Efficacy of neuromuscular exercises to promote movement quality and reduce musculoskeletal injury during initial military training in Royal Navy recruits.

INTRODUCTION: Musculoskeletal injuries (MSKIs) are a significant problem in the Royal Navy, contributing to 48% of all medical discharges from service between 2019 and 2020. The objective of the study was to assess efficacy of implementing a neuromuscular training intervention to improve movement quality and reduce MSKIs in Royal Navy recruits undertaking initial military training. METHODS: Neuromuscular training (pre-activation exercises, focusing on hip control) was integrated into the warm-up exercise regimen preceding physical training during the 10-week initial naval training (recruits) programme (January-March 2020) at HMS Raleigh (intervention group; n=162). A control group comprised (n=90) of recruits entering training from January 2019, who completed the standard warm-up programme prior to physical training. Movement control of the intervention group (intervention) was assessed before and after the 10-week programme using the Hip and Lower-Limb Movement Screen (HLLMS). Injury incidence proportion for both groups was determined retrospectively by review of medical notes. RESULTS: The control group's MSKI incidence proportion was 31%, which was higher (p<0.05) than the 8% reported in the intervention group. The majority of MSKIs were of the lower limb, and were reported in weeks 1, 2 and 5 of the 10-week training programme. Movement control, as assessed by the HLLMS score, improved (pretraining (week 1) and post-training (week 10) HLLMS score (mean (SD) pre: 11.2 (5.6); post: 8.4 (3.9); t=5.829, p<0.001) following the neuromuscular training in the intervention group but was not assessed in the control group. CONCLUSION: A neuromuscular control intervention was successfully implemented during the initial military training in the Royal Navy. The cohort undertaking the intervention demonstrated lower injury incidence compared with an equivalent cohort of recruits who undertook standard training. Movement control improved following the intervention, indicating better movement quality. Continued use of the programme may reduce military training attrition in the Royal Navy.

Baseline renal function and renal ultrasound findings in patients with obstetric fistulas (RENFRU): a prospective cohort study.

OBJECTIVE: To describe and compare baseline renal anatomy and renal function in patients with obstetric fistulas, and to evaluate whether preoperative renal testing and imaging may aid with operative decision making. DESIGN: A prospective cohort study. SETTING: Fistula Care Centre in Malawi. POPULATION: Women with an obstetric fistula. METHODS: Baseline creatinine testing and renal ultrasounds were performed. Surgeons completed a short questionnaire on the usefulness of creatinine and renal ultrasound on operative decision making. MAIN OUTCOME MEASURES: Baseline creatinine and renal ultrasound findings. RESULTS: Four surgeons performed operations on 85 patients. The mean creatinine in patients with vesicovaginal fistulas (VVF) was 0.60 ng/ml versus patients with uretero-vaginal fistulas (UVF) (0.79 ng/ml, P = 0.012). When a grade 3 or more hydronephrosis is absent on renal ultrasound, the negative predictive value of the presence of UVF is 93.3% (95% confidence interval [CI] 88.6-96.2) with a specificity of 97.2% (95% CI 90.3-99.6). In cases of UVF, surgeons found the renal ultrasound results useful or very useful 87.5% of the time, and the creatinine useful or very useful 75% of the time. CONCLUSION: In this pilot study, most patients with obstetric fistulas presented with a normal creatinine. In the absence of a grade 3 hydronephrosis or above on renal ultrasound, the probability of not having a UVF is 93.3%. Surgeons should consider performing preoperative renal ultrasound testing in all patients with an obstetric fistula, particularly in women with a prior laparotomy, as this population has risk factors for ureterovaginal fistula. TWEETABLE ABSTRACT: Most patients with obstetric fistulas have normal renal function. Preoperative renal ultrasounds should be performed.

Measuring scapular kinematics during arm lowering using the acromion marker cluster.

