Association of physical activity with fatty infiltration of muscles after total hip arthroplasty.

OBJECTIVE: This study aimed to investigate the association between muscle density as an indicator of fatty infiltration of lower extremity muscles and physical activity (PA) after total hip arthroplasty (THA) and identify the patient characteristics with high postoperative PA. METHODS: This study included 62 female patients who underwent THA for unilateral hip osteoarthritis. Muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles was measured using computed tomography (CT). PA was assessed using University of California, Los Angeles (UCLA) activity scores. CT and UCLA activity score were obtained before and 1 year after THA. The patients were divided into two groups, sufficient (score ≥ 6) and insufficient (score < 6) activity groups, based on their level of PA as determined by their UCLA activity score 1 year after THA. The association of PA with the amount of changes in muscle density was examined with Spearman's rank correlation coefficient. Logistic regression analysis was performed to identify postoperative factors determining PA at 1 year after THA. RESULTS: Spearman's rank correlation coefficient showed a significantly positive association between recovery in PA and an increase in muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles. Additionally, logistic regression analysis confirmed that postoperative muscle densities of the gluteus maximus and quadriceps muscles were variables determining the PA 1 year after THA. CONCLUSION: The findings of this study indicated that the improvement of fatty infiltration in lower limb muscles, especially in the gluteus maximus and quadriceps, is likely to promote the increase in postoperative PA.

Attention to the domains of Revised Hasegawa Dementia Scale and Mini-Mental State Examination in patients with Alzheimer's disease dementia.

BACKGROUND: In Japan, Alzheimer's disease dementia (AD) is the most common cognitive disease, and the most widely used dementia screening tests are the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental State Examination (MMSE). This study sought to elucidate the relationships of the individual domains of these tests with age and duration of school education in a large group of patients with AD. METHODS: Participants were 505 new outpatients diagnosed with AD who completed the HDS-R and MMSE at the first visit. We investigated the relationships of total and individual domains of these tests with age and duration of school education using the least squares method. Next, we plotted regression lines of the individual domain scores against the total test scores. RESULTS: Younger age and longer duration of school education were significantly associated with higher total HDS-R and MMSE scores in AD. Domain-specific results indicated that younger age was significantly associated with a higher immediate memory score on both the HDS-R and MMSE and with a higher orientation (time), repetition score on the MMSE. Longer duration of school education was significantly associated with a higher working memory score on the HDS-R and with higher serial 7, repetition and writing scores on the MMSE. In addition, shorter duration of school education was significantly associated with higher naming score on the MMSE. The regression lines of orientation of time, remote memory, visual memory, and verbal frequency hit the bottom on the HDS-R (4/30, 8/30, 4/30, and 6/30, respectively) and of orientation of time, serial 7, remote memory, and writing also hit the bottom on the MMSE (8/30, 9/30, 11/30, and 8/30, respectively). CONCLUSIONS: We should pay attention to age, duration of school education, and the individual domains when using the HDS-R or MMSE to assess patients with AD.

The Neurophysiological Features Associated with Unilateral Spatial Neglect Recovery: A Scoping Review.

The purpose of this scoping review is to provide updated information on the neural basis and neurophysiological features associated with unilateral spatial neglect (USN) recovery. We applied the Preferred Reporting Systems for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework and identified 16 relevant papers from the databases. Critical appraisal was performed by two independent reviewers using a standardized appraisal instrument developed by the PRISMA-ScR. We identified and categorized investigation methods for the neural basis and neurophysiological features of USN recovery after stroke using magnetic resonance imaging (MRI), functional MRI, and electroencephalography (EEG). This review found two brain-level mechanisms underlying USN recovery at the behavioral level. These include the absence of stroke-related damage to the right ventral attention network during the acute phase and compensatory recruitment of analogous areas of the undamaged opposite hemisphere and prefrontal cortex during visual search tasks in the subacute or later phases. However, the relationship between the neural and neurophysiological findings and improvements in USN-related activities of daily living remains unknown. This review adds to the growing body of evidence regarding the neural mechanisms underlying USN recovery.

Interactive Combinations Between Gait Speed and Physical Function at Acute Phase Can Predict the Physical Activity at 2 Years After Total Knee Arthroplasty Using Classification and Regression Tree Analysis.

