Distribution of Bioelectrical Impedance Vector Analysis and Phase Angle in Korean Elderly and Sarcopenia.

PURPOSE: This study aimed to verify whether bioelectrical impedance vector analysis (BIVA) can support the clinical evaluation of sarcopenia in elderly individuals and evaluate the relationships between phase angle (PhA), physical performance, and muscle mass. METHODS: The sample comprised 134 free-living elderly individuals of both sexes aged 69-91 years. Anthropometric parameters, grip strength, dual-energy X-ray absorptiometry findings, bioimpedance analysis results, and physical performance were also measured. The impedance vector distributions were evaluated in elderly individuals using BIVA. RESULTS: BIVA revealed significant differences between the sarcopenia and non-sarcopenia groups (both sexes). The sarcopenia group had a significantly lower PhA than the non-sarcopenia group in both sexes (p < 0.05). PhA was significantly correlated with age, appendicular skeletal muscle (ASM), handgrip strength (HGS), and muscle quality in both sexes and significantly correlated with ASM/Height2 and physical performance in males. CONCLUSION: BIVA can be used as a field assessment method in elderly Koreans with sarcopenia. PhA is a good indicator of muscle strength, muscle quality, and physical performance in males. These methods can help diagnose sarcopenia in elderly individuals with reduced mobility.

Two-megahertz impedance index prediction equation for appendicular lean mass in Korean older people.

BACKGROUND: Whole-body bioelectrical impedance analysis (BIA) has been accepted as an indirect method to estimate appendicular lean mass (ALM) comparable to dual-energy X-ray absorptiometry (DXA). However, single or limited frequencies currently used for these estimates may over or under-estimate ALM. Accordingly, there is a need to measure the impedance parameter with appendicular lean-specific across multiple frequencies to more accurately estimate ALM. We aimed to validate muscle-specific frequency BIA equation for ALM using multifrequency BIA (MF-BIA) with DXA as the reference. METHODS: 195 community-dwelling Korean older people (94 men and 101 women) aged 70 ~ 92y participated in this study. ALM was measured by DXA and bioimpedance measures at frequencies of 5 kHz ~ 3 MHz were assessed for independent predictive variables. Regression analyses were used to find limb-specific frequencies of bioimpedance, to develop the ALM equations and to conduct the internal cross-validation. The six published equations and the final equation of MF-BIA were externally cross-validated. RESULTS: 195 participants completed the measurements of MF-BIA and DXA. Using bivariate regression analysis, the 2 MHz impedance index explained R2 = 91.5% of variability (P < 0.001) in ALM and predictive accuracy of standard error of estimate (SEE) was 1.0822 kg ALM (P < 0.001). Multiple stepwise regression analysis obtained in the development group had an adjusted R2 of 9.28% (P < 0.001) and a SEE of 0.97 kg ALM. The cross-validation group had no significant difference between the measured ALM and the predicted ALM (17.8 ± 3.9 kg vs. 17.7 ± 3.8 kg, P = .486) with 93.1% of R2 (P < 0.001) and 1.00 kg ALM of total error. The final regression equation was as follows: ALM = 0.247ZI@2 MHz + 1.254SEXM1F0 + 0.067Xc@5 kHz + 1.739 with 93% of R2 (P < 0.001), 0.97 kg ALM of SEE (Subjective Rating as "excellent" for men and "very good" for women). In the analysis of the diagnostic level for sarcopenia of the final regression, the overall agreement was 94.9% (k = 0.779, P < 0.001) with 71.4% of sensitivity, 98.8% of specificity, 91.3 of positive prediction value and 95.3% of negative prediction value. CONCLUSION: The newly developed appendicular lean-specific high-frequency BIA prediction equation has a high predictive accuracy, sensitivity, specificity, and agreement for both individual and group measurements. Thus, the high-frequency BIA prediction equation is suitable not only for epidemiological studies, but also for the diagnosis of sarcopenia in clinical settings.

