Impact of anatomical placement of an accelerometer on prediction of physical activity energy expenditure in lower-limb amputees

Measurement properties of device-based physical activity instruments in ambulatory adults with physical disabilities and/or chronic diseases: a scoping review

BACKGROUND

People with physical disabilities and/or chronic diseases tend to have an inactive lifestyle. Monitoring physical activity levels is important to provide insight on how much and what types of activities people with physical disabilities and/or chronic diseases engage in. This information can be used as input for interventions to promote a physically active lifestyle. Therefore, valid and reliable physical activity measurement instruments are needed. This scoping review aims 1) to provide a critical mapping of the existing literature and 2) directions for future research on measurement properties of device-based instruments assessing physical activity behavior in ambulant adults with physical disabilities and/or chronic diseases.

METHODS

Four databases (MEDLINE, CINAHL, Web of Science, Embase) were systematically searched from 2015 to April 16th 2023 for articles investigating measurement properties of device-based instruments assessing physical activity in ambulatory adults with physical disabilities and/or chronic diseases. For the majority, screening and selection of eligible studies were done in duplicate. Extracted data were publication data, study data, study population, device, studied measurement properties and study outcome. Data were synthesized per device.

RESULTS

One hundred three of 21566 Studies were included. 55 Consumer-grade and 23 research-grade devices were studied on measurement properties, using 14 different physical activity outcomes, in 23 different physical disabilities and/or chronic diseases. ActiGraph (n = 28) and Fitbit (n = 39) devices were most frequently studied. Steps (n = 68) was the most common used physical activity outcome. 97 studies determined validity, 11 studies reliability and 6 studies responsiveness.

CONCLUSION

This scoping review shows a large variability in research on measurement properties of device-based instruments in ambulatory adults with physical disabilities and/or chronic diseases. The variability highlights a need for standardization of and consensus on research in this field. The review provides directions for future research.

Gait Alteration in Individual with Limb Loss: The Role of Inertial Sensors

Amputation has a big impact on the functioning of patients, with negative effects on locomotion and dexterity. In this context, inertial measurement units represent a useful tool in clinical practice for motion analysis, and in the development of personalized aids to improve a patient's function. To date, there is still a gap of knowledge in the scientific literature on the application of inertial sensors in amputee patients. Thus, the aim of this narrative review was to collect the current knowledge on this topic and stimulate the publication of further research. Pubmed, Embase, Scopus, and Cochrane Library publications were screened until November 2022 to identify eligible studies. Out of 444 results, we selected 26 articles focused on movement analysis, risk of falls, energy expenditure, and the development of sensor-integrated prostheses. The results showed that the use of inertial sensors has the potential to improve the quality of life of patients with prostheses, increasing patient safety through the detection of gait alteration; enhancing the socio-occupational reintegration through the development of highly technologic and personalized prosthesis; and by monitoring the patients during daily life to plan a tailored rehabilitation program.

Influence of traumatic lower-limb amputation on physical activity, body composition, and cardiometabolic risks: A descriptive preliminary study

BACKGROUND

Following traumatic lower-limb amputation (LLA), humans are predisposed to numerous unfavorable changes in health, including the development of secondary chronic health conditions such as metabolic disorders and cardiovascular disease.

OBJECTIVE

To determine within and between group differences in cardiometabolic component risks, body composition, and physical activity (PA) in individuals with traumatic unilateral and bilateral LLA, compared to noninjured controls.

DESIGN

Prospective observational cohort study.

SETTING

A military complex trauma rehabilitation center.

PARTICIPANTS

Sixteen males with traumatic LLA (8 unilateral, mean age 30 ± 5 years and 8 bilateral, mean age 29 ± 3 years). Thirteen active age-matched males with no LLA (28 ± 5 years) acted as controls and performed habitual activities of daily living.

INTERVENTION

Participants with LLA attended two 4-week periods of inpatient rehabilitation, separated by two 6-week periods of home-based recovery.

MAIN OUTCOME MEASURES

Venous blood samples were taken prior to and following a 75 g oral glucose load, for determination of biomarkers, including insulin and glucose, at baseline and 20 weeks. Body composition (dual X-ray absorptiometry) was measured at baseline, 10 weeks, and 20 weeks. Daily PA was recorded using a triaxial accelerometer for 7 days during inpatient rehabilitation and while at home. Energy expenditure was estimated using population-specific equations.

