Physical Inactivity: A Behavioral Disorder in the Physical Therapist's Scope of Practice

Prestroke Physical Activity Matters for Functional Limitations: A Longitudinal Case-Control Study of 12,860 Participants

OBJECTIVE

In the chronic phase after a stroke, limitations in basic activities of daily living (ADLs) and instrumental activities of daily living (IADLs) initially plateau before steadily increasing. The benefits of prestroke physical activity on these limitations remain unclear. To clarify this relationship, the effect of physical activity on the long-term evolution of functional limitations in a cohort of people with stroke compared to a cohort of matched adults without stroke was examined.

METHODS

Longitudinal data from 2143 people with stroke and 10,717 adults without stroke aged 50 years and older were drawn from a prospective cohort study based on the Survey of Health, Ageing and Retirement in Europe (2004-2022; eight data collection waves). Physical activity was assessed in the prestroke wave. Functional limitations were assessed in the poststroke waves. Each person with stroke was matched with five adults without stroke who had similar propensity scores computed on the basis of key covariates, including baseline age, sex, body mass index, limitations in ADLs and IADLs, chronic conditions, and country of residence, before any of the participants from either cohort had experienced a stroke.

RESULTS

Results showed an interaction between stroke status and physical activity on ADL limitations (b = -0.076; 95% CI = -0.142 to -0.011), with the beneficial effect of physical activity being stronger in people with stroke (b = -0.345; 95% CI = -0.438 to -0.252) than in adults without stroke (b = -0.269; 95% CI = -0.269 to -0.241).

CONCLUSION

The beneficial effect of prestroke physical activity on ADL limitations after stroke is stronger than its effect in matched adults without stroke followed for a similar number of years.

IMPACT

Physical activity, an intervention within the physical therapist's scope of practice, is effective in reducing the risk of functional dependence after stroke. Moreover, prestroke levels of physical activity can inform the prognosis of functional dependence in people with stroke.

Relationship between reward-related brain activity and opportunities to sit

The present study tested whether energy-minimizing behaviors evoke reward-related brain activity that promotes the repetition of these behaviors via reinforcement learning processes. Fifty-eight healthy young adults in a standing position performed a task where they could earn a reward either by sitting down or squatting while undergoing electroencephalographic (EEG) recording. Reward-prediction errors were quantified as the amplitude of the EEG-derived reward positivity. Results showed that reward positivity was larger on reward versus no reward trials, confirming the validity of our paradigm to measure evoked reward-related brain activity. However, results showed no evidence that sitting (versus standing and squatting) trials led to larger reward positivity. Moreover, we found no evidence suggesting that this effect was moderated by typical physical activity, physical activity on the day of the study, or energy expenditure during the experiment. However, at the behavioral level, results showed that the probability of choosing the stimulus more likely to lead to sitting than standing increased as the number of trials increased. In addition, results revealed that the probability of changing the selected stimulus was higher when the previous trial was a stand trial relative to a sit trial. In sum, neural results showed no evidence supporting the theory that opportunities to minimize energy expenditure are rewarding. However, behavioral findings suggested participants tend to choose the less effortful behavioral alternative and were therefore consistent with the theory of effort minimization (TEMPA).

Association between COVID-19 emergency declarations and physical activity among community-dwelling older adults enrolled in a physical activity measurement program: Evidence from a retrospective observational study using the regression discontinuity design

BACKGROUND

The current study examines the negative impact of the coronavirus disease 2019 (COVID-19) emergency declarations on physical activity among the community-dwelling older adults, the participants of a physical activity measurement program, in Japan.

METHODS

This retrospective observational study included 1,773 community-dwelling older adults (aged 74.6 ± 6.3 years, 53.9% women) who had participated in the physical activity measurement project from February 2020 to July 2021. We measured physical activity using a tri-axial accelerometer during 547 consecutive days. Three emergency declarations, requesting people to avoid going outside, occurred during the observational period. We multiply-imputed missing values for daily physical activity, such as steps, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) for several patterns of datasets according to the maximum missing rates on a person level. We mainly report the results based on less than 50% of the maximum missing rate (n = 1,056). Other results are reported in the supplemental file. Changes in physical activity before and after the start of each emergency declaration were examined by the regression discontinuity design (RDD) within 14-, 28-, and 56-day bandwidths.

