Validity of the Community Balance and Mobility Scale in Community-Dwelling Persons After Stroke

Knorr S, Brouwer B, Garland SJ. Validity of the Community Balance and Mobility Scale in community-dwelling persons after stroke.

Objectives

To examine the convergent validity, sensitivity to change, floor and ceiling effects of the Community Balance and Mobility Scale (CB&M) in community-dwelling stroke survivors. The secondary objective was to determine the correlations between the CB&M and lower-limb motor recovery and strength.

Design

Validity study.

Setting

Two university-based research centers.

Participants

Community-dwelling persons after stroke (N=44; 24 men, 20 women; mean age, 62.6±12.6y). Baseline measures were taken 3 months after the onset of stroke (98.6±52.6d); participants were reassessed 8 months poststroke (246.8±57.2d).

Interventions

Not applicable.

Main Outcome Measures

CB&M, Berg Balance Scale (BBS), Timed Up & Go (TUG), Chedoke McMaster Stroke Assessment (CMSA) Impairment Inventory for leg and foot, concentric bilateral isokinetic strength of the lower-limb flexor and extensor muscle groups using a dynamometer. The magnitude of the associations and the standardized response means (SRMs) among the CB&M, BBS, and TUG were used to examine the convergent validity and sensitivity to change, respectively.

Results

Moderate to high convergent validities (ρ=.70 to .83, P<.001) were observed among the CB&M, BBS, and TUG. The CB&M was moderately correlated with the CMSA leg and foot scores (ρ=.61 and .63, respectively, P<.001) and the paretic limb strength (ρ=.67, P<.001). The CB&M demonstrated the greatest ability to detect change between the baseline and follow-up assessments (SRM=.83).

Conclusions

The CB&M is valid and sensitive to change in assessing functional balance and mobility in ambulatory stroke survivors with moderate to mild neurologic impairments.     

How Reproducible Is Home-Based 24-Hour Ambulatory Monitoring of Motor Activity in Patients With Multiple Sclerosis?

Rietberg MB, van Wegen EE, Uitdehaag BM, de Vet HC, Kwakkel G. How reproducible is home-based 24-hour ambulatory monitoring of motor activity in patients with multiple sclerosis?

Objective

To determine the reproducibility of 24-hour monitoring of motor activity in patients with multiple sclerosis (MS).

Design

Test-retest design; 6 research assistants visited the participants twice within 1 week in the home situation.

Setting

General community.

Participants

A convenience sample of ambulatory patients (N=43; mean age ± SD, 48.7±7.0y; 30 women; median Expanded Disability Status Scale scores, 3.5; interquartile range, 2.5) were recruited from the outpatient clinic of a university medical center.

Interventions

Not applicable.

Main Outcome Measures

Dynamic activity and static activity parameters were recorded by using a portable data logger and classified continuously for 24 hours. Reproducibility was determined by calculating intraclass correlation coefficients (ICCs) for test-retest reliability and by applying the Bland-Altman method for agreement between the 2 measurements. The smallest detectable change (SDC) was calculated based on the standard error of measurement.

Results

Test-retest reliability expressed by the ICC_agreement was .72 for dynamic activity, .74 for transitions, .77 for walking, .71 for static activity, .67 for sitting, .62 for standing, and .55 for lying. Bland and Altman analysis indicated no systematic differences between the first and second assessment for dynamic and static activity. Measurement error expressed by the SDC was 1.23 for dynamic activity, 66 for transitions, .99 for walking, 1.52 for static activity, 4.68 for lying, 3.95 for sitting, and 3.34 for standing.

Conclusions

The current study shows that with 24-hour monitoring, a reproducible estimate of physical activity can be obtained in ambulatory patients with MS.     

Test position and hip strength in healthy adults and people with chronic stroke

Barbic S, Brouwer B. Test position and hip strength in healthy adults and people with chronic stroke.

Objective

To determine if peak torques generated by the hip flexors and extensors are dependent on test position in healthy adults and in people with chronic stroke.

Design

Cross-sectional study.

Setting

Motor performance laboratory.

Participants

Volunteers were 10 young (20.7±1.5y), 10 older adults (62.1±7y), and 10 stroke survivors (60.6±10y) who were an average of 5 years poststroke.

Interventions

Not applicable.

Main Outcome Measures

Isokinetic (60°/s) peak concentric hip flexor and extensor torques (in Nm/kg) generated in supine and standing positions.

