symptoms and increased knee extension with cervical extension. The results indicated that the slump test has high inter-therapist reliability which is consistent with reliability findings for related clinical tests of pain.

Visual analysis of single-case time series: Effects of variability, serial dependence, and magnitude of intervention effects

Visual analysis is the dominant method of analysis for single-case time series. The literature assumes that visual analysts will be conservative judges. We show that previous research into visual analysis has not adequately examined false alarm and miss rates or the effect of serial dependence. In order to measure false alarm and miss rates while varying serial dependence, amount of random variability, and effect size, 37 students undertaking a postgraduate course in single-case design and analysis were required to assess the presence of an intervention effect in each of 27 AB charts constructed using a first-order autoregressive model. Three levels of effect size and three levels of variability, representative of values found in published charts, were combined with autocorrelation coefficients of 0, 0.3 and 0.6 in a factorial design. False alarm rates were surprisingly high (16% to 84%). Positive autocorrelation and increased random variation both significantly increased the false alarm rates and interacted in a nonlinear fashion. Miss rates were relatively low (0% to 22%) and were not significantly affected by the design parameters. Thus, visual analysts were not conservative, and serial dependence did influence judgment.

Bilateral training does not facilitate performance of copying tasks in poststroke hemiplegia

OBJECTIVE

Previous studies in rehabilitation in poststroke hemiplegia have suggested that brief periods of bilateral training improve subsequent unilateral performance of the paretic upper limb. The bilateral training protocol involved task-specific practice using both upper limbs simultaneously and homologously (such that they mirrored each other). This study aimed to determine the generalizability of the bilateral training phenomenon by replicating the work with different tasks, measures, and a different experimenter.

METHODS

Five single-case experiments were performed using a within-participant multiple-baseline design. Participants with post-stroke hemiplegia underwent 25 to 40 daily training sessions involving repetitive practice of 3 copying tasks. Pen movements were recorded on a digitizing pad. During the baseline phase, participants performed tasks unilaterally with their hemiplegic limb. Bilateral therapy was then applied in a staggered fashion to each task in turn. Quality of movement was measured in terms of temporal performance (jerkiness, speed, task duration), spatial performance (accuracy of copy), and arm posture (pen tilt).

RESULTS

Movement quality of the hemiplegic limb was not improved during or subsequent to regular bilateral training.

CONCLUSIONS

The training phenomenon observed in previous work was not replicated when participants with hemiplegia practiced copying tasks bilaterally.

Responses of the densely hemiplegic upper extremity to bilateral training

OBJECTIVE

Recovery of movement in the densely hemiplegic upper extremity remains a problem after stroke. This study aimed to determine whether movement recovery could be improved in the hemiplegic arm with bilateral isokinematic training.

METHODS

Within and between groups, planned comparisons investigated the effects of bilateral training on attempts at two movements by subjects with acute and chronic problems with one and two bilateral practice phases. Electromyographic (EMG) activity of middle deltoid and extensor carpi radialis longus in the hemiplegic arm was recorded during unilateral and bilateral isometric shoulder abduction and wrist extension.

RESULTS

Small increases in muscle activity were demonstrated by both experimental and control subjects during most bilateral practices in both actions. However, these increases were not significantly different from the previous unilateral trial, and the bilateral effect failed to generalize to subsequent trials. Previous studies with less densely hemiplegic subjects had demonstrated generalization of improvements in movement patterns with bilateral training to unimanual actions of the densely hemiplegic arm.

CONCLUSIONS

Extensive lesions may limit brain reorganization and recover of dense hemiplegia after stroke. Nonetheless, on the basis of findings from other studies in which functional improvements occurred in both acute and chronic severely stroke-affected subjects, outcome forecasting for the hemiplegic upper extremity should only eventuate after provision of practice under optimal learning conditions.

Training novice clinicians improves observation accuracy of the upper extremity after stroke

OBJECTIVES

To determine whether training influenced the accuracy of observational kinematic assessment (OKA) of hemiplegic upper extremity impairment and to elucidate the contribution of knowledge of results to learning.

DESIGN

Intervention study; before-after testing of OKA accuracy after training, using 2 trained groups (with knowledge of results, KR group; without, NKR group) and 1 control group with a 1-week retention test.

SETTING

Tertiary teaching.

PARTICIPANTS

Fifty-one first-year physical therapy student volunteers acted as observers. They were ranked on pretest accuracy and then randomized into groups. A consecutive sample of 11 stroke patients and 4 nondisabled subjects acted as performers.

