Knee osteoarthritis patients assessed during walking for ankle inversion movement discrimination sensitivity

Background: Knee osteoarthritis (KOA) is a common musculoskeletal condition that affects dynamic balance control and increases the risk of falling during walking. However, the mechanisms underlying this are still unclear. Diminished ankle proprioception during walking has been found to be related to fear of falling in older adults, with a gender difference in incidence of falling. This study aimed to determine 1) whether ankle inversion proprioceptive acuity during walking is impaired in patients with KOA; and 2) whether there is any difference between genders. Methods: Thirty-two patients with KOA (F:M = 17:15, Median age = 52.5, BMI = 22.3 ± 3.0) and 34 healthy controls without KOA (HC) (F:M = 17:17; median age = 49.0, BMI = 22.5 ± 2.7) were recruited. In patients with KOA, ankle inversion proprioceptive acuity was measured on the affected side using the ankle inversion discrimination apparatus for walking (AIDAW), whilst HC were assessed on a randomly selected side. Two-way (2*2) analysis of variance (ANOVA) was performed to determine the main effects and interaction between gender and KOA condition. Results: Two-way ANOVA showed a significant KOA main effect (F = 26.6, p < 0.001, ƞp 2 = 0.3) whereby AIDAW scores during walking for individuals with KOA were significantly lower than those without KOA (KOA vs. HC: 0.746 ± 0.057 vs. 0.807 ± 0.035). There was neither a gender main effect nor interaction (both p > 0.05). Conclusion: Individuals with KOA demonstrated lower ankle proprioception scores during walking compared to their healthy counterparts, with a similar level of impairment in ankle proprioceptive acuity between male and female patients. A low score may contribute to an increased risk of falling in the KOA population. The current findings suggest the need for global concern about lower limb proprioception in the clinical management of KOA.

Voluntary postural sway control and mobility in adults with low back pain

Introduction

Low back pain (LBP) is associated with altered somatosensory perception, which is involved in both involuntary and voluntary control of posture. Currently, there is a lack of methods and tools for assessing somatosensory acuity in patients with LBP. The purpose of this study was (1) to assess the reliability of the sway discrimination apparatus (SwayDA) (2) to evaluate the differences in somatosensory acuity between patients with LBP and pain-free individuals, and (3) to examine relationships between somatosensory acuity, severity of LBP, and mobility in patients with LBP.

Methods

Twenty participants (10 patients with LBP and 10 matched asymptomatic controls) were recruited in a test-retest reliability test. Another 56 participants were recruited for this study with 28 individuals presenting with LBP and a further twenty-eight being asymptomatic. The SwayDA was custom-built to measure somatosensory perception during voluntary anterior-posterior (SwayDA-AP), medial-lateral to the dominant side (SwayDA-ML-D), and non-dominant side (SwayDA-ML-ND) postural sway control. Participants also completed mobility tests, including 10 times and 1-min sit-to-stand tests (10-STS, 1 m-STS). The area under the receiver operating characteristic curve (AUC) was calculated to quantify somatosensory acuity in discriminating different voluntary postural sway extents.

Results

The ICC (2.1) for the SwayDA-AP, SwayDA-ML-D, and SwayDA-ML-ND were 0.741, 0.717, and 0.805 with MDC95 0.071, 0.043, and 0.050. Patients with LBP demonstrated significantly lower SwayDA scores (tSwayDA-AP = -2.142, p = 0.037; tSwayDA-ML-D = -2.266, p = 0.027) than asymptomatic controls. The AUC values of the SwayDA-AP test were significantly correlated with ODI (rSwayDA-AP-ODI = -0.391, p = 0.039). Performances on the 1 m-STS and the 10-STS were significantly correlated with the AUC scores from all the SwayDA tests (-0.513 ≤ r ≤ 0.441, all p < 0.05).

Discussion

The SwayDA tests evaluated showed acceptable reliability in assessing somatosensory acuity during voluntary postural sway. Somatosensory acuity was diminished in patients with LBP compared to asymptomatic controls. In patients with LBP, lower somatosensory acuity was associated with increased LBP-related disability. Future research could focus on investigating the factors contributing to the decreased somatosensory perception and mobility in individuals with LBP.

Generalized Hyperalgesia in Children and Adults Diagnosed With Hypermobility Syndrome and Ehlers-Danlos Syndrome Hypermobility Type: A Discriminative Analysis

OBJECTIVE

Lowered pressure-pain thresholds have been demonstrated in adults with Ehlers-Danlos syndrome hypermobility type (EDS-HT), but whether these findings are also present in children is unclear. Therefore, the objectives of the study were to determine whether generalized hyperalgesia is present in children with hypermobility syndrome (HMS)/EDS-HT, explore potential differences in pressure-pain thresholds between children and adults with HMS/EDS-HT, and determine the discriminative value of generalized hyperalgesia.

METHODS

Patients were classified in 1 of 3 groups: HMS/EDS-HT, hypermobile (Beighton score ≥4 of 9), and healthy controls. Descriptive data of age, sex, body mass index, Beighton score, skin laxity, and medication usage were collected. Generalized hyperalgesia was quantified by the average pressure-pain thresholds collected from 12 locations. Confounders collected were pain locations/intensity, fatigue, and psychological distress. Comparisons between children with HMS/EDS-HT and normative values, between children and adults with HMS/EDS-HT, and corrected confounders were analyzed with multivariate analysis of covariance. The discriminative value of generalized hyperalgesia employed to differentiate between HMS/EDS-HT, hypermobility, and controls was quantified with logistic regression.