OBJECTIVE: To clarify the interactive combinations of various clinical factors associated with physical activity (PA) at 2 years after total knee arthroplasty (TKA) using classification and regression tree (CART) analysis. DESIGN: A retrospective cohort study. SETTING: A single university hospital. PARTICIPANTS: 286 patients who underwent TKA (N=286). MAIN OUTCOME MEASURES: PA was assessed preoperatively, 3 weeks, and 2 years after TKA. Physical functions, namely, 10 m walking test (10MWT), timed Up and Go test, 1-leg standing time, isometric knee extension and flexion strength, knee joint stability, knee pain, femora-tibial angle, and the passive knee extension and flexion angle, were measured before surgery as a baseline and 3 weeks after TKA as acute phase. CART analysis was conducted to clarify the interactive combinations that accurately predict the PA at 2 years after TKA. RESULTS: The results of CART analysis indicated that gait speed (≥1.05 m/s) at the acute phase after TKA was the primal predictor for the postoperative PA at 2 years. The highest postoperative PA at 2 years was determined by gait speed (≥1.05 m/s) and PA (>74.5) at the acute phase. The PA at baseline and at acute phase, as well as the body mass index were also selected as predictors of postoperative PA at 2 years. CONCLUSION: The present study suggested that acquiring gait speed (≥1.05 m/s) and PA (>74.5) in the postoperative acute phase is the predictive of a high PA at 2 years after TKA.

Three-dimensional quantitative measurements of atrophy and fat infiltration in sub-regions of the supraspinatus muscle show heterogeneous distributions: a cadaveric study.

INTRODUCTION: Rotator cuff tears are common in the older population. Atrophy and fat infiltration develop un-evenly in torn supraspinatus (SSP) muscles leading to pre- and post-surgical complications. The purpose of the current study was twofold: first, to implement a volumetric and quantitative magnetic resonance imaging (MRI) approach to quantify the degree of muscle atrophy and fat infiltration within the SSP muscle and its four sub-regions (AS, PS, AD, and PD); second to compare 3-D MRI outcomes to the standard 2-D assessment and investigate their relationship with tear size. MATERIALS AND METHODS: Fifteen cadaveric shoulders were obtained and MRI performed. Quantitative 3-D outcomes included SSP muscle volume, fossa volume, fat-free muscle volume, and fat fraction for the whole SSP muscle and its four sub-regions. 2-D and qualitative measurements included tear size, 2-D fat infiltration using the Goutallier classification, tangent sign, and occupation ratio. RESULTS: Linear regression outcomes with tear size were not significant for both cross-sectional area (r = - 0.494, p = 0.061) and occupation ratio (r = - 0.011, p = 0.969). Tear size negatively correlated with fat-free muscle volume for both AS and PS sub-regions (AS: r = - 0.78, p < 0.001; PS: r = - 0.68, p = 0.005, respectively) while showing no significant correlation with fat fraction outcomes. AD and PD sub-regions positively correlated with tear size and fat fraction outcomes (AD: r = 0.70, p = 0.017; PD: r = 0.52, p = 0.045, respectively), while no significant correlation was observed between tear size and fat-free muscle volumes. CONCLUSION: Quantitative 3-D volumetric assessment of muscle degeneration resulted in better outcomes compared to the standard 2-D evaluation. The superficial supraspinatus muscle sub-regions primarily presented muscle atrophy, while the deep sub-regions were mainly affected by fat infiltration. 3-D assessments could be used pre-surgically to determine the best course of treatment and to estimate the muscles' regenerative capacity and function.

Influence of fat infiltration, tear size, and post-operative tendon integrity on muscle contractility of repaired supraspinatus muscle.

BACKGROUND: The purpose of this study was to evaluate the effect of fat infiltration, tear size, and post-operative tendon integrity, on post-operative contractility. METHODS: Thirty-five patients who underwent rotator cuff repair were included. The fat infiltration, tear size, and post-operative tendon integrity were evaluated by Goutallier stage, Cofield classification, and Sugaya classification, respectively. The muscle elasticity at rest and at contraction was assessed by real-time tissue elastography pre- and one-year post-operatively. We defined the difference in elasticity between at rest and at contraction as the activity value which reflects muscle contractility. RESULTS: The activity value in patients with Sugaya Type I tended to increase regardless of Cofield classification, whereas those with Sugaya Type III and IV tended to decrease. While the activity value in the patients classified as stage 1 and Type I tended to increase, patients classified as stage 2 showed decreased or constant in contractility even in those subjects classified as Type I. Stepwise multiple regression analysis showed both pre- (p = 0.004, r = -0.47) and post-operative activity values (p = 0.022, r = -0.39) to be significantly correlated only with the Goutallier stage. CONCLUSION: Multiple regression analysis indicated only the Goutallier stage was a significant independent factor for contractility of the supraspinatus muscle. Supraspinatus muscle contractility in patients classified as Types III and IV based on the Sugaya classification tended to decrease post-operatively, while patients whose contractility increased post-operatively were characterized by having a Type I tendon integrity.