INTERVENTIONS

Performers were videotaped with 3 cameras and upper extremity kinematics derived using computer-assisted motion analysis. Training and test videotapes were generated. Training groups received video-based training of path indirectness accuracy on 4 occasions. The OKA accuracy of all observers' judgments of speed, jerkiness, and path indirectness were examined pretest and posttest.

MAIN OUTCOME MEASURE

Accuracy reported as mean absolute error, which was calculated as difference between observers' judgments and criterion kinematic values.

RESULTS

The KR and NKR groups showed reduction in mean absolute error after training of 34.8% and 6.2%, respectively. Improvements were retained after a 1-week no intervention period. Transfer to trained, but not untrained kinematic parameters occurred. The control group did not change.

CONCLUSIONS

OKA accuracy is susceptible to training and knowledge of results aids learning. However, training is task specific.

Gait after stroke: initial deficit and changes in temporal patterns for each gait phase

OBJECTIVE

To examine which phases of the gait cycle contributed to decreased gait velocity after stroke.

DESIGN

Experimental.

SETTING

Inpatient rehabilitation centers.

PARTICIPANTS

Forty-two patients with unilateral first stroke who were able to walk 10 meters; and 42 age- and gender-matched controls with no history of stroke.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Deficit and change expressed as duration (s) and proportion (%) for the 4 phases of the gait cycle at the time of admission to rehabilitation (test 1), a median of 31 days poststroke onset, and again 8 weeks later (test 2). Affected and unaffected single-limb support (SLS) and initial double-limb support (DLS) were compared.

RESULTS

At tests 1 and 2, the durations of the 2 DLS and unaffected SLS phases were significantly (p <.001) longer in the stroke patients than in control subjects. No difference was found between the 2 groups for duration of affected SLS at either test time. Significant (p <.001) decreases occurred over the 8-week period in the 3 phases identified to be abnormally long at test 1.

CONCLUSION

If the goal of rehabilitation is to increase gait velocity and normalize the gait pattern, treatment should focus on decreasing the DLS and unaffected SLS phases of the gait cycle.

Can simultaneous bilateral movement involve the undamaged hemisphere in reconstruction of neural networks damaged by stroke?

Normalization of upper limb movement remains a difficult problem for a significant subpopulation of hemiplegic stroke patients. Clinical observations prompted investigation of a novel approach using simultaneous identical bilateral movements performed independently. We briefly report 12 controlled single-case experiments using multiple-baseline designs across three separate grasp/reach activities. Unilateral performance tests with the hemiplegic arm using the bilaterally trained actions demonstrated clinically and statistically significant improvements in movement patterns. These improvements were specific to the trained movement and well maintained. Using recent literature we develop a theoretical model proposing that bilateral simultaneous movement promotes interhemispheric disinhibition likely to allow reorganization by sharing of normal movement commands from the undamaged hemisphere. Disinhibition may also encourage recruitment of undamaged neurones to construct new task-relevant neural networks. The potential contribution of spared ipsilateral pathways in the damaged hemisphere, indirect corticospinal pathways and ipsilateral pathways from the undamaged hemisphere is discussed.

Hemodynamic profile of stress-induced anticipation and recovery

Systolic and diastolic blood pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance were measured in 100 healthy men and women with the aim of investigating hemodynamic profile during anticipation of, and recovery from, exposure to active and passive laboratory stressors. A 5-min anticipatory period preceded two tasks, both of which lasted 2.5 min. The tasks were mental arithmetic ('beta-adrenergic' stress) and the cold pressor test ('alpha-adrenergic' stress). Each task was followed by a 5-min recovery period. Blood pressure and heart rate were measured with a FinaPres 2300e, and stroke volume, cardiac output, and total peripheral resistance were computed from these parameters. Salivary cortisol was measured in relation to both tasks, and participants completed tests of state and trait anxiety, locus of control, and hostility. As expected, mental arithmetic and the cold pressor test elicited myocardial and vascular patterns of reactivity, respectively. However, contrary to expectations, anticipatory and recovery hemodynamic profile involved essentially vascular responding for both stressors. Salivary cortisol increased in response to both tasks but only weakly correlated with hemodynamic changes. None of the subjective measurements was a strong predictor of physiological reactivity. The findings suggest that stress-induced anticipatory and recovery reactivity may be generally vascular rather than myocardial. This could have important implications in light of suggestions that anticipatory and recovery responses may be better predictors of subsequent cardiovascular disease than direct stress-induced reactivity.

Prediction of gait velocity in ambulatory stroke patients during rehabilitation

OBJECTIVE

To quantify prediction of gait velocity in ambulatory stroke patients during rehabilitation.

DESIGN

Single group (n = 42) at the beginning of rehabilitation (Test 1) and 8 weeks later (Test 2).

