Feasibility of the physiological cost index as an outcome measure for the assessment of energy expenditure during walking

Objective: To determine if the Physiological Cost Index (PCI) can be recommended as an outcome measure in clinical trials. Design: Three assessments were performed, 2 with shoes, 1 without. The difference between walking with shoes and walking barefoot was used to study the ability of the PCI to detect a change in the criterion standard. Setting: A research department affiliated with a rehabilitation hospital in the Netherlands. Participants: Twelve children with cerebral palsy. Interventions: During the first and third assessments, the children walked with shoes. During the intermediate assessment, the children walked without shoes. Main Outcome Measures: Breath-by-breath oxygen uptake, heart rate (HR), and walking speed were measured at a self-selected comfortable speed. Oxygen cost (EO2) and the PCI were subsequently calculated offline. Feasibility judgments were made regarding the ability of the PCI to detect changes in a criterion standard and the statistical power of the outcome measure. Results: Pearson correlation coefficients were .66 and .62 for HRwalking-HRbaseline and HRwalking, respectively. The smallest detectable difference of the PCI and EO2 were 69% and 32%, respectively. A difference of at least 69% or 32% should be found before one can conclude a difference with a certainty of 95%. Conclusions: The reproducibility of the PCI and the ability to show small differences in EO2 were moderate. Subtracting HRbaseline when calculating the PCI is probably not useful because it only increased within-subject variability. With respect to statistical power of a new clinical trial, we recommend using EO2 instead of the PCI

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Fine-Wire Electromyography Response to Neuromuscular Electrical Stimulation in the Triceps Surae

Neuromuscular electrical stimulation (NMES) has previously been used to enhance venous return from the lower leg. By artificially activating lower leg muscles, venous blood may be effectively ejected from the muscle and adjacent veins. It could easily be assumed that combined NMES of the gastrocnemius and soleus would be the most effective single-channel application in this regard, as these muscles represent the largest muscular bulk in the lower leg. However, we have previously reported that soleus stimulation in isolation is substantially more effective. To understand why this is the case, we recorded fine-wire electromyography during NMES of the gastrocnemius and soleus muscles. We found that gastrocnemius and soleus stimulation are effective in eliciting selective stimulation of these muscles. However, combined stimulation of these muscles using a single set of electrodes was only capable in generating of the response in each muscle, insufficient to generate their theoretical maximum venous return

Fine-wire electromyography response to neuromuscular electrical stimulation in the triceps surae

Neuromuscular electrical stimulation (NMES) has previously been used to enhance venous return from the lower leg. By artificially activating lower leg muscles, venous blood may be effectively ejected from the muscle and adjacent veins. It could easily be assumed that combined NMES of the gastrocnemius and soleus would be the most effective single-channel application in this regard, as these muscles represent the largest muscular bulk in the lower leg. However, we have previously reported that soleus stimulation in isolation is substantially more effective. To understand why this is the case, we recorded fine-wire electromyography during NMES of the gastrocnemius and soleus muscles. We found that gastrocnemius and soleus stimulation are effective in eliciting selective stimulation of these muscles. However, combined stimulation of these muscles using a single set of electrodes was only capable in generating of the response in each muscle, insufficient to generate their theoretical maximum venous return

The effect of FES of the tibial nerve on physiological activation of leg muscles during gait

The effects of surface functional electrical stimulation (FES) of the tibial nerve of healthy subjects were evaluated. The FES was applied at three different times during gait: early, mid and late stances. The purpose of this work is to understand the effect of unilateral stimulation on the bilateral activation patterns of leg muscles, because FES is used in practice to improve gait, while associated neuromuscular change is not often measured. The experimental protocol presented here will be transferred to stroke subjects, who could benefit from improved push-off during gait. Results show that FES of the tibial nerve changes the offset timing of the tibialis anterior muscle on the stimulated side and the on- and offset timings of the tibialis anterior muscle of the leg contralateral to stimulation. Additionally, activity levels of the semitendinosus ipsilateral and tibialis anterior contralateral to the stimulated leg significantly decreased, with respect to the non-stimulated condition. For the semitendinosus, this was a difference of 6–7 μV, with p < 0.05. For the tibialis anterior, this was a difference of 7–15 μV, with a significance of p = 0.00, respectively.\ud \ud This information is important for future applications of stimulation as it means that stimulation not only affects the stimulated muscle but also the physiological motor control by the CNS.\ud \u

Effect of Electrical Stimulation of Hamstrings and L3/4 Dermatome on Gait in Spinal Cord Injury