Accuracy of Estimated Bioimpedance Parameters with Octapolar Segmental Bioimpedance Analysis.

The validity of the impedance parameters of the five body segments estimated using octapolar segmental bioelectrical impedance analysis (OS-BIA) has not been confirmed. This study aimed to verify the accuracy of the resistance (R), reactance (Xc), and phase angle of each five-body segment. The accuracy of the OS-BIA at 50 kHz was measured based on the direct tetrapolar segmental BIA. The differences in the estimated impedance parameters of the five body segments were compared to those measured from the OS-BIA in elderly men (N = 73) and women (N = 63). The estimated 50 kHz-R (Ω) was significantly higher than the measured 50 kHz-R in the right and left arms, and lower than the measured 50 kHz-R of the trunk, right leg, and left leg (all, p < 0.05). The estimated 50 kHz-phase angles in all the five body segments were significantly lower than the measured ones (all, p < 0.05). The findings suggest that the estimated impedance parameters, R, Xc, and phase angle of the trunk, were remarkedly underestimated, limiting the assessment of the physiological state of the organs in the body. Therefore, further intensive research is needed in the field of estimated segmental BIA in the future.

The intrinsically disordered N-terminal arm of the brome mosaic virus coat protein specifically recognizes the RNA motif that directs the initiation of viral RNA replication.

In the brome mosaic virus (BMV) virion, the coat protein (CP) selectively contacts the RNA motifs that regulate translation and RNA replication (Hoover et al., 2016. J. Virol. 90, 7748). We hypothesize that the unstructured N-terminal arm (NTA) of the BMV CP can specifically recognize RNA motifs. Using ion mobility spectrometry-mass spectrometry, we demonstrate that peptides containing the NTA of the CP were found to preferentially bind to an RNA hairpin motif that directs the initiation of BMV RNA synthesis. RNA binding causes the peptide to change from heterogeneous structures to a single family of structures. Fluorescence anisotropy, fluorescence quenching and size exclusion chromatography experiments all confirm that the NTA can specific recognize the RNA motif. The peptide introduced into plants along with BMV virion increased accumulation of the BMV CP and accelerated the rate of minus-strand RNA synthesis. The intrinsically disordered BMV NTA could thus specifically recognize BMV RNAs to affect viral infection.

On the conformational stability of the smallest RNA kissing complexes maintained through two G·C base pairs.

Two identical 5'GACG3' tetra-loop motifs with different stem sequences (called H2 and H3) are found in the 5' end region of Moloney Murine Leukemia Virus (MMLV) genomic RNA. They play important roles in RNA dimerization and encapsidation through two identical tetra-loops (5'GACG3') forming a loop-to-loop kissing complex, the smallest RNA kissing complex ever found in nature. We examined the effects of a loop-closing base pair as well as a stem sequence on the conformational stability of the kissing complex. UV melting analysis and gel electrophoresis were performed on eight RNA sequences mimicking the H2 and H3 hairpin tetra-loops with variation in loop-closing base pairs. Our results show that changing the loop-closing base pair from the wildtype (5'A·U3' for H3, 5'U·A3' for H2) to 5'G·C3'/5'C·G3' has significant effect on the stability of the kissing complexes: the substitution to 5'C·G3' significantly decreases both thermal and mechanical stability, while switching to the 5'G·C3' significantly increases the mechanical stability only. The kissing complexes with the wildtype loop-closing base pairs (5'A·U3' for H3 and 5'U·A3' for H2) show different stability when attached to a different stem sequence (H2 stem vs. H3 stem). This suggests that not only the loop-closing base pair itself, but also the stem sequence, affects the conformational stability of the RNA kissing complex.

Effects of Exercise Type on Hemodynamic Responses and Cardiac Events in ACS Patients.

