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1.
Gait Posture ; 110: 129-137, 2024 05.
Article En | MEDLINE | ID: mdl-38581933

OBJECTIVE: To examine whether immersive virtual reality (VR) can improve balance, gait, mobility and fear of falling in older people. DATA SOURCES: MEDLINE, EMBASE, CINAHL, PsycINFO, ProQuest Central (Engineering and Computer Science) and reference lists of included articles. STUDY SELECTION: Randomised controlled trials that administered immersive VR training and assessed balance, gait and mobility outcomes in older adults without neurological disorders (mean age ≥ 65). Primary outcomes were standing balance (e.g. postural sway), multi-item balance scales (e.g. Berg Balance Scale), gait (e.g. gait speed) and mobility (e.g. Timed Up and Go test). Secondary outcomes comprised measures of enjoyment, fear of falling, adherence (e.g. dropout rate), feasibility/usability and adverse effects (e.g. motion sickness). RESULTS: Meta-analyses showed that immersive VR training significantly improved standing balance (SMD: 0.51, 95% CI: .15, 0.86, p = 0.005, I2 = 28% - 3 studies, n = 79) and performance on the Berg Balance Scale (MD: 2.36, 95% CI: 1.17, 3.56, p=0.0001, I2=0% - 4 studies, n = 190). No significant improvement in gait, mobility or fear of falling was found. Subgroup analyses revealed higher training doses (≥4.5 total hours) and VR interventions using non-head mounted displays were more likely to improve standing balance. No meta-analyses were conducted for enjoyment, adherence, feasibility/usability and adverse events. CONCLUSIONS: The findings indicate immersive VR has beneficial effects on balance, but not gait, mobility or fear of falling. Further research is required to examine these outcomes in trials that also include quantitative measurements of enjoyment, adherence, clinical feasibility, usability and adverse effects.


Accidental Falls , Gait , Postural Balance , Humans , Postural Balance/physiology , Aged , Gait/physiology , Accidental Falls/prevention & control , Virtual Reality Exposure Therapy/methods , Virtual Reality
2.
Gait Posture ; 109: 226-232, 2024 03.
Article En | MEDLINE | ID: mdl-38364509

BACKGROUND: Standing at height, and subsequent changes in emotional state (e.g., fear of falling), lead to robust alterations in balance in adults. However, little is known about how height-induced postural threat affects balance performance in children. Children may lack the cognitive capability necessary to inhibit the processing of threat and fear-related stimuli, and as a result, may show more marked (and perhaps detrimental) changes in postural control compared to adults. This work explored the emotional and balance responses to standing at height in children, and compared responses to young and older adults. METHODS: Children (age: 9.7 ± 0.8 years, n = 38), young adults (age: 21.8 ± 4.0 years, n = 45) and older adults (age: 73.3 ± 5.0 years, n = 15) stood in bipedal stance in two conditions: at ground level and 80 cm above ground. Centre of pressure (COP) amplitude (RMS), frequency (MPF) and complexity (sample entropy) were calculated to infer postural performance and strategy. Emotional responses were quantified by assessing balance confidence, fear of falling and perceived instability. RESULTS: Young and older adults demonstrated a postural adaptation characterised by increased frequency and decreased amplitude of the COP, in conjunction with increased COP complexity (sample entropy). In contrast, children demonstrated opposite patterns of changes: they exhibited an increase in COP amplitude and decrease in both frequency and complexity when standing at height. SIGNIFICANCE: Children and adults adopted different postural control strategies when standing at height. Whilst young and older adults exhibited a potentially protective "stiffening" response to a height-induced threat, children demonstrated a potentially maladaptive and ineffective postural adaptation strategy. These observations expand upon existing postural threat related research in adults, providing important new insight into understanding how children respond to standing in a hazardous situation.


Fear , Longevity , Young Adult , Child , Humans , Aged , Adolescent , Adult , Fear/psychology , Standing Position , Postural Balance/physiology
3.
Exp Gerontol ; 184: 112338, 2023 12.
Article En | MEDLINE | ID: mdl-38016571

The purpose of this study was to explore the effects of arm movements on postural control when standing under different sensory conditions in healthy young and older adults. Fifteen young (mean ± SD age; 21.3 ± 4.2 years) and 15 older (mean ± SD age; 73.3 ± 5.0 years) adults completed the modified Romberg test, which uses four task manipulations (i.e. eyes open and eyes closed on a firm and foam surface) to compromise the fidelity of sensory feedback mechanisms. Each participant completed the tasks under two arm movement conditions: restricted and free arm movements. Centre of pressure (COP) range and frequency were calculated to characterise postural performance and strategy, respectively. Older adults showed greater COP range with restricted compared to free arm movements during all modified sensory conditions, with these effects most prominent in the medio-lateral (ML) plane (all p < .05, Cohen's d = 0.69-1.61). Compared to the free arm movement condition, there was an increase in ML displacement and frequency when arm movements were restricted during only the most challenging (i.e. vestibular dominant) task in young adults (all p < .05, d = 0.645-0.83). Finally, main age effects for the arm restriction cost (p < .05) indicates a greater reliance on an upper body strategy in older compared to young adults, independent of sensory availability/accuracy. These findings indicate that older adults compensate for the loss of accuracy in sensory input by increasing reliance on upper body movement strategies.