The aim of the present study was to examine the acromion marker cluster (AMC) method of measuring scapular kinematics during the arm lowering, eccentric, phase. Twenty six participants completed arm elevation and lowering in the sagittal, frontal and scapular plane. The participants held their arm at 30° increments while the orientation of the scapula was recorded using an AMC and a scapular locator (SL). There were no significant differences between the AMC and SL during the lowering phase for sagittal and scapular plane arm movements. The AMC significantly underestimated upward rotation (max RMSE = 6.0°), and significantly overestimated posterior tilt (max RMSE = 7.2°) during arm lowering in the frontal plane. The reported root mean square errors, however, were within the ranges observed during the elevation phase and reported in previous literature. The AMC therefore provides a reasonable description of scapular kinematics during the arm lowering phase.

Comparison of curvilinear and linear ultrasound imaging probes for measuring cross-sectional area and linear dimensions.

The aim of the study was to determine whether different ultrasound probe/transducer configurations produce the same measurements. Two investigators undertook 10 scans of a general purpose semi-solid multi-tissue ultrasound phantom (phantom A) using two ultrasound scanners with a linear and curvilinear probe. From those 10 scans, two measurements of cross-sectional area (CSA), width and thickness were made. These measurements were then repeated with an open-top fluid-filled phantom, with 10% ethanol solution (phantom B). Intra- and inter-rater reliability were examined using Bland and Altman plots. Agreement between measurements made with the two probe types was also assessed using Bland and Altman plots. An independent samples t-test was used to compare statistical differences between probe type configuration. There was a significant difference (p < 0.05) and a tendency for increased measurements in CSA and width, and decreased measurements in thickness when using a curvilinear probe on phantom A, and these differences were not scanner specific. When imaging phantom B there were no significant differences in measurements between probe configurations; however there was a small bias for smaller CSA measurements with a curvilinear probe. In conclusion there are small differences in measurements obtained from different ultrasound probe configurations using a semi-solid phantom, but their clinical significance is unknown.

Thermoluminescence of MgSO4 doped with Eu and P impurities.

CaSO4:Eu, MgSO4:Eu and MgSO4:Eu,P phosphors have been prepared and their thermoluminescence (TL) characteristics were studied. A main glow peak due to Eu2+ ions is seen at approximately 146 degrees C and 440 nm and glow peaks at approximately 145 degrees C, approximately 190 degrees C, approximately 260 degrees C and approximately 360 degrees C for 590 nm and 625 nm wavelengths are identified as Eu3+ ion emissions in MgSO4:Eu. Emission spectra in MgSO4:Eu and the MgSO4:Eu,P show that the MgSO4:Eu3+ glow peak at 260 degrees C for 590 nm and 625 nm shifts to 280 degrees C with enhanced intensity while the Eu2+ ion glow peak at 146 degrees C remains but with reduced intensity. The main glow peak at approximately 146 degrees C and 440 nm from Eu2+ ions shows significant difference from the characteristic glow peaks of Eu3+ ions. It is observed that the wavelength of the Eu2+ ion glow peak is inversely proportional to the radius of the cation of the host sulphate in alkaline-earth sulphate phosphors. By contrast the wavelengths of the Eu3+ ion glow peaks remain unchanged in different sulphates. Besides, the glow curve at approximately 146 degrees C obtained using a conventional blue sensitive reader shows simply the first order kinetics. It is concluded that the luminescence centres and distribution of traps related to Eu2+ ions are different from that of Eu3+ ions in MgSO4:Eu and MgSO4:Eu,P phosphors.

Determination of multi-element profiles of soil using energy dispersive X-ray fluorescence (EDXRF).

The source profile for soil in Hong Kong is important both for determination of the main air pollutant source in Hong Kong and for assessment of the impact of Asian dust storms on Hong Kong. Soil associated with different rock types have been sampled, and the concentrations of 19 chemical elements, Na, Al, Si, Ti, V, Cr, Mn, Fe, Co, K, Ca, Ni, Cu, Zn, Pb, Rb, Sr, Y and Zr, have been determined using energy dispersive X-ray fluorescence. A profile for the average soil for Hong Kong has been determined by taking average values for the different soil categories. The values for the Hong Kong soil are commensurate with values for rural soil derived by other workers, except that Hong Kong soil has much lower Fe and Ca concentrations. The abundance of Al, Ca and Fe in the average Hong Kong soil are 9.23%, 0.11% and 0.85%. We conclude that Ca provides a good marker element for identifying dust episodes in Hong Kong while Al does not.