[Purpose] This study investigated the effects of mid, and high exercise intensities on hemodynamic responses and cardiac events during two exercise types of treadmill exercise (TM) and cycle ergometer exercises (CE) in patients with acute coronary syndrome (ACS). [Subjects] Patients who had percutaneous coronary intervention (PCI) for ACS and were participating in cardiac rehabilitation program were included. [Methods] The patients were assessed for hemodynamic responses, cardiac events, and rate of perceived exertion (RPE) with target heart rates of 60% and 85% heart rate reserve (HRR) during TM and CE. [Results] Maximum systolic blood pressure (SBP), diastolic blood pressure (DBP), RPE, and rate pressure product (RPP) measured during CE were significantly higher than their values in TM at the same exercise intensities. The highest SBP was shown at 85% HRR during CE. SBPmax to SBPmax ratios obtained during the graded exercise test (GXT) showed that all %SBPmax were significantly greater in CE than in TM at the same exercise intensities. Out of 102 patients, cardiac events occurred in 8 at 85% HRR during CE, and 1 at 85% HRR during TM. Patients with cardiac events (CE-E) had significantly higher %SBP, %RPP, and RPE at 85% HRR than those without events (CE-NE) during CE. [Conclusion] Prescribing exercise based on the intensity obtained in a treadmill GXT may expose patients to cardiovascular complications such as higher RPP, higher exercise intensity, and cardiac events during CE.

Association between Complex ACTN3 and ACE Gene Polymorphisms and Elite Endurance Sports in Koreans: A Case-Control Study.

ACTN3 R577X and ACE I/D polymorphisms are associated with endurance exercise ability. This case-control study explored the association of ACTN3 and ACE gene polymorphisms with elite pure endurance in Korean athletes, hypothesizing that individuals with both ACTN3 XX and ACE II genotypes would exhibit superior endurance. We recruited 934 elite athletes (713 males, 221 females) and selected 45 pure endurance athletes (36 males, 9 females) requiring "≥90% aerobic energy metabolism during sports events", in addition to 679 healthy non-athlete Koreans (361 males, 318 females) as controls. Genomic DNA was extracted and genotyped for ACTN3 R577X and ACE I/D polymorphisms. ACE ID (p = 0.090) and ACTN3 RX+XX (p = 0.029) genotype distributions were significantly different between the two groups. Complex ACTN3-ACE genotypes also exhibited significant differences (p = 0.014), with dominant complex genotypes positively affecting endurance (p = 0.039). The presence of RX+II or XX+II was associated with a 1.763-fold higher likelihood of possessing a superior endurance capacity than that seen in healthy controls (90% CI = 1.037-3.089). Our findings propose an association of combined ACTN3 RX+XX and ACE II genotypes with enhanced endurance performance in elite Korean athletes. While causality remains to be confirmed, our study highlights the potential of ACTN3-ACE polymorphisms in predicting elite endurance.

Effects of Enteric-Coated Formulation of Sodium Bicarbonate on Bicarbonate Absorption and Gastrointestinal Discomfort.

Sodium bicarbonate is used as an ergogenic supplement to enhance people's performances in various exercises. This study aimed to evaluate the effects of intestinal delivery of sodium bicarbonate on bicarbonate absorption and associated side effects in an experimental human trial. After preparing and assessing enteric-coated and uncoated sodium bicarbonate tablet formulations, pharmacokinetic analysis and gastrointestinal symptom tests were performed after oral administration in the human body. The dose required to increase blood bicarbonate concentration over 5 mmol∙L-1 for the purpose of improving performance during high-intensity exercise was also determined. Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions and releases bicarbonate in the intestine. Enteric-coated tablet formulation also reduced the oral dose required to achieve a blood bicarbonate concentration over 5 mmol∙L-1 from 300 mg∙kg-1 of uncoated tablet formulation to 225 mg∙kg-1. Gastrointestinal discomfort was significantly decreased for the group given 225 mg∙kg-1 enteric-coated tablets compared to that given 300 mg∙kg-1 uncoated tablets. These results suggest that enteric-coated tablet formulation could reduce the oral dose required in order to achieve a blood bicarbonate concentration over 5 mmol∙L-1 by 25%, from 300 mg∙kg-1 to 225 mg∙kg-1, along with its ability to reduce gastrointestinal discomfort associated with the dosage.