Movement , Postural Balance , Humans , Aged , Standing Position , Feedback, Sensory
4.
Hum Mov Sci ; 89: 103093, 2023 Jun.
Article En | MEDLINE | ID: mdl-37088011

Emerging evidence highlights that arm movements exert a substantial and functionally relevant contribution on quiet standing balance control in young adults. Ageing is associated with "non-functional" compensatory postural control strategies (i.e., lower limb co-contraction), which in turn, may increase the reliance on an upper body strategy to control upright stance. Thus, the primary purpose of this study was to compare the effects of free versus restricted arm movements on balance performance in young and older adults, during tasks of different difficulty. Fifteen young (mean ± SD age; 21.3 ± 4.2 years) and fifteen older (mean ± SD age; 73.3 ± 5.0 years) adults performed bipedal, semi-tandem and tandem balance tasks under two arm position conditions: restricted arm movements and free arm movements. Centre of pressure (COP) amplitude and frequency were calculated as indices of postural performance and strategy, respectively. Especially in older adults, restriction of arm movement resulted in increased sway amplitude and frequency, which was primarily observed for the mediolateral direction. Further, increasing balance task difficulty raised the arm restriction cost (ARC; a new measure to quantify free vs. restricted arm movement differences in postural control) that was more prominent in older adults. These findings indicate the ARC provides a measure of reliance on the upper body for balance control and that arm movement is important for postural control in older adults, especially during tasks of greater difficulty.


Aging , Movement , Young Adult , Humans , Aged , Postural Balance , Lower Extremity , Standing Position
5.
Gait Posture ; 103: 73-79, 2023 06.
Article En | MEDLINE | ID: mdl-37121215

BACKGROUND: It is firmly established that postural threat seems to lead to an increased reliance on an ankle control ('stiffening') strategy. However, little is known about how postural threat affects performance in challenging tasks that require the use of upper body postural control strategies for stability. It is logical to assume that in such conditions, being able to utilise an upper body strategy may reduce the reliance on such ankle stiffening strategy. RESEARCH QUESTION: The objective of this study was to determine how arm movement influences balance control during a challenging balance task performed under conditions of postural threat. METHODS: Thirty young adults (mean ± SD age; 22.0 ± 4.0 years) balanced in tandem stance whilst standing at both ground-level (no threat) and 0.8 m above ground (threat). In both conditions, participants performed the task under two different arm positions: restricted arm movements and free arm movements. Postural sway amplitude and frequency were calculated to infer postural stiffening response. Self-reported emotional responses were quantified by assessing balance confidence, fear of falling, perceived stability, and conscious balance processing. RESULTS: Independent of arm movements, postural threat evoked an increase in fear of falling and conscious balance processing, and reductions in balance confidence and perceived stability. These threat-related changes in emotional state were further amplified when arm movements were restricted. Whilst significant increases in sway frequency during threat were observed in both arm conditions, reductions in sway amplitude were only observed during the restricted arm movement condition. SIGNIFICANCE: We propose that these responses likely reflect a fear-related cautious strategy intended to reduce the postural destabilisation associated with individuals being unable to use their arms to counter any destabilisation, as would normally be the case in daily life.


Arm , Fear , Humans , Young Adult , Fear/physiology , Movement/physiology , Postural Balance/physiology
6.
Occup Med (Lond) ; 73(3): 161-166, 2023 04 26.
Article En | MEDLINE | ID: mdl-36893360