RESULTS

Significantly lower pressure-pain thresholds were found in children with HMS/EDS-HT compared to normative values (range -22.0% to -59.0%; P ≤ 0.05). When applying a threshold of 30.8 N/cm² for males and 29.0 N/cm² for females, the presence of generalized hyperalgesia discriminated between individuals with HMS/EDS-HT, hypermobility, and healthy controls (odds ratio 6.0).

CONCLUSION

Children and adults with HMS/EDS-HT are characterized by hypermobility, chronic pain, and generalized hyperalgesia. The presence of generalized hyperalgesia may indicate involvement of the central nervous system in the development of chronic pain.

Clinical characteristics of mephedrone toxicity reported to the U.K. National Poisons Information Service

Objective

To describe the patterns and clinical features of toxicity related to recreational use of mephedrone and other cathinones in the UK using data collected by the National Poisons Information Service (NPIS).

Methods

The number of accesses to TOXBASE, the NPIS online poisons information database, details of consecutive cases uploaded onto TOXBASE and the number and details of telephone enquiries made to the NPIS by health professionals in the UK were collected for the period March 2009 to February 2010.

Results

Over the year of study there were 2901 TOXBASE accesses and 188 telephone enquiries relating to cathinones, the majority relating to mephedrone (TOXBASE 1664, telephone 157), with a month-on-month increase in numbers. In 131 telephone enquiries concerning mephedrone, alone or in combination with alcohol, common clinical features reported included agitation or aggression (n=32, 24%, 95% CI 18% to 33%), tachycardia (n=29, 22%, 95% CI 16% to 30%), confusion or psychosis (n=18, 14%, 95% CI 9% to 21%), chest pain (n=17, 13%, 95% CI 8% to 20%), nausea (n=15, 11%, 95% CI 7% to 18%), palpitations (n=14, 11%, 95% CI 6% to 18%), peripheral vasoconstriction (n=10, 8%, 95% CI 4% to 14%) and headache (n=7, 5%, 95% CI 2% to 11%). Convulsions were reported in four cases (3%, 95% CI 1% to 8%). One exposed person died following cardiac arrest (1%, 95% CI 0% to 4%), although subsequent investigation suggested that mephedrone was not responsible.

Conclusions

Toxicity associated with recreational mephedrone use is increasingly common in the UK. Sympathomimetic adverse effects are common and severe effects are also reported. Structured data collected by the NPIS may be of use in identifying trends in poisoning and in establishing toxidromes for new drugs of abuse.

Effect of anterior cruciate ligament injury and reconstruction on proprioceptive acuity of knee rotation in the transverse plane

BACKGROUND

Studies assessing proprioceptive acuity in anterior cruciate ligament (ACL)-deficient knees have only considered proprioception for knee movements in the sagittal plane rather than in the transverse plane (ie, rotation), despite the fact that the ACL plays a critical role in knee rotational stability and that the ACL is injured almost exclusively with a rotation mechanism. Therefore a test of proprioception is needed that involves movements similar to the mechanism of injury, in this case, rotation.

PURPOSE

To determine whether proprioceptive acuity in rotation changes after ACL injury and reconstruction, and to examine differences in proprioceptive acuity, range, laxity, and activity level among injured knees, contralateral knees, and healthy controls.

DESIGN

Cohort study; Level of evidence, 2.

METHODS

Proprioceptive acuity for active knee rotation movements, passive rotation range of motion, anterior knee laxity, and knee function were measured in 20 consecutive participants with unilateral ACL rupture and 20 matched controls. Reconstruction was performed using a single-incision technique with a 4-strand hamstring tendon autograft. Thirty participants (15 control and 15 ACL reconstructed) were retested at 3 months, and 14 with ACL reconstruction were tested at 6 months.

RESULTS

A deficit was found in preoperative knee rotation proprioception compared with healthy controls (P = .031). Three months after reconstruction, there was a significant improvement (P = .049) in proprioceptive acuity, single-plane anterior laxity (P = .01), and self-reported knee function (P = .001). At 3 months after reconstruction, proprioceptive acuity of the ACL-reconstructed knee was correlated with reported activity level (r = .63; P = .021).

CONCLUSION

Knee rotation proprioception is reduced in ACL-deficient participants compared with healthy controls. Three to 6 months after reconstruction, rotation proprioceptive acuity, laxity, and function were improved. While these findings are consistent with a return to previous activity level 6 months after reconstruction, the extent of graft maturation and restoration of kinematics should also inform the decision about return to sport.

UK childhood exposures to pesticides 2004-2007: a TOXBASE toxicovigilance study

OBJECTIVE

There are no systematic methods for toxicovigilance of non-medicinal products in the UK. This is particularly relevant for pesticides, where there is significant public concern about potential adverse effects. This study describes a prospective toxicovigilance scheme based on follow-up of enquiries to the National Poisons Information Service (NPIS) through its online poisons information system TOXBASE. These enquiries reflect acute exposures and the patterns of acute illness that result.

RESULTS

A total of 10 061 pesticide-related enquiries were identified. After follow-up, data were gathered on 2364 suspected exposures, of which 1162 involved children. After exclusions, 1147 exposures are reported here. No deaths were reported and only 37 children were admitted to hospital. The majority were considered to have either minimal or no features (925, 80.6%). Symptoms for 38 children were unknown. Symptoms reported in the other 184 children included nausea or vomiting (58), eye irritation, pain or conjunctivitis (29), skin irritation (28), abdominal pain (24), mouth or throat irritation (18) and diarrhoea (15). Where age was recorded, 60.5% (680) of children involved in suspected pesticide exposures were aged 2 years or less. The most common scenario for acute accidental exposure to pesticide in children was exposure after application (329, 28.7%) or due to poor storage (228, 19.9%).

