Validity of physical activity measures in individuals after total knee arthroplasty

Accelerometry-based physical activity, disability and quality of life before and after lumbar decompression surgery from a physiotherapeutic perspective: An observational cohort study

BACKGROUND

The effect of lumbar decompression on physical activity (PA) measures (measured as number of steps/day and as moderate to vigorous PA (MVPA)) is poorly understood. The aim of the current study was to compare PA in patients before and after lumbar decompression and to determine the association between change in steps/day and MVPA with change in disability, health-related quality of life (HRQOL) and pain.

METHODS

Patients undergoing lumbar decompression surgery were recruited. Steps/day and MVPA MVPA were recorded with an accelerometer. Oswestry Disability Index (ODI), HRQOL (Short Form 36 questionnaire (SF-36)) and pain levels (visual analogue scale (VAS)) were collected prior to surgery and six and twelve weeks postoperatively. Steps/day were compared to the lower bound of steps/day in healthy persons (7,000 steps per day), and the relationship between changes in steps/day, MVPA, ODI, SF-36, and VAS were calculated.

RESULTS

Twenty-six patients aged 37 to 75 years met inclusion criteria and were included in the study. Lumbar decompressions were performed for stenosis and/or disc herniation. Preoperatively, patients took an average 5,073±2,621 (mean±standard deviation) steps/day. At 6 weeks postoperatively, patients took 6,131±2,343 steps/day. At 12 weeks postoperatively, patients took 5,683±2,128 steps/day. Postoperative MVPA minutes per week increased compared to preoperative MVPA (preoperative: 94.6±122.9; 6 weeks: 173.9±181.9; 12 weeks: 145.7±132.8). From preoperative to 12 weeks postoperative, change in steps correlated with MVPA (R=0.775; P<0.001), but not with ODI (R=0.069; P=0.739), SF-36 (R=0.138; P=0.371), VAS in the back (R=0.230; P=0.259) or VAS in the leg (R=-0.123; P=0.550).

CONCLUSIONS

During the first 12 postoperative weeks, daily steps did not reach the lower bound of normal step activity of 7,000 steps/day, however postoperative steps/day were higher than before surgery. Steps/day and MVPA appear to be independent of ODI and SF-36 and represent additional outcome parameters in patients undergoing lumbar decompression surgery and should be considered e.g., by physiotherapists especially from 6 to 12 weeks postoperatively.

LEVEL OF EVIDENCE

2, prospective cohort study.

Stationary Behavior and the Step-Defined Sedentary Lifestyle Index in Older Adults After Total Knee Arthroplasty

OBJECTIVES

To measure stationary behavior in a cohort of older adults after total knee arthroplasty (TKA) and determine the clinical utility of the step-defined sedentary lifestyle index (SLI) as a measure of stationary behavior after TKA.

DESIGN

Cross-sectional measurement study.

SETTING

Participants were recruited from a community intake clinic for hip and knee surgeries.

PARTICIPANTS

Sixty-five older adults 3 months after TKA (N=65).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Stationary behaviors, including stationary time, stationary bouts, breaks from stationary time, and the proportion of participants meeting the SLI, were measured in older adults 3 months post TKA using accelerometry. A 2-way analysis of variance test (α=0.05) was conducted to determine the effects of SLI (<5000 or ≥5000 daily steps) and possible interactions with sex on stationary behavior.

RESULTS

Participants spent 80% (13.17±2.3h) of their waking time in stationary time and had an average of 6.06 bouts of stationary time >30 minutes per day. Forty (61.5%) of the participants fell below the SLI of 5000 steps/d. SLI had significant effects on both waking stationary time (P<.001) and number of breaks in stationary time (P<.001), with participants taking <5000 daily steps having longer stationary times and fewer breaks in stationary time. Sex had a significant effect on the number of breaks in stationary time (P=.04), with men (n=23, 35%) reporting more breaks than women (n=42, 65%) (mean difference 13.36; 95% confidence interval, -2.67 to 18.69). No interactions were found between SLI and sex.