Shoulder scaption is dependent on the behavior of the different partitions of the infraspinatus muscle.

PURPOSE: The purpose of this study was to investigate if the three partitions (superior, middle, and inferior partitions) of the infraspinatus muscle previously described in anatomical studies will present different behavior during scapular plane abduction (scaption) as described using shear-wave elastography, especially during initial range of motion. METHODS: Eight volunteers held their arm against gravity 15° intervals from 30° to 150° in scaption. Shear-wave elastography was implemented at each position to measure shear modulus at rest and during muscle contraction, as a surrogate for muscle stiffness, of each partition. Muscle activity was defined as the difference in stiffness values between the resting positions and those during muscle contraction (ΔE = stiffness at contraction-stiffness at rest). RESULTS: The activity value for the middle partition was 25.1 ± 10.8 kPa at 30° and increased up to 105° (52.2 ± 10.8 kPa), with a subsequent decrease at larger angle positions (p < .001). The superior partition showed a flatter and constant behavior with smaller activity values except at higher angles (p < .001). Peak activity values for the superior partition were observed at 135° (23.0 ± 12.0 kPa). Increase activity for inferior partition began at 60° and showed a peak at 135° (p < .001; 32.9 ± 13.8 kPa). CONCLUSION: Stiffness measured using shear-wave elastography in each partition of the infraspinatus muscle demonstrated different behavior between these partitions during scaption. The middle partition generated force throughout scaption, while the superior and inferior partitions exerted force at end range.

Capsular attachment of the subregions of rotator cuff muscles.

PURPOSE: This study aimed to morphologically and histologically investigate the relationship between deep subregions of the rotator cuff muscle and shoulder joint capsule as well as the relationship between the rotator cuff tendon or capsule and bony insertion. METHODS: We examined 13 shoulders of embalmed cadavers and measured the capsular attachments and footprints macroscopically. We also histologically examined the fibres in three shoulders. RESULTS: Loose attachment, which was less tight with spaced connective tissue, and firm attachment, which was tight with dense connective tissue, were found under the surface of the supraspinatus and infraspinatus. The anterior-deep and posterior-deep subregions of the supraspinatus and the middle partition and inferior partition of the infraspinatus formed firm attachments to the capsule. The mean areas of firm attachment for the anterior-deep subregion, posterior-deep subregion and middle partition were 118.8 mm2, 267.8 mm2 and 399.3 mm2, respectively, while the area of the inferior partition was small. The transverse fibres were located just lateral to the medial edge of the firm attachment area. The thick capsule had a substantial footprint. Both tendon fibres and the capsule inserted into the superior and middle facets through the attachment fibrocartilage. CONCLUSIONS: The posterior-deep subregion of the supraspinatus and middle partition of the infraspinatus evenly occupied the capsular attachment area. The transverse fibres were located just lateral to the medial edge of the firm attachment area, and the thick capsule had a substantial footprint. Both tendon fibres and the capsule inserted into the superior and middle facets through the attachment fibrocartilage.

Contractile property measurement of the torn supraspinatus muscle using real-time tissue elastography.

