Peak torque, rate of torque development and average torque of isometric ankle and elbow contractions show excellent test-retest reliability

Background

Peak Torque (PT), Rate of Torque Development (RTD) and Average Torque (AT) over a single contraction assess the three components of muscle function during isometric contractions. Surprisingly, AT has never been reported or its reliability confirmed.

Objectives

This study aims to establish protocol reliability for ankle dorsiflexion and elbow extension isometric muscle function (PT, RTD, AT) in healthy participants using the Biodex System 3 Dynamometer.

Methods

Twelve participants (6 male, 6 female, mean age 39 . 8 ± 16 . 0 years) performed four maximal isometric contractions on two occasions. Intraclass Correlation Coefficient (ICC), Typical Error (TE) and Coefficient of Variation (CV) for PT, RTD and AT were reported.

Results

The ICC for all strength parameters varied from 0.98-0.92. TE for ankle dorsiflexion PT was 1.38 Nm, RTD 7.43 Nm/s and AT 1.33 Nm, CV varied from 6 . 26 ± 6 . 25 % to 11 . 72 ± 8 . 27 % . For elbow extension, TE was 3.36 Nm for PT, 14.87 Nm/s for RTD and 3.03 Nm for AT, CV varied from 5 . 97 ± 4 . 52 % to 18 . 46 ± 14 . 78 % .

Conclusion

Maximal isometric ankle dorsiflexion and elbow extension PT, RTD and AT can be evaluated with excellent reliability when following the described protocol. This testing procedure, including the application of AT, can be confidently applied in research, exercise or clinical settings.

Mapping the contact area of the patellofemoral joint: the relationship between stability and joint congruence

AIMS

The aim of this study was to determine and compare the congruency of the articular surface contact area of the patellofemoral joint (PFJ) during both active and passive movement of the knee with the use of an MRI mapping technique in both the stable and unstable PFJ.

PATIENTS AND METHODS

A prospective case-control MRI imaging study of patients with a history of PFJ instability and a control group of volunteers without knee symptoms was performed. The PFJs were imaged with the use of an MRI scan during both passive and active movement from 0° through to 40° of flexion. The congruency through measurement of the contact surface area was mapped in 5-mm intervals on axial slices. In all, 40 patients were studied. The case group included 31 patients with symptomatic patellofemoral instability and the control group of nine asymptomatic volunteers. The ages were well matched between the case and control groups. The mean age was 25 years (16 to 42; sd 6.9) in the case group and 26 years (19 to 32; sd 5.1) in the control group. There were 19 female and 12 male patients in the case group.

RESULTS

The unstable PFJs were demonstrably less congruent than the stable PFJs throughout the range of knee movement. The greatest mean differences in congruency between unstable and stable PFJ's were observed between 11° and 20° flexion (1.73 cm² vs 4.00 cm²; p < 0.005).

CONCLUSION

The unstable PFJ is less congruent than the stable PFJ throughout the range of knee movement studied. This approach to mapping PFJ congruency produces a measurable outcome and will allow the assessment of pre- and postoperative results following surgical intervention. This may facilitate the design of new procedures for patients with PFJ instability. If a single axial series is to be obtained on MRI scan, the authors recommend 11° to 20° of tibiofemoral flexion, as this was shown to have the greatest difference in contact surface area between the case and control groups. Cite this article: Bone Joint J 2019;101-B:552-558.

Mirror therapy and treadmill training for patients with chronic stroke: a pilot randomized controlled trial

BACKGROUND

Previous lower-limb mirror therapy research has focused on non-weight bearing interventions.

OBJECTIVES

The primary aim of this study was to investigate the effect and feasibility of a combination of mirror therapy and treadmill training on post-stroke lower-limb recovery compared to a placebo intervention.

METHODS

All patients (N = 30) walked on a treadmill for 30 min per day, 3 days per week, for 4 weeks. The mirror therapy and treadmill training group (n = 15) walked on the treadmill while viewing a reflection of their non-paretic limb in a mirror positioned in their mid-sagittal plane. The placebo group (n = 15) received no mirror visual feedback due to an altered mirror position.

PRIMARY OUTCOME MEASURES

Ten Metre Walk Test (10MWT) and Six Minute Walk Test (6MWT).

SECONDARY OUTCOME MEASURES

Modified Ashworth Scale (MAS) and Fugl-Meyer Assessment-Lower Extremity (FMA-LE). Feasibility was appraised by examining participant compliance and any adverse events.