Results

Peak flexor torques measured in standing were generally higher than in supine (P=.018); a pattern evident in all groups, but significant only in stroke. An interaction between test position and group for hip extensor strength (P=.016) reflected 2 distinct patterns in which torques were highest in standing among the young subjects and highest in supine after stroke.

Conclusions

Isokinetic hip flexor and extensor strength measured in standing and supine are comparable in young and older healthy people. In chronic stroke, the test position may over or underestimate maximum peak torque depending on the muscle group tested, particularly on the side ipsilateral to the lesion. These findings may have implications for predicting functional ability from strength measurements.     

Prediction of Postoperative Ambulatory Status 1 Year After Hip Fracture Surgery

Hirose J, Ide J, Yakushiji T, Abe Y, Nishida K, Maeda S, Anraku Y, Usuku K, Mizuta H. Prediction of postoperative ambulatory status 1 year after hip fracture surgery.

Objectives

To assess the validity of Estimation of Physiologic Ability and Surgical Stress (E-PASS) for predicting the postoperative risk and ambulatory status long-term follow-up after hip fracture surgery and to establish an algorithm for predicting their ambulatory status.

Design

Cohort study.

Setting

Twelve hospitals belonging to the regional network for hip fracture in Japan.

Participants

The study population was composed of 421 patients; 268 underwent surgery between April 2004 and March 2006 (group A), and 153 were treated surgically between April 2006 and March 2007 (group B). All were operated at 3 surgical hospitals and, subsequently, transferred to 9 rehabilitation centers.

Interventions

Not applicable.

Main Outcome Measures

We evaluated various factors, including their E-PASS scores to determine whether there was a correlation with the patients' mortality rate and their ability to walk at discharge and 1 year after surgery (group A). Using multiple regression analysis, we then developed algorithms to predict the ability of elderly patients to walk after hip fracture surgery. We applied the algorithms to group B patients and compared their actual and predicted ambulatory status.

Results

In group A patients, the postoperative walking ability and mortality rate were highly correlated with their E-PASS scores and dementia status. In group B, our algorithms exhibited good correlations between the predicted and actual walking ability at both time points (ρ=0.6, P<.001).

Conclusions

In candidates for hip fracture surgery, the E-PASS scores exhibited a good correlation with the patients' functional and survival prognoses, and the algorithm including E-PASS scores and dementia status can accurately estimate the ambulatory status at discharge and 1 year after surgery.     

Association of activity limitations and lower-limb explosive extensor power in ambulatory people with stroke

Saunders DH, Greig CA, Young A, Mead GE. Association of activity limitations and lower-limb explosive extensor power in ambulatory people with stroke.

Objective

To determine whether the explosive lower-limb extensor power of the affected and unaffected sides, and any asymmetry, are associated with activity limitations after stroke.

Design

Cross-sectional observational study of baseline data from a randomized controlled trial.

Setting

Measurements made in a hospital clinical research facility.

Participants

Community-dwelling (N=66) subjects with stroke who were independently ambulatory. Subjects’ mean age was 72±10 years.

Interventions

Not applicable.

Main Outcome Measures

The lower-limb extensor power of each lower limb (in W/kg), performance of specific functional activities (comfortable walking velocity, Functional Reach Test, chair-rise time, Timed Up & Go test), and global indices of activity limitation (FIM instrument, Rivermead Mobility Index, Nottingham Extended Activities of Daily Living).

Results

Low lower-limb extensor power in either lower limb was the principal factor from among the confounders we recorded that significantly (R² range, .21-.46) predicted the limitation of specific functional activities, and low lower-limb extensor power in either lower limb was the principal predictive factor for global indices of activity limitation (R² range, .13-.38). The degree of asymmetry of lower-limb extensor power between legs was low and had little or no predictive value.

Conclusions

In ambulatory persons with stroke, activity limitations are associated with deficits in lower-limb extensor power of both lower limbs, and not the severity of any residual asymmetry. These findings suggest that interventions to increase lower-limb extensor power in both lower limbs might reduce activity limitations after stroke.     

Internally and Externally Paced Finger Movements Differ in Reorganization After Acute Ischemic Stroke

Askim T, Indredavik B, Håberg A. Internally and externally paced finger movements differ in reorganization after acute ischemic stroke.

Objective

To identify adaptive changes within the motor network for internally and externally paced finger movements in the acute and chronic phase after ischemic stroke.

