ObjectiveTo determine the reliability and validity of hand-held dynamometer (HHD) depending on its fixation in measuring isometric knee extensor strength by comparing the results with an isokinetic dynamometer.MethodsTwenty-seven healthy female volunteers participated in this study. The subjects were tested in seated and supine position using three measurement methods: isometric knee extension by isokinetic dynamometer, non-fixed HHD, and fixed HHD. During the measurement, the knee joints of subjects were fixed at a 35° angle from the extended position. The fixed HHD measurement was conducted with the HHD fixed to distal tibia with a Velcro strap; non-fixed HHD was performed with a hand-held method without Velcro fixation. All the measurements were repeated three times and among them, the maximum values of peak torque were used for the analysis.ResultsThe data from the fixed HHD method showed higher validity than the non-fixed method compared with the results of the isokinetic dynamometer. Pearson correlation coefficients (r) between fixed HHD and isokinetic dynamometer method were statistically significant (supine-right: r=0.806, p<0.05; seating-right: r=0.473, p<0.05; supine-left: r=0.524, p<0.05), whereas Pearson correlation coefficients between non-fixed dynamometer and isokinetic dynamometer methods were not statistically significant, except for the result of the supine position of the left leg (r=0.384, p<0.05). Both fixed and non-fixed HHD methods showed excellent inter-rater reliability. However, the fixed HHD method showed a higher reliability than the non-fixed HHD method by considering the intraclass correlation coefficient (fixed HHD, 0.952-0.984; non-fixed HHD, 0.940-0.963).ConclusionFixation of HHD during measurement in the supine position increases the reliability and validity in measuring the quadriceps strength.

ObjectiveTo evaluate sarcopenic indices in relation to respiratory muscle strength (RMS) in elderly people.MethodsThis study included 65 volunteers over the age of 60 (30 men and 35 women). The skeletal muscle mass index (SMI) was measured using bioimpedance analysis. Limb muscle function was assessed by handgrip strength (HGS), the Short Physical Performance Battery (SPPB), and gait speed. RMS was addressed by maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) using a spirometer. The relationships between RMS and other sarcopenic indices were investigated using the Pearson correlation coefficients and multiple regression analysis adjusted for age, HGS, and SPPB.ResultsBoth MIP and MEP were positively correlated with SMI (r=0.451 and r=0.388, respectively, p<0.05 in both). HGS showed a significant correlation with both MIP and MEP (r=0.560, p<0.01 and r=0.393, p<0.05, respectively). There was no significant correlation between gait speed and either MIP or MEP. The SPPB was positively correlated with MEP (r=0.436, p<0.05). In the multiple regression analysis, MIP was significantly associated with HGS and SMI (p<0.001 and p<0.05, respectively), while MEP was related only with HGS (p<0.05).ConclusionThis study suggests that respiratory muscles, especially inspiratory muscles, are significantly related to limb muscle strength and skeletal muscle mass. The clinical significance of MIP and MEP should be further investigated with prospective studies.

ObjectivesIt has been reported that low skeletal muscle mass correlates with knee osteoarthritis in obese individuals. This study aimed to investigate whether lower limb skeletal muscle mass is independently associated with knee osteoarthritis in the general population.Materials and MethodsThis cross-sectional study used public data from the Fourth and Fifth Korean National Health and Nutrition Examination Survey. Subjects included 4924 community-dwelling adults aged ≥50 years (821 subjects with knee osteoarthritis and 4,103 controls). Skeletal muscle mass index (SMI) was calculated from the appendicular skeletal muscle mass measured by dual energy X-ray absorptiometry. Independent effects of total and lower limb SMI values on knee osteoarthritis were determined using odds ratios (OR) adjusted for age, sex, obesity, total femur bone mineral density, serum vitamin D level, diabetes mellitus status, and physical activity on multivariate logistic regression analysis.ResultsThe adjusted logistic regression model revealed that older age, female sex, and obesity were significantly associated with knee osteoarthritis. A higher serum vitamin D level was also positively correlated with knee osteoarthritis (OR, 1.015; 95% CI, 1.003–1.027; P = 0.010). Although total SMI was not significantly associated with knee osteoarthritis (OR, 0.976; 95% CI, 0.946–1.007; P = 0.127), a low lower limb SMI had an independent effect on knee osteoarthritis (OR, 0.941; 95% CI, 0.900–0.983; P = 0.006).ConclusionsLow skeletal muscle mass in the lower limbs but not in the whole body was independently associated with knee osteoarthritis.

