Artificial Neural Network Learns Clinical Assessment of Spasticity in Modified Ashworth Scale.

OBJECTIVE: To propose an artificial intelligence (AI)-based decision-making rule in modified Ashworth scale (MAS) that draws maximum agreement from multiple human raters and to analyze how various biomechanical parameters affect scores in MAS. DESIGN: Prospective observational study. SETTING: Two university hospitals. PARTICIPANTS: Hemiplegic adults with elbow flexor spasticity due to acquired brain injury (N=34). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Twenty-eight rehabilitation doctors and occupational therapists examined MAS of elbow flexors in 34 subjects with hemiplegia due to acquired brain injury while the MAS score and biomechanical data (ie, joint motion and resistance) were collected. Nine biomechanical parameters that quantify spastic response described by the joint motion and resistance were calculated. An AI algorithm (or artificial neural network) was trained to predict the MAS score from the parameters. Afterwards, the contribution of each parameter for determining MAS scores was analyzed. RESULTS: The trained AI agreed with the human raters for the majority (82.2%, Cohen's kappa=0.743) of data. The MAS scores chosen by the AI and human raters showed a strong correlation (correlation coefficient=0.825). Each biomechanical parameter contributed differently to the different MAS scores. Overall, angle of catch, maximum stretching speed, and maximum resistance were the most relevant parameters that affected the AI decision. CONCLUSIONS: AI can successfully learn clinical assessment of spasticity with good agreement with multiple human raters. In addition, we could analyze which factors of spastic response are considered important by the human raters in assessing spasticity by observing how AI learns the expert decision. It should be noted that few data were collected for MAS3; the results and analysis related to MAS3 therefore have limited supporting evidence.

Swallowing Function Defined by Videofluoroscopic Swallowing Studies after Anterior Cervical Discectomy and Fusion: a Prospective Study.

This study evaluated factors related to swallowing dysfunction after anterior cervical discectomy and fusion (ACDF) using videofluoroscopic swallowing studies (VFSS). Preoperative and postoperative VFSSs were done with 5 mL diluted barium. Oral transit time, pharyngeal delay time, pharyngeal response time (PRT), and pharyngeal transit time were measured. Hyoid bone movement and upper esophageal sphincter (UES) diameter were measured serially. Thickness of prevertebral soft tissue was measured from digitized VFSS images. In results, 12 of 20 patients showed abnormal postoperative VFSS findings. PRT decreased significantly after surgery. Hyoid bone movement did not change significantly after surgery. The maximal distance of UES opening decreased significantly after surgery, and the higher the level of surgery (C3 > C4 > C5 > C6), the greater the decrease in maximal distance of the UES opening after surgery. The time to widest opening of the UES was prolonged significantly. At the C3 and C4 levels, the change in prevertebral soft tissue thickness of patients with VFSS abnormalities was significantly greater than those without abnormalities. In conclusion, patients after ADCF with their highest surgery level at C3 and C4 showed more abnormal VFSS findings, significantly increased soft tissue thickness, and decreased maximal distance of UES opening. VFSS provided objective data related with swallowing dysfunction after ACDF.

Bilateral ischemic lumbosacral plexopathy from chronic aortoiliac occlusion presenting with progressive paraplegia.

Spinal cord ischemia is rare but causes significant morbidity and mortality. Spinal cord ischemia has been reported after open and endovascular interventions of the thoracic and abdominal aorta, and, rarely, acute occlusion of aorta from in situ thrombosis or acute embolic occlusion. Acute interruption of the critical blood supply to the spinal cord or root contributes to this devastating neurologic deficit. However, gradually worsening lumbosacral plexopathy and consequent paraplegia related to chronic aortic occlusion is extremely rare. We present a case of a 58-year-old man with progressive lower limb paralysis from atherosclerotic aortoiliac occlusion without history of aortic surgery or evidence of thromboembolism.

Investigation of brain mechanisms underlying upper limb function in bilateral cerebral palsy using EEG.

OBJECTIVE: Few studies focus on upper limbs in bilateral cerebral palsy (CP) despite potential bimanual deficits. Electroencephalography (EEG) was utilized to investigate brain mechanisms underlying upper limb tasks in bilateral CP and typical development (TD) and relationships to function. METHODS: 26 (14 CP; 12 TD) completed the Box and Blocks Test and transport task with paper, sponge or mixed blocks, while recording EEG and motion data. RESULTS: Group effects for path time, path length and Box and Blocks Test revealed bimanual deficits. Four sensorimotor-related EEG clusters were identified. Group effects were found in premotor and dominant motor clusters with greater beta event-related desynchronization (ERD) in CP. Hand and hand by group effects were found in the dominant motor cluster, showing greater ERD with the more affected hand in CP. Condition effects were prominent in the posterior parietal cluster with higher ERD reflecting greater difficulty in force modulation. CONCLUSIONS: Higher brain activation associated with greater bimanual deficits is similar to our lower limb findings but contrasts studies in TD or unilateral CP linking higher ERD to greater proficiency. SIGNIFICANCE: Bilateral CP shows overreliance on the dominant hemisphere with the less functional hand and higher brain activity presumably related to excessive intracortical connectivity.

