Postural behaviour in people with multiple sclerosis: A complexity paradox.

BACKGROUND: Balance deficits are a major concern for people with multiple sclerosis (pwMS). Measuring complexity of motor behaviour can offer an insight into MS-related changes in adaptability of the balance control system when dealing with increasingly complex tasks. QUESTION: Does postural behaviour complexity differ between pwMS at early stages of the disease and healthy controls (HC)? Does postural behaviour complexity change across increasingly complex tasks? METHODS: Forty-eight pwMS and 24 HC performed four increasingly complex postural tasks with eyes open (EO), eyes closed (EC), on firm (FS) and compliant surface (CS). Lumbar and sternum sensors recorded 3D acceleration, from which complexity index (CI) was calculated using multiscale sample entropy (MSE) in the frontal and sagittal planes. RESULTS: We found that only the complexity index in both planes during the eyes closed on compliant surface (EC-CS) task was significantly lower in pwMS compared to HC. We also found that complexity in pwMS was significantly lower during EC-CS compared to the other three tasks when using both lumbar and sternum sensors. SIGNIFICANCE: Increasing the complexity of postural tasks reduces the complexity of postural behaviour in pwMS. This paradox may reflect reduced adaptability of the sensorimotor integration processes at early stages of MS. CI can provide a different perspective on balance deficits and could potentially be a more sensitive biomarker of MS progression and an early indicator of balance deficit.

Rehabilitation in adults with burn injury: an overview of systematic reviews.

PURPOSE: To systematically evaluate evidence from published systematic reviews for the effectiveness of rehabilitation interventions in adults with burn injury. MATERIALS AND METHODS: A comprehensive literature review conducted using medical and health science electronic databases up to 31 July 2022. Two independent reviewers selected studies, extracted data, and assessed methodological study quality using A Measurement Tool to Assess Systematic Reviews (AMSTAR-2), and the certainty of evidence for reported outcomes using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool. RESULTS: Twenty-one systematic reviews evaluated five categories of interventions: physical, psychological, technology-aided modalities, educational and occupational programs, complementary and alternative medicine. Outcomes included fitness level, hand function, oedema, pain, pruritus, psychological state, quality of life, range of motion, return to work, strength, scar characteristics, level of impairment and burn knowledge. The methodological quality was rated as "critically low" for all reviews. Quality of evidence for the effectiveness of evaluated interventions ranged from "moderate to very low." CONCLUSIONS: Beneficial effects of inhaled aromatherapy and extracorporeal shockwave therapy on pain reduction; inhaled or massage aromatherapy, music therapy on anxiety were reported. Safety of interventions was not evaluated, due to the lack of adverse event reporting in primary studies and the included reviews.

Burn injury is a leading cause of severe morbidity, and long-term disability, with significant health and economic burden.There is emerging evidence to support the use of complementary and alternative medicine interventions (such as aromatherapy and music therapy) for alleviating anxiety.Extracorporeal shockwave therapy with comprehensive rehabilitation therapy has positive effects on pain reduction.These interventions may be considered as adjunctive tools to enhance burn rehabilitation care and improve patient outcomes. However, further robust studies are required to strengthen the evidence, explore adverse effects and associated cost efficiency.

Sample Entropy Improves Assessment of Postural Control in Early-Stage Multiple Sclerosis.

Postural impairment in people with multiple sclerosis (pwMS) is an early indicator of disease progression. Common measures of disease assessment are not sensitive to early-stage MS. Sample entropy (SE) may better identify early impairments. We compared the sensitivity and specificity of SE with linear measurements, differentiating pwMS (EDSS 0-4) from healthy controls (HC). 58 pwMS (EDSS ≤ 4) and 23 HC performed quiet standing tasks, combining a hard or foam surface with eyes open or eyes closed as a condition. Sway was recorded at the sternum and lumbar spine. Linear measures, mediolateral acceleration range with eyes open, mediolateral jerk with eyes closed, and SE in the anteroposterior and mediolateral directions were calculated. A multivariate ANOVA and AUC-ROC were used to determine between-groups differences and discriminative ability, respectively. Mild MS (EDSS ≤ 2.0) discriminability was secondarily assessed. Significantly lower SE was observed under most conditions in pwMS compared to HC, except for lumbar and sternum SE when on a hard surface with eyes closed and in the anteroposterior direction, which also offered the strongest discriminability (AUC = 0.747), even for mild MS. Overall, between-groups differences were task-dependent, and SE (anteroposterior, hard surface, eyes closed) was the best pwMS classifier. SE may prove a useful tool to detect subtle MS progression and intervention effectiveness.