Spherical growth and surface-quasifree vibrations of Si nanocrystallites in Er-doped Si nanostructures.

Si-based Er-doped Si nanostructures were fabricated for exploring efficient light emission from Er ions and Si nanocrystallites. High-resolution transmission electron microscopy observations reveal that Si nanocrystallites are spherically embedded in the SiO2 matrix. Energy-dispersive x-ray analysis indicates that the Er centers are distributed at the surfaces of nanocrystallites surrounded by the SiO2 matrix. Low-frequency Raman scattering investigation shows that Lamb's theory can be adopted to exactly calculate the surface vibration frequencies from acoustic phonons confined in spherical Si nanocrystallites and the matrix effects are negligible.

Study on examinee's dose delivered in computed tomography.

Dose profiles are presented resulting from computed tomography (CT). The profiles are positioned at the central axis, 1 cm away from the outer surface of the phantom, for single and multiple scans. A Hitachi W-1000 scanner is used with a thermoluminescent dosimeter (TLD), and standard dosimetry head and trunk phantoms. Regression equations are found linking the dose resulting from scattered radiation associated with a single scan to the distance from the scanning centre. The impact on the CT dose index value (CTDI) for varying integrating lengths is analysed. Some problems associated with CT dose measurement are noted, which may assist in the practical application of IBSS (International Basic Standard of Radiation Protection and Safety of Radiation Sources) guide levels.

Blood irradiation with accelerator produced electron beams.

Blood and blood products are irradiated with gamma rays to reduce the risk of graft versus host disease (GVHD). A simple technique using electron beams produced by a medical linear accelerator has been studied to evaluate irradiation of blood and blood products. Variations in applied doses for a single field 20 MeV electron beam are measured in a phantom study. Doses have been verified with ionization chambers and commercial diode detectors. Results show that the blood product volume can be given a relatively homogeneous dose to within 6% using 20 MeV electrons without the need to rotate the blood bags or the beam entry point. The irradiation process takes approximately 6.5 minutes for 30 Gy applied dose to complete as opposed to 12 minutes for a dual field x-ray field irradiation at our centre. Electron beams can be used to satisfactorily irradiate blood and blood products in a minimal amount of time.

Reliability of tremor measurements using a multidimensional electromagnetic sensor system.

OBJECTIVE: To investigate the reliability of repeated measurements of normal physiological tremor made with a multidimensional measurement system. EQUIPMENT: Measurements of postural upper limb tremor at the hand were made in 10 normal subjects using a 3Space Fastrak (Polhemus, Inc.) which detects movement over six degrees-of-freedom (three of the measurement directions were examined). DATA COLLECTION: Reliability was assessed for two alternative upper limb postures (arm straight or bent) and data were collected on two days, twice at each session, to determine the repeatability between and within recording sessions. DATA ANALYSIS: The data were split into segments and subjected to autoregressive (AR) modelling. Three parameters (one for each of the measurement directions examined) were extracted from the models and used as variables for the reliability analysis. STATISTICAL TESTS: Variation within and between sessions was assessed by finding the median differences between efforts and days for each subject and then finding the overall median value and the corresponding 97.9% confidence intervals for each movement. This produced estimates of the population median value and indicated the precision of the estimates. RESULTS: All the confidence intervals encompassed the zero median difference point indicating that, in the population, this technique would produce repeatable results. For between-efforts comparisons there was some evidence that data collected for the bent arm posture were more repeatable than for a straight arm. CONCLUSION: Normal physiological tremor can be measured reliably, within and between sessions, using the 3Space Fastrak system.

EEG-based communication: a pattern recognition approach.

We present an overview of our research into brain-computer interfacing (BCI). This comprises an offline study of the effect of motor imagery on EEG and an online study that uses pattern classifiers incorporating parameter uncertainty and temporal information to discriminate between different cognitive tasks in real-time.

Coronary artery flow velocity is related to lumen area and regional left ventricular mass.

