The Weight-Bearing Rate on the Paretic Limb of Cerebrovascular Hemiplegic Patients Necessary for an Independent Obstacle Negotiation Gait

Purpose: The obstacle negotiation gait (ONG) is a fundamental activity of daily living. In cerebrovascular hemiplegic patients (stroke patients), the weight-bearing rate (WBR) on the paretic limb necessary for an independent ONG was studied. Methods: One hundred and seventeen stroke patients were involved. The patients'' average age at the time of the study was 67 years, and the average time from stroke onset was 102 days. There were 68 men and 49 women. Seventy patients were right hemiplegics, and 47 were left hemiplegics. The correlations between ONG and age, sex, body mass index (BMI), time from stroke onset, muscle strength of both the paretic and non-paretic limbs, Brunnstrom stage of the lower limbs, deep sensation, and the WBR on both the paretic and non-paretic limbs were studied. Patients who could perform ONG independently and safely were categorized as the independent group (IG), and those who needed observation or any assistance were categorized as the dependent group (DG). Results: The BMI, muscle strength of both the paretic and non-paretic limbs, Brunnstrom stage of the lower limbs, deep sensation and the WBR for both the paretic and non-paretic limbs were significantly different between the IG and DG groups. In particular, the WBR on the paretic limb was found to correlate significantly with the ONG, and a WBR value of 80.5% on the paretic limb gave a clear cut-off value. Conclusion: Although multiple factors influenced the ONG of stroke patients, the WBR on the paretic limb was the most influential.     

Electromyography Activity of Vastus Medialis Obliquus and Vastus Lateralis Muscles During Lower Limb Proprioceptive Neuromuscular Facilitation Patterns in Individuals with and without Patellofemoral Pain Syndrome

Objective: Exercise therapy to strengthen quadriceps muscle is recommended in rehabilitation program for people with patellofemoral pain syndrome (PFPS). This study aimed to investigate the electromyography (EMG) activity of vastus medialis obliquus (VMO), vastus lateralis (VL) and VMO/VL ratio during PNF in individuals with and without PFPS. Methods: 26 persons with PFPS and 26 healthy subjects participated to study. All subjects performed PNF patterns (Flexion-Adduction-External Rotation (D₁FL), Extension-Adduction-External Rotation (D₂EX), D₁FL+ load, D₂EX+ load) and straight leg raise (SLR). The normalized EMG activity of VMO, VL and VMO/VL ratio were measured and analyzed using repeated measure ANOVA. Results: There were significant main effects of group and exercises for the both VMO and VL (p<0.05). It was found that except SLR and D₂EX, in the other motions PFPS group had lower VMO activity compared to healthy group (p<0.05). For VL except SLR, in the other motions PFPS group had lower VL activity too (p<0.05). The PNF patterns activated VMO more than SLR, however it was not significant (p>0.05). Also; there weren''t any significant difference between the two groups in VMO/VL activation ratios. Also, performing the PNF patterns with load increased VMO and VL muscles activity significantly (p<0.05). It also found that in PFPS group the VMO/VL ratio values in PNF patterns were significantly more than SLR and the highest VMO/VL ratio value (0.96) was found during D₂EX. Conclusion: The PNF patterns due to provide optimal VMO/VL ratio value than SLR and proper balance between these two muscles can be recommended in rehabilitation of individuals with PFPS.     

EEG Fractal Analysis Reflects Brain Impairment after Stroke

Stroke is the commonest cause of disability. Novel treatments require an improved understanding of the underlying mechanisms of recovery. Fractal approaches have demonstrated that a single metric can describe the complexity of seemingly random fluctuations of physiological signals. We hypothesize that fractal algorithms applied to electroencephalographic (EEG) signals may track brain impairment after stroke. Sixteen stroke survivors were studied in the hyperacute (<48 h) and in the acute phase (∼1 week after stroke), and 35 stroke survivors during the early subacute phase (from 8 days to 32 days and after ∼2 months after stroke): We compared resting-state EEG fractal changes using fractal measures (i.e., Higuchi Index, Tortuosity) with 11 healthy controls. Both Higuchi index and Tortuosity values were significantly lower after a stroke throughout the acute and early subacute stage compared to healthy subjects, reflecting a brain activity which is significantly less complex. These indices may be promising metrics to track behavioral changes in the very early stage after stroke. Our findings might contribute to the neurorehabilitation quest in identifying reliable biomarkers for a better tailoring of rehabilitation pathways.     