Optimal sensor location and direction to accurately classify people with early-stage multiple sclerosis using gait stability.

BACKGROUND: The local divergence exponent (LDE) has been used to assess gait stability in people with multiple sclerosis (pwMS). Although previous studies have consistently found that stability is lower in pwMS, inconsistent methodologies have been used to assess patients with a broad range of disability levels. QUESTIONS: What sensor location and movement direction(s) are better able to classify pwMS at early stages of the disease? METHODS: 49 pwMS with EDSS ≤ 2.5 and 24 healthy controls walked overground for 5 min while 3D acceleration data was obtained from sensors placed at the sternum (STR) and lumbar (LUM) areas. Unidirectional (vertical [VT], mediolateral [ML], and anteroposterior [AP]) and 3-dimensional (3D) LDEs were calculated using STR and LUM data over 150 strides. ROC analyses were performed to assess classification models using single and combined LDEs, with and without velocity per lap (VELLAP) as a covariate. RESULTS: Four models performed equally well by using combinations of VELLAP, LUM3D, LUMVT, LUMML, LUMAP, STRML, and STRAP (AUC = 0.879). The best model using single sensor LDEs included VELLAP, STR3D, STRML, and STRAP (AUC = 0.878), whereas using VELLAP + STRVT (AUC = 0.869) or VELLAP + STR3D (AUC=0.858) performed best using a single LDE. SIGNIFICANCE: The LDE offers an alternative to currently insensitive tests of gait impairment in pwMS at early stages, when deterioration is not clinically evident. For clinical purposes, the implementation of this measure can be simplified using a single sensor at the sternum and a single LDE measure, but speed should be considered. Longitudinal studies to determine the predictive power and responsiveness of the LDE to MS progression are still needed.

Establishing an Australian pediatric spinal cord disorder register using consumer, health professional, and researcher perspectives.

CONTEXT/OBJECTIVE: Pediatric spinal cord disorders (SCD) are rare, and epidemiological data available to support treatment are lacking. The implementation of a national data register tailored to this population would greatly assist clinicians and therapists in guiding clinical practice. This study gathered perspectives surrounding a prospective national pediatric spinal cord disorder register. DESIGN: Survey and modified Delphi technique. SETTING: Australia. PARTICIPANTS: SCD consumers, health professionals, and researchers. INTERVENTIONS: None. OUTCOME MEASURES: None. RESULTS: Purposive sampling recruited 6 consumers and 52 health professionals and researchers working in the field of SCD to participate. The consumer survey contained items including demographic information, general and pediatric-specific SCD health issues, and questions regarding activity and participation. The modified Delphi survey required health professionals and researchers to identify which "collection items" and "administrative features" should be included in a national SCD register for both clinical and research purposes. Seventeen essential and nine optional items, two outcome measures, data collection methods, consumer access, definition of "pediatric," and use of International Data Standards were included in the consensus for a minimum dataset. CONCLUSION: This study developed a minimum dataset that could inform an Australian register for pediatric SCD. A register linking to an adult database is recommended to ensure coverage across the lifespan. While items for a minimum dataset have been recommended, this dataset is large. Review and refinement of this list are recommended to ensure the register is not overly time-consuming for practical use.

A Practical Post-Stroke Elbow Spasticity Assessment Using an Upper Limb Rehabilitation Robot: A Validation Study.

Spasticity is a motor disorder characterised by a velocity-dependent increase in muscle tone, which is critical in neurorehabilitation given its high prevalence and potential negative influence among the post-stroke population. Accurate measurement of spasticity is important as it guides the strategy of spasticity treatment and evaluates the effectiveness of spasticity management. However, spasticity is commonly measured using clinical scales which may lack objectivity and reliability. Although many technology-assisted measures have been developed, showing their potential as accurate and reliable alternatives to standard clinical scales, they have not been widely adopted in clinical practice due to their low usability and feasibility. This paper thus introduces an easy-to-use robotic based measure of elbow spasticity and its evaluation protocol. Preliminary results collected with one post-stroke patient and one healthy control subject are presented and demonstrate the feasibility of the approach.

Predicting strength outcomes for upper limb nerve transfer surgery in tetraplegia.

