Physical Fitness and Cognitive Function in Persons with Dementia and their Caregiver.

A cross-sectional design investigated the physical attributes of 15 dyads of people with dementia and their caregivers. Physical and cognitive markers determined deviations from clinical thresholds for loss of functional independence, where 100% of participants performed below criterion-referenced threshold values for aerobic endurance. Walking distance for people with dementia was associated with bath/shower activity ( = .

Declines in grip strength may indicate early changes in cognition in healthy middle-aged adults.

Declining grip strength is an indicator of cognitive loss in older individuals but it has not been explored people younger than 65 years old. The purpose of this study was to investigate the relationship between grip strength and specific cognitive tests known to decline with mild cognitive impairment in young and middle-aged adults. Declines in cognitive performance in middle-aged adults may provide evidence that these changes occur earlier than previously reported.

Asymmetries in force matching are related to side of stroke in right-handed individuals.

Asymmetries in grasp force matching extend beyond quantifying a single measure of maximum grip strength and advance our application of side-specific treatment interventions. A cross sectional study design investigated grasp-force matching performance in right-handed individuals with a stroke and age-matched healthy controls. A visual representation of the 20% Maximum Voluntary Contraction (MVC) was matched in three conditions in the absence of visual feedback with the same (Ipsilateral Remembered - IR) or opposite hand (Concurrent - CC and Contralateral Remembered - CR).

Upper Limb Asymmetry in the Sense of Effort Is Dependent on Force Level.

Previous studies have shown that asymmetries in upper limb sensorimotor function are dependent on the source of sensory and motor information, hand preference and differences in hand strength. Further, the utilization of sensory and motor information and the mode of control of force may differ between the right hand/left hemisphere and left hand/right hemisphere systems. To more clearly understand the unique contribution of hand strength and intrinsic differences to the control of grasp force, we investigated hand/hemisphere differences when the source of force information was encoded at two different force levels corresponding to a 20 and 70% maximum voluntary contraction or the right and left hand of each participant.

Handgrip strength as a means of monitoring progression of cognitive decline - A scoping review.

Cognitive decline in older adults contributes to reduced ability to perform daily tasks and continued disuse leads to muscle weakness and potentiates functional loss. Despite explicit links between the motor and cognitive systems, few health care providers assess motor function when addressing the needs of individuals with cognitive loss. Early and easy measurable biomarkers of cognitive decline have the potential to improve care for individuals with dementia and mild cognitive impairment.

Construct validity of the Modified Gait Efficacy Scale in older females.

There are few well-validated tools that focus on the assessment of walking confidence in older adults. The main objective of this study was to assess construct validity of the 10-item Modified Gait Efficacy Scale (mGES) as a measure of walking confidence in older adults. Twenty-four older females completed the mGES, the 16-item Activities-specific Balance Confidence (ABC-16) scale, and the Senior Fitness Test (SFT).

Reliability and validity of cervical position measurements in individuals with and without chronic neck pain.

Objectives: The cervical range of motion device (CROM) has been shown to provide reliable forward head position (FHP) measurement when the upper cervical angle (UCA) is controlled. However, measurement without UCA standardization is reflective of habitual patterns. Criterion validity has not been reported.

Contribution of Head Position, Standing Surface, and Vision to Postural Control in Community-Dwelling Older Adults.

Postural control requires the integration of sensorimotor information to maintain balance and to properly position and orient the body in response to external stimuli. Age-related declines in peripheral and central sensory and motor function contribute to postural instability and falls. This study investigated the contribution of head position, standing surface, and vision on postural sway in 26 community-dwelling older adults.

Age and task differences in functional fitness in older women: comparisons with Senior Fitness Test normative and criterion-referenced data.

Age-related changes in physical abilities, such as strength and flexibility, contribute to functional losses. However, older individuals may be unaware of what specific physical abilities compromise independent functioning. Three groups of women, aged 60 to 69, 70 to 79, and 80 to 92 years, were administered the Senior Fitness Test (SFT) to determine age differences in physical abilities and risk for functional losses.

Sense of effort revisited: relative contributions of sensory feedback and efferent copy.

Although controversial, muscular effort perception is frequently attributed to the efferent copy of the associated motor command. While peripheral/sensory information is thought to be necessary for force modulation/control, it is not involved in initial force production. We recently showed in right-handers, that perception of effort was asymmetric for grasp-force tasks.

Grasp force matching and brain iron content estimated in vivo in older women.

Increased brain iron content has been linked to neural degeneration and to age-related decline of cognitive and motor functions. The basal ganglia (BG), which contain significant amount of iron, play an important role in establishing and modulating force requirements in hand grasp to meet specific task demands. However, it is unclear if increased BG iron content contributes to age differences in hand grasp performance.

The contribution of head position, standing surface and vision to postural control in young adults.