Changes in Hip and Knee Muscle Strength in Patients Following Total Hip Arthroplasty

Objective: To investigate changes in hip and knee muscle strength in patients before and after total hip arthroplasty (THA) in comparison with that in healthy adults. Methods: The study included 21 women who underwent unilateral THA (THA group) and 21 age-matched healthy women (healthy group). Maximal isometric strengths of hip flexors, extensors, and abductors, and knee extensors and flexors were measured before surgery and at 4 weeks and 6 months after surgery. Results: Before surgery, muscle strength on both sides, except for hip flexors on the uninvolved side, was significantly lower in the THA group than the corresponding muscle strength in the healthy group. Up to 6 months after THA, strength of all muscle groups on both sides was significantly improved compared with their preoperative status, although the knee extensor strength on the involved side temporarily worsened at 4 weeks. However, the strength of hip extensors and knee extensors on the involved side, and hip abductors on both sides in the THA group remained below that in the healthy group. Conclusions: Our results suggest that rehabilitation specialists should consider increasing the focus on the uninvolved side and encourage patients to continue strength training beyond 6 months after surgery.     

Staining of Human Thyroarytenoid Muscle with Myosin Antibodies Reveals Some Unique Extrafusal Fibers, but no Muscle Spindles

This study describes the myosin composition of extrafusal and intrafusal muscle fibers found in the human thyroarytenoid (TA) and sternohyoid (control) muscles. We sought to determine the presence of muscle spindles in the TA muscle, and to identify unusual extrafusal fiber types, using the commonly accepted approach of tissue staining with myosin isoform specific antibodies. Extrafusal fibers are organized into motor units, which subsequently produce muscle movement, whereas intrafusal fibers compose muscle spindles, the primary stretch receptor that provides afferent (feed back) information to the nervous system for regulation of motor unit length and tonicity. Immunohistochemical identification of muscle spindles was confirmed in sternohyoid, but not in TA samples; however, some extrafusal fibers contained tonic myosin. These results indicate that human TA muscle functions similar to some mammalian extraocular muscle, performing unloaded (non-weight bearing) contractions without afferent information from native muscle spindles.     

Neuromuscular control of fundamental frequency and glottal posture at phonation onset

The laryngeal neuromuscular mechanisms for modulating glottal posture and fundamental frequency are of interest in understanding normal laryngeal physiology and treating vocal pathology. The intrinsic laryngeal muscles in an in vivo canine model were electrically activated in a graded fashion to investigate their effects on onset frequency, phonation onset pressure, vocal fold strain, and glottal distance at the vocal processes. Muscle activation plots for these laryngeal parameters were evaluated for the interaction of following pairs of muscle activation conditions: (1) cricothyroid (CT) versus all laryngeal adductors (TA/LCA/IA), (2) CT versus LCA/IA, (3) CT versus thyroarytenoid (TA) and, (4) TA versus LCA/IA (LCA: lateral cricoarytenoid muscle, IA: interarytenoid). Increases in onset frequency and strain were primarily affected by CT activation. Onset pressure correlated with activation of all adductors in activation condition 1, but primarily with CT activation in conditions 2 and 3. TA and CT were antagonistic for strain. LCA/IA activation primarily closed the cartilaginous glottis while TA activation closed the mid-membranous glottis.     