We report a retrospective study of 112 nerve transfers in 39 participants to investigate predictors of strength outcomes after nerve transfer surgery for upper limb reanimation in tetraplegia. We measured clinical and pre- and intraoperative neurophysiological assessment variables and compared them with strength outcomes 2 years after nerve transfer surgery. We found statistically significant improvement in Medical Research Council strength grades after nerve transfer surgery with lower cervical spine injuries (between one and two grades), lower donor nerve stimulation thresholds (half of a grade), greater motor evoked potential activity in recipient nerves (half of a grade) and greater muscle responses to intraoperative stimulation of donor (half of a grade) and recipient nerves (half of a grade).Level of evidence: III.

Gait stability reflects motor tracts damage at early stages of multiple sclerosis.

BACKGROUND: Gait in people with multiple sclerosis (PwMS) is affected even when no changes can be observed on clinical examination. A sensitive measure of gait deterioration is stability; however, its correlation with motor tract damage has not yet been established. OBJECTIVE: To compare stability between PwMS and healthy controls (HCs) and determine associations between stability and diffusion magnetic resonance image (MRI) measures of axonal damage in selected sensorimotor tracts. METHODS: Twenty-five PwMS (Expanded Disability Status Scale (EDSS) < 2.5) and 15 HCs walked on a treadmill. Stability from sacrum (LDESAC), shoulder (LDESHO) and cervical (LDECER) was calculated using the local divergence exponent (LDE). Participants underwent a 7T-MRI brain scan to obtain fibre-specific measures of axonal loss within the corticospinal tract (CST), interhemispheric sensorimotor tract (IHST) and cerebellothalamic tract (CTT). Correlation analyses between LDE and fibre density (FD) within tracts, fibre cross-section (FC) and FD modulated by FC (FDC) were conducted. Between-groups LDE differences were analysed using analysis of variance (ANOVA). RESULTS: Correlations between all stability measures with CSTFD, between CSTFDC with LDESAC and LDECER, and LDECER with IHSTFD and IHSTFDC were significant yet moderate (R < -0.4). Stability was significantly different between groups. CONCLUSIONS: Poorer gait stability is associated with corticospinal tract (CST) axonal loss in PwMS with no-to-low disability and is a sensitive indicator of neurodegeneration.

Prevention of work-related musculoskeletal disorders among dental professionals: A scoping review.

BACKGROUND: Musculoskeletal disorders (MSDs) are highly prevalent among dental professionals. Studies examining the prevention of dental work-related MSDs have been completed globally. OBJECTIVE: To identify and evaluate the available evidence regarding MSD prevention in dental practice, and to identify knowledge gaps. METHODS: An electronic search was conducted across multiple scientific databases. Identified articles were assessed according to inclusion/exclusion criteria. Systematic reviews, interventions and published expert opinion were included. RESULTS: Five systematic reviews, 27 intervention studies and 21 expert opinion articles were included. There was overall consensus that use of ergonomic equipment is beneficial in MSD prevention. Knowledge gaps identified included: a lack of systematic reviews on the role of exercise and therapy in MSD prevention; a lack of high-quality intervention studies; a lack of research in general outside of ergonomic equipment use. Expert opinion articles have been published despite a lack of dental-specific research. CONCLUSIONS: Whilst more robust research is required, current evidence supports the use of optical enhancement, saddle chairs, and wide-diameter silicone-handled instruments in MSD prevention. Knowledge gaps were identified relating to the use of exercise, therapy, and education in the prevention of dental work-related MSDs. Further research is required, specifically high-quality intervention studies.

Application of the extended technology acceptance model to explore clinician likelihood to use robotics in rehabilitation.