RESULTS

For all the participants in the multiply-imputed data with the 14-day bandwidth, steps (coefficients [[Formula: see text]][Formula: see text] 964.3 steps), LPA ([Formula: see text] 5.5 min), and MVPA ([Formula: see text] 4.9 min) increased after the first emergency declaration. However, the effects were attenuated as the RDD bandwidths were widened. No consistent negative impact was observed after the second and third declarations. After the second declaration, steps ([Formula: see text]-609.7 steps), LPA ([Formula: see text]-4.6 min), and MVPA ([Formula: see text]-2.8 min) decreased with the 14-day bandwidth. On the other hand, steps ([Formula: see text] 143.8 steps) and MVPA ([Formula: see text] 1.3 min) increased with the 56-day bandwidth. For the third declaration, LPA consistently decreased with all the bandwidths ([Formula: see text]-2.1, -3.0, -0.8 min for the 14, 28, 56-day bandwidth), whereas steps ([Formula: see text]-529 steps) and MVPA ([Formula: see text]-2.6 min) decreased only with the 28-day bandwidth.

CONCLUSIONS

For the community-dwelling older adults who regularly self-monitor their physical activity, the current study concludes that there is no evidence of consistently negative impacts of the emergency declarations by the COVID-19 pandemic.

Automatic approach-avoidance tendency toward physical activity, sedentary, and neutral stimuli as a function of age, explicit affective attitude, and intention to be active

Using computerized reaction-time tasks assessing automatic attitudes, studies have shown that healthy young adults have faster reaction times when approaching physical activity stimuli than when avoiding them. The opposite has been observed for sedentary stimuli. However, it is unclear whether these results hold across the lifespan and when error rates and a possible generic approach-avoidance tendency are accounted for. Here, reaction times and errors in online approach-avoidance tasks of 130 participants aged 21 to 77 years were analyzed using mixed-effects models. Automatic approach-avoidance tendencies were tested using physical activity, sedentary, and neutral stimuli. Explicit attitudes toward physical activity and intention to be physically active were self-reported. Results accounting for age, sex, gender, level of physical activity, body mass index, and chronic health condition confirmed a main tendency to approach physical activity stimuli (i.e., faster reaction to approach vs. avoid; p = .001) and to avoid sedentary stimuli (i.e., faster reaction to avoid vs. approach; p < .001). Results based on neutral stimuli revealed a generic approach tendency in early adulthood (i.e., faster approach before age 53 and fewer errors before age 36) and a generic avoidance tendency in older adults (i.e., more errors after age 60). When accounting for these generic tendencies, results showed a greater tendency (i.e., fewer errors) to avoid than approach sedentary stimuli after aged 50, but not before (p = .026). Exploratory analyses showed that irrespective of age, participants were faster at approaching physical activity (p = .028) and avoiding sedentary stimuli (p = .041) when they considered physical activity as pleasant and enjoyable (explicit attitude). However, results showed no evidence of an association between approach-avoidance tendencies and the intention to be physically active. Taken together, these results suggest that both age and explicit attitudes can affect the general tendency to approach physical activity stimuli and to avoid sedentary stimuli.

The Nexus of Sports-Based Development and Education of Mental Health and Physical Fitness