RESULTS

Individuals with bilateral LLA demonstrated more unfavorable mean body composition values, lower PA, and increased cardiometabolic health risk compared to controls. Cardiometabolic syndrome was identified in 63% of individuals with bilateral LLA. No statistically significant differences in cardiometabolic component risk factors, body composition, and estimated daily PA were reported between unilateral LLA and control groups (p > .05). While at home, mean PA counts.day^-1 reduced by 17% (p = .018) and 42% (p = .001) in the unilateral and bilateral LLA groups, respectively.

CONCLUSIONS

Despite extensive inpatient rehabilitation, cardiometabolic component risks are elevated in individuals with bilateral LLA but are comparable between unilateral LLA and active noninjured control groups. Innovative strategies that improve/support the long-term PA and cardiometabolic health of severely injured individuals with bilateral LLA are warranted.

General estimates of the energy cost of walking in people with different levels and causes of lower-limb amputation: a systematic review and meta-analysis

BACKGROUND

Energy cost of walking (ECw) is an important determinant of walking ability in people with a lower-limb amputation. Large variety in estimates of ECw has been reported, likely because of the heterogeneity of this population in terms of level and cause of amputation and walking speed.

OBJECTIVES

To assess (1) differences in ECw between people with and without a lower-limb amputation, and between people with different levels and causes of amputation, and (2) the association between ECw and walking speed.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

We included studies that compared ECw in people with and without a lower-limb amputation. A meta-analysis was done to compare ECw between both groups, and between different levels and causes of amputation. A second analysis investigated the association between self-selected walking speed and ECw in people with an amputation.

RESULTS

Out of 526 identified articles, 25 were included in the meta-analysis and an additional 30 in the walking speed analysis. Overall, people with a lower-limb amputation have significantly higher ECw compared to people without an amputation. People with vascular transfemoral amputations showed the greatest difference (+102%) in ECw. The smallest difference (+12%) was found for people with nonvascular transtibial amputations. Slower self-selected walking speed was associated with substantial increases in ECw.

CONCLUSION

This study provides general estimates on the ECw in people with a lower-limb amputation, quantifying the differences as a function of level and cause of amputation, as well as the relationship with walking speed.

Staged salvage of diabetic foot with Chopart amputation and intramedullary nailing

We present a stepwise surgical approach that can be used, in lieu of a transtibial amputation, to preserve the lower limb in the setting of severe diabetic foot infections. A 63-year-old male status post left midfoot (Lisfranc’s) amputation presented to our hospital with a 4-year history of a left foot diabetic ulcer with associated purulent drainage and intermittent chills. On initial exam, the patient’s left foot amputation stump was plantarflexed, grossly erythematous, and edematous. The associated diabetic foot ulcer was actively draining purulent fluid. Following workup with radiography and ultrasound, the patient was diagnosed with a post-operative infection of the midfoot at the level of the amputation stump secondary to diabetic neuropathy. Our approach to management was a staged and included (1) surgical irrigation and debridement of the distal stump wound, (2) provisional negative pressure therapy, (3) a second-look procedure, and (4) a tibiotalocalcaneal fusion was performed using a lateral transfibular and plantar approach, after wound closure and resolution of active infection was achieved. At 36-month follow-up, the patient was fully weight-bearing in stiff sole sneakers with no gross overt alteration of gait pattern. The patient scored 79 points when assessed by the hindfoot American Orthopaedic Foot and Ankle Society Ankle-Hindfoot outcome score. In the patient with diabetes and cardiological restrictions, a Chopart amputation is preferred due to the decreased level of energy expenditure required for ambulation as compared to over more proximal levels of amputation.