Design

A functional magnetic resonance imaging study of internally and externally paced thumb-index-finger opposition 4 to 7 days and 3 months after stroke and in healthy controls. Images were compared within and between groups, with the actual number of movements as regressors.

Setting

Stroke Unit, University Hospital.

Participants

Twelve patients with mild to moderate acute ischemic stroke and 15 controls (N=27).

Intervention

Stroke unit treatment focused on very early rehabilitation, followed by early supported discharge service.

Main Outcome Measure

Differences in brain activation between patients and controls and between the tasks.

Results

Patients showed significant improvement in hand function at follow-up. Brain activity related to internally paced finger movements normalized with time. For the externally paced, accurate timing task, brain activity in the chronic phase differed from that seen in the controls despite successful recovery of hand function. In comparing the externally and internally paced tasks, a trend toward recruiting a premotor-parietal-striatal network was found in patients in the chronic phase, whereas controls had increased activation of a sensorimotor network consisting of primary motor cortex, supplementary motor cortex, superior parietal lobe, thalamus, and cerebellum.

Conclusions

After ischemic stroke, brain activity subserving an internally paced motor task normalized with time, whereas motor activity in response to an externally paced task became dependent on a premotor network. These findings underscore the importance of task-specific training in the rehabilitation of stroke patients. In the future, physiotherapists should evaluate the possibility of enhancing the recovery of a more efficient network for externally paced tasks.     

Levodopa improves procedural motor learning in chronic stroke patients

Rösser N, Heuschmann P, Wersching H, Breitenstein C, Knecht S, Flöel A. Levodopa improves procedural motor learning in chronic stroke patients.

Objective

To test the hypothesis that administration of dopamine precursor levodopa improves procedural motor learning (defined as the ability to acquire novel movement patterns gradually through practice) in patients with residual motor deficits in the chronic phase after stroke (≥1y after stroke).

Design

A double-blind, placebo-controlled, randomized crossover design.

Setting

Neurology department in a German university.

Participants

Eighteen patients with chronic motor dysfunction because of stroke (13 men, 5 women; age range, 53-78y; mean time poststroke ± SD, 3.3±2.1y).

Intervention

Patients received 3 doses of levodopa (100mg of levodopa plus 25mg of carbidopa) or placebo before 1 session of procedural motor learning.

Main Outcome Measures

Procedural motor learning performed by using the paretic hand assessed by using a modified version of the serial reaction time task with a probabilistic sequence. The primary outcome measure was the difference in reaction times between random and sequential elements.

Results

Levodopa significantly improved our primary outcome measure, procedural motor learning, compared with placebo (P<.05). Reaction times to random elements, analysis of error rates, psychophysical assessments, and performance in a simple motor task were comparable between conditions, indicating that better learning under levodopa was not caused by differences in response styles, arousal, mood, or motor reaction times but that levodopa modulated learning.

Conclusions

Our results show that levodopa may improve procedural motor learning in patients with chronic stroke, in line with our hypothesis. These findings suggest that this interventional strategy in combination with customary rehabilitative treatments could significantly improve the outcome of neurorehabilitation in the chronic stage after stroke. (Clinicaltrials.gov identifier NCT00126087.)     

Mean flow velocity in the middle cerebral artery is associated with rehabilitation success in ischemic stroke patients

Treger I, Aidinof L, Lutsky L, Kalichman L. Mean flow velocity in the middle cerebral artery is associated with rehabilitation success in ischemic stroke patients.

Objective

To evaluate the association between mean flow velocity (MFV) in the middle cerebral artery (MCA) measured by using transcranial Doppler (TCD) and functional and neurologic impairment change during rehabilitation after acute stroke.

Design

Cross-sectional observational study.

Setting

Acute neurologic rehabilitation department.

Participants

Consecutive patients (N=67; 53 men, 14 women; mean ± SD age, 61.54±8.92y) referred to the rehabilitation center during the first 6 months of 2006 for a first ischemic stroke in the MCA area.

Interventions

Not applicable.

Main Outcome Measures

All subjects were evaluated on admission and at discharge by using the National Institutes of Health Stroke Scale (NIHSS) and the FIM. TCD measurements of MFV of the ipsilateral and contralateral MCA were performed on admission (during the first 20 days after stroke) and a few days before discharge.

Results

Contralateral MFV at admission was associated significantly with all indexes of functional rehabilitation success (FIM score at discharge [β=.169; P=.010], change in FIM score [β=.554; P=.010], relative improvement in FIM score [β=.783; P=.003]). No significant association was found between indexes of NIHSS change and ipsilateral or contralateral MFV.