Aging Thyroarytenoid and Limb Skeletal Muscle: Lessons in Contrast

Voice production is vital throughout life because it allows for the communication of basic needs as well as the pursuit and enjoyment of social encounters. Unfortunately, for many older individuals the ability to produce voice is altered. Structural and functional declines in the neuromuscular system occur with aging and likely contribute to the modification of voice. One specific target of the aging process is the thyroarytenoid (TA) muscle, the primary muscle of voice production. The objectives of this overview article are to (1) share current findings related to the aging of limb skeletal muscle, (2) identify age-related morphological and physiological features of TA muscle, (3) compare and contrast age-related changes in TA with those in limb skeletal muscle, and (4) describe therapies for reversing sarcopenia in limb muscle and consider the applicability of these therapies for addressing vocal fold atrophy and age-related voice changes. The article shares current knowledge from the basic sciences related to skeletal muscle aging and compares/contrasts typical muscle aging to TA aging. Current evidence suggests that (1) the TA muscle undergoes notable remodeling with age, (2) aging of the TA is multifactorial, resulting from a myriad of neurologic, metabolic, and hormonal changes, many of which are distinct from the age-related processes of typical limb skeletal muscle, (3) investigation of the aging of the TA and its role in the aging of voice is in its infancy, and (4) potential behavioral and nonbehavioral therapies for reversing aging of the TA must be further examined.     

Postural Sway during Local Vibratory Stimulation for Proprioception in Elderly Individuals with Pre-Sarcopenia

Objective: Many studies have demonstrated that the loss of muscle mass (LMM) poses a risk of postural instability in the elderly; however, few studies have shown how LMM decreases proprioception. In this study, we investigated the changes in postural sway among older individuals with LMM induced by application of a local vibratory stimulus. Method: We enrolled 64 older adults (mean age). Postural sway was measured while applying vibration stimuli of 30, 60, and 240 Hz to both the gastrocnemius and lumbar multifidus muscles. We also measured the relative proprioceptive weighting ratio (RPW) of postural sway. The patients were divided into LMM and non-LMM (NLMM) groups. The study subjects were compared in terms of their age, height, weight, body mass index (BMI), lower leg skeletal muscle mass index (LSMI), L4/5 lumbar multifidus cross-sectional area ratio, and RPW at 30, 60, and 240 Hz. Results: Subjects in the LMM group showed a significantly lower RPW at 60 Hz, LSMI, and BMI than did those in the NLMM group. Conclusions: Decrease in RPW with 60-Hz stimulation concerning the lower leg proprioception is a risk factor for LMM-associated postural instability in the elderly. Consequently, with respect to the gastrocnemius muscles proprioception in LMM, it is necessary to perform assessments using muscle spindle stimuli.     

Recovery process of respiratory muscle strength in patients following stroke: A Pilot Study

Objective: To determine the recovery process of respiratory muscle strength during 3 months following stroke, and to investigate the association of change in respiratory muscle strength and physical functions. Additionally, we compared respiratory muscle strength with those of healthy subjects. Method: In this prospective, observational study, 19 stroke patients and 19 healthy subjects were enrolled. Maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), motricity index, trunk control test, 6-minute walk test (6MWT) and functional independence measure were assessed at 1, 2, and 3 months from stroke onset in stroke patients. MIP and MEP were assessed at arbitrary times in healthy subjects. Repeated one-way analysis of variance with Bonferroni post-hoc test was used to compare the change in respiratory muscle strength in each period in stroke patients. Pearson''s correlation coefficient was computed for changes in respiratory muscle strength and physical functions. Student''s t-test was used to compare respiratory muscle strength between stroke patients at 3 months from onset and healthy subjects. Results: MIP was significantly increased at 3 months compared to 1 month. MEP was significantly increased in 2 months and 3 months, compared to 1 month. MIP changes associated with 6MWT changes. Compared to healthy subjects, MIP and MEP at 3 months were significantly lower in stroke patients. Conclusion: Respiratory muscle strength significantly increased during 3 months following stroke. However, the trend of recovery may be different. MIP changes may associated with walking endurance changes. During 3 months following stroke, respiratory muscle strength did not recover to healthy subjects.     

