Effect of Cyber-Golfing on Balance Amongst the Elderly in Hong Kong: A Pilot Randomised Trial

Functional Mobility Studies in Younger Adults: Instrumented Timed Up and Go (iTUG) Test Using Inertial Devices

Functional Mobility Assessment (FMA) is a challenging task. One example of an FMA is an instrumented Timed Up and Go test (iTUG). Sensor-based interventions are more effective than traditional interventions that use clinical tests to assess a patient's FMA. Background/Objectives: The aim of this study is to investigate the variability of selected parameters of the instrumented Time Up and Go test using inertial measurements in healthy younger adults. Methods: A total of 73 subjects participated in the study, including 37 women and 36 men. The mean age was 31 years (SD 5.5 years), the mean height [cm] was 176.2 (SD 91), and the mean BMI [kg/m2] was 26.6 (SD 3.1). The Noraxon MyoMotion Research 18 motion analysis system was used to record raw spatial data. Results: The mean total time to complete the iTUG test was 13.1 ± 1.9 s with a low coefficient of variation (CV), suggesting consistent performance between participants. The recorded spatial and temporal parameters of the gait variables, as well as the kinematic variables of the iTUG test of the studied group of healthy adults, show low variability, except for the mean double support ratio (R - L)/(R + L), which was 4.1 ± 11.0% with a CV of 271.5%, indicating a very high variability. Conclusions: The low variability observed in key parameters, such as total time and percentage of posture, suggests that the iTUG test provides reliable, objective, and reproducible measurements that can serve as normative benchmarks for healthy adults.

Balance Board or Motion Capture? A Meta-Analysis Exploring the Effectiveness of Commercially Available Virtual Reality Exergaming in Enhancing Balance and Functional Mobility Among the Elderly

Force platforms and motion capture are commonly used as feedback mechanisms in exergaming; nevertheless, their therapeutic effectiveness may vary. Therefore, the primary objective of this study was to evaluate the effectiveness of commercially available virtual reality (VR) exergaming systems on balance and functional mobility, with a supplementary analysis considering the administered dose of exergaming. The search was conducted in five databases. Commercially available exergaming platforms were classified into two categories: VR exergaming with a balance board (including Wii Balance Board) and motion capture (including Xbox Kinect). Two categories of control interventions (treatment as usual [TAU] and no treatment [NT]) were extracted. The meta-analysis was performed separately for static, dynamic, and proactive balance outcomes and for the aggregated results of all included outcomes with subgroup analysis of lower, moderate, and higher doses. In total, 28 studies with 1457 participants were included. Both exergaming systems were particularly effective in improving the single leg stance outcome. VR exergaming with motion capture was found to be more effective than TAU with a standardized mean difference (SMD) of 0.48 (P = 0.006) and NT (SMD = 0.86; P = 0.02). In conclusion, commercially available VR exergaming with a motion capture feedback mechanism has demonstrated effectiveness as an intervention for balance training when compared with NT. Specifically, high doses (above 134 minutes per week) appear to be more beneficial for healthy older adults. Moreover, the findings provide some weak evidence supporting the effectiveness of VR exergaming with a balance board for improving functional mobility, particularly when compared with NT.

Effectiveness of sensor-based interventions in improving gait and balance performance in older adults: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Sensor-based interventions (SI) have been suggested as an alternative rehabilitation treatment to improve older adults' functional performance. However, the effectiveness of different sensor technologies in improving gait and balance remains unclear and requires further investigation.

METHODS

Ten databases (Academic Search Premier; Cumulative Index to Nursing and Allied Health Literature, Complete; Cochrane Central Register of Controlled Trials; MEDLINE; PubMed; Web of Science; OpenDissertations; Open grey; ProQuest; and Grey literature report) were searched for relevant articles published up to December 20, 2022. Conventional functional assessments, including the Timed Up and Go (TUG) test, normal gait speed, Berg Balance Scale (BBS), 6-Minute Walk Test (6MWT), and Falling Efficacy Scale-International (FES-I), were used as the evaluation outcomes reflecting gait and balance performance. We first meta-analyzed the effectiveness of SI, which included optical sensors (OPTS), perception sensors (PCPS), and wearable sensors (WS), compared with control groups, which included non-treatment intervention (NTI) and traditional physical exercise intervention (TPEI). We further conducted sub-group analysis to compare the effectiveness of SI (OPTS, PCPS, and WS) with TPEI groups and compared each SI subtype with control (NTI and TPEI) and TPEI groups.