CONCLUSIONS

Areas of potential concern identified included storage, access of young children to "laid" baits and pesticides, and exposures as a result of medication errors, with liquid head lice preparations being confused with other medicines. Use of NPIS systems provides a potentially useful method of toxicovigilance.

Diverticulation of the cerebral ventricles: a cause of progressive focal encephalopathy

Diverticulation of the lateral ventricles of the brain has received little attention in the literature on hydrocephalus. From clinical observations on one child and one adult with diverticulation, it is apparent that force of CSF within the diverticulum is greater than that against the normal parts of the ventricular wall. In both cases, regression of focal symptoms occurred after insertion of a shunt.

Stress analysis of adhesive-bonded lap joints

Stresses in a standard metal-to-metal adhesive-bonded lap joint are analysed by a two-dimensional finite-element method and comparisons are made with previous analyses. Particular attention is paid to the stresses at the ends of the adhesive layer. Unlike previous work, which assumes the adhesive to have a square edge, the adhesive spew is treated as a triangular fillet. The highest stresses exist at the adherend corner within the spew. Linear elastic behaviour is assumed throughout.

A rubber model is reported which confirms these results physically.

Good agreement was also obtained between some practical results and the finite-element predictions.

Rubber model for adhesive lap joints

Models of adhesive joints have been constructed in which hard rubber has been used as the adherends and relatively soft foam rubber as the adhesive. The models were scaled to represent various types of lap joint. Very good agreement was obtained when the experimental results were compared with available theory, showing that the model accurately represented the shear-stress distribution in the adhesive.

Two joints are shown in which the adhesive thickness was profiled (one optimally, the other linearly) to reduce or eliminate the shear-stress concentration at the ends.

Effect of poisson's ratio strains in adherends on stresses of an idealized lap joint

Poisson's ratio strains in the adherends of a simple adhesive lap joint induce transverse stresses both in the adhesive and in the adherends.

Two simultaneous second-order partial-differential equations were set up to describe the normal stresses along and across an adherend and were solved both by an approximate analytical method and a finite-difference technique: the two solutions agreed closely. The adhesive shear stresses can then be obtained by differentiating these solutions. The transverse shear stress has a maximum value for metals of about one-third of the maximum longitudinal shear stress, and this occurs at the corners of the lap, thus making the corners the most highly stressed parts of the adhesive.

Bonding adherends of dissimilar stiffness was shown to produce greater stress concentrations in the adhesive than when similar adherends are used.

Responsiveness of two methods for measuring foot and ankle volume

BACKGROUND

Measurements of volume are taken in the clinical environment to determine the extent of swelling and to evaluate the effects of treatment interventions. In the research setting, volume measurements are taken to determine experimental outcomes. Water displacement and figure-of-eight methods are highly reliable for measuring foot and ankle volumes, but the responsiveness of the two methods has not been compared. This study was designed to investigate effects of manipulating hydrostatic and blood pressures on foot and ankle volume and responsiveness of the two methods to induced changes in foot and ankle volume.

METHODS

Intervention effects on volume were compared using water displacement and tape (figure-of-eight) methods. Foot and ankle volume was measured in each of the 30 participants while they were supine, sitting, and sitting with a sphygmomanometer cuff inflated around the lower thigh to occlude blood flow into the leg. These variations allowed manipulation of the hydrostatic and blood pressures acting on the foot and ankle.

RESULTS

Data from the water displacement method showed that a significant increase in volume of 31 mL (p < 0.002) occurred with the cuff in place, but this was not detected using the figure-of-eight method. No significant difference (p > 0.136) between the sitting and supine positions was detected using either method.

CONCLUSIONS

Limb dependency while sitting or lying had no effect on measures from either method, but volumetry had a higher responsiveness to changes induced by application of the cuff. This effect was interpreted as arterial leakage past the cuff.

CLINICAL RELEVANCE

The figure-of-eight tape method and the water displacement technique for measuring ankle and foot volume may not be interchangeable. Changes in volume of the ankle and foot are better measured by the water displacement technique, but for measurements of ankle volume alone, the tape method is appropriate. The responsiveness of the tape method to changes in volume is yet to be determined.

Functional strength training in cerebral palsy: a pilot study of a group circuit training class for children aged 4-8 years

OBJECTIVE

To determine the effects of intensive task-specific strength training on lower limb strength and functional performance in children with cerebral palsy.

DESIGN

A nonrandomized ABA trial.

SETTING

Sydney school.

SUBJECTS

Eight children with cerebral palsy, aged 4-8 years, seven with diagnosis of spastic diplegia, one of spastic/ataxic quadriplegia.

INTERVENTION

Four weeks of after-school exercise class, conducted for one hour twice weekly as group circuit training. Each work station was set up for intensive repetitive practice of an exercise. Children moved between stations, practising functionally based exercises including treadmill walking, step-ups, sit-to-stands and leg presses.

MAIN OUTCOME MEASURES

Baseline test obtained two weeks before training, a pre-test immediately before and a post-test following training, with follow-up eight weeks later. Lower limb muscle strength was tested by dynamometry and Lateral Step-up Test; functional performance by Motor Assessment Scale (Sit-to-Stand), minimum chair height test, timed 10-m test, and 2-minute walk test.