Treadmill exercise represses neuronal cell death and inflammation during Aß-induced ER stress by regulating unfolded protein response in aged presenilin 2 mutant mice.

Alzheimer's disease (AD) is characterized by the deposition of aggregated amyloid-beta (Aß), which triggers a cellular stress response called the unfolded protein response (UPR). The UPR signaling pathway is a cellular defense system for dealing with the accumulation of misfolded proteins but switches to apoptosis when endoplasmic reticulum (ER) stress is prolonged. ER stress is involved in neurodegenerative diseases including AD, but the molecular mechanisms of neuronal apoptosis and inflammation by Aß-induced ER stress to exercise training are not fully understood. Here, we demonstrated that treadmill exercise (TE) prevented PS2 mutation-induced memory impairment and reduced Aß-42 deposition through the inhibition of ß-secretase (BACE-1) and its product, C-99 in cortex and/or hippocampus of aged PS2 mutant mice. We also found that TE down-regulated the expression of GRP78/Bip and PDI proteins and inhibited activation of PERK, eIF2α, ATF6α, sXBP1 and JNK-p38 MAPK as well as activation of CHOP, caspase-12 and caspase-3. Moreover, TE up-regulated the expression of Bcl-2 and down-regulated the expressions of Bax in the hippocampus of aged PS2 mutant mice. Finally, the generation of TNFα and IL-1α and the number of TUNEL-positive cells in the hippocampus of aged PS2 mutant mice was also prevented or decreased by TE. These results showed that TE suppressed the activation of UPR signaling pathways as well as inhibited the apoptotic pathways of the UPR and inflammatory response following Aß-induced ER stress. Thus, therapeutic strategies that modulate Aß-induced ER stress through TE could represent a promising approach for the prevention or treatment of AD.

Comparing zero-profile and conventional cage and plate in anterior cervical discectomy and fusion using finite-element modeling.

Conventional cage and plate (CCP) implants usually used in ACDF surgery, do have limitations such as the development of postoperative dysphagia, adjacent segment degeneration, and soft tissue injury. To reduce the risk of these complications, zero-profile stand-alone cage were developed. We used finite-element modeling to compare the total von Mises stress applied to the bone, disc, endplate, cage and screw when using CCP and ZPSC implants. A 3-dimensional FE (Finite element) analysis was performed to investigate the effects of the CCP implant and ZPSC on the C3 ~ T1 vertebrae. We confirmed that the maximum von Mises stress applied with ZPSC implants was more than 2 times greater in the endplate than that applied with CCP implants. The 3D analysis of the ZPSC model von Mises stress measurements of screw shows areas of higher stress in red. Although using ZPSC implants in ACDF reduces CCP implant-related sequalae such as dysphagia, we have shown that greater von Mises stress is applied to the endplate, and screw when using ZPSC implants. This may explain the higher subsidence rate associated with ZPSC implant use in ACDF. When selecting an implant in ACDF, surgeons should consider patient characteristics and the advantages and disadvantages of each implant type.

Biomechanical Effects of Different Sitting Postures and Physiologic Movements on the Lumbar Spine: A Finite Element Study.

This study used the finite element method(FEM) to investigate how pressure on the lumbar spine changes during dynamic movements in different postures: standing, erect sitting on a chair, slumped sitting on a chair, and sitting on the floor. Three load modes (flexion, lateral bending, and axial rotation) were applied to the FEM, simulating movements of the lumbar spine. Results showed no significant difference in pressure distribution on the annulus fiber and nucleus pulposus, representing intradiscal pressure, as well as on the cortical bone during movements between standing and erect sitting postures. However, both slumped sitting on a chair and sitting on the floor postures significantly increased pressure on the nucleus pulposus, annulus fibrosus, and cortical bone in all three movements when compared to standing or erect sitting on a chair. Notably, sitting on the floor resulted in even higher pressure on the nucleus pulposus and annulus fibers compared to slumped sitting on a chair. The decreased lumbar lordosis while sitting on the floor led to the highest increase in pressure on the annulus fiber and nucleus pulposus in the lumbar spine. In conclusion, maintaining an erect sitting position with increased lumbar lordosis during seated activities can effectively reduce intradiscal pressure and cortical bone stress associated with degenerative disc diseases and spinal deformities.