HYPOTHESIS: In the restoration of shoulder abduction, decreased contractility of the torn rotator cuff muscle may be a cause of a poor result. The aim of this study was to investigate the relationship between the contractile property of the torn supraspinatus muscle measured by real-time tissue elastography and the Goutallier stage as modified by Fuchs et al. METHODS: The muscular hardness of the torn supraspinatus muscle was measured in 32 patients at rest and during isometric contraction with the shoulder abducted to 60° in the scapular plane. The muscular hardness was calculated as the strain ratio. Fatty degeneration was assessed according to the modified Goutallier stage. Because the activity value (defined as the difference between the strain ratio at rest and the strain ratio during isometric contraction) estimated the contractile property of the muscle, stepwise multiple regression analysis was used to compare the activity value with age, sex, side, time from injury onset to obtaining the measurements, and modified Goutallier stage. RESULTS: The mean activity value was 0.26 ± 0.16. Fatty degeneration of the supraspinatus muscle was grade 0 in 5 patients, grade 1 in 16, grade 2 in 10, and grade 3 in 1. The activity value was significantly correlated only with the modified Goutallier stage (r = -0.78, P < .001). CONCLUSION: The contractile property of the supraspinatus muscles decreased with an increase in the modified Goutallier stage. Real-time tissue elastography can measure the contractile property of the muscles before surgery and thus may be a predictor for the resulting restoration of lost muscle function.

Functions of the subregions of the supraspinatus muscle.

The aim of this study was to investigate the functions of the six subregions of the supraspinatus muscle (SSP) determined by Kim et al. in Clin Anat 2007;20:648-655, using real-time tissue elastography (RTE). Twelve young male volunteers participated. The muscular hardness of the SSP was measured at rest and with contraction of the MMT3 in internal, neutral and external rotations. The SSP was functionally divided into five groups on the basis of the RTE results. These functional areas were roughly classified into three property groups: the anterior-superficial, anterior-middle, and anterior-deep subregions, which produce contractile force for abduction; the posterior-deep subregion, which produces contractile force for external rotation; and the posterior-superficial and posterior-middle subregions, which maintain tension. RTE was appropriate for measuring the functions of these muscular subregions. Clin. Anat. 30:347-351, 2017. © 2017 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Functions of the subregions of the infraspinatus during lateral rotation.

PURPOSE: Although recent morphological studies have revealed that the infraspinatus muscle is subdivided, the functions of the subregions remain unknown. The aim of this study is to investigate the functions of the infraspinatus subregions during lateral rotation using real-time tissue elastography (RTE). METHODS: Ten young male volunteers participated in the study. In addition to the infraspinatus subregions, the teres minor and two of six subregions of the supraspinatus determined by Kim were examined. The muscle stiffness of these subregions was measured in six conditions during lateral rotation, i.e., at rest and during manual muscle testing (MMT) 3 contraction at 0°, 35°, and 70° of lateral rotation. RESULTS: The middle and inferior subregions of the infraspinatus, teres minor, and the posterior deep supraspinatus acted as a lateral rotator. The inferior subregion of the infraspinatus was somewhat an abductor. The superior subregion of the infraspinatus was an abductor but did not contribute to the lateral rotational motion at 35° and 70° of rotation. The anterior superficial supraspinatus played an abduction role at neutral rotation but this role gradually decreased with an increasing lateral rotational angle. CONCLUSIONS: Three subregions of the infraspinatus are functionally distinct. The superior subregion contributes to abduction, the middle subregion acts as a lateral rotator, and the inferior subregion has both functions.

Tension Distribution in Articular Surfaces of the Rotator Cable and Crescent: A Cadaveric Study.

BACKGROUND: The rotator cable functions as a stress and/or load transfer structure. Some studies suggested that a disruption of the cable negatively affects shoulder function and tendon integrity in patients with rotator cuff tears, while others found no functional impairment regardless of rotator cable tear severity. Although anatomical studies have identified distinct regions within the rotator cuff muscles, the strain distribution within the articular sides of the rotator cuff tendons that results from the tension in each region remains unknown. We hypothesized that the posterior region of the supraspinatus (SSP) muscle and the middle region of the infraspinatus (ISP) muscle, with their firm capsular attachments to the cable, transmit 3D strains, and thus tension, to the whole cable, leading to differences in tension within the cable. METHODS: The 3D strain distributions in the articular sides of the SSP and ISP tendons of 8 fresh-frozen cadaveric intact shoulders were determined when tension was applied to the various SSP and ISP muscle regions. RESULTS: Loading the anterior SSP muscle region yielded significantly higher strains in the anterior third of the cable compared with the posterior third (p < 0.05). Loading the posterior SSP muscle region yielded no significant differences among the cable and crescent regions. Loading the middle ISP muscle region yielded higher strains in the anterior and posterior thirds of the cable compared with the middle third (p < 0.01). Loading the superior ISP muscle region yielded no significant differences among the cable and crescent regions (p > 0.05). CONCLUSIONS: Tension generated from the posterior region of the SSP muscle and middle region of the ISP muscle was evenly distributed to the anterior and posterior attachments of the rotator cable, while the tension generated from other SSP and ISP muscle regions was locally transmitted to the respective attachment area. CLINICAL RELEVANCE: The rotator cable and crescent serve pivotal roles in transmitting tension generated from the deep regions of the rotator cuff muscles, i.e., the posterior SSP and middle ISP. These findings indicate that both the rotator cable and the rotator crescent play crucial roles as tension transmitters for the deep regions of the rotator cuff muscles. This information could have important implications for developing anatomically relevant repair techniques and enhancing rehabilitation protocols.