Postural control requires the integration of sensory information and is essential for performing every day movements and activities. Integrating sensory information from multiple sources may be challenging when competing sources of sensory information are affected. To further understand this complex relationship, this study investigated the contribution of varying sources of sensory information to postural control in healthy, young participants.

Age differences in virtual environment and real world path integration.

Accurate path integration (PI) requires the integration of visual, proprioceptive, and vestibular self-motion cues and age effects associated with alterations in processing information from these systems may contribute to declines in PI abilities. The present study investigated age-related differences in PI in conditions that varied as a function of available sources of sensory information. Twenty-two healthy, young (23.

Establishing hand preference: why does it matter?

Hand preference has been associated with psychological and physical well-being, risk of injury, pathological irregularities, longevity, and cognitive function. To determine hand preference, individuals are often asked what hand they use to write with, or what hand is used more frequently in activities of daily living. However, relying only on one source of information may be misleading, given the strong evidence to support a disassociation between self-reported hand preference and outcomes of hand performance assessments.

Upper limb kinesthetic asymmetries: gender and handedness effects.

Proprioceptive and motor information contribute to movement representation; however, the equivalence of homologous contralateral sensorimotor processes as a function of gender and handedness has received little attention. The present work investigated asymmetry in contralateral reproductions of movements elicited by tendon vibration in right and left handed young adults of both genders. With eyes closed, illusions of elbow flexion movement elicited by a 100 Hz vibration applied to the distal tendon of the right or left triceps muscle were matched concurrently with the opposite limb.

Contribution of sensory and motor components to motor control asymmetries: an analytical model approach.

Proprioceptive and motor information contribute to movement representation; however, the equivalence of homologous contralateral information has received little attention. In a recent study using the matching paradigm we showed that upper limb position sense, based on feedback control, is asymmetric and this asymmetry could be associated with a difference in gain between left (L) and right (R) sensorimotor systems. The current results also show that movement sense is asymmetric in males and this asymmetry is dependent on handedness.

Asymmetry in grasp force matching and sense of effort.

While asymmetries in upper limb force matching have been observed, the mechanisms underlying asymmetry in the sense of effort have not been conceptualized. The aim of this study was to investigate asymmetries in the perception and reproduction of grasp force. Forty-two young adults, 22 right-handed (RH) and 20 left-handed (LH), were, respectively, divided into three groups according to differences between their right and left-hand strength (left stronger than right, right stronger than left and right & left equivalent).

Age-related declines in the detection of passive wrist movement.

Age-related changes in proprioceptive ability and their contributions to postural instability have been well documented. In contrast, and despite the known importance of proprioceptive feedback in the control of coordinated arm and hand movement, studies focusing on upper limb proprioception in older populations are few and equivocal in their findings. This study focused on kinesthetic awareness about the wrist joint in healthy young and older adults.

The influence of age and physical activity on upper limb proprioceptive ability.

Our understanding of age-related declines in upper limb proprioceptive abilities is limited. Furthermore, the extent to which physical activity might ameliorate age-related changes in proprioception is not known. Upper limb proprioceptive acuity was examined in young and older (active and sedentary) right-handed adults using a wrist-position-matching task that varied in terms of processing demands.

Position sense asymmetry.

Asymmetries in upper limb position sense have been explained in the context of a left limb advantage derived from differences in hemispheric specialization in the processing of kinesthetic information. However, it is not clearly understood how the comparison of perceptual information associated with passive limb displacement and the corresponding matching movement resulting from the execution of a motor command contributes to these differences. In the present study, upper limb position sense was investigated in 12 right-hand-dominant young adults performing wrist position matching tasks which varied in terms of interhemispheric transfer, memory retrieval and whether the reference position was provided by the same or opposite limb.

Age-related differences in upper limb proprioceptive acuity.

Although upper limb movements are known to be slower and more variable in elderly persons, the extent to which these changes are associated with deficits in movement-related sensory feedback is poorly understood, despite the importance of proprioception in the control of skilled movement. Age-related changes were examined with 22 participants (10 of M age 27 years and 12 of M age 75 years) in performance of an elbow position-matching task which varied in terms of interhemispheric transfer and/or the need to retrieve memory-based proprioceptive information. Matching errors were significantly greater, and movements more prolonged, and irregular in their time course in the elderly group than in the young group.

Vibration-induced muscle fatigue, a possible contribution to musculoskeletal injury.

Localized muscle fatigue resulting from 30-min sustained and intermittent grip exertions of 5% maximal voluntary contraction (MVC) with and without hand-vibration exposure (10 Hz, 7 mm displacement amplitude) was investigated. Muscle fatigue was quantified by the magnitude of the twitch force elicited in the right flexor digitorum superficialis muscle of the long finger using the low-frequency fatigue (LFF) method. The influence of vibration in the sustained grip exertion condition exacerbates fatigue as seen with the reduction in twitch force 30-60 min post-work task.