Factor Analysis Affecting Degree of Depression in Family Caregivers of Patients with Spinal Cord Injury: A Cross-Sectional Pilot Study.

This study was conducted to determine the degree of depression in family caregivers of spinal-cord-injury patients and to identify factors influencing family caregivers' depression. The final study subjects were 30 (family caregivers: 6 males and 24 females). The CES-D of family caregivers; general characteristics of spinal-cord-injury patients and family caregivers; and information on physical health, household income, leisure, social activity, family relationship, and life-in-general status of family caregiver were collected. A frequency analysis, normality test, Mann-Whitney test, Kruskal-Wallis test, Spearman Correlation analysis, hierarchical regression analysis, and spider network through a path model analysis were performed. As for the general characteristics, when the patient was economically active, the caregiver's depression was mean ± SD; 2.04 ± 0.71; otherwise, it was mean ± SD 2.86 ± 0.74, indicating that the caregiver of the non-economic activity patient was more depressed (p = 0.013). In Model 1 of the multiple regression analysis to understand the effect on the depression of the caregiver, it was confirmed that the depression of the caregiver decreased as the family caregiver had more leisure and social activities (B = -0.718, p = 0.001). In Model 2, it was found that the depression of caregivers increased when the patient did not engage in economic activity (B = 0.438, p = 0.016). In the spider-web form through the path model analysis, as the family's economic level increased, physical health increased by B = 0.755 (p < 0.001), and the increase in physical health (B = 0.424, p = 0.042) was, in turn, a factor in the increase of engagement in leisure and social activities. Various policies will be needed for the successful return to society of spinal-cord-injury patients by ensuring that their leisure and social activities and establishing measures to support their economical income.

Physical Activity and Quality of Life in Adult Men and Women with Distorted Perception of Weight Status: Nationwide Surveys (KNHANES 2016-2018).

This study analyzed the distorted perception of weight in adults aged 20 years or older and investigated the difference in the amount of physical activity and health-related quality of life (HRQOL). This study examined 21,326 adults regarding their body mass index (BMI), subjective body recognition (SBR), physical activity (according to the Global Physical Activity Questionnaire; GPAQ), and HRQOL (EuroQol-5 Dimension; EQ-5D) from the 7th Korea National Health and Nutrition Examination Survey (2016−2018). Independent t-test, analysis of variance (ANOVA), chi-square test, and multiple regression analysis were conducted. The group with the same BMI and SBR significantly showed a long time of activity vigorous-intensity (F = 21.25, p = 0.003) and moderate-intensity time (F = 17.24, p < 0.001). In the 'BMI = SBR' group, the sub-group with normal BMI and normal SBR showed the highest vigorous-intensity (mean ± SD = 7.20 ± 26.05, F = 37.86, p < 0.001) and moderate-intensity (mean ± SD = 13.89 ± 30.18, F = 43.27, p < 0.001) activity times. The sub-group with normal BMI and normal SBR had the highest percentage of responding as normal in the five EQ-5D sub-items. For the score of the EQ-5D Index, the highest score was shown in the group that felt subjectively more obese than the actual BMI (F = 56.83, p < 0.001). In the 'BMI = SBR' group, these factors related to physical activity (vigorous-intensity, moderated-intensity, and walking) are factors influencing health-related quality of life in this regression model (F = 396.57, p < 0.001, R2 = 0.165). Various health promotion programs and policy recommendations to reduce the distorted perception of weight are required.