CONCLUSIONS

Both women and men had high levels of stationary behavior 3 months post TKA. The SLI discriminated waking stationary time and breaks in stationary time and may have clinical utility in measurement of stationary behavior.

Validity of Tools to Measure Physical Activity in Older Adults Following Total Knee Arthroplasty

Few validated tools exist for measuring physical activity following total knee arthroplasty (TKA) despite the importance of returning to sufficient levels of physical activity post-TKA to achieve health benefits. This study examined the validity of two clinical measures-the Fitbit, a commercially available personal activity monitor, and the Community Healthy Activities Model Program for Seniors (CHAMPS), a self-report questionnaire-compared with a reference standard accelerometer, the SenseWearTM Armband (SWA). At 6-month post-TKA, 47 participants wore the Fitbit and SWA for 4 days and then completed the CHAMPS. Moderate-to-good correlation was observed between the Fitbit and SWA for steps (intraclass correlation coefficient [ICC] = .79), energy expenditure (ICC = .78), and energy expenditure <3 METS (ICC = .79). Poor-to-moderate correlation was observed between the CHAMPS and SWA (ICC = .43) with the questionnaire reporting lower daily energy expenditures than the SWA. Results showed that Fitbit may be a reasonable measurement tool to measure steps and energy expenditures in older adults following TKA.

Use of the pedometer in the evaluation of the effects of rehabilitation treatment on deambulatory autonomy in patients with lower limb arthroplasty during hospital rehabilitation: long-term postoperative outcomes

[Purpose] To provide data on the applicability of pedometers in the evaluation of the results of rehabilitative treatment on total daily walking activity after total knee arthroplasty (TKA) and total hip arthroplasty (THA). [Participants and Methods] One hundred fifty six hospitalized patients (age 63.9 ± 12.2 years) involved. On the day of hospitalization and at the end of the rehabilitation treatment the following were performed: clinical examination, X-ray examination and weight. On the same day the pedometer was applied and removed after 48 hours. Only on 30 participants, the same evaluation was carried out 5 days before the hospitalization to measure reliability and responsiveness. Compliance was measured by a face-to-face interview. Visual analogic scale (VAS), Barthel Index (BI) and Ambulation Index (AI) were used to better describe the analyzed sample. [Results] VAS, BI and AI improved by 29.8%, 19.4 and 60.6% respectively. The data obtained on testing-retesting showed a good reliability and a mean Total Error of 7.3% for steps and 15.8% for distance. A good response in the test-retest was detected. The deambulatory autonomy of patients passed from 2,070 ± 740 m to 3,100 ± 810 m. Average improvement in the number of daily steps is 25%. [Conclusion] The data showed a good applicability of pedometer. The results on responsiveness can be used to better interpret the results of rehabilitative treatment on total daily walking activity after THA and TKA.

A Step in the Right Direction: Body Location Determines Activity Tracking Device Accuracy in Total Knee and Hip Arthroplasty Patients

INTRODUCTION

Step counts measured by activity monitoring devices (AMDs) and smartphones (SPs) can objectively measure a patient's activity levels after total hip and knee arthroplasty (total joint arthroplasty [TJA]). This study investigated the use and optimal body location of AMDs and SPs to measure step counts in the postoperative period.

METHODS

This was a two-armed, prospective, observational study of TJA inpatients (n = 24) and 2-week status after TJA (n = 25) completing a 100-ft walk. Observer-counted steps were compared with those measured by AMDs (wrist and ankle) and SPs (hip and neck). Acceptable error was defined as <30%. Error rates were treated as both dichotomous and continuous variables.