Relationship of the Japanese Old Stories Cognitive Scale With the Revised Hasegawa Cognitive Scale and Mini-Mental State Examination.

The Revised Hasegawa Dementia Scale (HDS-R) is the most widely used instrument to screen for dementia in Japan and is similar to the Mini-Mental State Examination (MMSE). The development of a quicker and simpler screening tool, the Japanese Old Stories Cognitive Scale (JOSS), was previously reported. A total of 953 new outpatients from 8 memory clinics in Japan completed the JOSS, HDS-R, and MMSE at first visit. We investigated the relationship of JOSS score with both the total and individual domain scores on the HDS-R and MMSE. We found a significant relation between JOSS score and total HDS-R and MMSE scores. In addition, JOSS score was significantly related to scores on 8 of the 9 HDS-R domains and 7 of the 11 MMSE domains. We obtained regression lines for JOSS score versus HDS-R and MMSE scores. JOSS score could be useful for predicting HDS-R and MMSE scores and thus in estimating cognitive functioning.

Predictors for the Knee Extension Strength at 2 Yrs After Total Knee Arthroplasty Using Regression Tree Analysis.

OBJECTIVE: The aim of the study is to clarify the interactive combinations of clinical factors associated with knee extension strength 2 yrs after total knee arthroplasty. DESIGN: A retrospective cohort study was conducted on 264 patients who underwent total knee arthroplasty. Knee extension strength was assessed preoperatively, 3 wks, and 2 yrs after total knee arthroplasty. Physical functions were measured with 10-m walking test, Timed Up and Go test, one-leg standing time, isometric knee flexion strength, knee joint stability, knee pain, femora-tibial angle, and passive knee extension and flexion angle before surgery as a baseline and 3 wks after total knee arthroplasty as acute phase. Regression tree analysis was conducted to clarify the interactive combinations that accurately predict the knee extension strength 2 yrs after total knee arthroplasty. RESULTS: Operational side knee extension strength (>1.00 Nm/kg) at acute phase was the primal predictor for the highest knee extension strength at 2 yrs after total knee arthroplasty. Acute phase Timed Up and Go test (≤10.13 secs) and baseline 10-m walking test (≤11.72 secs) was the second predictor. Acute phase nonoperative side knee extension strength (>0.90 Nm/kg) was also selected as the predictor. CONCLUSIONS: This study demonstrated that knee extension strength or Timed Up and Go test in the acute phase and 10-m walking test before total knee arthroplasty are useful for estimating the knee extension strength after total knee arthroplasty. The results will help determine specific postoperative rehabilitation goals and training options.

Strain distribution in the bursal rotator cuff based on whole-muscle and muscle subregion-specific loading: A cadaveric study.

Rotator cuff (RC) tears are common injuries leading to significant dysfunction of the shoulder. Rotator cuff tears alter tension and strain in muscles and tendons. Anatomical studies demonstrated that rotator cuff muscles are comprised of anatomical subregions. However, the strain distribution within the rotator cuff tendons generated from the tension from each anatomical subregion is unknown. We hypothesized that subregions would present distinct 3-dimensional (3D) strain distributions within the rotator cuff tendons, and that the anatomical insertion configuration of the supraspinatus (SSP) and infraspinatus (ISP) tendons might dictate strain, thus tension, transmission. 3D-strains in the bursal side of the SSP and ISP tendons of eight fresh-frozen cadaveric intact shoulders were obtained by applying tension on the whole SSP and ISP muscles, and on their subregions using an MTS system. Strains in the anterior region of the SSP tendon were higher than in the posterior region with whole-SSP anterior-region (p < 0.05) and whole-SSP muscle loading. Higher strains were observed in the inferior half of the ISP tendon with whole-ISP muscle (p < 0.05), middle-subregion (p < 0.01), and superior-subregion (p < 0.05) loading. Tension generating from the posterior-region of the SSP was primarily transmitted to the middle facet via an overlap between the SSP and ISP tendons insertions, while the anterior-region mainly distributed its tension into the superior facet. Tension generating from the middle and superior-regions of the ISP was distributed into the inferior portion of the ISP tendon. These results emphasize the importance of the distinct anatomical subregions of the SSP and ISP muscles in distributing the tension to the tendons.