Usefulness of videofluoroscopic swallow study with mixed consistency food for patients with stroke or other brain injuries.

This study evaluated the feasibility of mixed consistency foods test in patients with dysphagia which developed after stroke or other brain injuries. The findings of a videofluoroscopic swallow study (VFSS) were compared using single versus mixed consistency foods. Forty-nine patients with stroke or other brain injuries who had no significant abnormal findings in the single consistency food VFSS and started regular hospital diet were recruited for this study. Twenty-five (51%) of the 49 patients showed normal findings whereas 24 (49%) patients showed abnormal findings in the mixed consistency food VFSS. Abnormal findings included posterior spillage of liquid prematurely to pyriform sinus (n = 23), laryngeal penetration (n = 6), subglottic aspiration in the oral preparatory phase of swallowing (chewing), solid components (n = 2), and significant (more than 10%) residue in valleculae or pyriform sinus (n = 2). There was an increased risk of abnormal findings in mixed consistency food VFSS such as aspiration and penetration when a patient showed delayed pharyngeal delay time in single consistency food using liquids. In conclusion, VFSS protocols using mixed consistency foods would be useful before starting regular diet for patients after stroke or other brain injuries.

Association between sensory nerve action potential and lumbar dorsal root ganglion area.

OBJECTIVE: To quantify the cross-sectional area (CSA) of lumbar dorsal root ganglion (DRG) by magnetic resonance imaging (MRI) and investigate the relationship between the cross-sectional area (CSA) of DRGs and sensory nerve action potentials (SNAP) amplitude in the lower extremities. METHODS: Thirty-eight DRGs (20 L5 roots and 18 S1 roots) in 10 adult subjects were reviewed retrospectively. The CSA of the DRG was calculated from MR images of the coronal plane. SNAP amplitudes of the superficial peroneal nerve and sural nerve were corresponded to L5 and S1-DRGs. RESULTS: The mean CSA of DRGs was 66.6 ±â€¯13.7 mm2 in L5-DRG and 79.5 ±â€¯14.3 mm2 in S1-DRG. The means of SNAP amplitudes were 19.6 ±â€¯6.2 µV in superficial peroneal nerves and 24.6 ±â€¯9.0 µV in sural nerves. In multivariate regression analysis, the CSA of DRGs had a significant correlation with SNAP amplitude. CONCLUSION: The area of L5 and S1-DRGs may be positively correlated with SNAP amplitude.

Correlation Between Mechanography and Clinical Parameters at Six Months After Hip Fracture Surgery.

OBJECTIVE: To investigate the correlation between mechanography and clinical parameters in older people at 3 and 6 months after hip fracture surgery. METHODS: A longitudinal follow-up study was conducted in university hospitals with 38 patients at 3 months and 29 patients at 6 months after hip fracture surgery. Subjects 65 years and older completed measurements on the Berg Balance Scale (BBS), Functional Ambulation Category (FAC), walking ability by Koval, Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight (K-FRAIL) scale, and hand grip strength. The Romberg test with center of foot pressure (COP), chair rise test (CRT), and maximal power (W/kg) were conducted using the Leonardo Mechanograph. RESULTS: COP area and pathway length were correlated with BBS at 3 and 6 months. Change in BBS was correlated with change in COP area, but not with change in COP length. COP area and pathway length were correlated with K-FRAIL at 3 months after hip fracture surgery. The same COP variables showed correlations with FAC and walking ability by Koval at 6 months after surgery. Maximal power during CRT had correlation with chair rise time but not with other clinical parameters. CONCLUSION: The study revealed correlations between mechanography and clinical parameters in older people at 3 and 6 months after hip fracture surgery. Both the clinical assessment and objective test with mechanography may be required for the quantitative and sensitive measurement of postural balance and lower limb muscle power.

Modifying and evaluating efficacy of interactive computerized program using motion tracking technology to improve unilateral neglect in patients with chronic stroke.