RESULTS

No significant between group differences were demonstrated for the 10MWT, 6MWT or FMA-LE at post-training or 3-month follow-up assessment. A significant between group difference on the MAS was demonstrated in the reduction of ankle dorsiflexion muscle tone (p = 0.006) and ankle plantarflexion muscle tone (p = 0.01) in the mirror therapy group compared to the placebo group at post-training assessment but not at 3-month follow-up.

CONCLUSION

Our study reveals that in our group of patients with chronic stroke, mirror therapy combined with treadmill training facilitated significant reductions in ankle muscle tone (p < 0.05) compared to a placebo intervention.

Data Integration for the Assessment of Population Exposure to Ambient Air Pollution for Global Burden of Disease Assessment

Air pollution is a leading global disease risk factor. Tracking progress (e.g., for Sustainable Development Goals) requires accurate, spatially resolved, routinely updated exposure estimates. A Bayesian hierarchical model was developed to estimate annual average fine particle (PM_2.5) concentrations at 0.1° × 0.1° spatial resolution globally for 2010-2016. The model incorporated spatially varying relationships between 6003 ground measurements from 117 countries, satellite-based estimates, and other predictors. Model coefficients indicated larger contributions from satellite-based estimates in countries with low monitor density. Within and out-of-sample cross-validation indicated improved predictions of ground measurements compared to previous (Global Burden of Disease 2013) estimates (increased within-sample R² from 0.64 to 0.91, reduced out-of-sample, global population-weighted root mean squared error from 23 μg/m³ to 12 μg/m³). In 2016, 95% of the world's population lived in areas where ambient PM_2.5 levels exceeded the World Health Organization 10 μg/m³ (annual average) guideline; 58% resided in areas above the 35 μg/m³ Interim Target-1. Global population-weighted PM_2.5 concentrations were 18% higher in 2016 (51.1 μg/m³) than in 2010 (43.2 μg/m³), reflecting in particular increases in populous South Asian countries and from Saharan dust transported to West Africa. Concentrations in China were high (2016 population-weighted mean: 56.4 μg/m³) but stable during this period.

Mirror therapy for improving lower limb motor function and mobility after stroke: A systematic review and meta-analysis

BACKGROUND

Mirror therapy has been proposed as an effective intervention for lower limb rehabilitation post stroke.

RESEARCH QUESTION

This systematic review with meta-analysis examined if lower limb mirror therapy improved the primary outcome measures of muscle tone and motor function and the secondary outcome measures balance characteristics, functional ambulation, walking velocity, passive range of motion (PROM) for ankle dorsiflexion and gait characteristics in patients with stroke compared to other interventions.

METHODS

Standardised mean differences (SMD) and mean differences (MD) were used to assess the effect of mirror therapy on lower limb functioning.

RESULTS

Nine studies were included in the review. Among the primary outcome measures there was evidence of a significant effect of mirror therapy on motor function compared with sham and non-sham interventions (SMD 0.54; 95% CI 0.24-0.93). Furthermore, among the secondary outcome measures there was evidence of a significant effect of mirror therapy for balance capacity (SMD -0.55; 95% CI -1.01 to -0.10), walking velocity (SMD 0.71; 95% CI 0.35-1.07), PROM for ankle dorsiflexion (SMD 1.20; 95% CI 0.71-1.69) and step length (SMD 0.56; 95% CI -0.00 to 1.12).

SIGNIFICANCE

The results indicate that using mirror therapy for the treatment of certain lower limb deficits in patients with stroke may have a positive effect. Although results are somewhat positive, overly favourable interpretation is cautioned due to methodological issues concerning included studies.

An intuitive Bayesian spatial model for disease mapping that accounts for scaling

In recent years, disease mapping studies have become a routine application within geographical epidemiology and are typically analysed within a Bayesian hierarchical model formulation. A variety of model formulations for the latent level have been proposed but all come with inherent issues. In the classical BYM (Besag, York and Mollié) model, the spatially structured component cannot be seen independently from the unstructured component. This makes prior definitions for the hyperparameters of the two random effects challenging. There are alternative model formulations that address this confounding; however, the issue on how to choose interpretable hyperpriors is still unsolved. Here, we discuss a recently proposed parameterisation of the BYM model that leads to improved parameter control as the hyperparameters can be seen independently from each other. Furthermore, the need for a scaled spatial component is addressed, which facilitates assignment of interpretable hyperpriors and make these transferable between spatial applications with different graph structures. The hyperparameters themselves are used to define flexible extensions of simple base models. Consequently, penalised complexity priors for these parameters can be derived based on the information-theoretic distance from the flexible model to the base model, giving priors with clear interpretation. We provide implementation details for the new model formulation which preserve sparsity properties, and we investigate systematically the model performance and compare it to existing parameterisations. Through a simulation study, we show that the new model performs well, both showing good learning abilities and good shrinkage behaviour. In terms of model choice criteria, the proposed model performs at least equally well as existing parameterisations, but only the new formulation offers parameters that are interpretable and hyperpriors that have a clear meaning.