Conclusions

Ipsilateral or contralateral MFV measured at admission did not change during the 2-month rehabilitation period. Our data showed a significant association between blood flow velocity in the contralateral MCA and functional rehabilitation parameters of patients after first ischemic stroke in the MCA area.     

Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study

Stoquart GG, Detrembleur C, Palumbo S, Deltombe T, Lejeune TM. Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study.

Objective

To study the effect of botulinum toxin type A (BTX-A) injection in the rectus femoris on the decreased knee flexion during the swing phase of gait (stiff-knee gait) in people with stroke.

Design

Intervention study (before-after trial) with an observational design.

Setting

Outpatient rehabilitation clinic and gait laboratory.

Participants

Nineteen chronic hemiparetic adults presenting with stiff-knee gait.

Intervention

Injection of 200U of BTX-A (Botox) into the rectus femoris.

Main Outcome Measures

Before and 2 months after BTX-A rectus femoris injection: Stroke Impairment Assessment Set (SIAS), Duncan-Ely test, and an instrumented gait analysis.

Results

Median SIAS score improved from 53 (range, 36−65) to 57 (range, 42−70) (signed-rank test, P=.005) and the Duncan-Ely score from 3 (range, 1−3) to 1 (range, 0−3) (P<.001). In gait analysis, mean (± standard deviation) maximum knee flexion improved from 26°±13° to 31°±14° during the swing phase (paired t test, P<.001), knee flexion speed at toe-off improved from 82°±63° to 112°±75°/s (P=.009), and knee negative joint power (eccentric muscular contraction) improved from −.27±.23 to −.37±.26W/kg (P<.001). The 4 patients who almost did not flex the knee (<10°) before the BTX-A rectus femoris injection did not improve after the injection. The other 14 patients who flexed the knee more than 10° before the BTX-A rectus femoris injection decreased the walking energy cost from 5.4±1.6 to 4.6±1.3J·kg⁻¹·m⁻¹ (P=.006).

Conclusions

BTX-A rectus femoris injection may be beneficial in patients with a stiff-knee gait after stroke, particularly in patients with some knee flexion (>10°).     

Assistive Walking Devices in Nonambulant Patients Undergoing Rehabilitation After Stroke: The Effects on Functional Mobility, Walking Impairments, and Patients' Opinion

Tyson SF, Rogerson L. Assistive walking devices in nonambulant patients undergoing rehabilitation after stroke: the effects on functional mobility, walking impairments, and patients' opinion.

Objective

To assess the immediate effects of assistive walking devices on functional mobility, walking impairments, and patients' opinions in nonambulant patients after stroke.

Design

Randomized crossover trial.

Setting

Inpatient rehabilitation units of 3 United Kingdom hospitals.

Participants

Twenty nonambulant patients with stroke undergoing rehabilitation to restore walking.

Interventions

Five walking conditions: (1) Walking with no device (the control condition), (2) walking with a walking cane, (3) ankle foot orthosis, (4) slider shoe, and (5) a combination of all 3 devices.

Main Outcome Measures

Functional mobility (functional ambulation categories), walking impairments (speed, step length of the weak leg), and patients' opinions.

Results

Functional mobility improved with all assistive devices (P<.0001-.005; effect sizes 1.68-0.52; number needed to treat=2-5). Walking impairments were unchanged (P<.800-.988). Participants were generally positive about the devices. They felt their walking, confidence, and safety improved and found the appearance and comfort of the devices acceptable. They would rather walk with the devices than delay walking until a normative gait pattern was achieved without them.

Conclusions

Assistive walking devices improved functional mobility in nonambulant rehabilitation patients with stroke. No changes in walking impairments were found. Participants were generally positive about using the devices. The results support the use of assistive walking devices to enable early mobilization after stroke; 2 patients would need to be treated with a cane or combined devices for 1 to improve functional mobility.     

The vastus medialis oblique:vastus lateralis electromyographic intensity ratio does not differ by gender in young participants without knee pathology

Objectives

To investigate whether there was a gender difference in the intensity of electromyographic (EMG) activity in vastus medialis oblique (VMO) relative to vastus lateralis (VL).

Design

A cross-sectional observational study measuring EMG activity during stepping down from a step and during straight leg raise exercises.

Setting

University campus laboratory.