Physical inactivity has increased globally, particularly in developed nations. A high proportion of the human population is unable to meet the physical activity recommendation of the World Health Organisation due to hypertension, metabolic syndrome, obesity, and other medical conditions. Non-communicable diseases and mental health problems are becoming more prevalent, particularly in low and middle-income nations. This study aimed to determine the effectivenessof a mentorship programmeon university students' mental health and physical fitness. The intervention comprised the effects of sports-based development and education on physical fitness and mental health. A total of 196 and 234 students from two universities were randomly assigned to the intervention and control groups, respectively. The primary outcomes were engagement in physical activities (number of push-ups for 1 min, the strength of hand grip (kg), and the Jump test while standing (cm)), body fat proportion and psychological resilience, self-efficacy, and relationship with family and schoolmates. Participants in the control group had access to a web-based health education game, whereas the intervention group wassubjected to intensive interventional activities for one month based on the eight principles of the National Research Council and Institute of Medicine. Data were analysed using Analysis of Variance (ANOVA) to compare the physical and mental components between the intervention and control groups. Relative to baseline, all the physical health components (push-ups, sit-ups, and jump tests), psychological resilience, relationship with family members, and self-efficacy increased significantly in the intervention compared to the control group. Body fat composition was significantly reduced in the intervention when compared tothe control group. In conclusion, the mentorship programme effectively improved the participants' physical and psychological health and could be developed further for application in a larger population.

Preventive Medicine via Lifestyle Medicine Implementation Practices Should Consider Individuals' Complex Psychosocial Profile

Noncommunicable chronic diseases are associated with lifestyle behaviors. Psychological and social factors may influence the adoption of such behaviors. Being mentally and physically energized or fatigued may influence the intention-behavior gap of healthy lifestyle adoption accordingly. We investigated the associations of age, sex, lifestyle behaviors, mood, and mental and physical energy and fatigue at both the trait and state levels. The participants (N = 670) completed questionnaires assessing their sleep, mood, mental and physical state energy and fatigue, physical activity, mental workload, and diet. The ordinary least squares regression models revealed an overlap between the mental state and trait energy levels for males who consume polyphenols, have a high mental workload, and sleep well. Being younger, having a high stress level, bad sleep habits, and being confused and depressed were associated with high mental fatigue. Physical energy and fatigue shared the same commonalities with the previous results, with greater discrepancies observed between the state and trait indicators compared to that between mental energy and fatigue. Diet and stress management seem to be predictors of high physical energy, and females report higher physical fatigue levels. Health care professionals should consider this psychosocial complex profiling in their differential diagnosis and when one is implementing lifestyle behavioral changes to address the facets of preventive medicine, wellness, and health promotion.

Altering the strength of the muscles crossing the lower limb joints only affects knee joint reaction forces

BACKGROUND

Generic musculoskeletal models based on literature data are often used to estimate joint reaction forces (JRFs) that otherwise could only be measured invasively. Estimated JRFs are sensitive to changes in maximum isometric force (F_iso) of the muscles, but these are normally simply scaled using a multiplicative coefficient. The impact of varying F_iso, or strength, of muscles crossing each lower limb joint on estimated JRFs has not been systematically explored in musculoskeletal models of the lower limb.

RESEARCH QUESTION

How do alterations in the strength of joint-crossing muscles influence the lower limb JRF magnitudes computed through a generic musculoskeletal model?

METHODS

By modifying F_iso of muscles crossing hip, knee, ankle, or all joints at once up to ± 40% in 10% increments, thirty-two models were created to simulate the gait of a patient with an instrumented tibial prosthesis (5^th Grand Challenge dataset). A standard workflow (inverse kinematics, static optimization, joint reaction analysis) was utilized to calculate JRFs. Both alterations in JRF magnitudes due to joint crossing muscles' strength modifications and their accuracy against in vivo knee loading measurements were quantified.

RESULTS

The knee JRF was the most sensitive force to changes in the joint-crossing muscles' strength (variations ranging from -37.9 ± 0.5% to +37.9 ± 3.2%), while the hip and ankle JRFs were almost unaffected (maximum variation: +6.1%). Reducing the strength of knee and ankle-crossing muscles and intensifying the strength of hip-crossing muscles lowered the knee JRF. The knee JRF was best estimated (peak error: 0.42 ± 0.15 body weight, root mean squared error: 0.37 ± 0.06 body weight, coefficient of determination: 0.76 ± 0.10) by the model with -40% weakened knee-crossing muscles.