BACKGROUND: No easy-to-use fall risk assessment tools have been devised to assess occupational fall risk in older workers. AIMS: To develop an Occupational Fall Risk Assessment Tool (OFRAT) and report its predictive validity and reliability in older workers. METHODS: The baseline fall risk assessment was completed by 1113 participants aged ≥60 years who worked ≥4 days/month in Saitama, Japan. Participants were followed up for falls during occupational activities for 1 year, and 30 participants were assessed twice for test-retest reliability. The following assessment measures were summed to form the OFRAT risk score: older age, male sex, history of falls, physical work participation, diabetes, use of medications increasing fall risk, reduced vision, poor hearing, executive dysfunction and slow stepping. The scores were then classified into four grades (0-2 points: very low, 3 points: low, 4 points: moderate and ≥5 points: high). RESULTS: During follow-up, 112 participants fell 214 times during work. The negative binomial regression model showed that participants with higher grades had a higher incidence rate ratio [95% confidence interval] for falls than those with very low grades (low: 1.64 [1.08-2.47], moderate: 4.23 [2.82-6.34] and high: 6.12 [3.83-9.76]). The intraclass correlation coefficient for risk score was 0.86 [0.72-0.93], and the weighted kappa coefficient for grade assessment was 0.74 [0.52-0.95]. CONCLUSIONS: The OFRAT is a valid and reliable tool for estimating the occupational fall risk in older workers. It may assist occupational physicians implement strategies to prevent falls in this group.


Physical Examination , Humans , Male , Aged , Reproducibility of Results , Risk Assessment , Risk Factors
7.
Exp Brain Res ; 240(11): 2871-2883, 2022 Nov.
Article En | MEDLINE | ID: mdl-36112172

Obstacle crossing requires visuospatial working memory to guide the trailing leg trajectory when vision in unavailable. Visuospatial working memory, as assessed with neuropsychological tests, declines with age, however, this remains to be investigated functionally in obstacle crossing. There is also evidence that visuospatial encoding during a secondary task interferes with balance control during stepping and walking in older people. Here, we studied the interaction effects of age by delay (study 1) and age by secondary visuospatial task (study 2) conditions on obstacle clearance in a visuospatial working memory -guided obstacle crossing task. Healthy young adults aged 19 to 36 years (n = 20 in study 1 and n = 17 in study 2) and healthy older adults aged 66 to 83 years (n = 29 in study 1 and n = 21 in study 2) were instructed to step over an obstacle with their leading leg and straddle it for a delay period before completing the crossing with their trailing leg. In study 1, two obstacle height conditions (12 cm, 18 cm) and two delay durations (20 s, 60 s) were presented in random order. In study 2, participants were required to attend to either no secondary task (control), a visuospatial secondary (star movement) task, or a nonspatial secondary (arithmetic) task, while straddling the obstacle for a delay duration of 20 s, at obstacle heights of 12 cm and 18 cm, randomly presented. Trailing leg kinematics (mean and variability of maximum toe clearance over the obstacle) were determined via motion capture. There were no statistically significant age by delay or age by secondary task interactions. In study 1, toe clearance variability was significantly greater in young adults and increased with increasing delay duration in both groups. In study 2, compared with the control condition, toe clearance variability was significantly greater in the non-spatial secondary task condition but not in the visuospatial condition. Contrary to our hypotheses, these findings suggest that young and older adults alike can store an obstacle representation via visuospatial working memory for durations of at least 60 s and use this information to safely scale their trailing leg over an obstacle. However, the increase in trailing leg toe clearance variability with delay duration suggests that obstacle representation starts to deteriorate even within the first 20 s regardless of age. The finding that undertaking a concurrent arithmetic task impaired visuospatial working memory-guided obstacle clearance suggests a potential increased risk of tripping during obstacle crossing while dual-tasking in both young and older people.


Memory, Short-Term , Walking , Young Adult , Humans , Aged , Biomechanical Phenomena , Movement , Kinetics , Gait
8.
Breast Cancer Res ; 24(1): 34, 2022 05 17.
Article En | MEDLINE | ID: mdl-35581637

BACKGROUND: PET imaging of 18F-fluorodeoxygucose (FDG) is used widely for tumour staging and assessment of treatment response, but the biology associated with FDG uptake is still not fully elucidated. We therefore carried out gene set enrichment analyses (GSEA) of RNA sequencing data to find KEGG pathways associated with FDG uptake in primary breast cancers. METHODS: Pre-treatment data were analysed from a window-of-opportunity study in which 30 patients underwent static and dynamic FDG-PET and tumour biopsy. Kinetic models were fitted to dynamic images, and GSEA was performed for enrichment scores reflecting Pearson and Spearman coefficients of correlations between gene expression and imaging. RESULTS: A total of 38 pathways were associated with kinetic model flux-constants or static measures of FDG uptake, all positively. The associated pathways included glycolysis/gluconeogenesis ('GLYC-GLUC') which mediates FDG uptake and was associated with model flux-constants but not with static uptake measures, and 28 pathways related to immune-response or inflammation. More pathways, 32, were associated with the flux-constant K of the simple Patlak model than with any other imaging index. Numbers of pathways categorised as being associated with individual micro-parameters of the kinetic models were substantially fewer than numbers associated with flux-constants, and lay around levels expected by chance. CONCLUSIONS: In pre-treatment images GLYC-GLUC was associated with FDG kinetic flux-constants including Patlak K, but not with static uptake measures. Immune-related pathways were associated with flux-constants and static uptake. Patlak K was associated with more pathways than were the flux-constants of more complex kinetic models. On the basis of these results Patlak analysis of dynamic FDG-PET scans is advantageous, compared to other kinetic analyses or static imaging, in studies seeking to infer tumour-to-tumour differences in biology from differences in imaging. Trial registration NCT01266486, December 24th 2010.