Participants

Two groups of healthy participants were tested, one female (mean age 23.5 years, n = 15) and one male (mean age 23.5 years, n = 15).

Main outcome measures

Surface EMG activity (sampling rate 1000 Hz) was recorded from VMO and VL of the dominant limb during five repetitions of a step down activity and five repetitions of a straight leg raise exercise. The average intensity of the rectified and smoothed EMG activity from each activity was normalised to that elicited in a maximal quadriceps setting exercise. The ratio of normalised VMO:VL EMG intensity levels was calculated.

Results

The median difference in the VMO:VL ratio between the groups was 0.11 [approximate 95% confidence interval (CI) −0.62 to 1.00] during step down and −0.07 (approximate 95% CI −0.26 to 0.20) during straight leg raise. Using Mann Whitney U-tests, these differences were not statistically significant (P = 0.648 and 0.619, respectively).

Conclusions

This study found no gender difference in the VMO:VL EMG intensity ratio in asymptomatic participants. This suggests that the difference in incidence of patellofemoral pain syndrome between genders is not influenced by quadriceps intensity ratios, when participants are asymptomatic.     

5-Repetition Sit-to-Stand Test in Subjects With Chronic Stroke: Reliability and Validity

Mong Y, Teo TW, Ng SS. 5-repetition sit-to-stand test in subjects with chronic stroke: reliability and validity.

Objectives

To examine the (1) intrarater, interrater, and test-retest reliability of the 5-repetition sit-to-stand test (5-repetition STS test) scores, (2) correlation of 5-repetition STS test scores with lower-limb muscle strength and balance performance, and (3) cut-off scores among the 3 groups of subjects: the young, the healthy elderly, and subjects with stroke.

Design

Cross-sectional study.

Setting

University-based rehabilitation center.

Participants

A convenience sample of 36 subjects: 12 subjects with chronic stroke, 12 healthy elderly subjects, and 12 young subjects.

Interventions

Not applicable.

Main Outcome Measures

5-Repetition STS test time scores; hand-held dynamometer measurements of hip flexors, and knee flexors and extensors; ankle dorsiflexors and plantarflexors muscle strength; Berg Balance Scale (BBS); and limits of stability (LOS) test using dynamic posturography.

Results

Excellent intrarater reliability of intraclass correlation coefficient (ICC) (range, .970-.976), interrater reliability (ICC=.999), and test-retest reliability (ICC range, .989-.999) were found. Five-repetition STS test scores were also found to be significantly associated with the muscle strength of affected and unaffected knee flexors (ρ=-.753 to -.830; P<.00556) of the subjects with stroke. No significant associations were found between 5-repetition STS test and BBS and LOS tests in subjects with stroke. Cut-off scores of 12 seconds were found to be discriminatory between healthy elderly and subjects with stroke at a sensitivity of 83% and specificity of 75%.

Conclusions

The 5-repetition STS test is a reliable measurement tool that correlates with knee flexors muscle strength but not balance ability in subjects with stroke.     

Reliability of Ambulatory Walking Activity in Patients With Hematologic Malignancies

Knols RH, de Bruin ED, Aufdemkampe G, Uebelhart D, Aaronson NK. Reliability of ambulatory walking activity in patients with hematologic malignancies.

Objectives

To determine the relative and absolute reliability of the assessment of ambulatory walking activity during 2 consecutive weeks in patients with hematologic malignancies recovering at home from their medical treatment and to compare the physical activity level of hematologic cancer patients after high-dose chemotherapy with healthy subjects.

Design

Test-retest study of 2 consecutive 7-day recordings using the microprocessor-based step accelerometer 3 (SAM3).

Setting

Home and community.

Participants

Patients (n=23) with hematologic malignancies recovering from high-dose chemotherapy and healthy controls (n=30).

Interventions

Not applicable.

Main Outcome Measures

The intraclass correlation coefficient (ICC_3,1) and its 95% confidence interval (CI), SE of measurement procedure and its 95% CI, the smallest detectable difference (SDD), the coefficient of variation (CV), and t tests for the variables total steps and peak activity.