Estimation of 3D Body Center of Mass Acceleration and Instantaneous Velocity from a Wearable Inertial Sensor Network in Transfemoral Amputee Gait: A Case Study

The analysis of the body center of mass (BCoM) 3D kinematics provides insights on crucial aspects of locomotion, especially in populations with gait impairment such as people with amputation. In this paper, a wearable framework based on the use of different magneto-inertial measurement unit (MIMU) networks is proposed to obtain both BCoM acceleration and velocity. The proposed framework was validated as a proof of concept in one transfemoral amputee against data from force plates (acceleration) and an optoelectronic system (acceleration and velocity). The impact in terms of estimation accuracy when using a sensor network rather than a single MIMU at trunk level was also investigated. The estimated velocity and acceleration reached a strong agreement (ρ > 0.89) and good accuracy compared to reference data (normalized root mean square error (NRMSE) < 13.7%) in the anteroposterior and vertical directions when using three MIMUs on the trunk and both shanks and in all three directions when adding MIMUs on both thighs (ρ > 0.89, NRMSE ≤ 14.0% in the mediolateral direction). Conversely, only the vertical component of the BCoM kinematics was accurately captured when considering a single MIMU. These results suggest that inertial sensor networks may represent a valid alternative to laboratory-based instruments for 3D BCoM kinematics quantification in lower-limb amputees.

Quantifying Step Count and Oxygen Consumption with Portable Technology during the 2-Min Walk Test in People with Lower Limb Amputation

Step counts and oxygen consumption have yet to be reported during the 2-min walk test (2MWT) test in persons with lower-limb amputations (LLA). The purpose of this study was to determine step counts and oxygen consumption during the 2MWT in LLA. Thirty-five men and women walked for two minutes as quickly as possible while wearing activity monitors (ActiGraph Link on the wrist (LW) and ankle (LA), Garmin vivofit^®3 on the wrist (VW) and ankle (VA), and a modus StepWatch on the ankle (SA), and a portable oxygen analyzer. The StepWatch on the ankle (SA) and the vivofit3 on the wrist (VW) had the least error and best accuracy of the activity monitors studied. While there were no significant differences in distance walked, oxygen consumption (VO₂) or heart rate (HR) between sexes or level of amputation (p > 0.05), females took significantly more steps than males (p = 0.034), and those with unilateral transfemoral amputations took significantly fewer steps than those with unilateral transtibial amputations (p = 0.023). The VW and SA provided the most accurate step counts among the activity monitors and were not significantly different than hand counts. Oxygen consumption for all participants during the 2MWT was 8.9 ± 2.9 mL/kg/min, which is lower than moderate-intensity activity. While some may argue that steady-state activity has not yet been reached in the 2MWT, it may also be possible participants are not walking as fast as they can, thereby misclassifying their performance to a lower standard.

Falls After Dysvascular Transtibial Amputation: A Secondary Analysis of Falling Characteristics and Reduced Physical Performance

INTRODUCTION

Over half of all people with lower limb amputation (LLA) experience at least one fall annually. Furthermore, the majority of LLAs result from dysvascular health complications, contributing to balance deficits. However, fall-related research specific to dysvascular LLA remains limited.

OBJECTIVE

To characterize falls among adults with dysvascular LLA, using an existing Fall-Type Classification Framework and to describe the functional characteristics of participants across the framework categories.

DESIGN

Secondary data analysis from two randomized controlled trials.

SETTING

Outpatient setting.

PARTICIPANTS

People (n = 69) 6 months to 5 years from dysvascular lower extremity amputation, who were ≥50 years of age and independently ambulatory using a prosthesis.

INTERVENTION

None.

OUTCOME

Descriptions of self-reported falls were collected on a weekly basis for 12 weeks, and analyzed using an existing Fall-Type Classification Framework. Fall frequencies, estimated count, and estimated proportions were compared across all framework categories, with 95% confidence intervals. Functional measures (Timed Up and Go, Two Minute Walk, Five Meter Walk, and average step count) were collected, and averages for each participant who experienced a fall were calculated.

RESULTS

Thirty participants (43.5%) reported 42 falls within 12 weeks. A variety of fall types were described. Incidence of falls was highest for intrinsic destabilization sources, from incorrect weight shift patterns during transfer activities.

CONCLUSION

Patients with dysvascular LLAs experience a variety of fall types. The high frequency of intrinsically sourced, incorrect weight-shift falls during transfer activities emphasizes the need to focus rehabilitation efforts on improving postural control in patients with dysvascular LLAs during activities such as reaching, turning, and transferring.

A review of accelerometer-derived physical activity in the idiopathic inflammatory myopathies

Background

The idiopathic inflammatory myopathies (IIMs) are a group of rare conditions characterised by muscle inflammation (myositis). Accurate disease activity assessment is vital in both clinical and research settings, however, current available methods lack ability to quantify associated variation of physical activity, an important consequence of myositis.