RESULTS

Isometric strength improved pre- to post-training by a mean of 47% (SD 16) and functional strength, on Lateral Step-up Test, by 150% (SD 15). Children walked faster over 10 m, with longer strides, improvements of 22% and 38% respectively. Sit-to-stand performance had improved, with a reduction of seat height from 27 (SD 15) to 17 (SD 11) cm. Eight weeks following cessation of training all improvements had been maintained.

CONCLUSIONS

A short programme of task-specific strengthening exercise and training for children with cerebral palsy, run as a group circuit class, resulted in improved strength and functional performance that was maintained over time.

A pilot study of the home application of transcutaneous neuromodulation in children with urgency or urge incontinence

PURPOSE

We evaluated the efficacy of transcutaneous neuromodulation to treat urinary urgency and urge incontinence in children with nonneurological bladder dysfunction.

MATERIALS AND METHODS

Surface neuromodulation was delivered via skin electrodes away from the genital region for a short duration daily on a home treatment basis. Clinical outcome was measured by 3 tools previously tested for reliability including the frequency volume chart, urgency visual analog scale and accident diary ("Dry Pie").

RESULTS

After at least 1 month of application dryness had improved in 73.3% of children, mean urgency score had improved to equate action at urge as being 'easy to hold on' and there was a significant increase in mean voided volume.

CONCLUSIONS

Initial evaluation of the home application of surface neuromodulation in children with urgency and/or urge incontinence revealed positive results and warrants a randomized controlled investigation. The finding that children were not completely dry with this treatment in isolation suggests that further study is needed to identify optimal treatment duration and stimulus intensity.

A novel clinical evaluation of childhood incontinence and urinary urgency

PURPOSE

There are few clinic based objective tools for the evaluation of urinary urgency and incontinence in children. We report on the known method of frequency volume chart, and describe 2 new tools to determine their effectiveness and reliability.

MATERIALS AND METHODS

The mean and standard deviation values for affected children in each age group from 5 to 12 years were calculated from 321 consecutive frequency volume charts. Two new child-based scoring tools quantifying urinary urgency were developed to measure the sensation of urgency and the intensity of response at urge (visual analog score 1 and 2). These tools were tested for reliability. As the quantification of incontinence is problematic in children, a new system of documenting functional severity of leakage per day was designed (Dry Pie) and also tested for reliability.

RESULTS

Age related mean bladder storage volumes and standard deviations were established for children with incontinence. The novel urgency visual analog measure proved reliable, although only scale 2 would be useful in clinical practice. The incontinence Dry Pie diary was also shown to be reliable for 2 weeks and easily completed at home by the children.

CONCLUSIONS

As a result of this study clinic based intervention can include reliable quantification of urinary urgency (visual analog scale 2) and a functional measure of the severity of incontinence (Dry Pie).

Acute angles of head-up tilt do not affect forearm and hand volume

Physiotherapists utilise the effect of gravity in treatment of conditions associated with increased limb volume. In contrast with knowledge about the relationship between body position and lower limb volume, the effect of body position on arm volume is not well understood. To assess the efficacy of a simple intervention proposed for patients to reduce arm volume during sleep, this study investigated the effects on forearm and hand volume of two hours of head-up tilt in supine at three angles of 8, 11 and 14 degrees. Six asymptomatic subjects were measured at each tilt angle over a three-week period. Data indicated that no angle of head-up lying over a two-hour period was associated with any significant reduction in upper limb volume.

Indenter head area and testing frequency effects on posteroanterior lumbar stiffness and subjects' rated comfort

Although several mechanical devices have been developed to objectively assess posteroanterior (PA) stiffness of the lumbar spine, no standardized testing protocol has been adopted. Two factors that may vary across protocols, and that effect measured stiffness and the comfort of the test subject, are the size of the indenter head used to apply the PA pressure, and indenting frequency. Three variables; PA stiffness, defined as the slope of the stiffness curve (K), the displacement of the indenter at 30N (D30), and rating of perceived comfort, were measured in 36 subjects asymptomatic for low back pain. For each subject nine tests were conducted, using three different indenter head sizes (300mm(2), 720mm(2)and 1564mm(2)) at each of three different testing frequencies (0.25 Hz, 0.5 Hz and 2 Hz). Machine testing with a large indenter head produced a lower K value, an increased D30 value and higher perceived comfort, while a fast testing frequency produced a higher K value and a lower D30 value. An indenter size by frequency interaction showed small indenter heads to be least comfortable at slow speed. The differences found suggest that the indenter head size and the testing frequency should be standardized during mechanical spinal stiffness testing.

Relationships among age-associated strength changes and physical activity level, limb dominance, and muscle group in women

This study investigated the magnitude and rate of age-associated strength reductions in Australian independent urban-dwelling women and the relationship to muscle groups, limb dominance, and physical activity level. Independent urban-dwelling women aged 20 to 89 years (N = 217) performed maximal voluntary contractions with the dominant and nondominant knee extensors, plantar flexors, and handgrip. Anthropometric measurements were made and questionnaire responses used to obtain current physical activity levels. Trend analysis within analysis of variance and regression analysis on strength was performed. Limb muscle strength was found to be associated with increased age, muscle group, limb dominance, and activity. Self-reported physical activity levels declined with age but women who were more physically active for their age group were stronger in all muscle groups and had more lean body mass and lean thigh and leg cross-sectional area than relatively inactive women. Slopes of the linear reductions of maximal voluntary strength of the knee extensors, plantar flexors, and handgrip with age were significantly different (p < .05) at 9.3%, 7.4%, and 6.2% per decade, respectively. The limb muscle strength of healthy Australian independent and urban-dwelling women aged 20 to 89 years was found to be associated with age and three aspects of disuse: muscle group, relative levels of physical activity, and limb dominance.