Breast Neoplasms , Fluorodeoxyglucose F18 , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/genetics , Female , Glucose , Humans , Kinetics , Positron-Emission Tomography/methods , Radiopharmaceuticals
9.
Mech Ageing Dev ; 203: 111634, 2022 04.
Article En | MEDLINE | ID: mdl-35104475

INTRODUCTION: This review examined the impact of ageing, fall history and exercise on postural reflexes and adaptation to unpredictable perturbations. METHODS: MEDLINE, EMBASE, Scopus, SportDiscus and Web of Science were systematically searched for cross-sectional and intervention studies that assessed muscle onset latency following unpredictable postural perturbations in adults (CRD42020170861). RESULTS: Thirty-seven articles (n = 1257) were included in this review. Older adults had slower onset latencies compared to young adults (mean difference 14 ms, 95% CI: 10, 18, P < 0.001). Regular exercisers had faster onset latencies compared to sedentary/untrained participants (mean difference 11 ms, 95%CI: -19, -4, P = 0.002). Exercise interventions delivered in randomised control trials (RCTs) led to faster onset latencies (mean difference -4 ms, 95%CI: -9, 0, P = 0.04) compared to controls. Uncontrolled clinical trials of exercise (mainly short-term) did not show changes in onset latency in pre-post tests (mean difference -2 ms, 95%CI: -5, 1, P = 0.36). CONCLUSION: This review demonstrated that in response to postural perturbation, muscle activation is significantly delayed in older compared to young adults, and that adults who regularly exercised had faster muscle activation compared to their less active counterparts. No significant changes in onset latencies were evident in uncontrolled clinical trials of short duration, but longer-term RCTs indicated postural reflexes are responsive to training.


Exercise , Postural Balance , Accidental Falls , Aged , Aging/physiology , Humans , Postural Balance/physiology , Time Factors
10.
Gait Posture ; 91: 247-253, 2022 01.
Article En | MEDLINE | ID: mdl-34775227

BACKGROUND: People with Parkinson's disease (PD) have difficulties adapting their gait. While underlying neural mechanisms involving the prefrontal cortex (PFC) have been studied across various complex walking tasks, less is known about the premotor cortex (PMC) and supplementary motor area (SMA), key cortical regions for motor planning. This study compared frontal cortical regions activation patterns using functional near-infrared spectroscopy (fNIRS), between people with PD and healthy controls (HC) during gait adaptability tasks. METHODS: Forty-nine people with PD (mean (SD) age: 69.5 (7.9) years) and 21 HC (69.0 (5.9) years) completed a simple walk and three randomly presented gait adaptability tasks: (i) stepping on targets, (ii) avoiding obstacles and (iii) negotiating both targets and obstacles. Cortical activity in the dorsolateral PFC (DLPFC), SMA and PMC were recorded using fNIRS. Step length, velocity and accuracy and cortical activity were contrasted between the groups and walking conditions. RESULTS: Compared with the HC, the PD group exhibited greater PMC activation and walked significantly slower and took shorter steps in all conditions. A statistically significant group by condition interaction indicated an increase in DLPFC cortical activation in the HC participants when undertaking the obstacle avoidance task compared with the simple walk but no increase in cortical activation in the PD group when undergoing this more challenging gait task. CONCLUSIONS: Our findings suggest people with PD have little or no DLPFC, SMA and PMC capacity beyond what they need for simple walking and in consequence need to slow their gait velocity to meet the demands of target stepping and obstacle avoidance tasks. Such behavioral and neural patterns appear consistent with concepts of compensatory over-activation and capacity limitation.