RESULTS

We scanned 6255 articles and performed meta-analyses of 58 selected trials (sample size = 2713). The results showed that SI groups were significantly more effective than control or TPEI groups (p < 0.000) in improving gait and balance performance. The subgroup meta-analyses between OPTS groups and TPEI groups revealed clear statistically significant differences in effectiveness for TUG test (mean difference (MD) = - 0.681 s; p < 0.000), normal gait speed (MD = 4.244 cm/s; p < 0.000), BBS (MD = 2.325; p = 0.001), 6MWT (MD = 25.166 m; p < 0.000), and FES-I scores (MD = - 2.036; p = 0.036). PCPS groups also presented statistically significant differences with TPEI groups in gait and balance assessments for normal gait speed (MD = 4.382 cm/s; p = 0.034), BBS (MD = 1.874; p < 0.000), 6MWT (MD = 21.904 m; p < 0.000), and FES-I scores (MD = - 1.161; p < 0.000), except for the TUG test (MD = - 0.226 s; p = 0.106). There were no statistically significant differences in TUG test (MD = - 1.255 s; p = 0.101) or normal gait speed (MD = 6.682 cm/s; p = 0.109) between WS groups and control groups.

CONCLUSIONS

SI with biofeedback has a positive effect on gait and balance improvement among a mixed population of older adults. Specifically, OPTS and PCPS groups were statistically better than TPEI groups at improving gait and balance performance, whereas only the group comparison in BBS and 6MWT can reach the minimal clinically important difference. Moreover, WS groups showed no statistically or clinically significant positive effect on gait and balance improvement compared with control groups. More studies are recommended to verify the effectiveness of specific SI. Research registration PROSPERO platform: CRD42022362817. Registered on 7/10/2022.

Examining technology-assisted rehabilitation for older adults' functional mobility: a network meta-analysis on efficacy and acceptability

Technological advancements facilitate feedback adaptation in rehabilitation through virtual reality (VR) exergaming, serious gaming, wearables, and telerehabilitation for older adults fall prevention. Although studies have evaluated these technologies, no comparisons of their effectiveness have been conducted to date. Thus, this study aims to assess the differences in effectiveness of these interventions on balance and functional mobility in the older adults. A systematic review and network meta-analysis (NMA) were conducted to identify the most effective interventions for improving balance and functional mobility in adults aged 60 and over. The search was conducted in five databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science) up to June 10, 2023. The eligibility criteria were: (1) older adults, (2) functional mobility, balance, or gait as the primary outcome, (3) new technology intervention, and (4) randomized study design. New technology interventions were classified into five categories: exergaming with balance platforms or motion capture technologies, other serious gaming, interventions with wearables, and telerehabilitation. Additionally, two categories of control interventions (conventional exercises and no treatment) were extracted. The NMA was performed for the aggregated results of all outcomes, and separately for clinical functional scales, functional mobility, and gait speed results. Fifty-two RCTs with 3081 participants were included. Exergaming with motion capture was found to be statistically significant in producing a better effect than no treatment in the analysis of the functional mobility with an SMD of -0.70 (P < 0.01). The network meta-analysis revealed that exergaming with motion capture offers greater therapeutic benefits for functional mobility and balance compared to no treatment control. The effectiveness of this approach is similar to that of conventional exercises. Further RCTs are needed to provide a more definitive conclusion, particularly with respect to the effectiveness of serious games, telerehabilitation, and interventions with wearables.