PURPOSE: Evidence suggests that patients with upper limb impairment following a stroke do not receive recommended amounts of motor practice. Robotics provide a potential solution to address this gap, but clinical adoption is low. The aim of this study was to utilize the technology acceptance model as a framework to identify factors influencing clinician adoption of robotic devices into practice. MATERIALS AND METHOD: Mixed methods including survey data and focus group discussions with allied health clinicians whose primary caseload was rehabilitation of the neurologically impaired upper limb. Surveys based on the technology acceptance measure were completed pre/post exposure to and use of a robotic device. Focus groups discussions based on the theory of planned behaviour were conducted at the conclusion of the study. RESULTS: A total of 34 rehabilitation clinicians completed the surveys with pre-implementation data indicating that rehabilitation clinicians perceive robotic devices as complex to use, which influenced intention to use such devices in practice. The focus groups found that lack of experience and time to learn influenced confidence to implement robotic devices into practice. CONCLUSION: This study found that perceived usefulness and perceived ease of use of a robotic device in clinical rehabilitation can be improved through experience, training and embedded technological support. However, training and embedded support are not routinely offered, suggesting there is a discordance between current implementation and the learning needs of rehabilitation clinicians.IMPLICATIONS FOR REHABILITATIONPatients do not receive adequate amounts of upper limb motor practice following a stroke, and although robotic devices have the potential to address this gap, clinical adoption is low.The technology acceptance model identified that clinicians perceive robotic devices to be complex to use with current implementation efforts failing to consider their training needs.Implementation adoption of robotic devices in rehabilitation should be supported with adequate training and technological support if sustainable practice change is to be achieved.

Responsiveness of the International Classification of Functioning, Disability And Health (ICF) Clinical Functioning Information Tool (ClinFIT) in Routine Clinical Practice in an Australian Inpatient Rehabilitation Setting.

OBJECTIVE: To examine the responsiveness of the International Classification of Functioning, Disability and Health (ICF) Clinical Functioning Information Tool (ClinFIT) in routine clinical practice in an Australian context. METHODS: A prospective observational study with consecutive recruitment of inpatients at a tertiary rehabilitation facility. The assessments were at admission (T0), discharge (T1) and 3-month postdischarge (T2), using the following questionnaires: ClinFIT, Functional Independence Measure (FIM) and European Quality of Life (EQ-5D-5L). Extension Indices (EI) were calculated for the ClinFIT set, and responsiveness measured as a change in scores over time. The association between FIM and ClinFIT scores was explored. RESULTS: Participants (n = 91, mean age 66.8±13.0 years, 52% male, 48% following stroke) reported ≥ 1 issue related to ClinFIT categories. ClinFIT total raw scores improved significantly across all health conditions compared with T0 (median (interquartile range): 196 (110, 228)) at both T1: 69 (37, 110); p < 0.001 and T2: 46.5 (20.8, 77); p < 0.001, with a medium effect size (r = 0.61 for both). There were significant changes in EI in the entire ClinFIT set from T0 to T1, and from T0 to T2 (p < 0.001 for both), with small to medium effect sizes. Analyses confirmed significant correlation in improvements between ClinFIT and FIM scores. CONCLUSION: ClinFIT is useful in evaluating patient functioning and can detect changes in functioning over time and across different health conditions.

Factors influencing thigh muscle volume change with cycling exercises in acute spinal cord injury - a secondary analysis of a randomized controlled trial.

Objective: To conduct a per-protocol analysis on thigh muscle volume outcomes from the Spinal Cord Injury and Physical Activity (SCIPA) Switch-On Trial.Design: Secondary analysis from an assessor-blind randomized, controlled trial.Setting: Four acute/sub-acute hospitals in Australia and New Zealand.Participants: 24 adults (1 female) within four weeks of motor complete or incomplete spinal cord injury (SCI)Intervention: Functional electrical stimulation-assisted cycling (FESC) or passive cycling (PC) 4x/week for 12 weeks.Outcome Measures: Whole thigh and muscle group volumes calculated from manually segmented MR images.Results: 19/24 participants completed ≥ twelve weeks of the intervention. Five participants experienced hypertrophy (4 FESC; 1 PC) and eight attenuation of atrophy (<20% volume loss) (3 FESC; 5 PC) in thigh muscle volume. Six participants were non-responders, exhibiting atrophy >20% (3 FESC; 3 PC). Mean (SD) change for FESC was -2.3% (25.3%) and PC was -14.0% (12.3%). After controlling for baseline muscle volumes, a strong significant correlation was found between mean weekly exercise frequency and quadriceps and hamstring volumes (r=6.25, P=0.006), regardless of mode. Average watts was highly correlated to quadriceps volumes only (r=5.92, P=0.01), while total number of sessions was strongly correlated with hamstring volumes only (r=5.91, P=0.01).Conclusion: This per-protocol analysis of FESC and PC early after SCI reports a partial response in 42% and a beneficial response in 25% of patients who completed 12 weeks intervention, regardless of mode. Strong correlations show a dose-response according to exercise frequency. Characteristics of non-responders are discussed to inform clinical decision-making.