RESULTS

AMD and SP step counts had overall unacceptable error in TJA inpatients. AMDs on the contralateral ankle and SPs on the contralateral hip had error rates less than 30% at 2 weeks postoperatively. Two-week postoperative patients required lower levels of assist (11/25 walker; 4/25 no assist), and significant improvements in stride length (total hip arthroplasty 1.27 versus 1.83 ft/step; total knee arthroplasty 1.42 versus 1.83 ft/step) and cadence (total hip arthroplasty 74.6 versus 166.0 steps/min; total knee arthroplasty 73.5 versus 144.4 steps/min) were seen between inpatient and postoperative patients. Regression analysis found that increases in postoperative day and cadence led to a decrease in device error.

CONCLUSION

In inpatients with TJA, AMDs and SPs have unacceptable variability and limited utility for step counting when using a walker. As gait normalizes and the level of ambulatory assist decreases, AMDs on the contralateral ankle and SPs on the contralateral hip demonstrated low error rates. These devices offer a novel method for measurement of objective outcomes and potential for remote monitoring of patient progress after TJA.

LEVEL OF EVIDENCE

Level II, prospective, three-armed study, prognostic study.

Validity of the Actigraph GT3x and influence of the sensor positioning for the assessment of active energy expenditure during four activities of daily living in stroke subjects

Objective:

To explore the validity of the Actigraph and the influence of the placement of the sensor when estimating the active energy expenditure in four common daily activities (transfers, manual task, walking in overground and walking up and down stairs) in stroke survivors.

Design:

Cross-sectional study.

Setting:

Department of Physical Medicine and Rehabilitation.

Subjects:

A total of 46 subjects affected with stroke sequelae were wearing the Actigraph on three different locations—ankle, hip and wrist on the non-affected side—and performed four tasks: transfers, manual task, walking on flat ground and walking up and down stairs.

Main measures:

The values of active energy expenditure estimated by the Actigraph were compared to those measured by a portable breathing gas exchange analyzer Metamax3B. The accuracy and agreement between Actigraph and Metamax values were analyzed with mean bias, root mean square error, correlation coefficient and Bland–Altman plots for each task and each sensor location.

Results:

The mean bias between the Metamax and Actigraph placed on wrist, hip and ankle were, respectively, MD = 1.16 kcal (%MD = 3%), MD =−20.44 kcal (%MD =−58%) and MD = 17.64 kcal (%MD = 50%). The agreement with the Metamax was poor in general regardless of the sensor location and type of task ( r = 0.12–0.58).

Conclusion:

This study found large differences and a poor agreement between the active energy expenditure as measured by the Actigraph and the Metamax according to the location of the sensor and the type of task performed by the subject.

The Role of the Environment on Sedentary Behavior in Community-Dwelling Older Adults

Objectives

To compare amounts of sedentary behavior and physical activity in adults residing in planned group residential settings to those residing in private homes.

Methods

Thirty-one older adults who resided in planned group residential settings (n=13) and in private homes (n=18) participated. Daily activities were measured using the Sensewear Armband for 7 days. Estimates of the duration of daily activities performed across sedentary, light, and moderate-to-vigorous intensities were captured.

Results

Participants in planned group residential settings were older (age 85.9±3.5 vs 78.3±7.2; p=0.001) and spent more time in sedentary behaviors (12.7±1.5 vs 11.3±1.6; p=0.02) than participants in private homes. The difference was attenuated slightly after controlling for age and wear time (adjusted difference 1.2±0.6 hours, p=0.06).

Discussion

Adults residing in planned group residential settings, which provide supportive services, were more sedentary than adults residing in private homes. The environment in which older adults live may contribute to sedentary behavior.

Skeletal Muscle Fat and Its Association With Physical Function in Rheumatoid Arthritis

OBJECTIVE

To characterize skeletal muscle fat (SMF), intermuscular adipose tissue (IMAT), and subcutaneous adipose tissue (SAT) in individuals with rheumatoid arthritis (RA), and assess the associations between these fat depots and physical function and physical activity.