Cooperative Regulation of Vocal Fold Morphology and Stress by the Cricothyroid and Thyroarytenoid Muscles

Voice is produced by vibrations of vocal folds that consist of multiple layers. The portion of the vocal fold tissue that vibrates varies depending primarily on laryngeal muscle activity. The effective depth of tissue vibration should significantly influence the vibrational behavior of the tissue and resulting voice quality. However, thus far, the effect of the activation of individual muscles on the effective depth is not well understood. In this study, a three-dimensional finite element analysis is performed to investigate the effect of the activation of two major laryngeal muscles, the cricothyroid (CT) and thyroarytenoid (TA) muscles, on vocal fold morphology and stress distribution in the tissue. Because structures that bear less stress can easily be deformed and involved in vibration, information on the morphology and stress distribution may provide a useful estimate of the effective depth. The results of the analyses indicate that the two muscles perform distinct roles, which allow cooperative control of the morphology and stress. When the CT muscle is activated, the tip region of the vocal folds becomes thinner and curves upward, resulting in the elevation of the stress magnitude all over the tissue to a certain degree that depends on the stiffness of each layer. On the other hand, the TA muscle acts to suppress the morphological change and controls the stress magnitude in a position-dependent manner. Thus, the present analyses demonstrate quantitative relationships between the two muscles in their cooperative regulation of vocal fold morphology and stress.     

Changes in orcine muscle water characteristics during growth--an in vitro low-field NMR relaxation study

This study investigates the effects of developmental stage and muscle type on the mobility and distribution of water within skeletal muscles, using low-field (1)H-NMR transverse relaxation measurements in vitro on four different porcine muscles (M. longissimus dorsi, M. semitendinosus, M. biceps femoris, M. vastus intermedius) from a total of 48 pigs slaughtered at various weight classes between 25 kg and 150 kg. Principal component analysis (PCA) revealed effects of both slaughter weight and muscle type on the transverse relaxation decay. Independent of developmental stage and muscle type, distributed exponential analysis of the NMR T(2) relaxation data imparted the existence of three distinct water populations, T(2b), T(21), and T(22), with relaxation times of approximately 1-10, 45-120, and 200-500 ms, respectively. The most profound change during muscle growth was a shift toward faster relaxation in the intermediate time constant, T(21). It decreased by approx. 24% in all four muscle types during the period from 25 to 150 kg live weight. Determination of dry matter, fat, and protein content in the muscles showed that the changes in relaxation time of the intermediate time constant, T(21), during growth should be ascribed mainly to a change in protein content, as the protein content explained 77% of the variation in the T(21) time constant. Partial least squares (PLS) regression revealed validated correlations in the region of 0.58 to 0.77 between NMR transverse relaxation data and muscle development for all the four muscle types, which indicates that NMR relaxation measurements may be used in the prediction of muscle developmental stage.     

Differences in dual-task performance and prefrontal cortex activation between younger and older adults

Background

The purpose of this study was to examine task-related changes in prefrontal cortex (PFC) activity during a dual-task in both healthy young and older adults and compare patterns of activation between the age groups. We also sought to determine whether brain activation during a dual-task relates to executive/attentional function and how measured factors associated with both of these functions vary between older and younger adults.

Results

Thirty-five healthy volunteers (20 young and 15 elderly) participated in this study. Near-infrared spectroscopy (NIRS) was employed to measure PFC activation during a single-task (performing calculations or stepping) and dual-task (performing both single-tasks at once). Cognitive function was assessed in the older patients with the Trail-making test part B (TMT-B). Major outcomes were task performance, brain activation during task (oxygenated haemoglobin: Oxy-Hb) measured by NIRS, and TMT-B score. Mixed ANOVAs were used to compare task factors and age groups in task performance. Mixed ANOVAs also compared task factors, age group and time factors in task-induced changes in measured Oxy-Hb. Among the older participants, correlations between the TMT-B score and Oxy-Hb values measured in each single-task and in the dual-task were examined using a Pearson correlation coefficient. Oxy-Hb values were significantly increased in both the calculation task and the dual-task within patients in both age groups. However, the Oxy-Hb values associated with there were higher in the older group during the post-task period for the dual-task. Also, there were significant negative correlations between both task-performance accuracy and Oxy-Hb values during the dual-task and participant TMT-B scores.

