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Bioimpedance (mfBIA) non-invasively assesses cellular muscle health. Our aim was to explore whether mfBIA captures abnormal cellular muscle health in patients with Parkinson's Disease (PD) and how such changes are modulated with the use of Parkinson's medication. In patients with PD (n = 20) mfBIA measurements were made of biceps brachii, triceps, and extensor carpi radialis longus muscles of the more affected arm whilst at rest, using a mobile mfBIA device (IMPEDIMED, Australia). mfBIA and assessment of motor symptoms were performed in a pragmatic off-medication state, as well as one and 3 h after oral intake of 200 mg levodopa. Age and sex-matched healthy subjects (HC; n = 20) served as controls. PD and HC mfBIA parameters were compared by applying an unpaired two-tailed adjusted t-test and ANOVA with Tukey's correction for multiple comparisons (p ≤ 0.05). The PD group consisted of 13 men (71 ± 17 years) and 7 women (65 ± 7 years). Independent of medication, internal (Ri) and external resistance (Re) were found to be significantly higher, and membrane capacitance (Mc) significantly lower, in m.biceps brachii in PD subjects compared to HC. Center frequency (fc) was significantly higher in m.biceps brachii of PD subjects in the “medication-off” state. There was no difference between PD and HC in mfBIA parameters in the measured extensor muscles. The upper limb flexor muscle shows a difference in mfBIA parameters in PD compared to HC. mfBIA may be useful in the diagnosis and assessment of PD patients and is objective, non-invasive, reliable, and easy to use.

OBJECTIVE: To study differences in pain reports between patients with ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (nr-axSpA), and to assess how pain sensitivity measures associate with disease and health outcomes. METHODS: Consecutive patients with axial SpA (axSpA) were enrolled in the population-based SPARTAKUS cohort (2015-2017) and classified as AS (n = 120) or nr-axSpA (n = 55). Pain was assessed with questionnaires (intensity/duration/distribution) and computerized cuff pressure algometry to measure pain sensitivity (pain threshold/pain tolerance/temporal summation of pain). Linear regression models were used to compare pain measures between patients with AS and nr-axSpA, and to assess associations between pain sensitivity measures and disease and health outcomes. RESULTS: Of 175 patients with axSpA, 43% reported chronic widespread pain, with no significant differences in any questionnaire-derived or algometry-assessed pain measures between patients with AS and nr-axSpA. Lower pain tolerance was associated with longer symptom duration, worse Ankylosing Spondylitis Disease Activity Score using C-reactive protein (ASDAS-CRP), Bath Ankylosing Spondylitis Functional Index, and Bath Ankylosing Spondylitis Metrology Index (BASMI), more pain regions, unacceptable pain, worse Maastricht AS Enthesitis Score (MASES), fatigue, anxiety, and health-related quality of life. Further, lower pain threshold was associated with worse ASDAS-CRP and MASES, whereas higher temporal summation was associated with longer symptom duration, unacceptable pain, and worse BASMI. CONCLUSION: Chronic pain is common in axSpA, with no observed differences in any pain measures between patients with AS and nr-axSpA. Further, higher pain sensitivity is associated with having worse disease and health outcomes. The results indicate that patients with AS and nr-axSpA, in line with most clinical characteristics, have a similar pain burden, and they highlight large unmet

Acoustic myography (AMG) is a non-invasive method to assess muscle function during daily activities. AMG has great scope for assessment of musculoskeletal problems. The aim of this study was to create an AMG data set for general clinical use and relate these findings to age and gender. 10 healthy subjects (5 men/5 women), in each decade from 20 to 69 years of age (n = 50), were assessed. Their clinical health was tested. AMG measurements were carried out on muscles involved in defined movements of the upper and lower extremities. Muscle performance was measured using efficiency (E-score) and fibre recruitment (temporal (T-score) and spatial (S-score) summation). AMG-measurements showed good reproducibility. In each age group, it was found that for all those daily living skills measured, there was no gender difference. A walking and stair climbing test revealed that both legs are used equally and in a balanced way in healthy subjects. Moreover, there was no change in this function with increasing age up to 69 years. However, a cycling test with loading revealed that in elderly subjects the coordination of muscle use is impaired compared to that of the younger adults. Finally, a flexion test of the arm revealed an age-related decrease in the efficiency/coordination of m.Biceps alone, and a keyboard writing test suggests no effect on m.Trapezius. This reference data set now illustrates the reproducibility and ease of use of acoustic myography in the clinic and provides a means of assessing individuals with musculoskeletal problems.

Isokinetic and isometric force measurements involving a dynamometer setup are widely used in training and in muscle assessment. For further understanding of the method, we investigated the activation of key functional muscles during isokinetic and isometric movements. During force measurements in an isokinetic Biodex System 3 ProTM, acoustic myography (AMG) was applied. Ten healthy subjects (5 men/5 women) in each decade from 20 to 69 years of age participated in the study. Measurements were carried out during extension and flexion of the ankle, knee and elbow joints. Muscle fibre use was measured by efficiency (E-score) and fibre recruitment (temporal (T-score) and spatial (S-score) summation). AMG measurements showed good reproducibility, and the recruitment pattern of muscle fibres did not change with gender or age. Overall, a significantly higher E-score (P < 0.05) was found at the lower angular velocities than at the higher ones, indicating a lower level of muscle efficiency at higher velocities. Muscles used for knee movement exhibited higher scores than muscles associated with the ankle and elbow joints, most likely related to the greater degree of force production at this joint compared to the ankle and elbow. The ability to activate and inactivate muscle fibres during periods of isokinetic activity becomes increasingly more difficult as the velocity increases. When assessing training effects in sports or rehabilitation, AMG in parallel with isokinetic measurements adds important additional information by giving a measure of possible improvements in efficiency and fibre use.