Objective: To determine the effect of electrical stimulation of hamstrings and L3/4 dermatome on the swing phase of gait. - Materials and Methods: Five subjects with incomplete spinal cord injury (SCI) with spasticity were included. Two electrical stimulation methods were investigated, i.e., hamstrings and L3/4 dermatome stimulation. Both interventions were applied during the swing phase of gait. The main outcome measures were step length, maximum hip, and knee flexion during the swing phase of gait. In three subjects changes of spinal inhibition during gait were evaluated using the Hoffman reflex/m (motor)–wave (H/M) ratio at mid swing. -\ud Results: The hip flexion decreased 4.6° (p < 0.05) when the hamstrings were stimulated during the swing phase, whereas the knee flexion was not changed. The step length did not change significantly. One subject showed a decrease of the H/M ratio to a nonpathologic level during hamstrings stimulation. -Conclusion: It was concluded that hamstrings stimulation during the swing phase results in a reduction of the hip flexion in all five SCI subjects. The H/M ratio of the vastus lateralis was normalized using hamstrings stimulation in one of three subjects. Stimulation of the L3/4 dermatome provides no significant changes in gait performance, but in one subject the H/M ratio increased

Development of a New Method for Objective Assessment of Spasticity Using Full Range Passive Movements

Objective: To develop a method for assessment of spasticity, in which the whole range of motion (ROM) at a wide variation of speeds is applied. - Design: Cross-sectional design to study construct validity. - Setting: Research department affiliated with a rehabilitation hospital in the Netherlands. - Participants:\ud Nine patients with complete spinal cord injury recruited from the rehabilitation hospital. - Interventions: Not applicable. - Main Outcome Measures: Thirty to 45 stretches over the whole ROM were applied to the triceps surae muscle at varying velocities measuring from 30° to 150°/s. Electromyographic responses were measured in order to assess reflex excitability. The torque over the ankle joint was measured during the whole stretch. The angle and velocity at which the reflex was initiated was also determined. - Results: The electromyographic responses increased significantly at increasing stretch velocities (P<.001). The applied maximum angles are reproducible (intraclass correlation coefficient, .81) and provide representative torque responses. - Conclusions: The assessment method of spasticity using full range passive movements provides objective outcomes. The angular velocity is responsible for an exponential increase in amplitude of the electromyographic response

Recovery of Gait After Stroke: What Changes?

Background. Little is known about whether changes in coordination patterns of muscle activation after stroke are related to functional recovery of walking. Objective . The present study investigated the longitudinal relationship between changes in neuromuscular activation patterns of paretic muscles in hemiplegic gait and improvement in walking ability after stroke. Methods. Thirteen patients diagnosed with a first unilateral ischemic stroke had their recovery of walking measured by the Rivermead Mobility Index, Functional Ambulation Categories, Barthel Index, Trunk Control Test, Motricity Index, and comfortable walking speed. Surface electromyography (SEMG) of the erector spinae, gluteus maximus, gluteus medius, rectus femoris, vastus lateralis, semitendinosus, gastrocnemius, and tibialis anterior muscles of both legs was used to quantify coordination patterns in comfortable walking mode. All clinical and electromyography-related measurements were taken at 3, 6, 9, 12, and 24 weeks poststroke. Timing parameters of the SEMG patterns were calculated, using an objective burst detection algorithm, and analyzed with the measures of functional recovery. Results . All functional measures, except Trunk Control Test, showed statistically significant improvement over time, whereas SEMG patterns did not change significantly over time. Conclusion. The lack of significant change in SEMG patterns over time suggests that functional gait improvements may be more related to compensatory strategies in muscle activation of the unaffected leg and biomechanical changes than by restitution of muscle coordination patterns in the affected leg. \ud \u

The Orthotic Effect of Functional Electrical Stimulation on the Improvement of Walking in Stroke Patients with a Dropped Foot: A Systematic Review\ud

Objective  Analysis of the available evidence on the improvement of walking in stroke patients with a dropped foot when using peroneus stimulation.\ud \ud Methods  A systematic review was performed to identify trials that investigated the orthotic effect of functional electrical stimulation (FES) on walking in stroke patients with a dropped foot. Two independent raters scored the methodological quality of the included articles. Walking speed and physiological cost index (PCI) were selected as the primary outcome measures. Studies that measured walking speed were pooled and a pooled difference including confidence interval was calculated.\ud \ud Results  Eight studies were included in the review, of which one was a randomized controlled trial. Methodological score ranged from 8 to 18 out of 19. Six studies measured walking speed. The pooled improvement in walking speed was 0.13 m/s (0.07–0.2) or 38% (22.18–53.8).\ud \ud Conclusions  The present review suggests a positive orthotic effect of functional electrical stimulation on walking speed\u