Mirror therapy and treadmill training for a patient with chronic stroke: A case report

INTRODUCTION

A large proportion of patients with chronic stroke have permanent lower limb functional disability leading to reduced levels of independent mobility. Individually, both mirror therapy and treadmill training have been shown to improve aspects of lower limb functioning in patients with stroke. This case report examined whether a new combination of both interventions would lead to improvements in lower limb functional disability for a patient with chronic stroke.

CASE DESCRIPTION

The participant was a 50-year-old female who had a left middle cerebral artery infarction (47 months' post stroke). Due to hemiparesis, she had lower limb motor impairment and gait deficits.

INTERVENTION

The participant engaged in a combination of mirror therapy and treadmill training for 30 minutes per day, 3 days per week, for 4 weeks.

OUTCOMES

Modified Ashworth Scale, Fugl-Meyer Assessment-Lower Extremity and the 10 m Walk Test demonstrated clinically meaningful change. The 6 Minute Walk Test did not demonstrate meaningful change.

DISCUSSION

The positive outcomes from this new combination therapy for this participant are encouraging given the relatively small dose of training and indicate the potential benefit of mirror therapy as an adjunct to treadmill training for enhancing lower limb muscle tone, motor function and walking velocity in patients with chronic stroke.

Pancarpal Arthrodesis in a Cat: A Case Report and Anatomical Study

A carpometacarpal hyperextension injury in a cat was treated by pancarpal arthrodesis, following the failure of conservative treatment. An 8-hole 1.5 mm mini plate was placed on the dorsal aspect of the distal radius, carpus and third metacarpal bone. An aluminium spoon splint was used for six weeks postoperatively, until radio-graphs revealed bone union. The body weights and the dimensions of the distal radius, radiocarpal bone and third metacarpal bone from the left limb of 15 cadavers were recorded in order to aid the selection of appropriate implants for future cases.

Pancarpal arthrodesis was used to treat a cat with a carpometacarpal hyperextension injury. The use of an 8-hole 1.5 mm mini plate applied to the dorsal surface of the carpus, in combination with limb splinting provided effective stabilization. An excellent functional result was obtained. Measurements of the radius, radial carpal and third metacarpal bones from 15 cadavers suggest that 1.5 mm bone screws are the largest that should be used for carpal arthrodesis in the average sized cat.

Automatic patient positioning and gating window settings in respiratory-gated stereotactic body radiation therapy for pancreatic cancer using fluoroscopic imaging

Before treatment delivery of respiratory-gated radiation therapy (RT) in patients with implanted fiducials, both the patient position and the gating window thresholds must be set. In linac-based RT, this is currently done manually and setup accuracy will therefore be dependent on the skill of the user. In this study, we present an automatic method for finding the patient position and the gating window thresholds. Our method uses sequentially acquired anterior-posterior (AP) and lateral fluoroscopic imaging with simultaneous breathing amplitude monitoring and intends to reach 100% gating accuracy while keeping the duty cycle as high as possible. We retrospectively compared clinically used setups to the automatic setups by our method in five pancreatic cancer patients treated with hypofractionated RT. In 15 investigated fractions, the average (±standard deviation) differences between the clinical and automatic setups were -0.4 ± 0.8 mm, -1.0 ± 1.1 mm, and 1.8 ± 1.3 mm in the left-right (LR), the AP, and the superior-inferior (SI) direction, respectively. For the clinical setups, typical interfractional setup variations were 1-2 mm in the LR and AP directions, and 2-3 mm in the SI direction. Using the automatic method, the duty cycle could be improved in six fractions, in four fractions the duty cycle had to be lowered to improve gating accuracy, and in five fractions both duty cycle and gating accuracy could be improved. Our automatic method has the potential to increase accuracy and decrease user dependence of setup for patients with implanted fiducials treated with respiratory-gated RT. After fluoroscopic image acquisition, the calculated patient shifts and gating window thresholds are calculated in 1-2 s. The method gives the user the possibility to evaluate the effect of different patient positions and gating window thresholds on gating accuracy and duty cycle. If deemed necessary, it can be used at any time during treatment delivery.