SETTING

Inpatient rehabilitation.

PATIENTS

Unilateral first stroke; informed consent; able to walk 10 meters.

MEASURES

INDEPENDENT VARIABLES

Gait velocity at Test 1, age, time from stroke to Test 1, side of lesion, neglect.

DEPENDENT VARIABLES

Gait velocity at Test 2, gait velocity change.

RESULTS

The correlation between initial gait velocity and gait velocity outcome at Test 2 was of moderate strength (r2 = .62, p<.05). However, even at its lowest, the standard error of prediction for an individual patient was 9.4 m/min, with 95% confidence intervals extending over a range of 36.8 m/min. Age was a weak predictor of gait velocity at Test 2 (r2 = -.10, p<.05). Gait velocity change was poorly predicted. The only significant correlations were initial gait velocity (r2 = .10, p<.05) and age (r2 = .10, p<.05).

CONCLUSION

While the prediction of gait velocity at Test 2 was of moderate strength on a group basis, the error surrounding predicted values of gait velocity for a single patient was relatively high, indicating that this simple approach was imprecise on an individual basis. The prediction of gait velocity change was poor. A wide range of change scores was possible for patients, irrespective of their gait velocity score on admission to rehabilitation.

When is a change a genuine change? A clinically meaningful interpretation of grip strength measurements in healthy and disabled women

The aim of this study was twofold: 1) to use estimates of random and systematic error to ascertain the test-retest reliability of grip strength measurements obtained with the Jamar hand dynamometer in healthy and disabled women, and 2) to determine the size of the change required to detect a genuine change in grip strength for accurate and meaningful clinical interpretation. Previous research has shown grip strength measurements obtained with a Jamar hand dynamometer from healthy and disabled subjects on different occasions to be reliable. However, the test-retest reliability has been based on correlation coefficients rather than on the actual size of the test-retest differences required to detect a genuine change in grip. The test-retest reliability of maximum grip strength measurements in 32 healthy women and painfree grip in 10 disabled women with nonspecific regional pain (NSRP) was determined. Reliability, based on estimates of systematic and random error, was high in both subject groups. There was no statistically significant systematic error between tests. Test-retest measurement error was +/-5.7 kg (12.5 lb) and +/-5.9 kg (13.0 lb) in healthy and disabled subjects, respectively, 95% of the time. In this population of healthy women and women with NSRP, any change in grip of less than 6 kg (13.2 lb) could have occurred by chance. The results of our study suggest that a change of more than 6 kg (13.2 lb) is necessary to detect a genuine change in grip strength 95% of the time.

Accuracy of observational kinematic assessment of upper-limb movements

BACKGROUND AND PURPOSE

This study investigated the accuracy of physical therapists' visual judgments about kinematic features of the upper-limb movements of people without neurological impairments and people with neurological impairments following a cerebrovascular accident (CVA).

SUBJECTS

Ten experienced physical therapists served as observers. Eleven people with a primary diagnosis of cortical or subcortical CVA and 4 older individuals without neurological impairments participated as "performers."

METHODS

The performers were videotaped as they completed a transport task. Three videotapes were edited to form three physical scales of peak movement speed, jerkiness, and hand path indirectness. On two occasions, therapists viewed these videotapes and made judgements about each performance on visual analog scales. Therapists' visual judgments were then compared with criterion measures determined by three-dimensional instrumented analysis.

RESULTS

The accuracy of the therapists' judgments was investigated using regression methods. Therapists were able to make moderately to highly accurate judgments of movement speed (r > or = .87), jerkiness (r > or = .78), and hand path indirectness (r > or = .68). These judgements remained highly stable over time (r > or = .82). Differences in therapists' judgement models, evident from slope and intercept variability in the regression models, were reflected in lower intertherapist agreement (intraclass correlation coefficients = .65-.85).

CONCLUSION AND DISCUSSION

Experienced physical therapists accurately and reliably judged kinematic aspects of performance using observational assessment. Observational kinematic assessment warrants further systematic investigation.

Impaired limb position sense after stroke: a quantitative test for clinical use

OBJECTIVE

A quantitative measure of wrist position sense was developed to advance clinical measurement of proprioceptive limb sensibility after stroke. Test-retest reliability, normative standards, and ability to discriminate impaired and unimpaired performance were investigated.

DESIGN

Retest reliability was assessed over three sessions, and a matched-pairs study compared stroke and unimpaired subjects. Both wrists were tested, in counterbalanced order.

SETTING

Patients were tested in hospital-based rehabilitation units.