Gait Disorders, Neurologic , Motor Cortex , Parkinson Disease , Aged , Dorsolateral Prefrontal Cortex , Gait , Gait Disorders, Neurologic/etiology , Humans , Walking
11.
Br J Cancer ; 126(4): 598-605, 2022 03.
Article En | MEDLINE | ID: mdl-34795409

BACKGROUND: 18F-fluciclovine is a synthetic amino acid positron emission tomography (PET) radiotracer that is approved for use in prostate cancer. In this clinical study, we characterised the kinetic model best describing the uptake of 18F-fluciclovine in breast cancer and assessed differences in tracer kinetics and static parameters for different breast cancer receptor subtypes and tumour grades. METHODS: Thirty-nine patients with pathologically proven breast cancer underwent 20-min dynamic PET/computed tomography imaging following the administration of 18F-fluciclovine. Uptake into primary breast tumours was evaluated using one- and two-tissue reversible compartmental kinetic models and static parameters. RESULTS: A reversible one-tissue compartment model was shown to best describe tracer uptake in breast cancer. No significant differences were seen in kinetic or static parameters for different tumour receptor subtypes or grades. Kinetic and static parameters showed a good correlation. CONCLUSIONS: 18F-fluciclovine has potential in the imaging of primary breast cancer, but kinetic analysis may not have additional value over static measures of tracer uptake. CLINICAL TRIAL REGISTRATION: NCT03036943.


Breast Neoplasms/diagnostic imaging , Carboxylic Acids/administration & dosage , Cyclobutanes/administration & dosage , Metformin/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carboxylic Acids/pharmacokinetics , Cyclobutanes/pharmacokinetics , Female , Humans , Neoplasm Grading , Positron Emission Tomography Computed Tomography , Sensitivity and Specificity , Treatment Outcome
12.
Exp Gerontol ; 142: 111116, 2020 12.
Article En | MEDLINE | ID: mdl-33086078

Impaired mobility often co-occurs with depression. However, there is no systematic review evidence as to whether mobility impairments precede the onset of depression. The objective of this systematic review and meta-analysis was to evaluate whether mobility impairment could predict incident depression. A systematic search of cohort studies were performed in MEDLINE, EMBASE, CINAHL and PsycINFO. The target population was people with no depressive symptoms at baseline and follow-up for depression or depressive symptoms of at least three months. Of 1061 identified abstracts, 13 studies met the review eligibility criteria. The majority of included studies (8 out of 13) were of high methodological quality. Follow-up periods ranged from 12 months to 16 years. Gait speed was the most consistently reported mobility measure. Participants with slow gait speed were at higher risk of developing depressive symptoms (pooled OR = 1.93, 95%CI: 1.54 to 2.42, 11 studies). This review shows that slow gait speed is predictive of the onset of depressive symptoms. Systematic review registration number: CRD42020153791.


Depression , Walking Speed , Cohort Studies , Depression/diagnosis , Depression/epidemiology , Humans
13.
BMC Public Health ; 20(1): 1353, 2020 Sep 04.
Article En | MEDLINE | ID: mdl-32887600

BACKGROUND: The population prevalence of many diseases is known. However, little is known of the population prevalence of motor impairments. METHODS: The aim of this study was to determine the point prevalence of specific motor impairments (weakness, fatigue, contracture, impaired balance and impaired coordination) in the population aged 55 years and older resident in New South Wales, Australia in 2018. 55,210 members of the 45 and Up cohort were invited to participate in a follow-up survey that included questions on motor impairment. Responses were received from 20,141 people (36%). Calibrated estimates of prevalence of specific motor impairments, and of having at least one motor impairment, were obtained using survey weights based on the known multivariate distributions of age, gender and geographical location (28 regions) in the population. RESULTS: More than one-third of adults aged over 55 residing in New South Wales have difficulty using their hands, arms or legs. The prevalence of each motor impairment (muscle weakness, fatigue, contracture, impaired balance or impaired coordination) in this population is between 4 and 12%. The prevalence of at least one of these impairments is 21%. The prevalence of at least one impairment in people aged 85 and over is 42%. Women consistently had more difficulty using hands, arms and legs, and more motor impairment, than men. Difficulty using hands, arms and legs and the prevalence of all motor impairments, especially poor balance, greatly increased with age. CONCLUSION: The prevalence of specific motor impairments in older Australian adults is high - comparable to that of the most prevalent diseases. There may be merit in considering motor impairment as a significant public health problem in its own right.