METHODS

In a cross-sectional analysis from an RA cohort, SMF, IMAT, and SAT were measured using computed tomography imaging of the midthigh cross-sectional region. Physical function was measured using the Health Assessment Questionnaire (HAQ) and a battery of performance-based tests that included quadriceps muscle strength, gait speed, repeated chair-stands, stair ascent, and single-leg stance. Physical activity was assessed using an activity monitor. Associations between SMF, IMAT, and SAT and physical function and activity were assessed by multiple linear regression models adjusted for potential confounders such as age, sex, body mass index (BMI), muscle area, and muscle strength.

RESULTS

Sixty subjects with RA (82% female, mean ± SD age 59 ± 10 years, mean ± SD BMI 31.79 ± 7.16 kg/m² ) were included. In the adjusted models, lower SMF was associated with greater gait speed, single-leg stance, quadriceps strength, and physical activity, and less disability (R² Δ range 0.06-0.25; P < 0.05), whereas IMAT was not associated with physical function or physical activity and SAT was negatively associated with disability (HAQ) (R² Δ = 0.13; P < 0.05) and weakly but positively associated with muscle strength (R² Δ = 0.023; P < 0.05).

CONCLUSION

Fat infiltration within the muscle seems to independently contribute to low physical function and physical activity, contrary to IMAT or SAT accumulation. Longitudinal studies are necessary to confirm the impact of SMF on disability and health promotion in persons with RA.

Responsiveness of Physical Activity Measures Following Exercise Programs after Total Knee Arthroplasty

Background

Few instruments that measure physical activity (pa) can accurately quantify pa performed at light and moderate intensities, which is particularly relevant to older adults. Evidence for responsiveness of these instruments after an intervention is limited.

Objectives

o estimate and compare the responsiveness of two activity monitors and one questionnaire in assessing PA after an intervention following total knee Arthroplasty.

Methods

This one-group pretest-posttest, repeated-measures study analyzed changes in duration of daily PA and the standardized response mean (SRM) to assess internal responsiveness that were compared across instruments. Correlations between changes in PA measured by the proposed instruments and the global rating of change were used to test external responsiveness. Agreement between PA instruments on identifying individuals who changed their PA based on measurement error was assessed using weighted-Kappa (K).

Results

Thirty subjects, mean age 67(6) and 73% female, were analyzed. Changes in PA measured by each instrument were small (p>0.05), resulting in a small degree of responsiveness (SRM<0.30). Global rating of change scores did not correlate with changes in PA (rho=0.13-0.28, p>0.05). The activity monitors agreed on identifying changes in moderate-intensity PA (K=0.60) and number of steps (K=0.63), but did not agree with scores from questionnaire(K≤0.22).

Conclusion

Analyzing group-based changes in PA is challenging due to high-variability in the outcome. Investigating changes in PA at the individual-level may be a more viable alternative.

Objectively measured physical activity and physical performance in old age

Background

physical performance is a key factor that determines how older people cope with daily tasks and maintain independency. There is strong evidence suggesting that physical activity (PA) is important in maintaining physical performance in old age. However, most studies have been done using self-reported PA. Our aim was to explore the association between objectively measured PA and physical performance in old age.

Methods

we studied 695 participants (mean age 70.7 years, SD 2.7) from the Helsinki Birth Cohort Study. Physical performance was assessed with the Senior Fitness Test (SFT) and PA with a multisensory activity monitor SenseWear Pro 3 Armband.

Results

total volume of PA was significantly associated with the overall SFT score (β = 0.08; 95% confidence interval: 0.07-0.10, P < 0.001). There were no significant differences between men and women. Both light and moderate to vigorous level of PA were positively associated with the overall SFT score, while sedentary time was negatively associated with the overall SFT score.

Conclusions

volume of objectively measured PA among older people was positively associated with the physical performance measured with a validated fitness test battery.