Home-Based Exergame Program to Improve Physical Function, Fall Efficacy, Depression and Quality of Life in Community-Dwelling Older Adults: A Randomized Controlled Trial

This study aimed to investigate the effects of home-based exergame programs on physical function, fall efficacy, depression, and health-related quality of life in community-dwelling older adults. Fifty-seven participants aged 75 years or older were divided into control and experimental groups. The experimental group received a home-based exergame program that included balance and lower-extremity muscle strength for 8 weeks. The participants exercised at home for 50 min three times a week and were monitored through a video-conference application. Both groups received online education on musculoskeletal health once a week, whereas the control group did not exercise. Physical function was assessed using the one-leg standing test (OLST), Berg balance scale (BBS), functional reaching test (FRT), timed up-and-go test (TUGT), and five-times sit-to-stand (FTSTS). Fall efficacy was assessed using the modified falls efficacy scale (MFES). Depression was assessed using the geriatric depression scale (GDS). Health-related quality of life was assessed using a 36-item short-form health survey (SF-36). The experimental group showed an overall improvement in OLST, BBS, FRT, TUGT, and FTSTS (p < 0.05). MFES was significantly increased in the experimental group after the intervention (p < 0.05). The GDS significantly decreased in the experimental group after the intervention (p < 0.05). In SF-36, role limitations due to physical health, general health, and fatigue (energy and fatigue) items improved in the experimental group after intervention (p < 0.05). An 8-week home-based exergame program improved physical function, fall efficacy, depression, and health-related quality of life in older adults. The study was registered on ClinicalTrials.gov (NCT05802537).

The relationship between physical activity, physical health, and mental health among older Chinese adults: A scoping review

The aging Chinese population is growing fast, and the proportion of the population aged 60 years old is projected to reach 28% by 2040, estimated 402 million. With increased life expectancy, the aging population tends to suffer from health risks and diseases, which create a burden on public health policy. Hence, it is essential to promote healthy and active aging, which includes improving older adults' physical and mental capacities and advocating for the achievement of a healthy life expectancy. Despite the rapidly growing aging population in China, there have been no reviews investigating the effect of physical activity on physical and mental health among older Chinese adults. Therefore, the current study aimed to review studies from the past 15 years that illustrate the effect of physical activity on physical and mental health among Chinese older adults. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews (PRISMA-ScR), this review addresses the associations between physical activity, physical health and mental health among older Chinese adults. A total of 371 studies were included in the scoping review, which covered the relationships between physical activity, physical health and mental health variables. The scoping review also revealed the impact of various kinds of physical activity affecting older adults' physical health, such as functional fitness, body composition, fall risk and balance, and mental health issues, such as depression, anxiety, cognitive function and quality of life. Moreover, studies have identified innovative forms of physical activity as emerging trends in physical activity interventions for older adults. To conclude, this scoping review captured the common effects between physical activity and overall wellbeing, including physical, mental, and cognitive health. Additionally, diverse forms of physical activity intervention, such as group-based and supervised individual interventions, should be supported, and cross-cultural exercise comparisons should be made in future explorations.

Strength and Balance in Recreational Golfers and Non-Golfers Aged 65-79 Years in Community Settings

Inactive older adults tend to have decreased strength and balance compared with their more active peers. Playing golf has the potential to improve strength and balance in older adults. The aim of the study was to compare the strength and balance of recreational golfers with non-golfers, aged 65-79 years. Grip strength, single leg balance, and Y Balance Test (YBT) were assessed. Golfers (n = 57) had significantly (right, p = .042; left, p = .047) higher maximal grip strength, than non-golfers (n = 17). Single leg stance times were significantly longer in golfers (right, p = .021; left, p = .001). Normalized YBT reach distances were significantly greater for golfers than non-golfers for composite, posteromedial, and posterolateral directions on both right and left legs. Playing golf appears to be associated with better grip and both static and dynamic balance in 65-79 year olds, indicating that a study of the effects of playing golf is warranted through a larger, fully powered, longitudinal study.

Effect of eHealth-delivered exercise programmes on balance in people aged 65 years and over living in the community: a systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Exercise that challenges balance is proven to prevent falls in community-dwelling older people, yet widespread implementation and uptake of effective programmes is low. This systematic review and meta-analysis synthesised the evidence and evaluated the effect of eHealth-delivered exercise programmes compared with control on balance in community-dwelling people aged ≥65 years.

METHODS

Nine databases including MEDLINE, CINAHL and Embase, were searched from inception to January 2022 to identify randomised controlled trials evaluating eHealth-delivered exercise programmes for community-dwelling people aged ≥65 years, published in English that included a balance outcome. Primary outcomes were static and dynamic balance. Secondary outcomes included fall risk and fear of falling. We calculated standardised mean differences (SMDs, Hedges' g) with 95% CIs from random effects meta-analyses.