Promoting clinical best practice in a user-centred design study of an upper limb rehabilitation robot.

PURPOSE: Despite their promise to increase therapy intensity in neurorehabilitation, robotic devices have not yet seen mainstream adoption. Whilst there are a number of contributing factors, it is obvious that the treating clinician should have a clear understanding of the objectives and limitations of robotic device use. This study sought to explore how devices can be developed to support a clinician in providing clinical best practice. METHODS AND MATERIALS: A user-centred design study of a robotic device was conducted, involving build-then-use iterations, where successive iterations are built based on feedback from the use cycle. This work reports results of an analysis of qualitative and quantitative data describing the use of the robotic device in the clinical sessions, and from a focus group with the treating clinicians. RESULTS AND CONCLUSIONS: The data indicated that use of the device did not result in patient goal-setting and may have resulted in poor movement quality. Therapists expected a higher level of autonomy from the robotic device, and this may have contributed to the above problems. These problems can and should be addressed through modification of both the study design and device to provide more explicit instructions to promote clinical best practice.IMPLICATIONS FOR REHABILITATIONEncouraging clinical best practice when using evaluating prototype devices within a clinical setting is important to ensure that best practice is maintained - and can be achieved through both study and device designSupport from device developers can significantly improve the confidence of therapists during the use of that device in rehabilitation, particularly with new or prototype devicesEnd effector-based robotic devices for rehabilitation show potential for a wide variety of patient presentations and capabilities.

Axonal loss in major sensorimotor tracts is associated with impaired motor performance in minimally disabled multiple sclerosis patients.

Multiple sclerosis is a neuroinflammatory disease of the CNS that is associated with significant irreversible neuro-axonal loss, leading to permanent disability. There is thus an urgent need for in vivo markers of axonal loss for use in patient monitoring or as end-points for trials of neuroprotective agents. Advanced diffusion MRI can provide markers of diffuse loss of axonal fibre density or atrophy within specific white matter pathways. These markers can be interrogated in specific white matter tracts that underpin important functional domains such as sensorimotor function. This study aimed to evaluate advanced diffusion MRI markers of axonal loss within the major sensorimotor tracts of the brain, and to correlate the degree of axonal loss in these tracts to precise kinematic measures of hand and foot motor control and gait in minimally disabled people with multiple sclerosis. Twenty-eight patients (Expanded Disability Status Scale < 4, and Kurtzke Functional System Scores for pyramidal and cerebellar function ≤ 2) and 18 healthy subjects underwent ultra-high field 7 Tesla diffusion MRI for calculation of fibre-specific measures of axonal loss (fibre density, reflecting diffuse axonal loss and fibre cross-section reflecting tract atrophy) within three tracts: cortico-spinal tract, interhemispheric sensorimotor tract and cerebello-thalamic tracts. A visually guided force-matching task involving either the hand or foot was used to assess visuomotor control, and three-dimensional marker-based video tracking was used to assess gait. Fibre-specific axonal markers for each tract were compared between groups and correlated with visuomotor task performance (force error and lag) and gait parameters (stance, stride length, step width, single and double support) in patients. Patients displayed significant regional loss of fibre cross-section with minimal loss of fibre density in all tracts of interest compared to healthy subjects (family-wise error corrected p-value < 0.05), despite relatively few focal lesions within these tracts. In patients, reduced axonal fibre density and cross-section within the corticospinal tracts and interhemispheric sensorimotor tracts were associated with larger force tracking error and gait impairments (shorter stance, smaller step width and longer double support) (family-wise error corrected p-value < 0.05). In conclusion, significant gait and motor control impairments can be detected in minimally disabled people with multiple sclerosis that correlated with axonal loss in major sensorimotor pathways of the brain. Given that axonal loss is irreversible, the combined use of advanced imaging and kinematic markers could be used to identify patients at risk of more severe motor impairments as they emerge for more aggressive therapeutic interventions.

Does respiratory muscle training improve respiratory function compared to sham training, no training, standard treatment or breathing exercises in children and adults with neuromuscular disease? A Cochrane Review summary with commentary.