Association of Light-Intensity Physical Activity With Lower Cardiovascular Disease Risk Burden in Rheumatoid Arthritis

OBJECTIVE

To characterize physical activity (PA) in individuals with rheumatoid arthritis (RA) and to determine the associations between PA participation at light to moderate intensities and cardiovascular disease risk factors, disability, and disease activity.

METHODS

The cross-sectional study used data from 2 RA cohorts. PA was measured using an accelerometry-based activity monitor, recording minutes/day spent in sedentary (≤1 metabolic equivalent [MET]), very light (1.1-1.9 METs), light (2-2.9 METs), and moderate activities (≥3 METs). Cardiovascular markers included body mass index, blood pressure, insulin resistance, and lipid profile. Disability and disease activity were measured using the Health Assessment Questionnaire (HAQ) and the Disease Activity Score in 28 joints (DAS28), respectively. Associations between PA at each intensity level and health markers were assessed by multiple linear regression models, adjusted for age, sex, and cohort.

RESULTS

Ninety-eight subjects (mean ± SD age 58 ± 9 years, 85% female) were included. Subjects spent 9.8 hours/day being sedentary, 3.5 hours/day engaged in very light PA, 2.1 hours/day engaged in light PA, and 35 minutes/day engaged in moderate PA. Only 17% were physically active (≥150 minutes/week of moderate PA in 10-minute bouts). Regression models showed that very light, light, and moderate PA were inversely associated with most cardiovascular disease risk factors and HAQ and DAS28 scores (R(2) Δ range 0.04-0.52, P < 0.05). The associations between PA and cardiovascular disease markers were either equivalent or stronger at very light and light intensities, as compared to moderate intensity.

CONCLUSION

Individuals with RA are mostly active at very light and light intensities. PA at these intensity levels associates favorably with cardiovascular markers and lower disability and disease activity in RA.

Reliability of Physical Activity Measures During Free-Living Activities in People After Total Knee Arthroplasty

BACKGROUND

Few instruments that measure physical activity (PA) can accurately quantify PA performed at light and moderate intensities, which is particularly relevant in older adults. The evidence of their reliability in free-living conditions is limited.

OBJECTIVE

The study objectives were: (1) to determine the test-retest reliability of the Actigraph (ACT), SenseWear Armband (SWA), and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire in assessing free-living PA at light and moderate intensities in people after total knee arthroplasty; (2) to compare the reliability of the 3 instruments relative to each other; and (3) to determine the reliability of commonly used monitoring time frames (24 hours, waking hours, and 10 hours from awakening).

DESIGN

A one-group, repeated-measures design was used.

METHODS

Participants wore the activity monitors for 2 weeks, and the CHAMPS questionnaire was completed at the end of each week. Test-retest reliability was determined by using the intraclass correlation coefficient (ICC [2,k]) to compare PA measures from one week with those from the other week.

RESULTS

Data from 28 participants who reported similar PA during the 2 weeks were included in the analysis. The mean age of these participants was 69 years (SD=8), and 75% of them were women. Reliability ranged from moderate to excellent for the ACT (ICC=.75-.86) and was excellent for the SWA (ICC=.93-.95) and the CHAMPS questionnaire (ICC=.86-.92). The 95% confidence intervals (95% CI) of the ICCs from the SWA were the only ones within the excellent reliability range (.85-.98). The CHAMPS questionnaire showed systematic bias, with less PA being reported in week 2. The reliability of PA measures in the waking-hour time frame was comparable to that in the 24-hour time frame and reflected most PA performed during this period.

LIMITATIONS

Reliability may be lower for time intervals longer than 1 week.

CONCLUSIONS

All PA measures showed good reliability. The reliability of the ACT was lower than those of the SWA and the CHAMPS questionnaire. The SWA provided more precise reliability estimates. Wearing PA monitors during waking hours provided sufficiently reliable measures and can reduce the burden on people wearing them.