Sedentary behaviour (especially accumulation pattern) has an independent negative impact on skeletal muscle size and architecture in community-dwelling older adults.

Prolonged sedentary behaviour (SB) i.e. longer bouts, is suggested to have a range of negative health effects, independent of habitual light and medium-to-vigorous physical activity (LIPA or MVPA).

Concurrent Validity of Four Activity Monitors in Older Adults.

Sedentary behaviour (SB) and physical activity (PA) have been shown to be independent modulators of healthy ageing. We thus investigated the impact of activity monitor placement on the accuracy of detecting SB and PA in older adults, as well as a novel random forest algorithm trained on data from older persons. Four monitor types (ActiGraph wGT3X-BT, ActivPAL3c VT, GENEActiv Original, and DynaPort MM+) were simultaneously worn on five anatomical sites during ten different activities by a sample of twenty older adults (70.

Impaired Weight-Shift Amplitude in People with Parkinson's Disease with Freezing of Gait.

Background: People with Parkinson's disease and freezing of gait (FOG; freezers) suffer from pronounced postural instability. However, the relationship between these phenomena remains unclear and has mostly been tested in paradigms requiring step generation.

Objective: To determine if freezing-related dynamic balance deficits are present during a task without stepping and determine the influence of dopaminergic medication on dynamic balance control.

Virtual Reality Balance Games Provide Little Muscular Challenge to Prevent Muscle Weakness in Healthy Older Adults.

Muscle weakness is an important risk factor for falls in older adults. Intensity and duration of muscle activity are important determinants of exercise effectiveness in combating muscle weakness. The aim of this article was to assess the intensity and duration of muscle activity in virtual reality (VR) balance games.

Understanding Motivations and Player Experiences of Older Adults in Virtual Reality Training.

Objective: We studied which games and underlying game mechanics are considered motivating by older adults, so that designers and therapists make informed choices when designing or selecting virtual reality (VR)-training interventions.

Materials And Methods: We conducted a repeated measures design with 30 older participants, who played eight different VR-training games and afterward filled out the intrinsic motivation inventory (IMI). Differences in intrinsic motivation between games were analyzed using Friedman's tests.

Adaptations to Postural Perturbations in Patients With Freezing of Gait.

Freezing of gait (FOG) is a powerful determinant of falls in Parkinson's disease (PD). Automatic postural reactions serve as a protective strategy to prevent falling after perturbations. However, differences in automatic postural reactions between patients with and without FOG in response to perturbation are at present unclear.

The Impact of Dual-Tasking on Postural Stability in People With Parkinson's Disease With and Without Freezing of Gait.

Background: Postural instability and freezing of gait (FOG) are major problems in patients with Parkinson's disease (PD), and both contribute to falls. However, the interrelationship between these 2 deficits is still unclear.

Objective: This study investigated whether dual-tasking influenced postural control differently in freezers (FOG+) and nonfreezers (FOG-).

Performance of thigh-mounted triaxial accelerometer algorithms in objective quantification of sedentary behaviour and physical activity in older adults.

Accurate monitoring of sedentary behaviour and physical activity is key to investigate their exact role in healthy ageing. To date, accelerometers using cut-off point models are most preferred for this, however, machine learning seems a highly promising future alternative. Hence, the current study compared between cut-off point and machine learning algorithms, for optimal quantification of sedentary behaviour and physical activity intensities in the elderly.

Virtual reality balance training for elderly: Similar skiing games elicit different challenges in balance training.

Background: Virtual Reality (VR) balance training may have advantages over regular exercise training in older adults. However, results so far are conflicting potentially due to the lack of challenge imposed by the movements in those games. Therefore, the aim of this study was to assess to which extent two similar skiing games challenge balance, as reflected in center of mass (COM) movements relative to their Functional Limits of Stability (FLOS).

Changes in gait characteristics of women with early and established medial knee osteoarthritis: Results from a 2-years longitudinal study.

Background: Despite the large number of cross-sectional studies on gait in subjects with knee osteoarthritis, there are scarcely any longitudinal studies on gait changes in knee osteoarthritis.

Methods: Gait analysis was performed on 25 women with early and 18 with established medial knee osteoarthritis, as well as a group of 23 healthy controls. Subjects were asked to walk at their comfortable speed.

Freezing-related perception deficits of asymmetrical walking in Parkinson's disease.

Patients with Parkinson's disease (PD), and especially those with freezing of gait (FOG), are known to experience impairments in gait rhythmicity, symmetry, and bilateral coordination between both legs. In the current study, we investigated whether deficits in perception of gait speed between limbs were more pronounced in freezers than in non-freezers and could explain some of these gait impairments. We also assessed cognitive ability and proprioception.

Do Psychosocial Factors Predict Muscle Strength, Pain, or Physical Performance in Patients With Knee Osteoarthritis?

Objective: The aim of this study was to examine the relationship of psychosocial factors, namely, pain catastrophizing, kinesiophobia, and maladaptive coping strategies, with muscle strength, pain, and physical performance in patients with knee osteoarthritis (OA)-related symptoms.

Methods: A total of 109 women (64 with knee OA-related symptoms) with a mean age of 65.4 years (49-81 years) were recruited for this study.

Dynamic and static knee alignment at baseline predict structural abnormalities on MRI associated with medial compartment knee osteoarthritis after 2 years.