RESULTS

We identified 14 eligible studies that included 1180 participants. Methodological quality ranged from 3 to 8 (mean, 5). The pooled effect indicated that eHealth-delivered exercise programmes have a medium significant effect on static balance (11 studies; SMD=0.62, 95% CI 0.27 to 0.72) with very low-quality evidence. There was small statistically significant effect on dynamic balance (14 studies; SMD=0.42, 95% CI 0.11 to 0.73) with very low-quality evidence, and fall risk (5 studies; SMD=0.32, 95% CI 0.00 to 0.64) with moderate-quality evidence. No significant effect of eHealth programmes on fear of falling was found (four studies; SMD=0.10, 95% CI -0.05 to 0.24; high-quality evidence).

CONCLUSION

This review provides preliminary evidence that eHealth-delivered exercise programmes improved balance and reduced fall risk in people aged ≥65 years. There is still uncertainty regarding the effect of eHealth delivered exercise programmes on fear of falling.

PROSPERO REGISTRATION NUMBER

CRD42018115098.

Physical Activity and Exergames Among Older Adults: A Scoping Review

Recently, exergames have been widely applied as exercise platforms among older adults. However, studies on the influence of exergames on older adults' physical activity remain scarce. The review article highlights the potential benefit of exergames as a physical activity tool for older adults. The literature search followed the PRISMA guidelines on databases PubMed (Public/Publisher MEDLINE), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, and Scopus. The literature included studies that evaluated the influence of exergames on older adults' physical activity. Articles were excluded if the mixed intervention was used, emphasizing specific limbs, improving specific tasks, or not mentioning intervention. The review article identified 25 studies that reported on 855 older adults 55 years of age and older. In addition, the common exergaming technology platforms examined were Microsoft Kinect™, Nintendo® Wii™, cybercycling, and interactive video dance games. Meanwhile, 11 studies used a pretest/post-test design and randomized controlled trial design in 14 studies. The review found that exergames significantly impacted the older adults' physical activity level as participants experienced improved balance and cognitive function, and enjoyed playing exergame, thus prolonging their game engagement. Although research on exergames is still new, current evidence showed a significant potential benefit of exergames as a physical activity tool for older adults. To overcome the limitation on various parameters that showed different effects and outcomes of exergames, the study recommends implementing randomized controlled trials with long-term observation using a mixed-method approach. Moreover, a multidisciplinary method involving exercise and neuromotor control experts could determine potential mechanisms of action that benefited from the exercises.

Effects of active video games on physical function in independent community-dwelling older adults: A systematic review and meta-analysis

AIM

To analyse the effects of active video games on physical function in independent community-dwelling older adults.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

DATA SOURCES

The CINAHL, LILACS, Medline, Proquest and Scopus databases were consulted, with no restriction by year of publication.

REVIEW METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The meta-analysis was performed using RevMan software.

RESULTS

The analysis included 22 randomized controlled trials with a total of 1208 participants (all ≥55 years old). In our meta-analyses, the effects produced by playing the active video games (mean differences) were statistically significant for the variables Gait speed and Timed up-and-go. The differences between the control and experimental groups were not significant in the following tests: 6-minute walk, 30-second chair stand, balance (measured with the Berg Balance Scale), cadence, grip strength, knee extension strength, 8-Foot Up-and-Go or velocity.

CONCLUSIONS

Physical exercise from participation in active video games has beneficial effects on two clinical parameters (Gait speed and Timed up-and-go) in independent community-dwelling older adults. However, the effects on other parameters do not differ from those obtained with conventional exercise training. Therefore, the clinical significance of these benefits is limited.

IMPACT

Older adults usually perform little physical activity. In consequence, researchers have increasingly considered alternatives to traditional forms of exercise. One such is that provided by active video games, which can be a source of stimulation, encouraging adherence and motivation in exercise programmes. Our review shows that active video games can improve gait speed and mobility, but in other respects obtain no differences from conventional exercises. Further tailored randomized clinical trials should be undertaken with diverse populations of older adults to evaluate different physical function variables to determine the most appropriate training approach and its optimal design and duration.