Analysis of the physiological load on lumbar vertebrae in patients with osteoporosis: a finite-element study.

This study aims to investigate the difference in physiological loading on the spine in three different motions (flexion-extension, lateral bending, and axial rotation) between osteoporotic and normal spines, using finite element modelling. A three-dimensional finite element (FE) model centered on the lumbar spine was constructed. We applied two different material properties of osteoporotic and normal spines. For the FE analysis, three loading conditions (flexion-extension, lateral bending, and axial rotation) were applied. The von Mises stress was higher on the nucleus pulposus at all vertebral levels in all movements, in the osteoporosis group than in the normal group. On the annulus fibrosus, the von Mises stress increased at the level of L3-L4, L4-L5, and L5-S in the flexion-extension group and at L4-L5 and L5-S levels in the lateral bending group. The values of two motions, flexion-extension and lateral bending, increased in the L4 and L5 cortical bones. In axial rotation, the von Mises stress increased at the level of L5 of cortical bone. Additionally, the von Mises stress increased in the lower endplate of L5-S and L4-L5 in all movements, especially lateral bending. Even in the group with no increase, there was a part that received increased von Mises stress locally for each element in the three-dimensional reconstructed view of the pressure distribution in color. The von Mises stress on the lumbar region in the three loading conditions, was greater in most components of osteoporotic vertebrae than in normal vertebrae and the value was highest in the nucleus pulposus. Considering the increase in the measured von Mises stress and the local increase in the pressure distribution, we believe that these results can contribute to explaining discogenic pain and degeneration.

Brome mosaic virus capsid protein regulates accumulation of viral replication proteins by binding to the replicase assembly RNA element.

Viruses provide valuable insights into the regulation of molecular processes. Brome mosaic virus (BMV) is one of the simplest entities with four viral proteins and three genomic RNAs. Here we report that the BMV capsid protein (CP), which functions in RNA encapsidation and virus trafficking, also represses viral RNA replication in a concentration-dependent manner by inhibiting the accumulation of the RNA replication proteins. Expression of the replication protein 2a in trans can partially rescue BMV RNA accumulation. A mutation in the CP can decrease the repression of translation. Translation repression by the CP requires a hairpin RNA motif named the B Box that contains seven loop nucleotides (nt) within the 5' untranslated regions (UTR) of BMV RNA1 and RNA2. Purified CP can bind directly to the B Box RNA with a K (d) of 450 nM. The secondary structure of the B Box RNA was determined to contain a highly flexible 7-nt loop using NMR spectroscopy, native gel analysis, and thermal denaturation studies. The B Box is also recognized by the BMV 1a protein to assemble the BMV replicase, suggesting that the BMV CP can act to regulate several viral infection processes.

Effects of the sliding rehabilitation machine on balance and gait in chronic stroke patients - a controlled clinical trial.

OBJECTIVE: To investigate the effects of a sliding rehabilitation machine on balance and gait in chronic stroke patients. DESIGN: A non-randomized crossover design. SETTING: Inpatient rehabilitation in a general hospital. SUBJECTS: Thirty patients with chronic stroke who had medium or high falling risk as determined by the Berg Balance Scale. INTERVENTIONS: Participants were divided into two groups and underwent four weeks of training. Group A (n = 15) underwent training with the sliding rehabilitation machine for two weeks with concurrent conventional training, followed by conventional training only for another two weeks. Group B (n = 15) underwent the same training in reverse order. The effect of the experimental period was defined as the sum of changes during training with sliding rehabilitation machine in each group, and the effect of the control period was defined as those during the conventional training only in each group. MAIN MEASURES: Functional Ambulation Category, Berg Balance Scale, Six-Minute Walk Test, Timed Up and Go Test, Korean Modified Barthel Index, Modified Ashworth Scale and Manual Muscle Test. RESULTS: Statistically significant improvements were observed in all parameters except Modified Ashworth Scale in the experimental period, but only in Six-Minute Walk Test (P < 0.01) in the control period. There were also statistically significant differences in the degree of change in all parameters in the experimental period as compared to the control period. CONCLUSIONS: The sliding rehabilitation machine may be a useful tool for the improvement of balance and gait abilities in chronic stroke patients.