PATIENTS AND OTHER PARTICIPANTS

Reliability was investigated on a consecutive sample of 35 adult stroke patients with a range of proprioceptive discrimination abilities and no evidence of neglect. A consecutive sample of 50 stroke patients and convenience sample of 50 healthy volunteers, matched for age, sex, and hand dominance, were tested in the normative-discriminative study. Age and sex were representative of the adult stroke population.

MAIN OUTCOME MEASURES

The test required matching of imposed wrist positions using a pointer aligned with the axis of movement and a protractor scale.

RESULTS

The test was reliable (r = .88 and .92) and observed changes of 8 degrees can be interpreted, with 95% confidence, as genuine. Scores of healthy volunteers ranged from 3.1 degrees to 10.9 degrees average error. The criterion of impairment was conservatively defined as 11 degrees (+/-4.8 degrees) average error. Impaired and unimpaired performance were well differentiated.

CONCLUSIONS

Clinicians can confidently and quantitatively sample one aspect of proprioceptive sensibility in stroke patients using the wrist position sense test. Development of tests on other joints using the present approach is supported by our findings.

Deficit and change in gait velocity during rehabilitation after stroke

OBJECTIVE

To quantify the initial deficit, change, and outcome in gait velocity during inpatient rehabilitation following stroke.

DESIGN

The initial deficit on admission to rehabilitation was quantified by comparing 42 stroke patients with 42 controls matched by gender and age. The change in the stroke patients during the next 8 weeks was quantified and gait outcome was compared with functional and normal criteria.

SETTING

Patients were referred from four inpatient rehabilitation centers at the time of admission following a median of 16.5 days in the acute hospital.

PATIENTS

SELECTION CRITERIA

ability to give informed consent; unilateral first stroke; ability to walk 10 meters.

INTERVENTION

Patients participated in a median of 17.38 hours of individual physical therapy including a median of 6.92 hours of gait training during the 8 weeks.

MAIN OUTCOME MEASURE

Gait velocity.

RESULTS

Gait velocity was initially 38.6% (26.7m/min SD = 14.9) of the performance of controls and improved to 55.1% (38.1m/min). At outcome only 24% exceeded the 5th percentile of controls (48.1m/min) or the velocity required to cross the typical signalled intersection (46.2m/min). The change was only 26% of the initial deficit. Fifty-five percent of the patients improved beyond the 95% confidence intervals surrounding the error of measuring change. Indices of responsiveness indicated that there was a high signal-to-noise ratio and a robust effect size.

CONCLUSION

Gait velocity discriminated the effect of stroke and the change during rehabilitation.

Maximum voluntary weight-bearing by the affected and unaffected legs in standing following stroke

OBJECTIVE: To compare stroke patients to control subjects for ability to transfer body weight onto the affected and unaffected leg in standing; to investigate intra-session reliability. DESIGN: Comparative clinical study conducted within a single session. BACKGROUND: There is a paucity of quantitative data about maximum voluntary weight-bearing in patients during rehabilitation following stroke. METHODS: A Kistler force platform was used to quantify maximum amount of body weight transferred to a single limb in the lateral and forward directions during weight-shifting. Twelve control subjects matched by gender and age (median 64 years) were compared to 12 inpatient stroke patients after a median of 37 days post-onset. RESULTS: The median score for control subjects was approximately 95% of body weight to each leg in both directions. In contrast, stroke patients transferred less body weight (P<0.01) to the affected leg (65.5% lateral; 54.9% forward) and also to the unaffected leg (85.0% lateral; 80.1% forward). For the stroke patients, transfer of body weight was more challenging in the forward direction than the lateral direction on the affected leg (P<0.05). Relative to individual differences in the stroke group, error due to the repeated measurement process was low. CONCLUSION: The testing procedure was found to discriminate between stroke patients and control patients and had high retest reliability within a single session.

Method-related variations in estimates of gravity correction values using electromechanical dynamometry: a knee extension study

Dynamometry is widely used to measure subject strength. The method employed to correct dynamometry scores for gravitational influences can result in differing correction estimates. This study investigates differences between mathematical estimates of correction values and directly measured passive forces. Using the Kin-Com dynamometer, passive force measurements from 90 degrees of knee flexion to full extension were collected for nine asymptomatic subjects. These measurements were then compared with correction estimates mathematically extrapolated from a force reading obtained at one point in the test range. Direct passive measurements obtained between 0 and 70 degrees of knee flexion and mathematical estimates of correction values differed by as much as 50 N. The equivalence of gravity correction values obtained using the two methods detailed cannot be assumed. Mathematical estimates of correction values for knee scores obtained between 0 and 90 degrees of flexion were found to be clinically identical to direct passive measurements when: 1) the limb was weighed close to 50 degrees of flexion and 2) the angular location of the lower limb mass relative to the horizontal was not assumed to be represented by the angular location of the lever arm, but rather 15 degrees further below the horizontal than the lever arm.