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ObjectiveTo assess cough reflex sensitivity using the simplified cough test (SCT) and to evaluate the usefulness of SCT to screen for silent aspiration.MethodsThe healthy control group was divided into two subgroups: the young (n=29, 33.44±9.99 years) and the elderly (n=30, 63.66±4.37 years). The dysphagic elderly group (n=101, 72.95±9.19 years) consisted of patients with dysphagia, who suffered from a disease involving central nervous system (ischemic stroke 47, intracerebral hemorrhage 27, traumatic brain injury 11, encephalitis 5, hypoxic brain damage 3, and Parkinson disease 8). The SCT was performed using the mist of a 1% citric acid from a portable nebulizer. The time from the start of the inhalation to the first cough was measured as the cough latency. All the dysphagic patients underwent the videofluoroscopic swallowing study.ResultsThe cough latency was more significantly prolonged in the healthy elderly group than in the healthy young group (p<0.001), and in the dysphagic elderly group than in the healthy elderly group (p<0.001). The sensitivity and specificity of SCT were 73.8% and 72.5% for detecting aspiration in the dysphagic patients, and 87.1% and 66.7% for detecting silent aspiration in the aspirated patients.ConclusionCough latency measured with the SCT reflects the impairment of cough reflex in healthy elderly and dysphasic subjects. The results of this study show that the SCT test can be a valuable method of screening aspiration with or without cough in dysphasic patients.

ObjectiveTo confirm the relationship between initial trunk performance and functional outcomes according to gait ability, and whether initial trunk performance is of predictive value in terms of functional prognosis in patients with stroke.MethodsWe reviewed 135 patients who suffered from stroke. Trunk performance of the patients was evaluated using the Trunk Impairment Scale (TIS). The patients were divided into 2 groups according to gait ability at initial stage of stroke. Correlation analyses were performed to assess relationship between initial TIS and functional outcomes. We also evaluated the relationship between initial TIS and the Korean version of Modified Barthel Index (K-MBI) subitems. Finally, stepwise multiple regression analyses were performed to examine the predictive validity of initial TIS and its subscales with functional outcomes.ResultsFor both groups, initial TIS was correlated with K-MBI and Functional Ambulation Categories at 4 weeks after stroke; however, the relationship did not remain stable at 6 months in ambulatory patients. All K-MBI subitems, which were associated with trunk movement, as well as others about basic skills was correlated with initial TIS. Finally, when of subscales TIS, dynamic sitting balance (TIS-D) was included in by stepwise multiple regression analyses, high proportion of the explained variance was represented.ConclusionThe strong relationship between trunk performance and functional outcomes in patients with stroke emphasizes the importance of trunk rehabilitation. Indeed, an evaluation of a patient's initial TIS after stroke, especially TIS-D, could be helpful in predicting patient's functional prognosis.

Objective To investigate the relationship between grip and pinch strength and independence in activities of daily living (ADL) in stroke patients. Methods Medical records of 577 stroke patients from January 2010 to February 2013 were retrospectively reviewed. Patients' grip and pinch strength of both hemiplegic and non-hemiplegic hands and the Korean version of Modified Barthel Index (K-MBI) score were collected. These patients were divided into three groups: group A (onset duration: ≤3 months), group B (onset duration: >3 months and <2 years), and group C (onset duration: ≥2 years). The correlation between grip and pinch strength and the K-MBI score was analyzed. Results In group A (95 patients), the K-MBI score was significantly (p<0.05) correlated with the grip and pinch strength of both hands in patients with right hemiplegia. Significant (p<0.05) correlation between the K-MBI score and the grip and pinch strength of the hemiplegic hand was shown in patients with left hemiplegia. In group B (69 patients) and group C (73 patients), the K-MBI score was significantly (p<0.05) correlated with the grip and pinch strength of the hemiplegic hand. Conclusion Stroke patients in subacute stage mainly performed activities of daily living using their dominant hand. However, independence in ADL was associated with the strength of the affected dominant hand. For stroke patients in chronic and late chronic stages, their hand power of the affected hand was associated with independence in ADL regardless whether the dominant hand was affected.

ObjectiveTo investigate the relationships between respiratory muscle strength and conventional sarcopenic indices such as skeletal muscle mass and limb muscle strength.MethodsEighty-nine young adult volunteers who had no history of medical or musculoskeletal disease were enrolled. Skeletal muscle mass was measured by bioelectrical impedance analysis and expressed as a skeletal muscle mass index (SMI). Upper and lower limb muscle strength were evaluated by hand grip strength (HGS) and isometric knee extensor muscle strength, respectively. Peak expiratory flow (PEF), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were evaluated using a spirometer to demonstrate respiratory muscle strength. The relationships between respiratory muscle strength and sarcopenic indices were investigated using Pearson correlation coefficients and multiple linear regression analysis adjusted by age, height, and body mass index.ResultsMIP showed positive correlations with SMI (r=0.457 in men, r=0.646 in women; both p<0.01). MIP also correlated with knee extensor strength (p<0.01 in both sexes) and HGS (p<0.05 in men, p<0.01 in women). However, PEF and MEP had no significant correlations with these sarcopenic variables. In multivariate regression analysis, MIP was the only independent factor related to SMI (p<0.01).ConclusionAmong the respiratory muscle strength variables, MIP was the only value associated with skeletal muscle mass.