Effects of Kinect exergames on balance training among community older adults: A randomized controlled trial

BACKGROUND

Recent years have witnessed wide applications of exergames to balance training among the older adults. However, research concerning balance training with the use of Kinect for Xbox has remained scarce. While previous studies have shown the positive effects of exergames on improving balance and preventing falling among the older adults, there has been a paucity of empirical evidence supporting the superiority of Kinect exercise to conventional exercise over balance training among the older adults. Therefore, this study aimed to compare the feasibility, safety, and effectiveness of Kinect exercise against conventional exercise over balance training among the community older adults.

METHOD

A total of 20 participants were randomly assigned to the Kinect Exercise Group (N = 10) or the Conventional Exercise Group (N = 10) for a 5-week balance training (45 minutes a time, 2 times a week). Assessor blinding was employed to assess the participants' performance before and after the treatment, including 30-Second Chair Stand Test (30-sec CST), Timed Up and Go (TUG), Functional Reach Test (FRT), and One-Leg Stance Test (OLST) respectively with eyes open and closed. Subjective feeling of the intensity of pain and side effects were recorded throughout the investigation period. Nonparametric statistics was used for data analysis.

RESULTS

Within-group comparison between the pre-test and post-test indicated that significant differences existed in all of the 5 tests (30-sec CST, TUG, FRT, OLST with eyes open, and OLST with eyes closed) in the Kinect exercise group. To the Conventional exercise group, however, significant differences were only observed in 30-sec CST, FRT and OLST with eyes open. With regard to between-group comparison, significant differences were only found in FRT.

CONCLUSION

Such results indicated that both treatments were helpful in improving the participants' balance performance, that Kinect exercise was more effective in terms of overall balance ability, and that Kinect exercise was particularly beneficial to functional reach enhancement in comparison with traditional exercise. Kinect exercise could be a feasible, safe, and effective alternative for dynamic balance training among older adults.

Acting together, destabilizing influences can stabilize human balance

The causes of falling in the elderly are multi-factorial. Three factors that influence balance stability are the time delay, a sensory dead zone and the maximum ankle torque that can be generated by muscular contraction. Here, the effects of these contributions are evaluated in the context of a model of an inverted pendulum stabilized by time-delayed proportional-derivative (PD) feedback. The effect of the sensory dead zone is to produce a hybrid type of control in which the PD feedback is switched ON or OFF depending on whether or not the controlled variable is larger or smaller than the detection threshold, Π. It is shown that, as Π increases, the region in the plane of control parameters where the balance time (BT) is greater than 60 s is increased slightly. However, when maximum ankle torque is also limited, there is a dramatic increase in the parameter region associated with BTs greater than 60 s. This increase is due to the effects of a torque limitation on over-control associated with bang-bang type switching controllers. These observations show that acting together influences, which are typically thought to destabilize balance, can actually stabilize balance. This article is part of the theme issue 'Nonlinear dynamics of delay systems'.

Movements of older adults during exergaming interventions that are associated with the Systems Framework for Postural Control: A systematic review

One in three older adults fall annually, in part due to impairments in the physiological systems that make up the postural control (PC) system. Exercise, particularly balance training, helps to prevent deterioration and even to improve outcomes in the PC system. Exergaming (exercise-gaming) is interactive computer gaming whereby an individual moves the body in response to onscreen cues in a playful format. Exergaming is an alternative method to standard practice for improving PC outcomes, which has been shown to reduce the risk of falling. Exergaming has received research attention, yet the intervention is still in its infancy. There could be benefit in exploring the movements trained with respect to a framework known for identifying underlying deficits in the PC system, the Systems Framework for Postural Control (SFPC). This may help target areas for improvement in balance training using exergames and shed light on the impact for fall prevention. A literature search was therefore conducted across six databases (CINAHL, EMBASE, PubMed, ISI, SPORTdiscus and Science Direct) using a range of search terms and combinations relating to exergaming, balance, exercise, falls and elderly. Quality assessment was conducted using the PEDro Scale and a custom-made quality assessment tool. Movements were rated by two reviewers based on the 9 operational definitions of the SFPC. Eighteen publications were included in the analysis, with a mean PEDro score of 5.6 (1.5). Overall, 4.99 (1.27) of the 9 operational definitions of the SFPC are trained in exergaming interventions. Exergaming does encourage individuals to stand up (3), lean while standing (4), move upper limbs and turn heads (6) and dual-task while standing (9), to some extent move the body forwards, backwards and sideways (1), and coordinate movements (2) but hardly at all to kick, hop, jump or walk (7), or to force a postural reaction from a physical force to the individual (5) and it does not mimic actual changes in sensory context (8). This is the first review, to our knowledge, that synthesises the literature on movements trained in exergaming interventions with respect to an established theoretical framework for PC. This review could provide useful information for designing exergames with PC outcomes in mind, which could help target specific exergames for multi-factorial training to overcome balance deficits. Some elements of PC are too unsafe to be trained using exergames, such as restricting sensory inputs or applying physical perturbations to an individual to elicit postural responses.