BACKGROUND: Coronary flow velocity varies widely between individuals, even at rest. Because of this variation, indices with less apparent deviation, such as the ratio of hyperemic to resting velocity (coronary flow reserve), have been more commonly studied. We tested the hypothesis that the flow continuity principle could be used to model resting coronary flow, and we examined the resulting velocity relationship. METHODS AND RESULTS: We studied coronary velocity in 59 patients using a Doppler wire to measure resting and hyperemic average peak velocities in the left anterior descending artery. Quantitative techniques were used to calculate lumen cross-sectional area and the lengths of all distal coronary branches. Branch lengths were used to estimate regional left ventricular mass. We then calculated the ratio of lumen area to regional mass (A/m). Regional perfusion was estimated from the double product of heart rate and systolic blood pressure. Resting velocity (V) varied inversely with A/m ratio [V=46.5/(A/m); r=0.68, P<0.001]. Disease in the left anterior descending artery was categorized as none or luminal irregularities only (n=22), mild (n=15), or moderate (n=22). The A/m ratio declined across these groups (8.7+/-4.0, 8.5+/-6.2, and 5. 6+/-3.0 mm(2)/100 g, respectively; P<0.04), and the resting average peak velocity increased (27+/-16, 33+/-11, and 37+/-20 cm/s, respectively; P=0.06). CONCLUSIONS: Resting coronary artery flow velocity is inversely related to the ratio of lumen area to regional left ventricular mass. Higher resting velocities are found when insufficient lumen size exists for the distal myocardial bed, as occurs with diffuse mild or moderate coronary atherosclerosis.

Corticospinal function in severe brain injury assessed using magnetic stimulation of the motor cortex in man.

We have assessed corticospinal function in 19 post-coma patients severely brain-injured by anoxia or physical trauma. Eleven patients were unresponsive (Category 1) and eight demonstrated minimal, non-verbal responses to simple commands (Category 2). Motor evoked potentials (MEPs) could be elicited in hand and leg muscles in nine Category 1 and all eight Category 2 patients in response to transcranial magnetic stimulation (TMS). In comparison with normal subjects, threshold to TMS was significantly elevated in Category 1 but not in Category 2. Central conduction times were within the normal range except for two patients (one in each category) in whom they were prolonged. The variability in MEP amplitude to constant TMS was not significantly different from normal in either category. The size of MEPs recorded simultaneously in different hand muscles were correlated in all three groups. The presence of H-reflexes in hand muscles was associated with an absence of MEPs or a high threshold to TMS. Variability of MEPs was substantially greater than that of H-reflexes. We conclude that brain injury of a severity that may preclude consciousness and voluntary movement does not invariably predicate a non-functional motor cortex and corticospinal system.

Classification of normal and pathological tremors using a multidimensional electromagnetic system.

A new multidimensional movement analysis system was used to record limb tremor over six degrees-of-freedom, and signal processing techniques were explored to develop a suitable classification method to distinguish between different types of tremor. The specific aims were to investigate the ability of the system to screen for differences between normal subjects and a group of neurological patients, and then to differentiate between three diagnostic groups of patients. Postural tremor at the hand was recorded in normal subjects (n=24) and patients with essential tremor (n=21), multiple sclerosis (n=17) and parkinsonism (n=19). Data were collected using a 3Space Fastrak((R)) (Polhemus, Inc.) over six degrees-of-freedom (three translational directions and three rotations). Spectral estimates produced measures of tremor frequency and amplitude. Mathematical models of the data, using autoregressive modelling and K-nearest neighbour classification, produced parameters used to classify, (1) the normal subjects and 24 patients (using the three rotational movements), and (2) the three patient groups (using all six movement directions). Results were given in terms of the probability of each subject belonging to the groups being classified. 70%). The diagnostic classification produced clear differences between the patient groups (60% for essential tremor, 80% for multiple sclerosis and 60% for parkinsonism). The ability of this assessment technique to distinguish between postural tremor in normal subjects and neurological patients suggests that it could be developed as a screening tool. Classification of tremors between the patients groups, with a high degree of sensitivity, indicates the potential for further development of the system as a diagnostic aid.