Catalytic macrocyclizations of thietanes and thiiranes by metal carbonyl complexes

This Account summarizes our recent studies of the catalytic transformations of thietanes and thiiranes by metal carbonyl complexes of the third row of the transition elements. The goal of the work has been to prepare polythioether macrocycles (thiacrowns) catalytically. This has been achieved with high success for certain thietane reactions. Thiiranes, on the other hand, tend to yield macrocyclic polydisulfides, but it has recently been found that these reactions can be redirected toward the thiacrown products by using certain alkyne carboxylates as cocatalysts. Vinylthiiranes are transformed into 3,6-dihydro-1,2-dithiins catalytically in excellent yield via W(CO)(5)(vinylthiirane) complexes.

Sitting balance II: reach direction and thigh support affect the contribution of the lower limbs when reaching beyond arm's length in sitting

The effects of reach direction and extent of thigh support on the contribution of the lower limbs during seated reaching were examined. Twelve healthy subjects aged 59-79 years performed self-paced reaching forwards and diagonally to both sides and under three thigh support conditions. Vertical ground reaction forces (GRF) and leg muscle activity were monitored bilaterally. Reach direction affected both the magnitude of peak vertical GRF and the relative distribution of vertical GRF through the feet, demonstrating that the lower limbs work cooperatively to control the motion of the body mass. Extent of thigh support also affected the magnitude of peak vertical GRF through the feet. In addition, the EMG data confirmed the active contribution of the lower limbs when reaching beyond arm's length, with muscles in both lower limbs activated in all trials.

Sphygmomanometer-induced increases in forearm and hand volume

Swelling, or increased volume, secondary to venous congestion is thought to be a factor in some upper limb conditions. This study aimed to establish a safe, easily applied method of inducing a transitory increase in forearm and hand volume that could be used as a symptom provocation test for upper limb conditions. Using the principles of venous occlusion plethysmography, movement of blood volume into the forearm and hand of asymptomatic subjects was measured after occlusion with three different sphygmomanometer cuff pressures over four minutes. Increases of between 37 and 62 ml (2.5% and 4.1%) were achieved at pressures between diastolic pressure minus 30 mm Hg and diastolic pressure plus 5 mm Hg, with minimal reported side effects. These data demonstrate that a sphygmomanometer can be used to induce transitory fluid congestion of the forearm and hand.

Human skeletal sarcoplasmic reticulum Ca2+ uptake and muscle function with aging and strength training

This study investigated the adaptations of skeletal muscle sarcoplasmic reticulum (SR) Ca2+ uptake, relaxation, and fiber types in young (YW) and elderly women (EW) to high-resistance training. Seventeen YW (18-32 yr) and 11 EW (64-79 yr) were assessed for 1) electrically evoked relaxation time and rate of the quadriceps femoris; and 2) maximal rates of SR Ca2+ uptake and Ca2+-ATPase activity and relative fiber-type areas, analyzed from muscle biopsies of the vastus lateralis. EW had significantly slower relaxation rates and times, decreased SR Ca2+ uptake and Ca2+-ATPase activity, and a larger relative type I fiber area than did YW. A subgroup of 9 young (YWT) and 10 elderly women (EWT) performed 12 wk of high-resistance training (8 repetition maximum) of the quadriceps and underwent identical testing procedures pre- and posttraining. EWT significantly increased their SR Ca2+ uptake and Ca2+-ATPase activity in response to training but showed no alterations in speed of relaxation or relative fiber-type areas. In YWT none of the variables was altered after resistance training. These findings suggest that 1) a reduced SR Ca2+ uptake in skeletal muscle of elderly women was partially reversed with resistance training and 2) SR Ca2+ uptake in the vastus lateralis was not the rate-limiting mechanism for the slowing of relaxation measured from electrically evoked quadriceps muscle of elderly women.

A urodynamic study of surface neuromodulation versus sham in detrusor instability and sensory urgency

PURPOSE

We studied the effect of surface neuromodulation on cystometric pressure and volume parameters in women with detrusor instability or sensory urgency. Electrical current was delivered to the suprapubic region and third sacral foramina via a transcutaneous electrical nerve stimulator with sham neuromodulation control.

MATERIALS AND METHODS

A consecutive series of women with proved detrusor instability or sensory urgency were randomized to 3 surface neuromodulation groups. Volume and pressure parameters were the main outcomes of transcutaneous electrical nerve stimulation applied during second cystometric fill.

RESULTS

Sham transcutaneous electrical nerve stimulation did not alter the outcome measures. However, neuromodulation delivered across the suprapubic and sacral skin effected a reduction in mean maximum height of detrusor contraction. A current which inhibits motor activity was not superior to that which inhibits sensory perception in reducing detrusor pressure. Response in sensory urgency was poor.

CONCLUSIONS

Results from our sham controlled study suggest that short-term surface neuromodulation via transcutaneous electrical nerve stimulation may have a role in the treatment of detrusor instability. Future studies must examine the clinical effect of long-term surface neuromodulation.