Conclusions

Older adults demonstrated age-specific PFC activation in response to dual-task challenge. There was also a significant negative correlation between PFC activation during dual-task and executive/attentional function. These findings suggest that the high cognitive load induced by dual-task activity generates increased PFC activity in older adults. However, this relationship appeared to be strongest in participants with better baseline attention and executive functions.     

Changes in diffusion tensor imaging (DTI) eigenvalues of skeletal muscle due to hybrid exercise training

Several studies have proposed the cell membrane as the main water diffusion restricting factor in the skeletal muscle cell. We sought to establish whether a particular form of exercise training (which is likely to affect only intracellular components) could affect water diffusion. The purpose of this study is to characterise prospectively the changes in diffusion tensor imaging (DTI) eigenvalues of thigh muscle resulting from hybrid training (HYBT) in patients with non-alcoholic fatty liver disease (NAFLD). Twenty-one NAFLD patients underwent HYBT for 30 minutes per day, twice a week for 6 months. Patients were scanned using DTI of the thigh pre- and post-HYBT. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), the three eigenvalues lambda 1 (λ1), λ2, λ3, and the maximal cross sectional area (CSA) were measured in bilateral thigh muscles: knee flexors (biceps femoris (BF), semitendinosus (ST), semimembranous (SM)) and knee extensors (medial vastus (MV), intermediate vastus (IV), lateral vastus (LV), and rectus femoris (RF)), and compared pre- and post-HYBT by paired t-test. Muscle strength of extensors (P < 0.01), but not flexors, increased significantly post-HYBT. For FA, ADC and eigenvalues, the overall picture was of increase. Some (P < 0.05 in λ2 and P < 0.01 in λ1) eigenvalues of flexors and all (λ1-λ3) eigenvalues of extensors increased significantly (P < 0.01) post-HYBT. HYBT increased all 3 eigenvalues. We suggest this might be caused by enlargement of muscle intracellular space.     

Dependence of residual dipolar couplings on foot angle in H MR spectra from skeletal muscle

Foot dorsi and plantar flexion affects the pennation angle of skeletal muscle fibers and changes the fiber direction with respect to the main magnetic field, thereby affecting MR spectrum of the muscle. In order to analyze the effect that foot flexion has on the MR spectrum, tibialis anterior (TA) and soleus muscles were studied in humans and rats. Localized MRS was performed at different foot angles in clinical and pre-clinical settings using a 3 T MRI/MRS GE Excite HD and 7 T Bruker Clinscan scanner, respectively. In this study we show the effect of foot angle variation on total Creatine (tCr) resonance of ¹H spectrum at 3.03 and 3.93 ppm for TA and soleus muscles. In addition to this, we observe a 4-line splitting pattern for methylene resonance of tCr in the rat TA spectrum for a specific foot angle. This observation is attributed to the individual splitting of creatine and phosphocreatine of the tCr signal. Novel hydrogel application is demonstrated and used to support our in vivo observations and for the first time splitting of individual resonances of Cr and PCr has been shown in an in vitro set-up.     

Localized in vivo H spectroscopy of human skeletal muscle: Normal and pathologic findings

To obtain high signal to noise ratio in small volume elements (8 cm³), in vivo ¹H NMR spectroscopy of normal and diseased human skeletal muscle was performed using a double spin-echo localization method on a 1.5-T whole body system. High resolved spectra of normal calf muscle show the well known resonances of lipids (methyl, methylene, olefinic, and other fatty acid resonances), creatine/phosphocreatine, choline/carnitine, taurine, and histidine with good intraindividual reproducibility. Pronounced intraindividual differences in the lipid range were found between different upper thigh muscle groups. On pathologic conditions like myopathia, myositis or irradiation damage the spectral lipid content was increased. Three months after local irradiation of the medial vastus muscle (50 Gy), the localized ¹H NMR spectrum showed a complete loss of the choline and creatine signals. In a case of M. Behçet with muscular involvement the relative reduction of the choline signal may provide an insight in the pathobiochemistry. The results of our investigations in nine healthy volunteers and three patients are presented in detail including relaxation times of the metabolites.     

