Grip strength differences in middle-aged and older adults and individuals with stroke.

BACKGROUND: How the natural deterioration of aging, sex difference, and pathological effect of stroke affect the prediction of hand strength is still unknown. AIM: This study aimed to compare and predict grip strength in both hands between normal controls (NCs) and stroke patients. DESIGN: Observational, cross-sectional study. SETTING: Two urban hospitals and the community. POPULATION: A total of 160 participants aged from 40 to 80 (80 NCs and stroke patients) were recruited. METHODS: The Jamar® Plus+ Digital Hand Dynamometer was used to measure the grip strength. Stroke participants were additionally assessed by the Fugl-Meyer Assessment and Modified Ashworth Scale. RESULTS: The linear regression models of the grip strength in both right and left hands were good fits (the adjusted R2 of 0.680-0.751) between NCs and stroke patients with either the right dominant or left non-dominant hand affected. Group (NCs versus stroke), sex, and age were sequentially the first three statistically significant predictors in the grip strength of both hands between NCs and stroke patients with either the right dominant or left non-dominant hand affected. CONCLUSIONS: The pathological, sex, and age effects play complementary roles in predicting the grip strength in middle-aged and older adults between NCs and stroke patients. CLINICAL REHABILITATION IMPACT: In clinical practice, the recovery of the grip strength in stroke patients should take pathological, sex, and age effects together with the right dominant or left non-dominant hand affected into consideration, rather than merely comparing the differences in the grip strength of both right and left hands as a reference.

Development and user experience of an innovative multi-mode stroke rehabilitation system for the arm and hand for patients with stroke.

Many individuals with stroke experience upper-limb motor deficits, and a recent trend is to develop novel devices for enhancing their motor function. This study aimed to develop a new upper-limb rehabilitation system with the integration of two rehabilitation therapies into one system, digital mirror therapy (MT) and action observation therapy (AOT), and to test the usability of this system. In the part I study, the new system was designed to operate in multiple training modes of digital MT (i.e., unilateral and bilateral modes) and AOT (i.e., pre-recorded and self-recorded videos) with self-developed software. In the part II study, 4 certified occupational therapists and 10 stroke patients were recruited for evaluating usability. The System Usability Scale (SUS) (maximum score = 100) and a self-designed questionnaire (maximum score = 50) were used. The mean scores of the SUS were 79.38 and 80.00, and those of the self-designed questionnaire were 41.00 and 42.80, respectively, for the therapists and patients after using this system, which indicated good usability and user experiences. This novel upper-limb rehabilitation system with good usability might be further used to increase the delivery of two emerging rehabilitation therapies, digital AOT and MT, to individuals with stroke.

Age and sex differences in the biomechanical and viscoelastic properties of upper limb muscles in middle-aged and older adults: A pilot study.

Whether muscle properties gradually change with age and how muscle properties are affected by sex remain unclear. In this study, we investigated the influence of age and sex on the biomechanical and viscoelastic properties of arm muscles in middle-aged and older adults. In this cross-sectional study, 80 healthy participants were divided by sex (male and female), and each sex group, by 10-year age ranges (40-49, 50-59, 60-69, and 70-79 years). Muscle properties, including tone, stiffness, elasticity, and mechanical stress relaxation time, were measured with the MyotonPRO. Our results showed that the muscle tone and elasticity of the deltoid and flexor carpi radialis, and the muscle tone of the flexor carpi ulnaris, were significantly greater in men than in women, whereas the stress relaxation time of the triceps was significantly greater in women than in men. Significantly greater muscle stiffness in the biceps brachii was found in the participants over 50 years old. Less muscle elasticity was found in the deltoid, triceps, and flexor carpi ulnaris in those over 70 years old. In conclusion, age and sex have considerable impacts on upper-limb muscle properties in middle-aged and older adults, which should be taken into consideration when planning health promotion projects.

Motor Cortical Activity during Observing a Video of Real Hand Movements versus Computer Graphic Hand Movements: An MEG Study.