The influence of subject and test design on dynamometric measurements of extremity muscles

In the context of broader discussions of clinical dynamometry, earlier reviews have raised concerns about the potential effects of variations in subject factors and test procedures on measurements. None, however, have dealt exclusively with these effects. We therefore reviewed more than 200 articles to evaluate in detail the effects of variations in subject factors and test procedures on measurements. Factors relating to subjects that affected measurements were age, gender, weight, athletic background, disability, and limb dominance. Test conditions that led to variations in measurements were range of movement in which values were obtained, type of contraction or movement (concentric, eccentric, isokinetic, isometric, isotonic), pretest procedures (warm-up and gravity-correction procedures, starting position, stabilization, axes alignment, lever arm length, preload, damp/ramp settings), test conditions (speed, test sequence, rest intervals, feedback), and type of data analysis (the data selected and how they are manipulated). In the majority of the publications, the authors failed to provide sufficient detail for accurate replication of test procedures or for comparison with other studies. We advocate that the factors identified in this review be included whenever measurements obtained with a dynamometer are reported. Effective development of normative data, formation of ratios, comparison of measurements across studies, and relating measurements with other performance criteria (eg, measurements of functional performance) all require descriptions of variables relating to subjects and testing. Similarly, meaningful use of these measurements in clinical practice requires consideration and documentation of these variables.

Temporal stability of gait in Parkinson's disease

BACKGROUND AND PURPOSE. Evaluation of physical therapy for gait disorders in patients with Parkinson's disease (PD) requires an under-standing of how the patients' medication cycle affects function. Four experiments were conducted to investigate stability of gait variables. METHODS AND RESULTS. In experiment 1, 15 subjects with idiopathic PD and 15 subjects without PD performed two sets of gait trials spaced 30 minutes apart, with the initial trial conducted with the subjects at a peak dose of medication. Strong correlations, as determined by intraclass correlation coefficients (ICC[2,1]), occurred between repeat measures of speed (ICC = .92), cadence (ICC = .92), stride length (ICC = .94), and time spent in double support (DS) (ICC = .93). In experiment 2, 16 subjects with PD were tested at the same time on two consecutive days. There was good repeatability for speed (ICC = .88), cadence (ICC = .85), stride length (ICC = .84), and DS (ICC = .80). When we assessed the repeatability of measurements taken at peak dose and at end of dose, there were low correlations for speed (ICC = -.54), cadence (ICC = -.07), stride length (ICC = -.35), and DS (ICC = -.38). In a final experiment on 16 subjects with PD, we used time-series analysis to examine the stability of measurements taken every 15 minutes for 2 1/2 hours. Slopes of regression models, standard deviations, and residual autocorrelations were negligible, indicating that the measurements were stable. CONCLUSION AND DISCUSSION. The parkinsonian gait pattern is reproducible across either brief time intervals or 24 hours when peak medication prevails. At the end of dose, however, marked changes in gait occur, apparently related to depletion of medication.

Stride length regulation in Parkinson's disease. Normalization strategies and underlying mechanisms

Results of our previous studies have shown that the slow, shuffling gait of Parkinson's disease patients is due to an inability to generate appropriate stride length and that cadence control is intact and is used as a compensatory mechanism. The reason for the reduced stride length is unclear, although deficient internal cue production or inadequate contribution to cortical motor set by the basal ganglia are two possible explanations. In this study we have examined the latter possibility by comparing the long-lasting effects of visual cues in improving stride length with that of attentional strategies. Computerized stride analysis was used to measure the spatial (distance) and temporal (timing) parameters of the walking pattern in a total of 54 subjects in three separate studies. In each study Parkinson's disease subjects were trained for 20 min by repeated 10 m walks set at control stride length (determined from control subjects matched for age, sex and height), using either visual floor markers or a mental picture of the appropriate stride size. Following training, the gait patterns were monitored (i) every 15 min for 2 h; (ii) whilst interspersing secondary tasks of increasing levels of complexity; (iii) covertly, when subjects were unaware that measurement was taking place. The results demonstrated that training with both visual cues and attentional strategies could maintain normal gait for the maximum recording time of 2 h. Secondary tasks reduced stride length towards baseline values as did covert monitoring. The findings confirm that the ability to generate a normal stepping pattern is not lost in Parkinson's disease and that gait hypokinesia reflects a difficulty in activating the motor control system. Normal stride length can be elicited in Parkinson's disease using attentional strategies and visual cues. Both strategies appear to share the same mechanism of focusing attention on the stride length. The effect of attention appears to require constant vigilance to prevent reverting to more automatic control mechanisms.