Inversion Table Fall Injury, the Phantom Menace: Three Case Reports on Cervical Spinal Cord Injury.

BACKGROUND: An inversion device, which is used to suspend one's body and perform traction therapy, was introduced as an inversion table under the name of "Geokkuri" in South Korea. Fall injuries while hanging on inversion tables are among the most devastating spine injuries, as the likelihood of severe neurological sequelae such as tetraplegia increases. However, its enormous danger has been overlooked and this devastating injury has become a common clinical entity over time. The limited number of studies reported imply the lack of interest of researchers in these injuries. We reviewed three cases of spinal cord injury sustained on inversion tables in different environments and report the potential danger associated with the use of inversion tables to facilitate a safer exercise environment.

Submandibular Push Exercise Using Visual Feedback from a Pressure Sensor in Patients with Swallowing Difficulties: A Pilot Study.

Objectives: We aimed to determine the usefulness and effectiveness of a submandibular push exercise with visual feedback from a pressure sensor in patients with dysphagia through continuous exercise sessions. Methods: Twelve patients with dysphagia of various etiologies were included. A total of five exercise sessions (every 3 or 4 days) over three weeks were conducted. During the submandibular push exercise, patients were instructed to maintain a maximum force for 3 s, repeated for 1 min to measure the number of exercises, the maximum pressure, and the area of the pressure-time graph. We statistically compared the values of each exercise trial. Results: Among the 12 patients, eight completed the exercise sessions. As the number of exercise trials increased, the maximum pressure and the area in the pressure-time graph showed a significant increase compared to the previous attempt (p < 0.05). The maximum pressure and the area of the pressure-time graph improved from the first to the fourth session (p < 0.05). The values were maintained after the fourth session, and there was no significant difference between the fourth and the fifth exercise (p > 0.05). There was no significant difference between successful and non-successful groups, except for the Modified Barthel Index (p < 0.05). Conclusion: Through repetitive exercise training, the submandibular push exercise using visual feedback from a pressure sensor can be applied as an exercise method to strengthen swallowing related muscles, such as the suprahyoid and infrahyoid muscles. However, additional studies including more patients and a long-term study period are warranted to evaluate the effects of the exercise for improvement of dysphagia.

Development and validation of bioimpedance prediction equations for fat-free mass in unilateral male amputees.

BACKGROUND: Metabolic disease due to increased fat mass is observed in amputees (APTs), thereby restricting their activity. Systemic health management with periodic body composition (BC) testing is essential for healthy living. Bioelectrical impedance analysis (BIA) is a non-invasive and low-cost method to test BC; however, the APTs are classified as being exempted in the BIA. OBJECTIVE: To develop segmental estimated regression equations (sEREs) for determining the fat-free mass (FFM, kg) suitable for APTs and improve the accuracy and validity of the sERE. METHODS: Seventy-five male APTs participated in this cross-sectional study. Multiple regression analysis was performed to develop highly accurate sEREs of BIA based on independent variables derived from anthropometric measurements, dual-energy X-ray absorptiometry (DXA), and BIA parameters. The difference in validity between the predicted DXA and sum of the segmentally-predicted FFM values by sEREs (Sum_sEREs) values was evaluated using bivariate linear regression analysis and the Bland-Altman plot. RESULTS: The coefficient of determination (R2 ) and total error (TE) between DXA and Sum_sEREs were 71% and 5.4 (kg) in the cross-validation analysis. CONCLUSIONS: We confirmed the possibility of evaluating the FFM of APTs through the sEREs developed in this study. We also identified several independent variables that should be considered while developing such sEREs. Further studies are required to determine the validity of our sEREs and the most appropriate BIA frequencies for measuring FFM in APTs.