Histological and histochemical effects after occlusion alteration in suprahyoid muscles

This study verified the effect of unilateral teeth extraction on the suprahyoid muscles in gerbils (Meriones unguiculatus). Ten adult male gerbils weighing about 50g had induced occlusal alterations by upper molar teeth extraction on the left side while the other ten animals were only subjected to surgical stress, control group. After 60 days, animals of both groups, experimental and control had the suprahyoid muscles removed and processed for histological and histochemical (adenosine triphosphatase (ATPase), nicotine adenine dinucleotide tetrazolium reductase (NADH-TR) and succinate dehydrogenase (SDH)) purposes. The fiber type area was estimated in % according to Weibel method (point-counting method) using a test-system. The myosinic ATPase pH 4.7 activity in the control group of the digastric, milohyoid and geniohyoid muscles presented a small area of type I fiber and a larger area of type IIa fibers; in the experimental group, significant contractile capacity alteration was not observed. Samples of the digastric, milohyoid and geniohyoid muscles, after SDH activity, showed a small area with high metabolic activity fibers, and a large area with intermediary and low metabolic activity fibers in the control group. The milohyoid muscle of the experimental group presented low metabolic fibers in a reduced area, in both sides, however without significant difference. In the experimental group, high metabolic fibers were observed on the left side in a reduced area in the geniohyoid muscle, but without statistical significance. Thus, the geniohyoid muscle did not change the metabolic activity after occlusal alteration. In conclusion, 60 days of unilateral malocclusion induced was able to alter the fibers oxidative activity of the suprahyoid muscles, however, it does not affect the contractile property of the fibers. The digastric muscle has adequate fibers to produce fast contraction and able to resist to fatigue in intermediate degrees, but became more fatigable after unilateral exodontia.     

Thermoacoustic assessment of hematocrit changes in human forearms

Abnormal hematocrit(Hct) is associated with an increased risk of pre-hypertension and all-cause death in general population, and people with a high Hct value are susceptible to arterial cardiovascular disease and venous thromboembolism.In this study, we report for the first time on the ability of thermoacoustic imaging(TAI) for in vivo evaluating Hct changes in human forearms. In vitro blood samples with different Hct values from healthy volunteers(n = 3) were prepared after centrifugation. TAI was performed using these samples in comparison with the direct measurements of conductivity. In vivo TAI was conducted in the forearm of healthy volunteers(n = 7) where Hct changes were produced through a vascular occlusion stimulation over a period of time. The results of in vitro blood samples obtained from the 3 healthy subjects show that the thermoacoustic(TA) signals changes due to the variation of blood conductivity are closely related to the changes in Hct. In addition, the in vivo TA signals obtained from the 7 healthy subjects consistently increase in the artery/muscle and decrease in the vein during venous or arterial occlusion because of the changed Hct value in their forearms. These findings suggest that TAI has the potential to become a new tool for monitoring Hct changes for a variety of pre-clinical and clinical applications.     