Results

The day-to-day and week-to-week CVs for walking activity and peak activity were 35.17% and 13.17% and 18.61% and 6.90%, respectively. For relative reliability, the ICCs for 2 consecutive 7-day recordings including the 95% CI for total steps and peak activity were 0.90 (95% CI, 0.75-0.98) and 0.85 (95% CI, 0.66-0.94), respectively. The absolute reliability for total steps and peak activity including the SE of measurement procedure and the 95% CI were 564 (95% CI, ±1106) and 2.42 steps (95% CI, ±4.74), respectively, for 2 consecutive 7-day recordings. The week-to-week SDD was 1564 for total steps and 6.70 for peak activity. The 7-day mean for total step activity was 5355 for the patients with hematologic malignancies and 6364 for healthy subjects (P<0.05).

Conclusions

The results of this study indicate that there is good relative reliability for the assessment of 2 consecutive 7-day recordings of ambulatory walking activity, and it showed that the SDD derived from this sample may be useful in detecting changes in daily walking activity in hematologic cancer patients who are recovering from intensive medical treatment. The study also documented compromised levels of ambulatory walking activity among hematologic cancer patients recovering from high-dose chemotherapy as compared with healthy controls.     

The effectiveness of progressively increasing stimulation frequency and intensity to maintain paralyzed muscle force during repetitive activation in persons with spinal cord injury

Chou L-W, Lee SC, Johnston TE, Binder-Macleod SA. The effectiveness of progressively increasing stimulation frequency and intensity to maintain paralyzed muscle force during repetitive activation in persons with spinal cord injury.

Objective

To compare the effectiveness of progressively increasing stimulation intensity, progressively increasing frequency, or progressively increasing both frequency and intensity on paralyzed quadriceps femoris muscle force maintenance during repetitive activation.

Design

Factorial design with different stimulation protocols as independent variables.

Setting

A muscle performance laboratory.

Participants

People (N=8) with spinal cord injury (SCI) (age, 14.63±1.77y).

Interventions

Not applicable.

Main Outcome Measure

Number of contractions when the peak force was 90% or more of a subject's maximal twitch force.

Results

The protocol involving progressively increasing stimulation intensity and then frequency generated more successful contractions (189.88±53.33) than progressively increasing the frequency followed by intensity (122.75±26.56 contractions). Regardless of the order, progressively increasing both intensity and frequency generated more successful contractions than progressively increasing intensity (97 contractions) or frequency (62 contractions) alone.

Conclusions

Our findings suggest that during repetitive electric activation, progressively increasing both stimulation frequency and intensity can produce more successful contractions than progressively increasing only frequency or intensity. These findings can help researchers and clinicians design more effective stimulation protocols for persons with SCI during functional electric stimulation applications.     

Estimating contraction level using root mean square amplitude in control subjects and patients with neuromuscular disorders

Boe SG, Rice CL, Doherty TJ. Estimating contraction level using root mean square amplitude in control subjects and patients with neuromuscular disorders.

Objectives

To assess the utility of the surface electromyographic signal as a means of estimating the level of muscle force during quantitative electromyography studies by examining the relationship between muscle force and the amplitude of the surface electromyographic activity signal; and to determine the impact of a reduction in the number of motor units on this relationship, through inclusion of a sample of patients with neuromuscular disease.

Design

Cross-sectional, cohort study design.

Setting

Tertiary care, ambulatory, electromyography laboratory.

Participants

A volunteer, convenience sample of healthy control subjects (n=10), patients with amyotrophic lateral sclerosis (n=9), and patients with Charcot-Marie-Tooth disease type X (n=5).

Interventions

Not applicable.

Main Outcome Measures

The first dorsal interosseous (FDI) and biceps brachii muscles were examined. Force values (at 10% increments) were calculated from two 4-second maximal voluntary contractions (MVCs). Surface electromyographic activity was recorded during separate 4-second voluntary contractions at 9 force increments (10% -90% of MVC). Additionally, a motor unit number estimate was derived for each subject to quantify the degree of motor unit loss in patients relative to control subjects.

Results

The relationships between force and surface electromyographic activity for both muscles (controls and patients) were best fit by a linear function. The variability about the grouped regression lines was quantified by 95% confidence intervals and found to be ±6.7% (controls) and ±8.5% (patients) for the FDI and ±5% (controls) and ±6.1% (patients) for the biceps brachii.

Conclusions

These results suggest that the amplitude of the surface electromyographic activity signal may be used as a means of estimating the level of muscle force during quantitative electromyography studies. Future studies should be directed at examining if the variability associated with these force and surface electromyographic activity relationships is acceptable in replacing previous methods of measuring muscle force.     

Validity and Interobserver Reliability of Visual Observation to Assess Partial Weight-Bearing

Hurkmans HL, Bussmann JB, Benda E. Validity and interobserver reliability of visual observation to assess partial weight-bearing.