End-expiratory lung volume during arm and leg exercise in normal subjects and patients with cystic fibrosis

There are no reports concerning the regulation of end-expiratory lung volume (EELV) and flow-volume relationships during upper limb exercise in health and disease. We studied EELV during such exercise in 22 adults with cystic fibrosis (CF) and nine age-matched healthy control subjects. Subjects with CF were grouped according to the severity of their lung disease, as follows: mild = FEV1 > 80% predicted; moderate = FEV1 40 to 80% predicted, and severe = FEV1 < 40% predicted. EELV was calculated from measurements of inspiratory capacity (IC) made at each workload during an incremental arm and leg ergometer test to peak work capacity. In the control group, the decrease in EELV was significantly smaller for arm than for leg exercise at peak work (-0.13 L versus -0.53 L, p < 0.001) and for arm than for leg exercise at an equivalent submaximal ventilation (-0.13 L versus -0.46 L, p < 0.01). In the groups with moderate and severe CF, arm exercise resulted in an increase in EELV from resting levels (dynamic hyperinflation) that was not significantly different from the increase observed for leg exercise. For CF subjects there was a significant inverse relationship between FEV1 and changes in EELV from rest to peak arm exercise (r = -0.46, p < 0.05). In normal subjects, there was a difference in the EELV response for arm versus leg exercise. In CF subjects with airflow limitation, dynamic hyperinflation occurred with both forms of exercise.

The effects of arm elevation and overnight head-up tilt on forearm and hand volume

Methods to reduce increased fluid volume, or swelling, were evaluated as short- and long-term interventions. Forearm and hand volumes were measured in 45 fit and healthy subjects using a water displacement device with previously established reliability. Volumes were measured before and after 2 hours of recumbency and before and after overnight sleep under different conditions of arm elevation or head-up tilt. No arms-at-side lying-down position, whether after 2 hours awake or after overnight sleep or with bed-head elevated or not, resulted in significant changes in forearm and hand volume. Only 2 hours in a supine lying-down position with 30 degrees of arm elevation caused a significant effect, with an average decrease of 51 ml in forearm and hand volume.

The effects of high and low loading forces on measured values of lumbar stiffness

OBJECTIVE

One explanation for the poor reliability of manual judgments of posteroanterior (PA) stiffness may be that if manual therapists use different forces when testing, different stiffness is perceived. This study was conducted to examine measurements of lumbar PA stiffness obtained using a device programmed to generate different loading forces.

SUBJECTS

Twenty-five subjects with no history of low back pain and a mean age of 23.5 yr were measured.

METHODS

Measures of lumbar PA stiffness were obtained using a mechanical device that applied a testing force of 200 N to the skin overlying the L3 spinous process. Six stiffness coefficients were determined from the force/displacement curve obtained from each subject by performing linear regressions from 30-80 N, 30-150 N, 30-200 N, and from 30-83.3 N, 83.3-136.7 N, and 136.7-200 N. Intraclass correlation coefficients and repeated measures analysis of variance were used to analyze the data.

RESULTS

Although moderate reliability [ICC 2,1 = 0.67] was found for stiffness measures arising from increasingly wide force-interval regressions (30-80 N, 30-150 N, 300-200 N), poor reliability [ICC (2,1) = 0.39] was found for stiffness measures arising from same-width, higher force regressions (30-83.3 N, 83-137 N, 137-200 N). In both cases there were significant differences between the obtained K stiffness values corresponding to different force intervals.

CONCLUSION

These results show that if therapists push harder, different stiffnesses will be felt. Studies using instrumental measurement of spinal stiffness to obtain 'K' values should report the force intervals used. Also, revised protocols for manually judging PA stiffness should ensure that stiffness is assessed by sampling specified force intervals rather than the raters determining their own force limits.

Evaluation of supported upper limb exercise capacity in patients with cystic fibrosis

Physiological responses to upper limb exercise have not been well documented in patients with cystic fibrosis (CF). This is the first study to quantify ventilatory responses to supported incremental upper limb exercise in this patient group. Twenty-four subjects with CF, with a wide range of pulmonary impairment, and ten normal control subjects were studied. Subjects performed pulmonary function tests and incremental arm and leg exercise to peak work capacity on an arm crank and bicycle ergometer. All subjects performed less work with the arms than legs. At an equivalent oxygen consumption, ventilation was higher for arm work than leg work. This higher ventilation was achieved mainly through a higher frequency of breathing. Only CF subjects with severe pulmonary impairment (FEV1 < 40% predicted, FEF25-75% < 20% predicted) had a reduced arm work capacity compared with control subjects. At peak arm work, these subjects had a mean ventilation to maximum voluntary ventilation ratio (VE/MVV) of 106% +/- 25, while maximum heart rate was less than 80% predicted. Despite the high ventilatory requirement for arm exercise, arm work capacity was well maintained in subjects with CF until severe lung disease impaired the ability to further increase ventilation.

Frequency-volume chart data from incontinent children

OBJECTIVE

To establish the mean and standard deviation about the mean for voiding variables of incontinent children aged 6-11 years as measured on a frequency-volume chart (FVC), and to determine the effect of type of incontinence, gender and age on these values.

PATIENTS AND METHODS

All children attending two continence clinics over a 3-year period completed a FVC as a routine part of their assessment. Voided volume and voiding interval data were collected from these charts. The mean maximum, mean minimum and overall mean voided volume and voiding interval were established for the whole group and then for each age, gender and type of incontinence.

RESULTS

The voiding patterns of incontinent children were very variable and thus the standard deviation for each voiding parameter was large. Multivariate analysis showed that the only variable that affected any of these apparent storage parameters was the child's age; gender and type of incontinence did not influence bladder storage patterns. Children with day-time incontinence did not have smaller voided volumes than those with nocturnal enuresis.