Both action observation (AO) and virtual reality (VR) provide visual stimuli to trigger brain activations during the observation of actions. However, the mechanism of observing video movements performed by a person's real hand versus that performed by a computer graphic hand remains uncertain. We aimed to investigate the differences in observing the video of real versus computer graphic hand movements on primary motor cortex (M1) activation by magnetoencephalography. Twenty healthy adults completed 3 experimental conditions: the resting state, the video of real hand movements (VRH), and the video of computer graphic hand movements (CGH) conditions with the intermittent electrical stimuli simultaneously applied to the median nerve by an electrical stimulator. The beta oscillatory activity (~20 Hz) in the M1 was collected, lower values indicating greater activations. To compare the beta oscillatory activities among the 3 conditions, the Friedman test with Bonferroni correction (p-value < 0.017 indicating statistical significance) were used. The beta oscillatory activities of the VRH and CGH conditions were significantly lower than that of the resting state condition. No significant difference in the beta oscillatory activity was found between the VRH and CGH conditions. Observing hand movements in a video performed by a real hand and those by a computer graphic hand evoked comparable M1 activations in healthy adults. This study provides some neuroimaging support for the use of AO and VR in rehabilitation, but no differential activations were found.

How do impairments in cognitive functions affect activities of daily living functions in older adults?

The assessment of daily living activities could provide information about daily functions and participation restrictions to develop intervention strategies. The purposes of this study were to assess the scores of the Barthel Index (BI) and Lawton Instrumental Activities of Daily Living (IADL) scale in older adults with cognitive impairment and to explore the different effects that levels of cognitive functions have on changes in IADL functions. We recruited 31 participants with dementia, 36 with mild cognitive impairment (MCI), and 35 normal controls (NCs) from the neurology outpatient department of a regional hospital. The results of the demographic and clinical characteristics through the Lawton IADL scale, BI, Quick Mild Cognitive Impairment (Qmci) screen, Montreal Cognitive Assessment (MoCA), and Mini-Mental State Examination (MMSE), were collected on the same day and compared with the Kruskal-Wallis test, Wilcoxon rank-sum test, Fisher's exact test, and a multiple linear regression analysis, as appropriate. In the BI, bathing was the most discriminating activity to differentiate patients with MCI and dementia; in the Lawton IADL scale, medication responsibility and shopping were the most discriminating activities to differentiate NCs and patients with MCI, and patients with MCI and dementia, respectively. In addition, the predictors of changes in Lawton IADL scale scores were the problem-solving score of the Clinical Dementia Rating scale, a Qmci score of > 20.4 and an age of ≤ 81.2 years, a MoCA score of < 9.4 and an age of > 81.2 years, and the MMSE score and an age of > 81.2 years. This study adds to the evidence that the description of basic and instrumental daily activities is integrated in older adults with cognitive impairment. Notably, the Qmci is the most significant predictor of changes in IADL function for "young" older adults, as are the MoCA and MMSE for "old" older adults.

Psychometric and diagnostic properties of the Taiwan version of the Quick Mild Cognitive Impairment screen.

There is a need for a screening tool with capacities of accurate detection of early mild cognitive impairment (MCI) and dementia and is suitable for use in a range of languages and cultural contexts. This research aims to evaluate the psychometric and diagnostic properties of the Taiwan version of Qmci (Qmci-TW) screen and to explore the discriminating ability of the Qmci-TW in differentiating among normal controls (NCs), MCI and dementia. Thirty-one participants with dementia and 36 with MCI and 35 NCs were recruited from a neurology department of regional hospital in Taiwan. Their results on the Qmci-TW, Taiwanese version of the Montreal Cognitive Assessment (MoCA), and Traditional Chinese version of the Mini-Mental State Examination (MMSE) were compared. For analysis, we used Cronbach's α, intraclass correlation coefficient, Spearman's ρ, Kruskal-Wallis test, receiver operating characteristic curve analysis, and multivariate analysis, as appropriate. The Qmci-TW exhibited satisfactory test-retest reliability, internal consistency, and interrater reliability as well as a strong positive correlation with results from the MoCA and MMSE. The optimal cut-off score on the Qmci-TW for differentiating MCI from NC was ≤ 51.5/100 and dementia from MCI was ≤ 31/100. The MoCA exhibited the highest accuracy in differentiating MCI from NC, followed by the Qmci-TW and then MMSE; whereas, the Qmci-TW and MMSE exhibited the same accuracy in differentiating dementia from MCI, followed by the MoCA. The Qmci-TW may be a useful clinical screening tool for a spectrum of cognitive impairments.