Objective

To determine the validity and interobserver reliability of visual observation to assess partial weight-bearing.

Design

Validation and interobserver reliability study.

Setting

University medical center.

Participants

Patients (N=10) with a total hip arthroplasty operated 1 to 12 months prior to the study referred by 10 physical therapists (5 experienced and 5 inexperienced in training patients in partial weight-bearing).

Interventions

Not applicable.

Main Outcome Measures

The amount of weight-bearing assessed by visual estimation (visual analog scale score) in percentage body weight (BW). Actual weight-bearing (percentage BW) as measured with the Pedar Mobile system. The mean difference (systematic error) between visual estimation and the Pedar system and the SD of the differences (random error) were determined by the limits of agreement (LOA) method with multiple observations per subject. The intraclass correlation coefficient (ICC) was calculated as a measure for the interobserver reliability.

Results

The mean difference ± SD between visual observation and the reference method was -9.5±20.1 percentage BW (95% confidence interval, -24.0 to 5.0 percentage BW) with LOA ranging from -49.8 to 30.8 percentage BW. The ICC was .57. The therapists' experience in partial weight-bearing training had no effect on the mean difference (P=.349) between the 2 methods.

Conclusions

Visual observation is not a valid and reliable method to assess partial weight-bearing.     

Comparing performance of manual wheelchair skills using new and conventional rear anti-tip devices: randomized controlled trial

Kirby RL, Corkum CG, Smith C, Rushton P, MacLeod DA, Webber A. Comparing performance of manual wheelchair skills using new and conventional rear anti-tip devices: randomized controlled trial.

Objective

To test the hypotheses that, compared with participants using manual wheelchairs equipped with conventional rear anti-tip devices (C-RADs), those using a new RAD design that deploys through an arc (Arc-RAD) perform RAD-relevant wheelchair skills better and as safely.

Design

A randomized controlled study.

Setting

A rehabilitation center.

Participants

Participants (N=30) including 16 able-bodied and 14 wheelchair users.

Intervention

Participants were provided with wheelchair skills training (up to 2.4h).

Main Outcome Measures

Total percentage score on a set of 23 RAD-relevant skills of the Wheelchair Skills Test (WST, version 3.2) administered a minimum of 3 days after training.

Results

For the C-RAD and Arc-RAD groups, the mean ± standard deviation RAD-relevant WST scores were 32.3%±8.5% and 85.1%±18.9% (Kruskal-Wallis, P<.001). Of the 23 RAD-relevant individual skills, the success rates for the Arc-RAD group were at least 20% higher (the criterion we set for clinical significance) in 17 (74%). For the C-RAD group, the success rate was 0% for the 12 wheelie-dependent skills, the 13-cm-high obstacle, and the 15-cm level change ascent. There were no serious adverse effects in either group.

Conclusions

The new RAD design allows much better performance on relevant wheelchair skills than the conventional design without compromising safety.     

Remote Influences of Acupuncture on the Pain Intensity and the Amplitude Changes of Endplate Noise in the Myofascial Trigger Point of the Upper Trapezius Muscle

Chou L-W, Hsieh Y-L, Kao M-J, Hong C-Z. Remote influences of acupuncture on the pain intensity and the amplitude changes of endplate noise in the myofascial trigger point of the upper trapezius muscle.

Objective

To investigate the remote effect of acupuncture on the pain intensity and the endplate noise (EPN) recorded from a myofascial trigger point (MTrP) of the upper trapezius muscle.

Design

Randomized controlled trial.

Setting

University hospital.

Participants

Patients (N=20) with active MTrPs in upper trapezius muscles and no experience in acupuncture therapy.

Interventions

Patients were divided into 2 groups. Those in the control group received sham acupuncture, and those in the acupuncture group received modified acupuncture therapy with needle insertion into multiple loci to elicit local twitch responses. The acupuncture points of Wai-guan and Qu-chi were treated.

Main Outcome Measures

Subjective pain intensity (numerical pain rating scale) and mean EPN amplitude in the MTrP of the upper trapezius muscle.