Ability to modulate walking cadence remains intact in Parkinson's disease

Gait hypokinesia (slowness) is a characteristic feature of Parkinson's disease. It is not clear, however, whether the slowness is due to a problem in regulation of the timing of consecutive steps or the control of stride size. Examination of cadence control for slow to medium walking speeds has shown an increase in step frequency that was a compensation for reduced stride length. In this investigation the ability of Parkinsonian patients to modulate their cadence (steps per minute) at the fast walking speeds exhibited by age and height matched controls was examined. The findings indicated that cadence control remains unaffected throughout its entire range in Parkinson's disease and that gait hypokinesia is directly attributable to an inability to internally generate sufficiently large steps.

The pathogenesis of gait hypokinesia in Parkinson's disease

To identify the fundamental deficit in gait hypokinesia in Parkinson's disease (PD) we conducted a series of experiments that compared PD subjects with age- and height-matched controls in their capacity to regulate either stride length, cadence (steps per minute) or both parameters to three conditions. In the first condition the spatial and temporal parameters of gait were documented for slow, normal and fast walking. The second condition compared parkinsonian gait with the walking pattern of elderly controls whilst controlling for two movement speeds: fast (control preferred) speed and slow (PD preferred) speed. In the third condition we examined the ability of PD subjects to regulate one parameter (e.g. stride length) when the other two parameters (e.g. velocity and cadence) were held at control values. A total of 34 PD subjects and 34 matched controls were tested using a footswitch stride analysis system that measured the spatial and temporal parameters of gait for a series of 10 m walking trials. Parkinsonian subjects exhibited marked gait hypokinesia in each of the experiments. Although they retained the capacity to vary their gait velocity in a similar manner to controls, their range of response was reduced. Within the lower velocity range, PD subjects could vary their speed of walking by adjusting cadence and, to a lesser extent, stride length. However, when the speed of walking was controlled, the stride length was found to be shorter and the cadence higher in PD subjects than in controls. Stride length could not be upgraded by internal control mechanisms in response to a fixed cadence set for age and height-matched velocity. In contrast, cadence was readily modulated by external cues and by internal control mechanisms when stride length was fixed to the values obtained for age- and height-matched controls. It was concluded that regulation of stride length is the fundamental problem in gait hypokinesia and the relative increase in cadence exhibited by PD subjects is a compensatory mechanism for the difficulty in regulating stride length. These findings are discussed in the context of the hypothesized role of the basal ganglia in generating internal cues for the maintenance of the gait sequence and in relation to the structuring of movement rehabilitation strategies.

Current status of the motor program

Motor program theory has provided physical therapists with one approach to understanding how the brain controls movement. Analogous with computer programs that specify the operations of computer hardware, motor programs are thought to contain commands for muscles that allow movements to occur without the need for continuous peripheral feedback. A review of the physical therapy literature reveals many instances in which motor program theory has been used as a theoretical framework for clinical practice. Yet despite the contribution programming theory has made to the advancement of movement science, the motor program construct is currently under considerable threat. Keele's (1968) original definition no longer seems tenable, given the problems of program storage, motor equivalence, movement flexibility, and context-conditioned variability. The finding that researchers from different disciplines define the motor program in a variety of ways adds difficulty to the task of evaluating the efficacy of the model. A critical appraisal of programming theory and its use in physical therapy suggests that clinicians need to reconsider the usefulness of the motor program model as a basis for movement rehabilitation following brain damage and musculoskeletal disorders.

Noninvasive discrimination of brachial plexus involvement in upper limb pain

The ability of Elvey's "brachial plexus tension test" to identify pain referred from the cervical region was investigated in 50 patients with unilateral shoulder and upper arm pain: 25 reported symptoms commencing after open heart surgery, indicating a high probability of referred pain due to that procedure; 25 were athletes with injuries from throwing movements, a cause appearing much less likely to cause referred pain. Twenty-five asymptomatic subjects with no history of spinal or limb pain also were tested. Cervical and upper limb maneuvers of the test were assessed goniometrically. The cardiac group showed significantly greater test results than those of the other groups, suggesting that the test is able to discriminate referred and local sources of upper limb pain.