Background: Dynamic and static varus alignment, both, have been reported as risk factors associated with structural progression of knee osteoarthritis. However the association of none of the static and dynamic alignment with structural, clinical, and functional progression associated with knee osteoarthritis has not been assessed yet in a longitudinal study.

Methods: Forty-seven women with early and established medial knee osteoarthritis were evaluated.

Clinical balance scales indicate worse postural control in people with Parkinson's disease who exhibit freezing of gait compared to those who do not: A meta-analysis.

Postural instability and freezing of gait (FOG) are key features of Parkinson's disease (PD) that are closely related to falls. Uncovering the postural control differences between individuals with and without FOG contributes to our understanding of the relationship between these phenomena. The objective of this meta-analysis was to investigate whether postural control deficits, as detected by clinical balance scales, were more apparent in FOG+ compared to FOG-.

Effects of attentional focus on walking stability in elderly.

Introduction: Balance performance in the elderly is related to psychological factors such as attentional focus. We investigated the effects of internal vs. external focus of attention and fall history on walking stability in healthy older adults.

Postural Stability During Single-Leg Stance: A Preliminary Evaluation of Noncontact Lower Extremity Injury Risk.

Study Design Controlled laboratory study with a prospective cohort design. Background Postural stability deficits during single-leg stance have been reported in persons with anterior cruciate ligament (ACL) injury, ACL reconstruction, and chronic ankle instability. It remains unclear whether impaired postural stability is a consequence or cause of these injuries.

Evaluation of cognitive subdomains, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D in the European Male Ageing Study.

Purpose: Although lower levels of vitamin D have been related to poor cognitive functioning and dementia in older adults, evidence from longitudinal investigations is inconsistent. The objective of this study was to determine whether 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)D] levels are associated with specified measures of cognitive decline in ageing men.

Methods: The European Male Ageing Study (EMAS) followed 3369 men aged 40-79 over 4.

Hip abductor neuromuscular capacity: A limiting factor in mediolateral balance control in older adults?

Background: Mediolateral balance impairment is an important cause of falling in older adults. We aimed to investigate whether hip abductor muscular strength and/or position sense are limiting factors in mediolateral balance control.

Methods: Sixteen community-dwelling older adults performed three different mediolateral weight-shifting tasks, by tracking (1) a sinusoidally moving visual target, "visual-MELBA"; (2) a sinusoidally translating platform without explicit visual feedback, "mechanical-MELBA"; and (3) an unpredictable platform translation, "sudden-platform-translation.

Effects of narrow base gait on mediolateral balance control in young and older adults.

The aim of this study was to examine the effect of narrowing step width on mediolateral (ML) center of mass (COM) kinematics and margin of stability (MOS) in young and older adults. Fourteen young and 18 healthy older adults were asked to walk on a treadmill at preferred speed, stepping on projected lines at their predetermined preferred step width (PSW) and at a 50% narrowed step width (NSW). Linear trunk accelerations were recorded by an inertial sensor, attached at the level of the lumbar spine and foot placement was determined from force sensors in the treadmill.

Changes in proprioceptive weighting during quiet standing in women with early and established knee osteoarthritis compared to healthy controls.

Objectives: Knee osteoarthritis (OA) is highly prevalent in people above the age of 60, and is typically associated with pain, stiffness, muscle weakness and proprioceptive deficits. Muscle-tendon vibration has been used to assess the spatial reweighting of proprioceptive input during standing. The current study aimed to investigate whether weighting of proprioceptive input is altered in patients with early and established knee OA compared to asymptomatic controls.

A review of the assessment and prevalence of sedentarism in older adults, its physiology/health impact and non-exercise mobility counter-measures.

This literature review focuses on aspects of sedentary behaviour (SB) in elderly. Since it has been identified as a distinct health risk, independent of physical activity, SB is a significant issue. This is particularly true for an ageing population as evidence shows that older adults (aged ≥65 years) are the most sedentary age group (on average 8.

Phase-dependent changes in local dynamic stability during walking in elderly with and without knee osteoarthritis.

Previously, we reported reduced time-averaged knee local stability, in the unaffected, but not the affected leg of elderly with knee osteoarthritis OA compared to controls. Since stability may show phase-related changes, we reanalyzed the dataset reported previously using time-dependent local stability, λ(t), and also calculated time-averaged local stability, λs, for comparison. We studied treadmill walking at increasing speeds, focusing on sagittal plane knee movements.

Can explicit visual feedback of postural sway efface the effects of sensory manipulations on mediolateral balance performance?

Explicit visual feedback on postural sway is often used in balance assessment and training. However, up-weighting of visual information may mask impairments of other sensory systems. We therefore aimed to determine whether the effects of somatosensory, vestibular, and proprioceptive manipulations on mediolateral balance are reduced by explicit visual feedback on mediolateral sway of the body center of mass and by the presence of visual information.

Muscle-bone interactions: From experimental models to the clinic? A critical update.

Bone is a biomechanical tissue shaped by forces from muscles and gravitation. Simultaneous bone and muscle decay and dysfunction (osteosarcopenia or sarco-osteoporosis) is seen in ageing, numerous clinical situations including after stroke or paralysis, in neuromuscular dystrophies, glucocorticoid excess, or in association with vitamin D, growth hormone/insulin like growth factor or sex steroid deficiency, as well as in spaceflight. Physical exercise may be beneficial in these situations, but further work is still needed to translate acceptable and effective biomechanical interventions like vibration therapy from animal models to humans.