Motor Disorders/epidemiology , Aged , Aged, 80 and over , Cohort Studies , Contracture/epidemiology , Cross-Sectional Studies , Fatigue/epidemiology , Female , Humans , Male , Middle Aged , Muscle Weakness/epidemiology , New South Wales/epidemiology , Prevalence
14.
Osteoarthritis Cartilage ; 27(7): 979-993, 2019 07.
Article En | MEDLINE | ID: mdl-31028883

OBJECTIVE: Falls are common after total hip arthroplasty (THA) and total knee arthroplasty (TKA). While previous studies have investigated various risk factors for falls in patients following THA and TKA, no systematic reviews have summarized these risk factors. Therefore, the current systematic review aimed to summarize evidence regarding risk factors for falls in patients after THA and/or TKA. METHODS: MEDLINE, EMBASE, CINAHL, SPORTDiscus, and Physiotherapy Evidence Database (from inception to June 30, 2018) were searched. The methodological quality and quality of evidence of the included studies were assessed by two independent reviewers. Relevant data regarding participants' characteristics, study design, follow-up time points, and identified risk factors were extracted. Meta-analyses and narrative syntheses were performed. RESULTS: Twelve studies with a total of 1,292,689 participants were included. Twenty-nine identified risk factors for post-THA/TKA falls were classified into either inpatient or post-discharge risk factors. Key risk factors for both post-THA and/or post-TKA inpatient falls that showed moderate level of evidence included: postoperative complications or comorbidities and revision THA/TKA. Likewise, risk factors for post-discharge falls after THA and/or TKA that demonstrated moderate level of evidence included: medications, psychiatric diseases, living alone, prior history of TKA, falls history and female gender. The quality of the included studies varied and sample sizes were not justified. CONCLUSIONS: This review summarized both non-modifiable and modifiable risk factors for post-THA/TKA falls. Our findings highlight the importance of developing strategies to lower the falls risk among patients following THA/TKA.


Accidental Falls/statistics & numerical data , Arthroplasty, Replacement, Hip/methods , Arthroplasty, Replacement, Knee/methods , Osteoarthritis, Hip/surgery , Osteoarthritis, Knee/surgery , Accidental Falls/prevention & control , Age Factors , Aged , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Knee/adverse effects , Female , Humans , Male , Middle Aged , Osteoarthritis, Hip/diagnostic imaging , Osteoarthritis, Knee/diagnostic imaging , Prevalence , Prognosis , Risk Assessment , Severity of Illness Index , Sex Factors
15.
Med Hypotheses ; 119: 32-36, 2018 Oct.
Article En | MEDLINE | ID: mdl-30122488

Fundamental to the advancement of scientific knowledge is unbiased, accurate and validated measurement techniques. Recent United Nations and landmark Nature publications highlight the global uptake of mobile technology and the staggering potential for big data to encourage people to be physically active and to influence health policy. However, concerns exist about inconsistencies in smartphone health apps. Big data has many benefits, but noisy data may lead to wrong conclusions. In reaction to the increasing availability of low quality data; we call for a rigorous debate into the validity of substituting big data for accurate data in health research. We evaluated the step counting accuracy of a smartphone app previously used by 717,527 people from 111 countries. Our new data (from 48 participants; aged 21-59 years; body mass index 17.7-33.5 kg/m2) revealed significant (15-66%) undercounting by Apple phones. In contrast to the generally positive performances of wearable devices for stereotypical treadmill like walking, we observed extraordinarily large (0-200% of steps taken) error ranges for both Android and Apple phones. Unconscious bias (developers' perceptions of usual behaviour) may be embedded into many unvalidated smartphone apps. Consumer-grade wearable devices appear unsuitable to detect steps in people with slow, short or non-stereotypical gait patterns. Specifically, there is a risk of systematically undercounting the steps by obese people, females or people from different ethnic groups resulting in biases when reporting associations between physical inactivity and obesity. More research is required to develop smartphone apps suitable for all people of the heterogeneous global population.


Bias , Medical Informatics/methods , Monitoring, Ambulatory/methods , Smartphone , Wearable Electronic Devices , Adult , Big Data , Body Mass Index , Data Accuracy , Exercise , Exercise Test , Female , Health Behavior , Humans , Male , Middle Aged , Obesity , Walking , Young Adult
16.
Br J Cancer ; 116(4): 472-478, 2017 Feb 14.
Article En | MEDLINE | ID: mdl-28095397