BACKGROUND: To modify and evaluate the efficacy of a computerized visual perception rehabilitation program using interactive motion tracking technology with unilateral neglect after chronic stroke. METHODS: Study design is single-blinded (analyst-blinded) controlled prospective clinical trial. Subjects are 16 patients with chronic stroke and unilateral neglect for over 6 months and 19 healthy volunteers. We modified our previous program to 9 tasks with built-in scoring system, and the subjects performed 3 sessions per week, 30 minutes per session for 4 weeks. RESULTS: Scores for the Modified Barthel Index (MBI), Mini-Mental State Examination (MMSE), Motor-free Visual Perception Test (MVPT), Line bisection test, Star cancellation test, Forward Digit Test, and Backward Digit Test showed significant improvement at the end of the sessions in the patient group. By comparing the parameters of built-in scoring system of each task among the control group, the first session of training in the patient group, and the last session of training in the patient group, we categorized the parameters for optional measurement to determine the effect of training or to be a candidate for evaluative use. CONCLUSIONS: Our modified computerized visual perception rehabilitation program using improved unilateral neglect in patients post-stroke. Built-in scoring system in this program was helpful to assess availability of it more objectively.

Sustained disconnection in sensorimotor pathways results in poor motor function outcome in a term infant after severe white matter injury: A case report.

INTRODUCTION: We report a case of an infant with severe white matter injury (WMI), which was serially evaluated using diffusion tensor imaging (DTI). CASE PRESENTATION: A male infant showed decreased muscle tone and weak breathing. A brain magnetic resonance imaging (MRI) 10 days after birth (first study) revealed diffuse microhemorrhages and encephalomalacia. DTI revealed lack of reconstruction of corticospinal tract (CSTs), minimal reconstruction of medial lemniscus, and related thalamocortical pathways (MLs) from the brain stem to the internal capsule level on the left side. The spinothalamic tract and related thalamocortical pathways (STTs) were reconstructed from the brain stem to the internal capsule level bilaterally. The second study one year later showed the absence of reconstruction of CSTs, but reconstruction of MLs and STTS from the brain stem to above the internal capsule showed increased visualization. The third study 3 years later still showed the absence of CSTs reconstruction and MLs and STTs showed no changes from the second study. During this 3-year observation period, the patient showed minimal motor development, and was unable to walk independently, although Gross Motor Function Measure (GMFM) scores were slightly increased. LESSONS: Sustained disconnection of major sensorimotor pathways after WMI confirmed by DTI was used to predict motor function outcome.

Clinical and Radiological Evaluation After Chemical Synovectomy With Rifampicin in Hemophilic Arthropathy: Korean Experience With a 2-Week Interval Protocol.

OBJECTIVE: To assess the clinical outcome of chemical synovectomy with rifampicin in hemophilic arthropathy by using the World Federation of Hemophilia (WFH) scoring system and plain radiograph. METHODS: We performed rifampicin synovectomy (RS) on 30 joints of 28 hemophilic patients diagnosed as hemophilic arthropathy stage I-III (based on Fernandez-Palazzi clinical classification). Clinical status (bleeding frequency, pain, joint physical status) and radiological staging were evaluated as parts of the WFH scoring system before and 1 year after RS. The patients were divided into two groups by the Arnold-Hilgartner scale of the initial X-ray as stage 3 or less for the low-stage group (n=17) and over 3 for the high-stage group (n=13). RESULTS: Total WFH joint physical scores were reduced after injection, and the number of bleeding episodes and pain showed especially significant improvement. For other subscores of the WFH joint physical score, only swelling, range of motion, and crepitus showed statistically significant improvement. According to the severity of the radiologic finding, the WFH joint physical score of both the low-stage and high-stage groups showed significant improvement. In the radiological aspect, the low-stage group, without joint space narrowing at the initial plain radiograph, showed no further aggravation after injection. However, in the high-stage group, radiology found aggravation regardless of the procedure. CONCLUSION: It is suggested that chemical synovectomy with rifampicin may prevent hemarthrosis and improve clinical symptoms. Especially in the early stage of arthropathy without joint-space narrowing, it seems to have an additional benefit that delays radiological aggravation and preserves joint status.

Independent factors associated with bicycle helmet use in a Korean population: A cross-sectional study.

