Timothy Michael. Bach

Orthotic management of plantar pressure and pain in rheumatoid arthritis

OBJECTIVE To investigate the effectiveness of foot orthoses in the management of plantar pressure and pain in subjects with rheumatoid arthritis. DESIGN A repeated measures study in which the independent variable was orthosis design. Dependent variables, including pressure, gait and pain parameters, were examined using analysis of variance and correlation statistics. BACKGROUND The aim of orthotic management of the rheumatoid foot is to relieve metatarsalgia through the reduction of metatarsal head pressure. Few studies have investigated the relative effectiveness of different orthosis designs. To date, no studies have examined the relationship between plantar pressure and second metatarsal head pain in rheumatoid arthritis subjects. METHODS Twelve rheumatoid arthritis subjects with foot involvement and second metatarsal head pain were tested. Four styles of foot orthosis (prefabricated, standard custom moulded, custom with metatarsal bar, custom with metatarsal dome) were compared to a shoe only control. An EMED Pedar system was used to measure plantar pressure during repeated trials of comfortable cadence walking and quiet standing. Reports of subjective pain were recorded for each orthosis as were orthosis preferences. RESULTS All orthoses significantly reduced pressure beneath the first and second metatarsal heads compared to the shoes only control. The custom moulded orthosis with metatarsal dome was the most effective orthosis for reducing subjective ratings of pain. A significant correlation (r=0.562) was found between ratings of pain and average pressure beneath the second metatarsal head. CONCLUSIONS Results from this study suggest that average pressure measurement may be a useful indicator in the management of metatarsalgia in RA. Further study is required to improve understanding of the relationship between rheumatoid foot mechanics and pain. RELEVANCE Appropriate foot orthosis design can substantially improve comfort in RA patients with symptomatic feet. A custom moulded foot orthosis incorporating a metatarsal dome was the most effective design for subjects with painful second metatarsal heads. Foot pressure measurement technology can be a useful adjunct to research and clinical management of the painful rheumatoid foot.

The Reliability of Selected Techniques in Clinical Arthrometrics

A number of studies which have examined reliability of spinal assessment procedures in manual therapy are reviewed. The tests examined were Passive Accessory Intervertebral Movements, Passive Physiological Intervertebral Movements, Straight Leg Raise and Forward Flexion. In general, tests of pain were found to be much more reproducible than tests of compliance. Straight Leg Raise and Forward Flexion tests were consistently more reliable than the Passive Intervertebral Movement tests. Possible explanations for these findings are advanced. The role of tests of compliance based on passive intervertebral movements in clinical decision-making may need to be re-examined. An appendix on reliability theory is included for the uninitiated reader.

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.

Video assessment of rearfoot movements during walking: a reliability study.

OBJECTIVE Rearfoot motion, particularly rearfoot pronation, has been associated with many foot and leg pathologies. The assessment of abnormal rearfoot pronation frequently involves the use of video assessment in both clinical and research settings, but the reliability of this assessment has not been addressed. DESIGN In this study, 14 participants were videotaped during walking. Five clinicians individually viewed the recordings on two separate occasions and assessed whether the participants rearfoot motion was abnormal. SETTING University Gait Analysis Laboratory. PATIENTS OR OTHER PARTICIPANTS Patients from the universitys podiatry clinic were assessed for rearfoot motion by five experienced clinicians. INTERVENTION Because this was a reliability study, no intervention was undertaken. MAIN OUTCOME MEASURES Clinicians were asked to assess the videotape of the patients walking and indicate on a 3-point scale if they considered the person to be abnormally pronating. Retest and intertester results were compared. RESULTS The results indicated that there was poor intertester agreement (kappa = .19). Retest agreement, while slightly higher, varied from poor to fair (kappa = -.12 to kappa = 59). CONCLUSIONS Although video recordings have been thought to enhance reliability of assessment of rearfoot motion, the results indicated that the exclusive use of video recordings in the assessment of motion of the rearfoot was not reliable.

A systematic review to determine best practice reporting guidelines for AFO interventions in studies involving children with cerebral palsy.

Studies which have examined the effects of ankle-foot orthoses (AFOs) on children with cerebral palsy (CP) often report insufficient detail about the participants, devices and testing protocols. The aim of this systematic review was to evaluate the level and quality of detail reported about these factors in order to generate best practice guidelines for reporting of future studies. A systematic search of the literature was conducted to identify studies which examined any outcome measure relating to AFO use in children with CP. A customized checklist was developed for data extraction and quality assessment. There was substantial variability in the level and quality of detail reported across the 41-paper yield. Many papers reported insufficient detail to allow synthesis of outcomes across studies. The findings of this review have been used to generate guidelines for best practice of reporting for AFO intervention studies. It is important to ensure homogeneity of gait pattern in a subject sample or to subdivide a sample to investigate the possibility that heterogeneity affected results. It is also important to describe the orthosis in sufficient detail that the device can be accurately replicated because differences in designs have been shown to affect outcomes. These guidelines will help researchers provide more systematic and detailed reports and thereby permit future reviewers to more accurately assess both the reporting and quality of orthotic interventions, and will facilitate synthesis of literature to enhance the evidence base.

Clinicians' assessment of the hindfoot: a study of reliability.