Sensory loss in stroke patients: effective training of tactile and proprioceptive discrimination

Although somatosensory loss following stroke is common, with negative consequences for functional outcome, studies of existing somatosensory retraining programs are limited by theoretical weaknesses, poor methodology, and negative findings. We, therefore, developed a new program for stroke patients and investigated its effect on tactile discrimination in four AB, single-case quasi-experiments and its effect on tactile and proprioceptive discrimination in four multiple-baseline experiments. Training involved specific, graded discrimination tasks, attentive exploration of stimuli with vision occluded, deliberate anticipation, and quantitative feedback. Graphic and statistical interrupted time-series analyses indicated that treatment produced improvements in seven of eight tactile time series and all four proprioceptive time series. Baseline improvement in one tactile time series prevented unequivocal evaluation of treatment effect. Improvements were clinically significant, discrimination in the affected hand becoming comparable to the other hand and normal performance. Therapeutic effects were maintained at 3-month to 5-month follow-up tests.

Confounds of insensitivity and blind luck: statistical conclusion validity in stroke rehabilitation clinical trials

We present theoretical analyses of some infrequently considered consequences of low power and quantitatively review power in 36 stroke rehabilitation clinical trials with multiple outcome variables. We demonstrate that low power affects the proportion of false alarms (type 1 errors) in the literature and probability of replication, not only the ability to detect true intervention effects; and that these consequences of low power are modulated by the probability that effective interventions have been preselected for study via theory and prior evidence. interventions have been preselected for study via theory and prior evidence. Rehabilitation trials showed low power to detect small, medium, or large treatment effects at alpha = 0.05 (0.09, 0.33, and 0.69, respectively). Effect sizes were generally small with adverse consequences on power. As expected, sample size was an important determinant of power. Power was lower for motor/reflex measures due to differences in sample sizes rather than effect sizes. These results and the conceptual analyses predict and address conflicting conclusions from stroke rehabilitation clinical trials.

The effect of training on physical therapists' ability to apply specified forces of palpation

BACKGROUND AND PURPOSE

The aim of this study was to evaluate whether postgraduate physical therapy students studying manipulation could learn to accurately produce specific forces during palpation of an intervertebral joint.

SUBJECTS

The 12 subjects (7 female, 5 male), aged 26 to 36 years (X = 29.5, SD = 2.9), had each completed a 4-year degree course in physical therapy and had worked between 3 and 10 years in clinical practice. All subjects were enrolled in a 12-month postgraduate manipulative therapy diploma course.

METHODS

Subjects in the experimental group (n = 6) trained to apply specific forces of 1, 5, 10, 15, 20, and 25 kiloponds using bathroom scales. They practiced for 10 minutes per day for 30 days. Their ability to produce these forces on command was measured using a force platform as they applied posteroanterior passive accessory intervertebral joint movements to the lumbar spine of the healthy subjects. This testing was done prior to training (pretest), immediately after training (posttest), and 1 month following cessation of training (retention test). The control group subjects (n = 6) had no training with scales but were also students of the postgraduate manipulative physical therapy course.

RESULTS

In comparison with the control group, the experimentally trained group showed reduced error in force production both immediately after training and 1 month later. This improvement was significant for the retention test. For the retention test, the experimental group subjects were also tested on the trained task (ie, their ability to apply specific forces to the scales). They developed higher levels of accuracy than did the control group.

CONCLUSION AND DISCUSSION

Experimental training, therefore, was an effective addition to normal training, suggesting that therapists can learn to quantify applied forces, with significant implications for communication and evaluation of joint behavior.

Electrogoniometric feedback: its effect on genu recurvatum in stroke

The purpose of this study was to determine the effect of combining electrogoniometric feedback with contemporary physical therapy procedures for treatment of genu recurvatum following stroke. Twenty-six patients suffering knee hyperextension resulting from cerebrovascular disorders were allocated to either a control group or an experimental group. Both groups received treatment for knee hyperextension during two consecutive phases. During phase I the control group received physical therapy and the experimental group received electrogoniometric feedback as an adjunct to physical therapy. In phase II both groups received physical therapy alone. Each phase lasted four weeks, during which time patients were treated 45 minutes daily, five days every week. Subjects in the experimental group showed greater reduction in knee hyperextension. This was particularly evident in phase II when the difference between groups for reduction in knee hyperextension reached statistical significance (U = 40, p = 0.011). These results suggest that the addition of electrogoniometric feedback to standard physical therapy enhanced the effectiveness of treatment for genu recurvatum in stroke.