Gaming for Health: Systematic Review and Meta-analysis of the Physical and Cognitive Effects of Active Computer Gaming in Older Adults

BACKGROUND

Active computer gaming (ACG) is a method of facilitating physical activity in older people to improve health outcomes.

PURPOSE

The purpose of this study was to update and extend a systematic review of the evidence for ACG to determine its effects on physical and cognitive health in older adults.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL in the Cochrane Library, and PsycINFO databases were searched from the date of the previous review (2011) to May 2016.

STUDY SELECTION

Eligible articles were randomized controlled trials (RCTs) investigating the effect of ACG in adults aged 65 and older.

DATA EXTRACTION

Thirty-five studies were eligible for inclusion. Two review authors independently conducted data extraction, risk-of-bias assessment, and coding of behavior change techniques. Outcomes of interest were analyzed as continuous data and pooled as standardized mean differences (SMD) and 95% confidence intervals (CI). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to determine the quality of the evidence.

DATA SYNTHESIS

Behavior change techniques (N = 106) were coded in the included studies (mean = 3.02). Data were pooled for 5 main outcomes of interest. Significant moderate effects in favor of ACG were observed for balance (SMD = 0.52, 95% CI = 0.24 to 0.79; 17 studies; 743 participants), for functional exercise capacity when intervention delivery was >120 minutes per week (SMD = 0.53, 95% CI = 0.15 to 0.90; 5 studies; 116 participants), and for cognitive function (SMD = -0.48, 95% CI = -0.80 to 0.17; 8 studies; 459 participants). There was no significant effect observed for functional mobility or fear of falling.

LIMITATIONS

The quality of the evidence for all comparisons was graded low or very low.

CONCLUSIONS

At present there is very little confidence that ACG improves physical and cognitive outcomes in older adults.

A systematic review and meta-analysis of outcome measures to assess postural control in older adults who undertake exergaming

Exergaming has been shown to be an effective tool to improve postural control (PC) in older community-dwelling individuals. The outcome measures (OMs) used to assess PC are varied and this could limit the estimation of the effectiveness of the intervention. This systematic review and meta-analysis aims to explore the OMs currently used to assess PC in exergaming interventions, for healthy elderly individuals aged over 60 years. The literature search was conducted across five databases (CINAHL, EMBASE, PubMed, ISI, SPORTdiscus and Science Direct) using a range of search terms and combinations relating to exergaming, balance, exercise, falls and elderly. Quality assessment was conducted using the PEDro Scale and a custom-made quality assessment tool. Eleven trials were included in the meta-analysis, with a mean (SD) PEDro score of 5.36 (1.57). Primary and secondary OMs showed small effects in favour of alternative training modes, although these effects were statistically insignificant for all primary OMs. Tertiary OMs could not be included in the meta-analysis due to varying output parameters from different instruments. Heterogeneity remained high across trials and no studies performed long-term follow-up. Exergaming is a potential alternative to PC training, although still in its infancy. Strong and well-designed RCTs are needed, targeting specific populations aged over 60 years. Variability in instrumented OMs prevents generalisation of results. Technological improvements may provide data not currently available from clinical and laboratory-based methods, and may allow PC to be assessed more realistically and specifically in relation to a population's activities of daily living, though this remains a new area of research.