OBJECTIVE: Although identification of factors that influence helmet use during bicycle riding is necessary for the selection of groups that require safe cycling education, limited baseline data are available. The aim of the present study was to analyze the rate of helmet use and the demographic factors that were independently associated with helmet use among Korean bicycle riders. METHODS: In this cross-sectional study, we used public data from the Sixth Korean National Health and Nutrition Examination Survey conducted in 2013 and 2014. Helmet users were defined as subjects who always, usually, or frequently wore helmets when cycling. Independent factors associated with helmet use were determined using odds ratios (ORss) adjusted for 5 demographic factors via multivariate logistic regression analysis. RESULTS: In the total population, 4,103 individuals were bicycle riders; among these, 782 individuals (19.1%) wore helmets. A total of 21.1% of male riders used helmets, compared to 15.5% of female riders (P <.001). The adjusted logistic regression model revealed that female sex (OR = 0.665; 95% confidence interval [CI], 0.554-0.797), teenage status (OR = 0.475, 95% CI, 0.333-0.678), and low household income (OR = 0.657, 95% CI 0.513-0.841) were significantly associated with nonuse of helmets. CONCLUSIONS: Female sex, teenage status, and low household income were independent factors associated with the nonuse of helmets. We identified factors associated with helmet use during bicycle riding through analysis of baseline data on helmet usage.

Association Between Walking and Low Back Pain in the Korean Population: A Cross-Sectional Study.

OBJECTIVE: To investigate if walking is independently associated with low back pain (LBP) in the general population. METHODS: This cross-sectional study used public data from the Fourth and Fifth Korean National Health and Nutrition Examination Survey. Subjects included 5,982 community-dwelling adults aged ≥50 years. Presence of current LBP was defined as LBP for 1 month or more in the past 3 months. Walking was measured as total walking duration for the past week and subjects were divided into four quartiles. Independent effect of walking on LBP was determined using odds ratios (OR) adjusted for age, sex, osteoporosis, depression or anxiety, and radiographic lumbar spondylosis. RESULTS: Prevalence of LBP was 26.4% in this population. Older people and women had higher prevalence of current LBP. Prevalence of obesity and osteoporosis was higher in subjects with current LBP and quality of life was poorer in subjects with current LBP. Adjusted logistic regression model revealed that older age (OR, 1.655; p=0.018), female sex (OR, 2.578; p<0.001), radiographic lumbar spondylosis (OR, 2.728; p<0.001), depression or anxiety (OR, 5.409; p<0.001), and presence of osteoporosis (OR, 1.467; p=0.002) were positively associated with current LBP. Walking decreased prevalence of current LBP proportionally (2nd quartile OR, 0.795; 3rd quartile OR, 0.770; and 4th quartile OR, 0.686 compared with the 1st quartile of walking). CONCLUSION: Walking was negatively associated with LBP. Further studies are needed to reveal causal relationship of this phenomenon.

Relation Between Respiratory Muscle Strength and Skeletal Muscle Mass and Hand Grip Strength in the Healthy Elderly.

OBJECTIVE: To evaluate sarcopenic indices in relation to respiratory muscle strength (RMS) in elderly people. METHODS: This 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. RESULTS: Both 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). CONCLUSION: This 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.

Changes in the corticospinal tract after wearing prosthesis in bilateral transtibial amputation.

BACKGROUND: After amputation, the brain is known to be reorganized especially in the primary motor cortex. We report a case to show changes in the corticospinal tract in a patient with serial bilateral transtibial amputations using diffusion tensor imaging. Case Description and Methods: A 78-year-old man had a transtibial amputation on his left side in 2008 and he underwent a right transtibial amputation in 2011. An initial brain magnetic resonance imaging with a diffusion tensor imaging was performed before starting rehabilitation on his right transtibial prosthesis, and a follow-up magnetic resonance imaging with diffusion tensor imaging was performed 2 years after this. Findings and Outcomes: In the initial diffusion tensor imaging, the number of fiber lines in his right corticospinal tract was larger than that in his left corticospinal tract. At follow-up diffusion tensor imaging, there was no definite difference in the number of fiber lines between both corticospinal tracts. CONCLUSION: We found that side-to-side corticospinal tract differences were equalized after using bilateral prostheses. Clinical relevance This case report suggests that diffusion tensor imaging tractography could be a useful method to understand corticomotor reorganization after using prosthesis in transtibial amputation.

Diagnostic Challenge of Diffusion Tensor Imaging in a Patient With Hemiplegia After Traumatic Brain Injury.

A 51-year-old man showed hemiplegia on his right side after a traumatic brain injury (TBI). On initial brain computed tomography (CT) scan, an acute subdural hemorrhage in the right cerebral convexity and severe degrees of midline shifting and subfalcine herniation to the left side were evident. On follow-up brain magnetic resonance imaging (MRI), there were multiple microhemorrhages in the left parietal and occipital subcortical regions. To explain the occurrence of right hemiplegia after brain damage which dominantly on the right side of brain, we used diffusion tensor imaging (DTI) to reconstruct the corticospinal tract (CST), which showed nearly complete injury on the left CST. We also performed motor-evoked potentials, and stimulation of left motor cortex evoked no response on both sides of upper extremity. We report a case of patient with hemiplegia after TBI and elucidation of the case by DTI rather than CT and MRI.