CONCLUSION

Both the mean and the standard deviation about the mean of all voided volumes varied widely amongst incontinent children. Only age appeared to influence trends in voided volumes. Any clinical investigation using the FVC in children should consider the high standard deviation when calculating sample size.

The epidemiology of childhood enuresis in Australia

OBJECTIVE

To establish the prevalence of enuresis in 5-12-year-old Australian children, to evaluate the impact of enuresis on the children and their families and to identify common methods of managing enuresis.

SUBJECTS AND METHODS

A self-administered questionnaire was completed voluntarily by the parents of 2292 5-12-year-old children during attendance at electoral polling booths in Sydney, Australia. The questionnaire inquired specifically after the child's age, gender and frequency of wetting.

RESULTS

From a response rate of 74%, the overall prevalence of any reported nocturnal enuresis was 18.9% and any day wetting 5.5%. The prevalence of marked nocturnal enuresis (at least weekly) and marked day wetting was 5.1% and 1.4%, respectively. Using a 10-point visual analogue scale to measure parental concern about their child's enuresis, the mean concern score was 3.1. There was a moderate but significant relationship between the frequency of enuretic episodes and the parental concern score. Of the enuretic children, 34% had consulted with a health worker. These children were 1.4 years older and wet more frequently than those enuretic children who had not sought help. The management of enuresis involved a mean of 3.9 strategies, primarily behavioural techniques administered by the family. The lowest cure rate was seen in the children who wet more frequently. Significantly more of the dry children woke spontaneously at night to void compared with the enuretic children. There was a trend towards greater spontaneous arousal in the children who wet less frequently.

CONCLUSION

These results suggest that prevalence rates for day and night wetting in Australia are similar to those in previous studies reported from the northern hemisphere. Australian families did not report a high level of concern about enuresis, even in the older child. The problem was managed primarily within the family.

Stiffness judgments are affected by visual occlusion

OBJECTIVE

The current protocol for judging posteroanterior (PA) spinal stiffness has been shown to provide unreliable estimates of PA stiffness. It is possible that a failure to standardize therapists' use of vision in the test protocol partly contributes to the disagreement between raters. This study sought to establish whether vision affects stiffness judgments and so needs to be standardized when judging PA stiffness.

DESIGN

Perceptual study using a mechanical device to provide stiffness stimuli with physiotherapists and lay people as judges.

SETTING

University psychophysics laboratory.

INTERVENTIONS

Occlusion of vision via opaque goggles.

MAIN OUTCOME MEASURES

Measures of interstimulus discriminability and bias.

RESULTS

Occluding vision had no effect on judges' ability to discriminate between stiffness stimuli; however, the same stimuli were judged as significantly stiffer under the visual occlusion condition.

CONCLUSION

The data from this study suggest that vision needs to be controlled when using manual tests to judge PA spinal stiffness.

Variability of grip strength during isometric contraction

The use of measures of strength variability as a means of determining sincerity of effort is becoming a more common practice, particularly in medico-legal and rehabilitation settings. The stability of such variability measures, however, has not been documented. This research investigated, in two studies, the trial-to-trial variability of grip strength under maximal and submaximal effort conditions. In the first study, 63 subjects were asked to give 100% grip effort, and in the second study 40 subjects from the original group were asked to give 50% grip effort. The Jamar hand dynamometer was used to measure grip strength in both experiments, and a coefficient of variation (CV) was calculated for every three repeat measures at each handle position. Testing was conducted on two separate occasions for both experiments. Although the interoccasion reliability of grip strength was very high, in comparison, the CV was not stable over test occasions, with interoccasion reliability indices close to zero. Factors significantly influencing CV were effort level, with submaximal effort producing larger CVs, and gender, with females having greater strength variability. If the rule is applied that one or more CVs above the 7.5% cut-off value could indicate submaximal effort, then for this sample of subjects giving maximal effort, 97% of females and 64% of males would be misclassified. Applying a single CV classification cut-off value to a mixed sample of subjects appears to unfairly discriminate against the females. Further research into the factors associated with high CV values is essential before the CV can be used with any confidence in a clinical setting as a method for determining sincerity of effort.

Breathing patterns during spontaneous speech

Lung volumes, speech intensity, the linguistic location of inspirations, and the variability of each, were studied during spontaneous speech in 6 healthy young women over 7 to 10 sessions each, using respiratory inductance plethysmography. Although average lung volume levels were within the vital capacity range previously reported for speech (Hixon, Goldman, & Mead, 1973), significant inter- and intrasubject variability was observed. This variability was considerable for some subjects (average initiation lung volume varying between 42 and 63% VC over the sessions) and relatively small for others (between 47 and 53% VC). Some of the lung volume variation was associated with changes in mood state, examined by self-report questionnaire at each measurement occasion. Linguistic factors were important influences in the lung volume variation. The majority of breaths in the conversations and monologues preceded structural (clause) boundaries. The volume of air inspired preutterance was found to be linked to the length of the ensuing breath group in each of our 6 subjects, as longer breath groups, spanning up to seven clauses in the spontaneous speech, were anticipated by inspiring to a higher lung volume. The subjects used a comfortable speaking intensity range, which varied for different individuals and sessions over 4 to 18 dB. Increases in speech intensity within individual ranges were not associated with increased lung volumes. The data provide novel insight into associations between physiological and linguistic factors in the control of speech breathing, and are suggestive of the existence of neural planning of the respiratory system, in anticipation of the demands of the utterance.