SIGNIFICANCE

Altering strengths mainly affects knee JRF estimated with generic musculoskeletal models, suggesting that personalization of strength of joint-crossing muscles is required for accurate knee JRF estimations. Rehabilitation regimes meant to strengthen muscles crossing a joint should be carefully designed to avoid undesired effects on the other joints.

Isotemporal Substitution of Sedentary Behavior With Moderate to Vigorous Physical Activity Is Associated With Lower Risk of Disability: A Prospective Longitudinal Cohort Study

OBJECTIVE

The purpose of the study was to estimate, using an isotemporal substitution model, the effect of replacing sedentary behavior (SB) with physical activity on the incidence of disability in community-dwelling older adults.

METHODS

This 2-year longitudinal cohort study enrolled 3691 community-dwelling older adults (57.2% women; mean age = 74.0 [SD = 5.0] years). Individuals with dementia, stroke, Parkinson disease, depression, low Mini-Mental State Examination scores, dependence on basic activities of daily living, and missing data were excluded. Physical activity and potential confounding factors were investigated as a baseline survey of disability incidence, defined by Japanese long-term care insurance certification, for 2 years in 2 regions. Physical activity data (SB, light-intensity physical activity, and moderate- to vigorous-intensity physical activity [MVPA]) were measured using triaxial accelerometers for 14 days, and daily mean time spent in each physical activity parameter was computed in increments of 10 minutes. The relationship between baseline physical activity and disability incidence adjusted for potential confounders was analyzed using multilevel Cox proportional hazards regression analyses with an isotemporal substitution model.

RESULTS

The disability incidence rate was 3.8%, excluding individuals who could not be followed-up. Replacing 10 minutes of SB per day with MVPA was associated with a decreased disability incidence (hazard ratio = 0.870; 95% CI = 0.766-0.988), whereas no evidence was found for replacing SB with light-intensity physical activity (hazard ratio = 0.980; 95% CI = 0.873-1.10).

CONCLUSIONS

Replacing SB with MVPA was associated with a lower risk of disability. These findings are helpful for establishing disability prevention strategies.

IMPACT

These results suggest that feasible changes in daily behavior, such as replacing 10 minutes of SB with MVPA daily, might have a protective effect on disability incidence. Clarifying these associations is useful for developing disability prevention strategies and may help reduce the incidence of disability in community-dwelling older adults.

The Theory of Effort Minimization in Physical Activity

Although the automatic attraction to effort minimization has been evidenced in multiple fields, its potential role in explaining the pandemic of physical inactivity has been overlooked. The theory of effort minimization in physical activity (TEMPA) fills this gap. TEMPA seeks to obtain a more accurate understanding of the neuropsychological determinants of movement-based behaviors.

Feasibility of integrating survivors of stroke into cardiac rehabilitation: A mixed methods pilot study

BACKGROUND

Survivors of stroke are often deconditioned and have limited opportunities for exercise post-rehabilitation. Cardiac Rehabilitation (CR), a structured exercise program offered post-cardiac event in the United States (U.S.), may provide an opportunity for continued exercise. The purpose of this study was to examine the feasibility of integrating survivors of stroke into an existing, hospital-based CR program through an assessment of (1) recruitment, uptake and retention, (2) adherence and fidelity, (3) acceptability and (4) safety.

METHODS

A mixed methods design combined a single group, pre-post design, pilot feasibility study with an imbedded qualitative inquiry. Survivors of stroke were recruited into a standard 12-week, 36 visit CR program.

RESULTS

Fifty-three survivors were referred, 29 started and 24 completed the program. Program uptake rate was 55% and completion rate was 83%. Eleven completers and one non-completer participated in the qualitative interviews. Program completers attended an average of 25.25 (SD 5.82) sessions with an average of 38.93 (SD 5.64) exercise minutes per session while reaching targeted rate of perceived exertion levels. Qualitative themes included perceived benefits of an individualized program in a group setting, positive interactions with qualified staff, opportunities for socialization, and regular monitoring and staff attentiveness promoting feelings of safety.