Relationship Between Types of Exercise and Quality of Life in a Korean Metabolic Syndrome Population: A Cross-Sectional Study.

BACKGROUND: Metabolic syndrome (MetS) significantly correlates with exercise. MetS also has an independent and inverse correlation to quality of life (QoL). However, few studies have examined the association between exercise and QoL in people with MetS. The aim of this study was to ascertain the relationship between exercise and QoL in a MetS population. METHODS: This was a cross-sectional study using public data from the Sixth Korean National Health and Nutrition Examination Survey in 2014 (n = 7550). MetS was defined on the basis of the revised National Cholesterol Education Program criteria. Demographic factors, three types of exercise (resistance, flexibility, walking), five subsets of EuroQoL (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), and QoL scores (EQ-VAS), were investigated. Independent associations of each exercise on five subsets of QoL were determined using odds ratios (OR) adjusted for four demographic factors (age group, sex, weight change, and area of residence) using multivariate logistic regression analysis. RESULTS: Prevalence of MetS was 26.4% and the ratio of subjects performing resistance, flexibility, or walking exercise was 17.7%, 45.8%, and 71.5% among this population, respectively. EQ-VAS of exercisers was significantly higher than that of non-exercisers in resistance, flexibility, and walking exercise. Although resistance and flexibility exercise did not correlate with any subsets of QoL, mobility and self-care were significantly associated with walking exercise (OR = 0.635, 95% CI = 0.439-0.919 and OR = 0.577, 95% CI = 0.348-0.958, respectively). CONCLUSIONS: All exercisers showed higher QoL scores than non-exercisers. Among QoL subsets, mobility and self-care were independently associated with walking exercise in the MetS population. Regular walking exercise was important to higher QoL in those with MetS. This is the first clinical report to indicate that QoL could be independently influenced by walking exercise.

Development of elbow spasticity model for objective training of spasticity assessment of patients post stroke.

Reliable assessment is essential for the management of spasticity, one of the most frequent complication of various neurological diseases. For the spasticity assessment, several clinical tools have been developed and widely used in clinics. The most popular one is modified Ashworth scale (MAS). It has a simple protocol, but is subjective and qualitative. To improve its reliability, quantitative measurement and consistent training would be needed. This study presents an elbow spasticity simulator which mimics spastic response of adult post stroke survivors. First, spastic responses (i.e. resistance and joint motion) from patients with a stroke were measured during conventional MAS assessment. Each grade of MAS was quantified by using three parameters representing three characteristics of the spasticity. Based on the parameters, haptic models of MAS were developed for implementing repeatable and consistent haptic training of novice clinicians. Two experienced clinicians participated in preliminary evaluation of the models.

EMG Activity of Masseter Muscles in the Elderly According to Rheological Properties of Solid Food.

OBJECTIVE: To assess the impact of aging on masticatory muscle function according to changes in hardness of solid food. METHODS: Each of fifteen healthy elderly and young people were selected. Subjects were asked to consume cooked rice, which was processed using the guidelines of the Universal Design Foods concept for elderly people (Japan Care Food Conference 2012). The properties of each cooked rice were categorized as grade 1, 2, 3 and 4 (5×10(3), 2×10(4), 5×10(4), and 5×10(5) N/m(2)) respectively. Surface electromyography (sEMG) was used to measure masseter activity from food ingestion to swallowing of test foods. The raw data was normalized by the ratio of sEMG activity to maximal voluntary contraction and compared among subjects. The data was divided according to each sequence of mastication and then calculated within the parameters of EMG activities. RESULTS: Intraoral tongue pressure was significantly higher in the young than in the elderly (p<0.05). Maximal value of average amplitude of the sequence in whole mastication showed significant positive correlation with hardness of food in both young and elderly groups (p<0.05). In a comparisons between groups, the maximal value of average amplitude of the sequence in whole mastication and peak amplitude in whole mastication showed that mastication in the elderly requires a higher percentage of maximal muscle activity than in the young, even with soft foods (p<0.05). CONCLUSION: sEMG data of the masseter can provide valuable information to aid in the selection of foods according to hardness for the elderly. The results also support the necessity of specialized food preparation or products for the elderly.

Low Skeletal Muscle Mass in the Lower Limbs Is Independently Associated to Knee Osteoarthritis.

OBJECTIVES: It 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 METHODS: This 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. RESULTS: The 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). CONCLUSIONS: Low skeletal muscle mass in the lower limbs but not in the whole body was independently associated with knee osteoarthritis.