BACKGROUND: Elderly patients are commonly under-represented in cancer clinical trials. The 321GO was undertaken in preparation for a definitive phase three trial assessing different chemotherapy regimens in a frail and/or elderly population with advanced gastroesophageal (GO) cancer. METHODS: Patients with advanced GO cancer considered unfit for conventional dose chemotherapy were randomly assigned in a 1 : 1 : 1 ratio to: epirubicin, oxaliplatin and capecitabine (EOX); oxaliplatin and capecitabine (OX); and capecitabine alone (X) (all 80% of full dose and unblinded). The primary end point was patient recruitment over an 18-month period. A registration study recorded treatment choice for all patients with advanced GO cancer at trial centres. RESULTS: A total of 313 patients were considered for palliative chemotherapy for GO cancer over the 18-month period: 115 received full dose treatment, 89 less than standard treatment or entered 321GO and 111 no treatment. Within 321GO, 55 patients were randomly assigned (19 to OX and X; 17 to EOX). Progression-free survival (PFS) for all patients was 4.4 months and by arm 5.4, 5.6 and 3.0 months for EOX, OX and X, respectively. The number of patients with a good overall treatment utility (OTU), a novel patient-centred endpoint, at 12 weeks was 3 (18%), 6 (32%) and 1 (6%) for EOX, OX and X, respectively. At 6 weeks, 22 patients (41%) had experienced a non-haematologic toxicity ⩾grade 3, most commonly lethargy or diarrhoea. The OTU was prognostic for overall survival in patients alive at week 12 (logrank test P=0.0001). CONCLUSIONS: It is feasible to recruit elderly and/or frail patients with advanced GO cancer to a randomised clinical trial. The OX is the preferred regimen for further study. Overall treatment utility shows promise as a comparator between treatment regimens for feasibility and randomised trials in the elderly and/or frail GO cancer population.


Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Esophageal Neoplasms/drug therapy , Frail Elderly , Palliative Care/methods , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Aged , Aged, 80 and over , Capecitabine/administration & dosage , Capecitabine/adverse effects , Deoxycytidine/administration & dosage , Deoxycytidine/adverse effects , Disease Progression , Epirubicin/administration & dosage , Epirubicin/adverse effects , Esophageal Neoplasms/mortality , Esophageal Neoplasms/pathology , Feasibility Studies , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Humans , Male , Organoplatinum Compounds/administration & dosage , Organoplatinum Compounds/adverse effects , Oxaliplatin
17.
Eur J Neurol ; 24(3): 523-529, 2017 03.
Article En | MEDLINE | ID: mdl-28117538

BACKGROUND AND PURPOSE: Falls are common in people with Parkinson's disease (PD) but few data exist on fall-related hospitalizations in this group. This population-based study compared fall-related hospital admissions, injury rates and consequences in people with and without PD, and determined whether PD was an independent predictor of fall-related hospital length of stay. METHODS: This was a retrospective study using probabilistic linkage of hospital data in people aged ≥65 years hospitalized for a fall between 1 July 2005 and 31 December 2013 in New South Wales, Australia. Rates of hospital admissions and injuries per person admitted over the study period were compared between people with and without PD using Poisson or negative binomial regression. Multilevel linear modelling was used to analyse length of stay by clustering individuals and adjusting for possible confounders. RESULTS: There were 342 265 fall-related hospital admissions in people aged ≥65 years during the study period, of which 8487 (2.5%) were for people with PD. Sixty-seven per cent of fall-related PD admissions were associated with injury and 35% were associated with fracture. People with PD had higher rate ratios for fall admissions (1.63, 95% confidence interval 1.59-1.67) and injury (1.47, 95% confidence interval 1.43-1.51) and longer median length of stay [9 (interquartile range 1-27) vs. 6 (interquartile range 1-20) days in people without PD; P < 0.001]. PD remained associated with increased length of stay after controlling for comorbidity, age, sex and injury (P < 0.001). CONCLUSIONS: This study provides important benchmark data for hospitalizations for falls and fall injuries for older people with PD, which may be used to monitor the effect of fall prevention programmes.


Accidental Falls/statistics & numerical data , Hospitalization/statistics & numerical data , Parkinson Disease/complications , Age Factors , Aged , Aged, 80 and over , Comorbidity , Female , Fractures, Bone/epidemiology , Fractures, Bone/etiology , Humans , Length of Stay , Male , New South Wales/epidemiology , Parkinson Disease/epidemiology , Retrospective Studies , Sex Factors
18.
Osteoporos Int ; 28(1): 59-70, 2017 01.
Article En | MEDLINE | ID: mdl-27394415