BACKGROUND: Progressive muscle weakness is a feature of neuromuscular diseases (NMDs), a heterogeneous group of conditions with variable onset, presentation and prognosis that affect both children and adults. Respiratory muscle weakness compromises respiratory function and may lead to respiratory failure. OBJECTIVE: To assess the effects of respiratory muscle training (RMT) in adults and children with NMD. METHODS: A Cochrane Review by Silva et al. was summarized with comments. RESULTS: Eleven studies involving 250 randomized participants with NMD were included. While the studies showed that RMT may lead to improvements in lung function and respiratory muscle strength in people with ALS and DMD, this was not a consistent finding. The evidence from all the included trials was of low or very low certainty. CONCLUSIONS: There may be some improvement in lung capacity and respiratory muscle strength following RMT in some NMD. There appears to be no clinically meaningful effect of RMT on physical functioning and quality of life in ALS. The low certainty of the evidence means that the results need to be interpreted with caution.

Transfer of the supinator nerve to the posterior interosseous nerve for hand opening in tetraplegia through an anterior approach.

We report a retrospective series of 44 transfers in 26 patients in whom a functioning supinator nerve was transferred to a paralyzed posterior interosseous nerve through a single, anterior approach to re-animate hand opening in mid-cervical tetraplegia. Eighteen patients underwent concurrent nerve or tendon transfers to re-animate grasp and/or pinch through the same anterior incision. We evaluated the strength of the innervated muscle at mean follow-up of 24 months (range 12-27). The strength attained in our patients was equivalent to the strength after the transfer through a posterior approach reported in the literature. Nineteen of our patients were satisfied with the hand opening procedure. First webspace opening was the only variable to correlate with patient satisfaction. We conclude that the anterior approach yields similar results to the posterior approach and has the advantage of allowing easier access for simultaneously performing nerve or tendon transfers to reconstruct grasp and pinch.Level of evidence: IV.

Functional correlates of motor control impairments in multiple sclerosis: A 7 Tesla task functional MRI study.

Upper and lower limb impairments are common in people with multiple sclerosis (pwMS), yet difficult to clinically identify in early stages of disease progression. Tasks involving complex motor control can potentially reveal more subtle deficits in early stages, and can be performed during functional MRI (fMRI) acquisition, to investigate underlying neural mechanisms, providing markers for early motor progression. We investigated brain activation during visually guided force matching of hand or foot in 28 minimally disabled pwMS (Expanded Disability Status Scale (EDSS) < 4 and pyramidal and cerebellar Kurtzke Functional Systems Scores ≤ 2) and 17 healthy controls (HC) using ultra-high field 7-Tesla fMRI, allowing us to visualise sensorimotor network activity in high detail. Task activations and performance (tracking lag and error) were compared between groups, and correlations were performed. PwMS showed delayed (+124 s, p = .002) and more erroneous (+0.15 N, p = .001) lower limb tracking, together with lower cerebellar, occipital and superior parietal cortical activation compared to HC. Lower activity within these regions correlated with worse EDSS (p = .034), lower force error (p = .006) and higher lesion load (p < .05). Despite no differences in upper limb task performance, pwMS displayed lower inferior occipital cortical activation. These results demonstrate that ultra-high field fMRI during complex hand and foot tracking can identify subtle impairments in lower limb movements and upper and lower limb brain activity, and differentiates upper and lower limb impairments in minimally disabled pwMS.

Comparison of segmental lean tissue mass in individuals with spinal cord injury measured by dual energy X-ray absorptiometry and predicted by bioimpedance spectroscopy.

STUDY DESIGN: Observational. OBJECTIVES: To compare two methods for predicting segmental (arms, legs, trunk) lean tissue mass (LTM: non-bone fat-free mass) from bioimpedance spectroscopy (BIS) against LTM measured from dual energy X-ray absorptiometry (DXA) in individuals with acute spinal cord injury (SCI). SETTING: Austin Health Victorian Spinal Cord Service, Victoria, Australia. METHODS: Fourteen participants (two female), within 8 weeks of traumatic SCI had BIS measured following an overnight fast and within 24 h of DXA scanning. Total body fat-free mass (FFM, body weight minus fat mass) and segmental LTM were predicted from BIS using manufacturer's proprietary software and a previously established SCI-specific prediction method. Appendicular LTM (ALM) was calculated from the sum of the LTM of the arms and legs. Agreement and strength of relationships with DXA for predicted LTM measures using both approaches were assessed using Lin's concordance coefficient and limits of agreement analysis (LOA). RESULTS: The BIS proprietary method performed better than the SCI-specific prediction method in predicting DXA LTM, demonstrating substantial concordance for total body FFM (rc = 0.80), ALM (rc = 0.78), arm (rc = 0.76) and leg LTM (rc = 0.65) and a smaller bias and LOA for ALM (+0.8 vs. -3.4 kg; LOA -4.9-6.4 vs. -11.9-5.1 kg), arm (+0.02 vs. -0.3 kg; LOA -1.1-1.1 kg vs. -2.2-1.6 kg) and leg (+0.4 vs. -1.4 kg; LOA -2.0-2.8 vs. -5.6-2.8) LTM. CONCLUSIONS: BIS can be used to accurately predict total body FFM, segmental LTM and ALM in individuals with acute SCI.