The condition of active muscles determines an individual′s ability to carry out daily activities and has implications for an athlete′s performance. Multi-frequency bioimpedance (mfBIA) is a non-invasive, well-known, validated, and much used method to assess muscle condition. However, it is rarely used to its full potential. Our aim was to apply mfBIA fully in the assessment of an adult healthy population, to compare muscle condition in different functional rested muscle groups, with age, and between men and women, and establish a control data set. Fifty healthy subjects (25 men/25 women) aged 20–69 years, participated. mfBIA measurements at a frequency range of 4–1000 kHz were taken from muscles of the lower and the upper extremities, the upper back, and the hand. Data were analyzed using ImpediMed software, giving Impedance, Resistance, Reactance, Phase Angle, Center Frequency, external and internal Resistance, and Membrane Capacitance. Differences between means were tested for statistical significance. A P value >0.05 was considered nonsignificant. While no difference in the mfBIA parameters was seen with age, a highly significant gender difference was seen. At rest, women′s muscles cf men's showed a significantly higher center frequency and intra- and extra-cellular resistance, while the membrane capacitance was lower. A set of values for mfBIA parameters for healthy adult individuals are given for some of the main muscles which are frequently part of muscle assessment. The documented gender difference in muscle condition at rest has important implications in work situations, during physical rehabilitation and when training for competitive sports.

Background/Purpose: Pain remains a common and debilitating symptom in arthritis, despite good options to treat inflammation. In axial spondyloarthritis (axSpA), data on chronic pain remain scarce. Objective: To assess self-reported and observed aspects of pain in subgroups of axial spondyloarthritis (axSpA), and to investigate associations between these pain aspects and different health outcome measures. Methods: A cross-sectional study of patients with axSpA (ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA, based on ICD10 codes)), consecutively enrolled in the SPARTAKUS cohort (n=226). Of 197 patients, for whom all relevant information was available, 173 patients fulfilled the ASAS axSpA criteria, and 115 the modified New York criteria. We investigated self-reported pain (intensity, duration, and distribution) and categorized patients into chronic widespread pain, chronic regional pain and no chronic pain. In addition, pain sensitivity (pain threshold, pain tolerance and temporal summation of pain), was assessed by computerized cuff pressure algometry (CPA). Comparisons between AS and USpA and between women and men were performed using Student`s t-test or Chi-squared test. Associations of pain sensitivity measures and different health outcome measures, adjusted for age and sex, were analyzed by multivariate linear regression. Results: All assessed pain measures, except for number of pain regions, were similar in AS and USpA. Almost 50% of the axSpA patients, reported chronic widespread pain (AS 42%, USpA 53%), which was more pronounced in women (60% vs. 34% for men, p<0.001). For pain sensitivity measures, women had lower pain tolerance as compared to men (AS (p=0.03), USpA (p=0.01)), while pain threshold was lower only for women with USpA (p<0.01) (Table). Furthermore, irrespective of diagnosis subgroup, lower pain tolerance was associated with higher disease activity, more fatigue and less spinal mobility. Conclusion: In this po

INTRODUCTION: Computerized pneumatic cuff pressure algometry (CPA) using the DoloCuff is a new method for pain assessment. Intra- and inter-rater reliabilities have not yet been established. Our aim was to examine the inter- and intrarater reliabilities of DoloCuff measures in healthy subjects.METHODS: Twenty healthy subjects (ages 20 to 29 years) were assessed three times at 24-hour intervals by two trained raters. Inter-rater reliability was established based on the first and second assessments, whereas intrarater reliability was based on the second and third assessments. Subjects were randomized 1:1 to first assessment at either rater 1 or rater 2. The variables of interest were pressure pain threshold (PT), pressure pain tolerance (PTol), and temporal summation index (TSI). Reliability was estimated by a two-way mixed intraclass correlation coefficient (ICC) absolute agreement analysis. Reliability was considered excellent if ICC > 0.75, fair to good if 0.4 < ICC < 0.75, and poor if ICC < 0.4. Bias and random errors between raters and assessments were evaluated using 95% confidence interval (CI) and Bland-Altman plots.RESULTS: Inter-rater reliability for PT, PTol, and TSI was 0.88 (95% CI: 0.69 to 0.95), 0.86 (95% CI: 0.65 to 0.95), and 0.81 (95% CI: 0.42 to 0.94), respectively. The intrarater reliability for PT, PTol, and TSI was 0.81 (95% CI: 0.53 to 0.92), 0.89 (95% CI: 0.74 to 0.96), and 0.75 (95% CI: 0.28 to 0.91), respectively.CONCLUSION: Inter-rater reliability was excellent for PT, PTol, and TSI. Similarly, the intrarater reliability for PT and PTol was excellent, while borderline excellent/good for TSI. Therefore, the DoloCuff can be used to obtain reliable measures of pressure pain parameters in healthy subjects.

The molecular beam epitaxy (MBE) system is being prepared for the preparation of manganese arsenide/gallium arsenide (MnAs/GaAs) composite films. The chamber has been evaluated for quality of the vacuum: A pressure in the 10(exp -8) Torr range was obtained within hours without bakeout. The bakeable all metal valve connected to the turbo pump was found to leak through the valve seating when the valve was closed. Repairs are being made on the chamber and on the Boostivac ion pump controller. Drawings have been prepared for the effusion cells in the molecular beam source. Professor Tamargo has agreed to provide access to her commercial MBE system to produce large are MnAs/GaAs samples. The effusion cells are available for deposition and it will be possible to exactly reproduce the deposition conditions of Rothberg and Harbison's work that was cited in the SBIR proposal. SKION will utilize AES, RHEED and LEED to provide in situ analysis to establish optimal growth parameters.