CONCLUSIONS

Survivors of stroke were able to meet Medicare standard dosage (frequency and session duration) and rate of perceived intensity goals, and perceived the program as needed regardless of their mobility limitations or previous exercise experience. Primary challenges included managing referrals and uptake. Results support feasibility and benefit for survivors to integrate into U.S. CR programs.

Patterns of Sitting, Standing, and Stepping After Lower Limb Amputation

OBJECTIVE

The objectives of this study were to describe sitting, standing, and stepping patterns for people with lower limb amputation (LLA) and to compare sitting, standing, and stepping between people with dysvascular LLA and people with traumatic LLA.

METHODS

Participants with dysvascular or traumatic LLA were included if their most recent LLA was at least 1 year earlier, they were ambulating independently with a prosthesis, and they were between 45 and 88 years old. Sitting, standing, and stepping were measured using accelerometry. Daily sitting, standing, and stepping times were expressed as percentages of waking time. Time spent in bouts of specified durations of sitting (<30, 30-60, 60-90, and >90 minutes), standing (0-1, 1-5, and >5 minutes), and stepping (0-1, 1-5, and >5 minutes) was also calculated.

RESULTS

Participants (N = 32; mean age = 62.6 [SD = 7.8] years; 84% men; 53% with dysvascular LLA) spent most of the day sitting (median = 77% [quartile 1 {Q1}-quartile 3 {Q3} = 67%-84%]), followed by standing (median = 16% [Q1-Q3 = 12%-27%]) and stepping (median = 6% [Q1-Q3 = 4%-9%]). One-quarter (median = 25% [Q1-Q3 = 16%-38%]) of sitting was accumulated in bouts of >90 minutes, and most standing and stepping was accrued in bouts of <1 minute (standing: median = 42% [Q1-Q3 = 34%-54%]; stepping: median = 98% [Q1-Q3 = 95%-99%]). Between-etiology differences included proportion of time sitting (traumatic: median = 70% [Q1-Q3 = 59%-78%]; dysvascular: median = 79% [Q1-Q3 = 73%-86%]) and standing (traumatic: median = 23% [Q1-Q3 = 16%-32%]; dysvascular: median = 15% [Q1-Q3 = 11%-20%]).

CONCLUSION

Participants had high daily volumes of long durations of sitting. Further, these individuals accumulated most physical activity in bouts of <1 minute.

IMPACT

High levels of sedentary behavior and physical inactivity patterns may place people with LLA at greater mortality risk relative to the general population. Interventions to minimize sedentary behaviors and increase physical activity are potential strategies for improving poor outcomes of physical therapy after LLA.

Physically active individuals look for more: An eye-tracking study of attentional bias

Attentional capture by exercise-related stimuli is important for the regulation of physical activity. Attentional processing underlying this capture has been investigated with indirect behavioral measures based on reaction times. To investigate more direct measures of visual spatial attention toward physical activity (vs. inactivity) stimuli, we used eye-tracking and a visual dot probe task in 77 young adults with various level of physical activity. Reaction times to detect a dot appearing in the area previously occupied by a physical activity (vs. inactivity) stimulus were an indirect measure of attentional bias. The first picture gaze and viewing time were more direct measures of attentional orienting and attentional engagement, respectively. Pupil dilation was an indicator of arousal. Reaction times revealed a two-way interaction between the location of the dot and participants' usual level of physical activity. Only participants with a high level of physical activity more quickly detected a dot when it appeared in the area previously occupied by a physical activity stimulus. Eye-tracking results showed greater odds of first gazing at physical activity stimuli and for a longer time, and a greater decrease in pupil size when viewing physical activity stimuli when usual level of physical activity was moderate or high, but not low. The variance explained in the outcomes ranged from 13.9% (pupil dilation) to 40% (reaction times). Overall, as hypothesized, compared to less physically active participants, participants who were more physically active demonstrated indirect (reaction times) and direct (first gaze, viewing time) evidence of a more pronounced attentional bias toward physical activity. Physical activity stimuli biased attention, with a pronounced effect when the level of physical activity was higher. These findings suggest that physical activity stimuli are relevant to the current concerns of moderately and highly active individuals.