Heterogeneity in microstructural deterioration following spinal cord injury.

BACKGROUND: Modelling and remodelling adapt bone morphology to accommodate strains commonly encountered during loading. If strains exceed a threshold threatening fracture, modelling-based bone formation increases bone volume reducing these strains. If unloading reduces strains below a threshold that inhibits resorption, increased remodelling-based bone resorption reduces bone volume restoring strains, but at the price of compromised bone volume and microstructure. As weight-bearing regions are adapted to greater strains, we hypothesized that microstructural deterioration will be more severe than at regions commonly adapted to low strains following spinal cord injury. METHODS: We quantified distal tibial, fibula and radius volumetric bone mineral density (vBMD) using high-resolution peripheral quantitative computed tomography in 31 men, mean age 43.5 years (range 23.5-75.0), 12 with tetraplegia and 19 with paraplegia of 0.7 to 18.6 years duration, and 102 healthy age- and sex-matched controls. Differences in morphology relative to controls were expressed as standardized deviation (SD) scores (mean ± SD). Standardized between-region differences in vBMD were expressed as SDs (95% confidence intervals, CI). RESULTS: Relative to controls, men with tetraplegia had deficits in total vBMD of -1.72 ± 1.38 SD at the distal tibia (p < 0.001) and - 0.68 ± 0.69 SD at distal fibula (p = 0.041), but not at the distal radius, despite paralysis. Deficits in men with paraplegia were -2.14 ± 1.50 SD (p < 0.001) at the distal tibia and -0.83 ± 0.98 SD (p = 0.005) at the distal fibula while distal radial total vBMD was 0.23 ± 1.02 (p = 0.371), not significantly increased, despite upper limb mobility. Comparing regions, in men with tetraplegia, distal tibial total vBMD was 1.04 SD (95%CI 0.07, 2.01) lower than at the distal fibula (p = 0.037) and 1.51 SD (95%CI 0.45, 2.57) lower than at the distal radius (p = 0.007); the latter two sites did not differ from each other. Results were similar in men with paraplegia, but total vBMD at the distal fibula was 1.06 SD (95%CI 0.35, 1.77) lower than at the distal radius (p = 0.004). CONCLUSION: Microarchitectural deterioration following spinal cord injury is heterogeneous, perhaps partly because strain thresholds regulating the cellular activity of mechano-transduction are region specific.

Evaluating Rehabilitation Progress Using Motion Features Identified by Machine Learning.

Evaluating progress throughout a patient's rehabilitation episode is critical for determining the effectiveness of the selected treatments and is an essential ingredient in personalised and evidence-based rehabilitation practice. The evaluation process is complex due to the inherently large human variations in motor recovery and the limitations of commonly used clinical measurement tools. Information recorded during a robot-assisted rehabilitation process can provide an effective means to continuously quantitatively assess movement performance and rehabilitation progress. However, selecting appropriate motion features for rehabilitation evaluation has always been challenging. This paper exploits unsupervised feature learning techniques to reduce the complexity of building the evaluation model of patients' progress. A new feature learning technique is developed to select the most significant features from a large amount of kinematic features measured from robotics, providing clinically useful information to health practitioners with reduction of modeling complexity. A novel indicator that uses monotonicity and trendability is proposed to evaluate kinematic features. The data used to develop the feature selection technique consist of kinematic data from robot-aided rehabilitation for a population of stroke patients. The selected kinematic features allow for human variations across a population of patients as well as over the sequence of rehabilitation sessions. The study is based on data records pertaining to 41 stroke patients using three different robot assisted exercises for upper limb rehabilitation. Consistent with the literature, the results indicate that features based on movement smoothness are the best measures among 17 kinematic features suitable to evaluate rehabilitation progress.