Background: Static measurements of position of the hindfoot and clinical assessment of motion of the hindfoot often are used in the assessment of foot function and manufacturing of orthoses. However, the reliability and validity of static measurements and dynamic observation and assessment of the hindfoot are controversial. The purpose of this investigation was to examine reliability of static and dynamic assessments of the hindfoot in a setting that reproduced clinical conditions. Methods: Twenty-four healthy participants were evaluated by four experienced clinicians for four commonly used static measurements and dynamic assessment of hindfoot function. The protocol was repeated 2 weeks later. Results: Results indicated that reliability of results, both intertester and from test to test were poor to fair for static measurements of the hindfoot (r = 0.075 to r = 0.755, p < 0.05). The error estimates associated with these measures were high; subtalar neutral position and resting calcaneal stance position both demonstrated measurement errors of more than 4 degrees (95% confidence intervals − 4.1 degrees and 5.1 degrees, respectively). Retest reliability of dynamic assessments were considered reasonable for only one clinician (κ = 0.55). Intertester agreement was poor among all clinicians. Conclusion: Clinicians taking static measurements demonstrated large errors that do not reflect the precision that has been assumed in clinical theory using these measurements. The availability of static assessments did not improve dynamic assessment. This poor reliability calls into question the importance placed on static and dynamic measurements of the hindfoot in clinical decision-making.

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.

The Effect of Stance Control Orthoses on Gait Characteristics and Energy Expenditure in Knee-Ankle-Foot Orthosis Users

Stance Control knee-ankle foot orthoses (SCO) differ from their traditional locked knee counterparts by allowing free knee flexion during swing while providing stability during stance. It is widely accepted that free knee flexion during swing normalizes gait and therefore improves walking speed and reduces the energy requirements of walking. Limited research has been carried out to evaluate the benefits of SCOs when compared to locked knee-ankle foot orthoses (KAFOs). The purpose of this study was to evaluate the effectiveness of SCOs used for patients with lower limb pathology. Energy expenditure and walking velocity were measured in 10 subjects using an orthosis incorporating a Horton Stance Control knee joint. A GAITRite walkway was used to measure temporospatial gait characteristics. A Cosmed K4b2 portable metabolic system was used to measure energy expenditure and heart rate during walking. Two conditions were tested: Walking with stance control active (stance control) and walking with the knee joint locked. Ten subjects completed the GAITRite testing; nine subjects completed the Cosmed testing. Walking velocity was significantly increased in the stance control condition (p < 0.001). There was no difference in the energy cost of walking (p = 0.515) or physiological cost index (PCI) (p = 0.093) between conditions. This study supports previous evidence that stance control knee-ankle foot orthoses increase walking velocity compared to locked knee devices. Contrary to expectation, the stance control condition did not decrease energy expenditure during walking.

Plantar pressure pain thresholds and touch sensitivity in Rheumatoid Arthritis

Background: In-shoe pressure redistribution to provide relief of forefoot pain in rheumatoid arthritis (RA) is based on assumed links between pressure and pain. However, little is known about the size of the pressure change required to reduce pain or the capacity of other plantar regions to bear increased pressure. Our primary aim was to quantify the plantar pressure pain threshold (PPT) in RA and compare it to age- and gender-matched control participants. Materials and Methods: This controlled trial involved 10 RA participants and 10 age- and gender-matched control subjects. PPT, measured using a force gauge, and touch sensitivity, measured via Semmes-Weinstein monofilaments, were tested in 19 plantar regions. Results: RA plantar PPTs were significantly reduced in eight foot regions (p < 0.05) and were more uniform across the plantar surface. Touch sensitivity was not different between groups. Plantar PPT was significantly related to age (p < 0.05) and to touch sensitivity (p < 0.05) in multiple foot regions of the control group but not in RA. PPT was significantly correlated with disease duration (p < 0.05). Conclusion: Plantar PPTs in RA were 60% to 80% of the control group and may be helpful in predicting the amount of pressure reduction needed to relieve pain. This study provides further evidence that RA disturbs normal pain sensory mechanisms. Level of Evidence: III, Retrospective Case Control

The effect of tone-reducing orthotic devices on soleus muscle reflex excitability while standing in patients with spasticity following stroke

Orthoses are commonly prescribed for the management of spasticity but their neurophysiologic effect on spasticity remains unsubstantiated. The purpose of this study was to investigate the effect of three tone-reducing devices (dynamic foot orthosis, muscle stretch, and orthokinetic compression garment) on soleus muscle reflex excitability while standing in patients with spasticity following stroke. A repeated-measures intervention study was conducted on 13 patients with stroke selected from a sample of convenience. A custom-made dynamic foot orthosis, a range of motion walker to stretch the soleus muscle and class 1 and class 2 orthokinetic compression garments were assessed using the ratio of maximum Hoffmann reflex amplitude to maximum M-response amplitude (Hmax:Mmax) to determine their effect on soleus muscle reflex excitability. Only 10 subjects were able to complete the testing. There were no significant treatment effects for the interventions (F = 1.208, df = 3.232, p = 0.328); however, when analyzed subject-by-subject, two subjects responded to the dynamic foot orthosis and one of those two subjects also responded to the class 1 orthokinetic compression garment. Overall, the results demonstrated that the tone-reducing devices had no significant effect on soleus reflex excitability suggesting that these tone-reducing orthotic devices have no significant neurophysiologic effect on spasticity.