Moment arms of the anatomical subregions of the rotator cuff muscles during shoulder rotation.

BACKGROUND: Rotator cuff muscles are responsible for humeral rotation. Moment arms of different regions of these muscles during humeral rotation were analyzed in neutral and abducted positions. METHODS: In eight cadaveric shoulders, subregions of the rotator cuff muscles were identified and their excursion during humeral rotation was measured in neutral and abducted positions from an internal rotation of 30° to an external rotation of 45°, with 15° increments, using a 3-D digitizing system. Statistical tests were used to assess differences between subregions within a single muscle. FINDINGS: The posterior-deep subregion of the supraspinatus muscle had greater moment arms compared to the anterior-superficial and anterior-middle subregions in both positions (p < 0.001). The middle and inferior subregions of the infraspinatus muscle and the teres minor muscle showed differences in moment arms compared to the superior region in an abducted position (p < 0.042). The superior subregion of the subscapularis muscle showed differences in moment arms compared to the middle and inferior subregions in an abducted position (p < 0.001). INTERPRETATION: The posterior-deep subregion of the supraspinatus muscle behaved similar to the infraspinatus muscle, as an external rotator. The anterior-superficial and anterior-middle subregions of the supraspinatus muscle showed a biphasic behavior during rotation at a neutral position, but acted as pure external rotators during rotation at an abducted position. Inferior subregions of the infraspinatus and subscapularis muscles showed the largest moment arms compared to superior subregions. These findings support distinct functional roles of the rotator cuff muscle subregions.

Muscle belly ratio is the most suitable estimate of the activity of the torn supraspinatus muscle.

Background: A torn rotator cuff muscle deteriorates over time leading with an increase in muscle atrophy and fatty infiltration. There are several clinical assessments for evaluating the atrophy of the torn supraspinatus muscle. However, it is unclear which approach can more accurately estimate the activity of the torn supraspinatus muscle. The purpose of this study was to determine which magnetic resonance imaging-based muscle atrophy imaging assessment currently implemented in the clinical setting accurately estimates the activity of the torn supraspinatus muscle. Methods: Forty patients who were diagnosed with a rotator cuff tear and were candidates for repairs were selected for this study. Cross-sectional area, occupation ratio, and tangent sign were analyzed on T1-weighted oblique sagittal plane magnetic resonance images in which the scapular spine leads to the Y-section. Muscle belly ratio of the supraspinatus muscle was analyzed by calculating the ratio of the width of the muscle belly to the distance from the greater tubercle to the proximal end of the muscle on T1-weighted coronal plane magnetic resonance imaging images. Fatty infiltration was evaluated using the Goutallier classification system. Tear size was obtained intraoperatively by measuring the width and length of the tear and classified based on the Cofield's classification. To assess activity of the torn supraspinatus muscle, participants were first instructed to sit on a chair with the affected arm resting on a table and the shoulder abducted to 60° in the scapular plane with neutral rotation. Elasticity of the supraspinatus muscle belly was then obtained at rest and during isometric contraction using with real-time tissue elastography. Muscle activity, a surrogate for contractility, was defined as the difference between the elasticities measured at rest and during isometric contraction. A stepwise multiple regression analysis was used to investigate independent factors, such as sex, tear width, cross-sectional area, occupation ratio, tangent sign, and muscle belly ratio, related to muscle activity. Results: Stepwise multiple regression analysis (R2 = 0.522, P < .001) revealed that supraspinatus muscle activity was significantly correlated with muscle belly ratio (ß = 0.306, P = .044) and Goutallier stage (ß = -0.490, P = .002). Conclusion: Estimations of muscle belly ratio are most suitable for assessing the activity of a torn supraspinatus muscle compared to other clinical measurements.