Selectivity in aortic root reconstruction

Anatomical variations in aortic root pathology, including combinations of dissection, aneurysmal dilatation, annuloaortic ectasia, and valve disease, defy standardized repair and mandate application of various surgical reconstructions. To examine these techniques, and their influence on morbidity and mortality, we reviewed 53 consecutive patients undergoing aortic root procedures. Thirty-two patients underwent total root reconstruction. Of these, 21 underwent Bentall procedures, 9 had a modification thereof, and 2 underwent a Cabrol reconstruction. Less extensive pathology was corrected in 21 patients with a partial root reconstruction. These included aortic valve replacement (AVR) and a separate tube graft in 14 patients, AVR and primary aortic repair +/- wrapping in 4 individuals, and AVR and patch aortic root enlargement in 3 patients. Mean age was 53.2 years (range 20 to 79). Nearly 20% had undergone previous cardiac surgery and 7.5% were emergencies. Early mortality was 4%. Complications included dysrhythmias (48%), myocardial infarction (4%), stroke (4%), pneumonia (14%), and pancreatitis (2%). There were no reoperations for bleeding. Three late complications, one pseudoaneurysm and two perivalvular leaks, were successfully repaired. Late deaths (13.7%) were caused by congestive heart failure (3), myocardial infarction (MI) (1), cancer (1), stroke (1), and accidental fall (1). Kaplan-Meier analysis reveals 1-, 5-, and 10-year survivals of 98%, 81%, and 66%. Survival and mortality data did not differ between groups, and except for the incidence of atrial dysrhythmias, complication rates also were not significantly different. This series illustrates the need for and the successful application of a selective approach to aortic root reconstruction.

Transhiatal stapled esophagojejunostomy without a pursestring suture in patients with previous gastric resection

Previous gastric resection complicates alimentary tract reconstruction after esophagectomy. Colonic interposition is the standard conduit in this circumstance, but has substantial mortality and morbidity, especially important when treatment goals are to provide effective alimentation and minimize hospital stay. This report details the technique of a transabdominal, intrathoracic, stapled esophagojejunostomy created without a pursestring suture, which was used to reconstruct the esophagus in 3 patients who had previously undergone partial gastrectomy. This technique avoids both colon interposition and thoracotomy, thereby minimizing the associated complications.

Variability and consistency in speech breathing during reading: lung volumes, speech intensity, and linguistic factors

Lung volumes during reading and associated factors such as speech intensity and linguistic influences were studied in six healthy young women over 7 to 10 sessions, using respiratory inductive plethysmography. Intrasubject variability of lung volumes over the sessions was almost as great as the intersubject variability. Some of the intrasubject variability was associated with natural variations of speech intensity within a "comfortable loudness" range. The lung volume variability during reading is contrasted with high degrees of both inter- and intrasubject consistency in the location of inspirations, which occurred almost exclusively at grammatically appropriate places in the texts (paragraph, sentence, clause, and phrase boundaries). Within each reading passage, lung volumes were significantly increased for (a) louder utterances, (b) inspirations at sentence and paragraph boundaries compared to inspirations at other locations within sentences, (c) longer utterances compared to shorter utterances, and (d) initial breaths compared to final breaths. The implications of these findings for the neural control of breathing during speech are considered.

A dose-response relationship between amount of weight-bearing exercise and walking outcome following cerebrovascular accident

To supplement a motor relearning approach to rehabilitation for patients following cerebrovascular accident (CVA), a weight-bearing exercise was used that was designed specifically to strengthen the leg extensor muscles to simulate the output required in the single support phase of walking. For patients who were initially able to stand on their affected leg and step forward with their other leg, a dose-response relationship was found between an increasing number of repetitions of this weight-bearing exercise and improved walking outcome as measured on the Motor Assessment Scale (MAS) for stroke. For patients who could not stand and step forward at initial assessment (MAS-0), there was no relationship between the amount of practice done and walking outcome, however, all of the patients who practiced the exercise achieved independent walking for at least a 3m distance, which gave a final MAS score of three or greater.

Chronic nontraumatic diseases of the spinal cord

This article reviews common chronic diseases of the spinal cord such as spinal multiple sclerosis, cervical spondylosis, and motor system diseases, including amyotrophic lateral sclerosis. Secondary epidural and meningeal tumors and syringomyelia are also discussed.

Pregnancy and the risk of hemorrhage from cerebral arteriovenous malformations

We conducted a retrospective analysis of 451 women with an arteriovenous malformation (AVM) of the brain to determine whether pregnancy is a risk factor for cerebral hemorrhages. A total of 540 pregnancies occurred among our patient population, resulting in 438 live births and 102 abortions. There were 17 pregnancies complicated by a cerebral hemorrhage. The hemorrhage rate during pregnancy for women with an unruptured AVM was 0.035 +/- 0.005 per person-year. The hemorrhage rate for nonpregnant women of childbearing age with an unruptured AVM was 0.031 +/- 0.002 per person-year. Pregnancy did not increase significantly the rate of first cerebral hemorrhage from an AVM (P = 0.35). We found that women with an AVM face a 3.5% risk of hemorrhage during pregnancy. Pregnancy is not a risk factor for hemorrhage in women without a previous hemorrhage. This conclusion assumes no selection bias exists in our study population; a bias would be introduced if the risk of fatal outcome after a hemorrhage were greater in pregnant women than in nonpregnant women.