Negative transfer of training following brief practice of elbow tracking movements with electromyographic feedback from spastic antagonists

This study aimed to overcome gaps in the literature by investigating effects of EMG feedback provided specifically from spastic muscles during antagonist phases of active movement, while controlling for the effects of practicing the movement and while testing for transfer of training without confounding several transfer phenomena. In a single training session, two groups of stroke patients practiced a pursuit tracking task by following a moving target with elbow flexion and extension, simultaneously attempting to reduce the activity of elbow flexors. Both groups tracked the target more accurately following training. Transfer tests failed to demonstrate effects of feedback on accuracy of tracking or on electromyographic activity during performance of the practiced task without feedback. Moreover, the group that was trained with electromyographic feedback exhibited negative transfer on variants of the practiced task: tracking faster or less predictable targets.

Postural control in standing following stroke: test-retest reliability of some quantitative clinical tests

Despite their importance to stroke rehabilitation, appropriate clinical tests of postural control in standing appear to be inadequately developed. Several quantitative clinical tests, therefore, were constructed. These tests were used to measure functionally relevant aspects of postural control in standing in 24 stroke patients within a mean time interval of two months following a cerebrovascular accident. Subjects were tested in two stance positions (step and parallel) for five tasks that assessed their ability to withstand perturbations produced by self-generated body movements during functional activities. Intrasession reliability coefficients were very high (r = .94-.99). Intersession reliability coefficients were also high (r = .85-.94). Because the test battery requires minimal training and equipment, it can be easily applied in the clinical setting. The high reliability obtained justifies further evaluation of these tests, which appear to be very promising for use in stroke rehabilitation.

Abstracts

No abstract available

Facilitation of the isometric maximum voluntary contraction with traction. A test of PNF predictions

Mean rectified electromyographic activity in vastus lateralis (VL) was recorded with surface electrodes during several Ss isometric maximum voluntary contractions performed in the PNF pattern of flexion-abduction-internal rotation, with the subject supine. The effects of longitudinally applied traction forces were compared in a within subject design employing latin square and counterbalanced presentation. Consistent with predictions, as traction force increased the group mean EMG showed a statistically significant increase. A brief survey using force platform measurements indicated that trained physical therapists tended to apply equal or greater forces than the 20 lb maximum used in the experiment.

Facilitation of the tonic vibration reflex (TVR) by cutaneous stimulation in hemiplegics

The study of TVR facilitation with cutaneous icing and brushing by Spicer and Matyas (1980) was replicated in 12 hemiplegics with paretic quadriceps femoris muscles. Icing and brushing were studied under experimental and placebo conditions. Facilitation of the TVR from quadriceps femoris was examined during stimulation and 45-60 sec after the end of stimulation. The results replicated the findings of Spicer and Matyas (1980): icing and brushing produced significant facilitation, with brushing being markedly more effective; the effects were observed only during stimulation but not after stimulation. Comparison of the facilitatory effect of brushing obtained in normal (Spicer and Matyas, 1980) and hemiplegic subjects indicated a more pronounced facilitation in the latter. An iverse relationship between baseline TVR amplitude and degree of facilitation was suggested by the combined evidence of the two studies.

Facilitation of the tonic vibration reflex (TVR) by cutaneous stimulation

Facilitation by cutaneous icing and brushing of the TVR elicited from the quadriceps femoris was studied in 15 normal subjects. Icing and brushing were studied under experimental and placebo conditions. In addition, TVR facilitation by each stimulus was examined during stimulation and 45-60 seconds after stimulation. The results confirmed that the cutaneous stimuli have a localized facilitatory action, with brushing being the stronger stimulus, as proposed by Rood (Goff, 1969). However, this effect was demonstrated only during stimulation and not 45-60 sec after stimulation, in contrast to the model proposed by Rood (1962).

Conditioning under carbolonium bromide and D--tubocurarine chloride paralysis

The findings of past research using d-tubocurarine chloride as a control procedure in heart rate conditioning have been equivocal. The present experiment compared classical heart rate conditioning under neuromuscular blockade by d-tubocurarine chloride, and a pharmacologically more specific blocker, carbolonium bromide. Both groups were compared to a placebo condition. The results indicated that carbolonium bromide and placebo treated animals acquired deceleratory cardiac conditional responses, but animals treated with d-tubocurarine chloride did not. Unconditional acceleratory responses were found in groups. The findings were discussed in relation to classical conditioning and the psychopharmacology of neuromuscular blockade.

The use of a punchcard information system: 1. The significance of early treatment in spinogenic pain

Spinogenic assessment has received voluminous attention (Cyriax, 1969; Grieve, 1970; Maitland, 1973; Mennell, 1952). However, spinogenic data recording is rarely presented. Although proforma systems have been used, they have typically served only as worksheets for the treatment and observation of individual patients (Grieve, op. cit.; James and Stuart, 1975; Maitland, op. cit.). Conclusions about even routine clinical information has rarely been subjected to statistical analysis for error.