Frontal midline theta rhythm and gamma activity measured by sheet-type wearable EEG device.

Introduction: The current study measured the frontal midline theta rhythm (Fmθ), which appears in the frontal midline region during the attentional focus state, using the sheet-type wearable electroencephalograph (EEG) device HARU-1, and examined the modulation of frontal gamma band activity by cognitive tasks. Methods: We measured the frontal EEG of 20 healthy subjects using HARU-1 for 2 min during the rest eyes-closed condition and simple mental calculation task condition, respectively. Statistical analyses were conducted using permutation testing based on t-test and cluster analysis to compare the results between the resting state and the task condition. Results: Twelve of 20 subjects showed Fmθ during the task condition. The 12 subjects with Fmθ showed significantly higher activity of the theta and gamma bands, and significantly low activity of the alpha band during the task condition compared to the resting condition. In the eight subjects without Fmθ were significantly low activity of the alpha and beta bands and no significant activity in the theta and gamma band activity during the task condition compared to the resting condition. Discussion: These results indicate that it is possible to measure Fmθ using HARU-1. A novel finding was the gamma band activity appearing with Fmθ in the left and right frontal forehead regions, suggesting that it reflects the function of the prefrontal cortex in working memory tasks.

Evaluating the contribution of fat infiltration in anterior gluteus minimus muscle to walking ability in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty.

BACKGROUND: The purpose of this study is to investigate the relationship between gait and fat infiltration in anterior and posterior gluteus minimus in the patients with hip osteoarthritis. METHODS: Ninety-one female patients who were diagnosed as the unilateral hip osteoarthritis, classified into Kellgren-Lawrence global scoring system grades 3 or 4, and candidate for total hip arthroplasty were retrospectively reviewed. The horizontally cross-sectional regions of interest for the gluteus medius and anterior and posterior gluteus minimus were manually circumscribed in a single transaxial computed tomography image and muscle density of those regions were obtained. The gait was assessed as the step and speed with the 10-Meter Walk Test. The multiple regression analysis was used to compare the step and speed with age, height, range of motion in flexion, the muscle density of anterior gluteus minimus in the affected side, and that of gluteus medius muscle in both affected and unaffected sides. FINDINGS: Multiple regression analysis for step revealed that the muscle density of anterior gluteus minimus in the affected side and height were the independent predictors for step (R2 = 0.389, p < 0.001). That for speed identified the muscle density of anterior gluteus minimus in the affected side as the only factor determining speed (R2 = 0.287, p < 0.001). INTERPRETATION: The fatty infiltration of anterior gluteus minimus muscle in affected side can be a predictor for the gait in in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty.

Intracompartmental pressure in lower leg muscles and tibial nerve in healthy volunteers correlate to the stiffness measured using shear wave elastography.

BACKGROUND: Acute compartment syndrome in the lower leg is a painful condition characterized by an increase in intracompartmental pressure. To prevent misdiagnosis and delay in the recognition of the condition, which can lead to severe complications, continuous monitoring of intracompartmental pressure for at least 24 h. from the onset of initial symptoms has been recommended. The purpose of the current study was to establish shear wave elastography as a potential imaging biomarker for the observed increase in pressure in four compartments of the lower leg. METHODS: Eighteen healthy participants (9 males) without any injury in their leg muscles were recruited for the study after internal review board approval. Subjects were instructed to sit on a table and pressures at 60, 90, and 120 mmHg were applied using a pressure cuff placed above the proximal pole of the patella. Shear wave elastography-measured stiffness outcomes at baseline (0 mmHg) and at each cuff pressure level were obtained from the tibialis anterior, the peroneus longs, gastrocnemius medialis, and tibialis posterior muscles, as well as the tibial nerve. FINDINGS: Spearman's rank correlation coefficient showed strong correlations between shear wave elastography-measured stiffness from all four muscles and cuff pressure levels (r > 0.80, P < 0.05). Stiffness from the tibial nerve was also significantly correlated with cuff pressure levels (r > 0.99, P < 0.05). INTERPRETATION: Shear wave elastography imaging of lower leg muscles and nerve can be useful to non-invasively monitor intracompartmental pressure in patients suspected of acute compartment syndrome.