Estimating cerebral venous oxygenation in human fetuses with ventriculomegaly using quantitative susceptibility mapping

Rationale and objectivesThe goal of this study was to estimate venous blood oxygen saturation (SvO2) in the superior sagittal sinus (SSS) in fetal brains with ventriculomegaly (VM) using quantitative susceptibility mapping (QSM).Materials and methodsA radiofrequency spoiled gradient echo sequence was used to evaluate data on 19 fetuses with VM (gestational age(GA): median = 29.9 weeks (range 23 to 37.3 weeks)) and 20 healthy fetuses (GA: median = 30.9 (range 22.7 to 38.7 weeks)) at 1.5 T. Susceptibility weighted images encompassing the entire fetal brain were acquired within 1 min. An iterative, geometry constraint-based thresholded k-space division algorithm was used for generating QSM data of the fetal brain. The venous oxygen saturation was calculated using the magnetic susceptibility of the SSS obtained from the QSM data. Mixed-model analysis of variance and interobserver variability assessment were used to analyze the results.ResultsThe median SvO2 values in the entire VM cohort as well as for second and third trimester fetuses (with interquartile range) were: 67.8% (63.2%, 73.6%), 73.1% (69.1%, 77.3%) and 63.8% (59.4%, 68.1%), respectively. The corresponding median SvO2 value in the healthy control group was: 65.3% (58.3%, 68.2%), 67.5% (61.7%, 69.2%) and 60.8% (53.6%, 68.2%), respectively. However, the difference of SvO2 between VM and control groups was not significant at the p = 0.05 level (p = 0.076). The SvO2 was found decreasing significantly with GA in the healthy control group (p < 0.05).ConclusionsWe report for the first time the estimation of cerebral SvO2 in human fetuses with VM using QSM. This measure of oxygen saturation might be beneficial in assessing and monitoring the metabolic status of the fetus in various clinical conditions.     

Effect of a Combined Exercise and Cognitive Activity Intervention on Cognitive Function in Community-dwelling Older Adults: A Pilot Randomized Controlled Trial

Objective: The purpose of this study is to investigate the effect of an intervention combining exercise and cognitive activity on cognitive function in healthy older adults. Methods: This pilot randomized controlled trial recruited 33 eligible, healthy communitydwelling older adults (mean age, 77.1 years old; women, 51.5%), who were divided into intervention and waitlist control groups. The intervention group was engaged weekly in a group activity comprising exercise and discussions of homework, which included reading aloud, simple arithmetic, and simple activities, like spotting differences, for cognitive stimulation. They were also required to complete cognitive activity homework twice a week. The waitlist control group received no intervention. The main outcomes were cognitive function assessed using the Mini-Mental State Examination, delayed recall score on the Logical Memory IIA of the Wechsler Memory Scale Revised, Trail Making Test, and digit symbol substitution test. Results: According to the results, Mini-Mental State Examination scores were maintained in the intervention group but declined in the control group [Mean change in outcomes in control group (95% confidence interval): -1.68 (-2.89 to -0.48)]. Additional mean change in outcomes in intervention group were found [1.68 (0.02 to 3.35)]. Conclusions: Interventions combining exercise and cognitive activity can be helpful for preserving cognitive function in healthy older adults.     

Association Between Social Network and Physical Function in Community-Dwelling Older Adults in Japan

Objective: A poor social network and the decline of physical function are known to be critical risk factors for functional decline in older adults. The aim of this study was to investigate the relationships between social network and physical function in Japanese community-dwelling older adults. Methods: Participants were 339 adults aged 65 years or older (mean age : 73.0 years, women :70.2%), living independently in their communities. A self-reported questionnaire was used to assess social network on two different scales―the 6-item Lubben Social Network Scale (6LSNS) and frequency of contact with other people. Handgrip strength, knee extension strength, gait speed, Timed Up and Go Test (TUG) results, and 5-repetition chair stand test (CST) scores were used to determine physical function. A multiple regression analysis that adjusted for confounding factors was used to analyze the relationship between the social network scales and each physical function test. Results: According to the results of a multiple regression analysis, a high 6LSNS score was significantly associated with greater handgrip strength (B = 0.63, p = 0.03), faster CST (B = −0.23, p = 0.01), and faster TUG (B = −0.12, p = 0.03), and high frequency of contact was significantly associated with greater handgrip strength (B = 1.08, p = 0.01). Conclusions: Social network was associated with muscle strength and physical performance. Consequently, older adults with poor social networks require an assessment of physical function, since their physical functions have possibly deteriorated.