Results

The pain intensity in the MTrP was significantly reduced after remote acupuncture (from 7.4±0.8 to 3.3±1.1; P<.001), but not after sham acupuncture (from 7.4±0.8 to 7.1±0.9; P>.05). The mean EPN amplitude was significantly lower than the pretreatment level after acupuncture treatment (from 21.3±9.5μV to 9.5±3.5μV; P<.01), but not after sham acupuncture treatment (from 19.6±7.6μV to 19.3±7.8μV; P>.05). The change in the pain intensity was significantly correlated with the change of EPN amplitude (r = 0.685).

Conclusions

Both subjective changes in the pain intensity and objective changes of the EPN amplitude in the MTrP region of the upper trapezius muscle were found during and after acupuncture treatment at the remote ipsilateral acupuncture points. This study may further clarify the physiological basis of the remote effectiveness of acupuncture therapy for pain control.     

Characteristics of people with chronic lung disease who rest during the six-minute walk test

Wong R, Sibley KM, Hudani M, Roeland S, Visconti M, Balsano J, Hill K, Brooks D. Characteristics of people with chronic lung disease who rest during the six-minute walk test.

Objectives

To examine the incidence of resting during the 6-minute-walk test (6MWT) in patients with chronic lung disease (CLD) and to explore differences in functional exercise capacity and response to pulmonary rehabilitation (PR) between resters and nonresters.

Design

Retrospective chart review.

Setting

Inpatient PR program.

Participants

Individuals (N=211) who performed the 6MWT at admission and discharge from PR.

Interventions

Not applicable.

Main Outcome Measures

Primary outcomes were total distance walked (6-minute walk distance [6MWD]) and rest frequency and duration. Secondary outcomes were walking speed, end-test dyspnea, and the Chronic Respiratory Questionnaire (CRQ).

Results

At admission, 45 people (21%) rested 1 to 4 times during the 6MWT (total duration, 105±80s) and 166 people walked continuously. At discharge, 9 people continued to rest (total duration, 28±55s). At admission, nonresters walked 315±93m, whereas resters walked 197±83m (P<.0001), and 6MWD increased in both groups after PR (P<.0001). Nonresters increased their walking speed at discharge, but resters did not (interaction P<.001). At admission, the mastery domain of the CRQ was 0.8 point lower in resters (3.7±1.2) compared with nonresters (4.5±1.7; P=.01). Resters' end-test dyspnea scores decreased from 5.7±0.3 to 4.3±0.2 from admission to discharge, whereas nonresters' end-test dyspnea scores did not significantly change from 4.5±0.2 to 4.2±0.2 at discharge (interaction P<.05).

Conclusions

One in 5 individuals with CLD rest during the 6MWT. Decreasing rest duration or increasing walking speed reflects different strategies used to improve 6MWD after rehabilitation, both suggesting a positive effect of PR. This may be related to improvements in an individual's sense of control over dyspnea. Future work should investigate potential factors related to resting during the 6MWT.     

Relationship Between Diabetes Codes That Affect Medicare Reimbursement (Tier Comorbidities) and Outcomes in Stroke Rehabilitation

Graham JE, Ripsin CM, Deutsch A, Kuo Y-F, Markello S, Granger CV, Ottenbacher KJ. Relationship between diabetes codes that affect Medicare reimbursement (tier comorbidities) and outcomes in stroke rehabilitation.

Objectives

To examine the extent to which diabetes codes that increase reimbursement (tier comorbidities) under the prospective payment system are related to length of stay and functional outcomes in stroke rehabilitation.

Design

Secondary data analysis.

Setting

Inpatient rehabilitation facilities (N=864) across the United States.

Participants

Patients (N=135,097) who received medical rehabilitation for stroke in 2002-2003.

Intervention

None.

Main Outcome Measures

Length of stay, FIM instrument, and discharge setting. Diabetes status was assigned to 1 of 3 categories: tier (increases reimbursement), nontier (no reimbursement effect), and no diabetes.

Results

Mean ± standard deviation age of the sample was 70.4±13.4 years, and 31% had diabetes (6% tier, 25% nontier). Diabetes status by age demonstrated significant (P<.05) interaction effects, which lead to the following age-specific findings. In younger stroke patients (60y), tier diabetes was associated with shorter lengths of stay compared with both groups, lower FIM discharge scores compared with both groups, and lower odds of discharge home relative to the no-diabetes group. In older stroke patients (80y), tier diabetes was associated with longer lengths of stay compared with both groups and with higher FIM discharge scores compared with the nontier group.

Conclusions

The diabetes-related conditions identified as tier comorbidities under the prospective payment system are significant predictors of stroke rehabilitation outcomes, but these relationships are moderated by patient age.