There is no clear consensus on definition, cut-points or standardised assessments of sarcopenia. We found a lower limb strength assessment was at least as effective in predicting balance, mobility and falls in 419 older people as muscle mass-based measures of sarcopenia. INTRODUCTION: There is currently no consensus on the definition, cut-points or standardised assessments of sarcopenia. This study aimed to investigate whether several published definitions of sarcopenia differentiate between older people with respect to important functional and health outcomes. METHODS: Four hundred nineteen community-living older adults (mean age 81.2 ± 4.5, 49 % female) completed assessments of body composition (dual-energy X-ray absorptiometry), strength, balance, mobility and disability. Falls were recorded prospectively for a year using monthly calendars. Sarcopenia was defined according to four skeletal mass-based definitions, two strength-based definitions (handgrip or knee extensor force) and a consensus algorithm (low mass and low strength or slow gait speed). Obesity was defined according to percentage fat mass or waist circumference. RESULTS: The four skeletal mass-based definitions varied considerably with respect to the percentage of participants classified as sarcopenic and their predictive accuracy for functional and health outcomes. The knee extension strength-based definition was equivalent to or better than the mass-based and consensus algorithm definitions; i.e. weaker participants performed poorly in tests of leaning balance, stepping reaction time, gait speed and mobility. They also had higher physiological fall risk scores and were 43 % more likely to fall at home than their stronger counterparts. Adding obesity to sarcopenia definitions identified participants with greater self-reported disability. CONCLUSIONS: A simple lower limb strength assessment was at least as effective in predicting balance, functional mobility and falls in older people as more expensive and time-consuming muscle mass-based measures. These findings imply that functional terms such as muscle weakness or motor impairment are preferable to sarcopenia.


Muscle Strength/physiology , Sarcopenia/diagnosis , Absorptiometry, Photon/methods , Accidental Falls , Aged , Aged, 80 and over , Algorithms , Anthropometry/methods , Body Composition/physiology , Exercise/physiology , Female , Geriatric Assessment/methods , Hand Strength/physiology , Humans , Male , Muscle, Skeletal/pathology , Obesity/physiopathology , Postural Balance/physiology , Prognosis , Prospective Studies , Sarcopenia/physiopathology , Terminology as Topic
19.
J Nutr Health Aging ; 20(6): 671-6, 2016.
Article En | MEDLINE | ID: mdl-27273359

Moving visual fields can have strong destabilising effects on balance, particularly when visually perceived motion does not correspond to postural movements. This study investigated relationships between visual field dependence (VFD), as assessed using the roll vection test, and reported dizziness, falls and sway under eyes open, eyes closed and optokinetic conditions. Ninety five falls clinic attendees undertook the roll vection test (i.e. attempted to align a rod to the vertical while exposed to a rotating visual field). Sway was assessed under different visual conditions by centre of pressure movement. Participants also completed questionnaires on space and motion discomfort, fear of falling, depression and anxiety. Thirty four (35.8%) participants exhibited VFD, i.e. had an error > 6.5º in the roll vection test. Compared to participants without VFD, participants with VFD demonstrated less movement of the centre of pressure across all visual conditions, were more likely to report space and motion discomfort and to have suffered more multiple falls in the past year. VFD was independent of fear of falling, anxiety and depression. VFD in a falls clinic population is associated with reduced sway possibly due to a stiffening strategy to maintain stance, dizziness symptoms and an increased risk of falls.


Accidental Falls/statistics & numerical data , Dizziness/etiology , Vision Disorders/complications , Visual Fields/physiology , Aged, 80 and over , Ambulatory Care , Female , Humans , Male , Movement , Postural Balance
20.
BMC Geriatr ; 16: 82, 2016 Apr 18.
Article En | MEDLINE | ID: mdl-27089927

BACKGROUND: Admission to hospital can lead to persistent deterioration in physical functioning, particularly for the more vulnerable older population. As a result of this physical deterioration, older people who have been recently discharged from hospital may be particularly high users of health and social support services. Quantify usage and costs of services in older adults after hospitalisation and explore the impact of a home-exercise intervention on service usage. METHOD: The present study was a secondary analysis of data from a randomised controlled trial (ACTRN12607000563460). The trial involved 340 participants aged 60 years and over with recent hospitalisation. Service use and costs were compared between intervention (12 months of home-exercise prescribed in 10 visits from a physiotherapist) and control groups. RESULTS: 33 % of participants were re-admitted to hospital, 100 % consulted a General Medical Practitioner and 63 % used social services. 56 % of costs were associated with hospital admission and 22 % with social services. There was reduction in General Medical Practitioner services provided in the home in the intervention group (IRR 0.23, CI 0.1 to 0.545, p < 0.01) but no significant between-group difference in service use or in costs for other service categories. CONCLUSION: There appears to be substantial hospital and social service use and costs in this population of older people. No significant impact of a home-based exercise program was evident on service use or costs. TRIAL REGISTRATION: Australian and New Zealand Clinical Trial Registry ACTRN12607000563460 >TrialSearch.


Exercise Therapy/economics , Exercise Therapy/statistics & numerical data , Home Care Services/economics , Home Care Services/statistics & numerical data , Patient Discharge/economics , Social Work/economics , Aged , Aged, 80 and over , Australia/epidemiology , Female , Hospital Costs , Hospitalization/economics , Humans , Male , Middle Aged , New Zealand/epidemiology , Patient Acceptance of Health Care , Social Support
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