Test rig and software for recording force and muscle activity.

OBJECTIVE: To design a test rig for measuring isometric quadriceps' force which is easily adjustable, dismountable, transportable, relatively lightweight and inexpensive. Also to produce a data-acquisition software program that enables real-time feedback of the force signal, automatic analysis of maximal voluntary contraction (MVC) force, and submaximal target levels to be displayed on a computer screen, as well as acquisition of other signals such as electromyographic (EMG) activity. METHODOLOGY: A test rig was constructed using an aluminium tubing system which was fully adjustable and could be flat-packed for transportation. The data acquisition software program was written in Borland C++ and is suitable for use with an IBM-compatible PC. The interface is user friendly, and the entire testing system is relatively inexpensive compared to commercially available systems. CONCLUSIONS: The equipment is suitable for various applications in rehabilitation research and clinical testing, and is suitable for examining different muscles. Further technical details are freely available from the authors.

Active measurements of indoor concentrations of radon and thoron gas using charcoal canisters.

Standardized charcoal canisters with diameters of 4 inch, of a type recommended by the USEPA for passive measurement of radon gas concentrations, have been modified for active air sampling. Simultaneous measurement of the concentrations of radon (Rn) and thoron (Tn) in air can be obtained by counting the areas under gamma-ray peaks. Sample results obtained in a laboratory and in a residence with different conditions are also given. The largest uncertainties are about 2% and 3% for Rn and Tn respectively. The minimum detection limits are around 2.0 Bq/m3 for both gases. If only Rn concentration is required, the measurement time can be significantly shortened.

Measurement of tracheobronchial dose from simultaneous exposure to environmental radon and thoron progeny.

According to the theory and idea of Hopke et al., a bronchial dosimeter consisting of multiple metal screens has been developed to measure the deposition fractions of radon and thoron progeny in the nasal (N) and tracheobronchial (T-B) regions of the human respiratory tract and to give the dose conversion factors in the T-B region in units of mGy WLM(-1) and mSv y(-1) per Bq m(-3). Different air treatments have been performed in a closed laboratory, which include the use of air conditioning and the application of positive and negative ions for the investigation of the change of the dose conversion factors. At the same time, the radon and thoron gas concentrations have also been measured in the laboratory by active sampling using newly designed activated charcoal canisters connected in series with the bronchial dosimeter for the calculation of the resulted annual effective dose under different air treatments. It is observed that the calculated dose conversion factors derived from the bronchial dosimeter have large discrepancies with those computed using existing lung models. It has also been found that the application of negative ions cannot reduce the annual effective dose in the T-B region; the application of positive ions can lead to a reduction, but not as much as the use of air conditioning. The mitigation of radon effects by air conditioning demonstrated using the bronchial dosimeter is more prominent than that shown by using lung models.

Radon properties in offices.

The radon concentration (RC), total potential alpha energy concentration of radon decay products (PAEC), equilibrium factor (F), and the fraction of unattached radon decay products (fp) were measured for 94 offices in Hong Kong. The mean values for RC, PAEC, F, and fp were 51 Bq m(-3), 1.19x10(-7) J m(-3) (5.7 mWL), 0.43, and 0.13, respectively. The first three are much higher than the corresponding values for dwellings. The radon properties vary significantly for different sites. The time for measurements, cumulative time since the air conditioning system was turned on, and whether smoking is allowed in the office have been identified from the available data as possible factors affecting the radon characteristics in offices. The mean contribution of the lung exposure to the annual effective dose equivalent due to radon in offices has been calculated to be 0.35 mSv y(-1). Considering other sources of natural radiation, a rough estimate of the total annual equivalent dose of about 2.7 mSv for a person living in Hong Kong is obtained. Two simple methods are proposed to mitigate the radon hazard in offices: (1) the provision of smoke-free environments and (2) switching on the air conditioners earlier. The first method reduces the equivalent dose by about 0.13 mSv y(-1) while the second reduces by about 0.1 mSv y(-1), which can be regarded as significant.