This study aims to review studies that have collected accelerometer-derived physical activity data in IIM populations, and to investigate if these studies identified associations between physical and myositis disease activity.

Methods

A narrative review was conducted to identify original articles that have collected accelerometer-derived physical activity data in IIM populations. The following databases were searched from February 2000 until February 2019: Medline via PubMed, Embase via OVID and Scopus.

Results

Of the 297 publications screened, eight studies describing accelerometer use in 181 IIM cases were identified. Seven out of the eight studies investigated juvenile dermatomyositis (JDM) populations and only one reported on an adult-onset population. Population sizes, disease duration, accelerometer devices used, body placement sites, and study duration varied between each study.

Accelerometer-derived physical activity levels were reduced in IIM cohorts, compared to healthy controls, and studies reported improvement of physical activity levels following exercise programme interventions, thus demonstrating efficacy.

Higher levels of accelerometer-derived physical activity measurements were associated with shorter JDM disease duration, current glucocorticoid use and lower serum creatine kinase. However, no clear association between muscle strength and accelerometer-derived physical activity measures was identified.

Conclusions

The use of accelerometer-derived physical activity in IIM research is in its infancy. Whilst knowledge is currently limited to small studies, the opportunities are promising and future research in this area has the potential to improve disease activity assessment for clinical and research applications.

Metabolic Costs of Standing and Walking in Healthy Military-Age Adults: A Meta-regression

INTRODUCTION

The Load Carriage Decision Aid (LCDA) is a U.S. Army planning tool that predicts physiological responses of soldiers during different dismounted troop scenarios. We aimed to develop an equation that calculates standing and walking metabolic rates in healthy military-age adults for the LCDA using a meta-regression.

METHODS

We searched for studies that measured the energetic cost of standing and treadmill walking in healthy men and women via indirect calorimetry. We used mixed effects meta-regression to determine an optimal equation to calculate standing and walking metabolic rates as a function of walking speed (S, m·s). The optimal equation was used to determine the economical speed at which the metabolic cost per distance walked is minimized. The estimation precision of the new LCDA walking equation was compared with that of seven reference predictive equations.

RESULTS

The meta-regression included 48 studies. The optimal equation for calculating normal standing and walking metabolic rates (W·kg) was 1.44 + 1.94S + 0.24S. The economical speed for level walking was 1.39 m·s (~ 3.1 mph). The LCDA walking equation was more precise across all walking speeds (bias ± SD, 0.01 ± 0.33 W·kg) than the reference predictive equations.

CONCLUSION

Practitioners can use the new LCDA walking equation to calculate energy expenditure during standing and walking at speeds <2 m·s in healthy, military-age adults. The LCDA walking equation avoids the errors estimated by other equations at lower and higher walking speeds.

Metabolic costs of activities of daily living in persons with a lower limb amputation: A systematic review and meta-analysis

Objective

To systematically review the literature on the metabolic costs of activities of daily living (ADL) in persons with a lower limb amputation (LLA).

Data sources

A literature search was undertaken in the Pubmed, Embase, CINAHL, CENTRAL, and PsycINFO databases using keywords and synonyms for LLA, metabolic costs, and ADL. The last search was performed on November 29^th, 2017.

Study selection

Studies were included if they met the following 2 criteria: participants were adults with a (unilateral or bilateral) LLA and metabolic costs were measured while participants performed a physical activity or ADL.

Data extraction and synthesis

Data of 1,912 participants from 61 studies were included in the systematic review and meta-analysis. The studies used different terms to describe metabolic costs. Participants were recruited in different settings, relatively healthy, with few comorbidities. Limited data were available on metabolic costs of other activities than walking with a prosthesis. A linear mixed model analysis was performed based on the means reported, with study as unit of analysis and test results of different groups and measurement conditions as repeated measures within the unit of analysis. Predictors entered in the analysis were e.g. level and reason of amputation, age, weight, and height. During walking, oxygen consumption (ml O₂/kg/min) and heart rate (beats/min) increased with a higher walking speed and a more proximal amputation. Additionally, oxygen consumption was determined by the interaction terms walking speed x amputation level and walking speed squared. Heart rate was determined by the interaction term walking speed squared.

Conclusion

During walking, oxygen consumption (ml O₂/kg/min) and heart rate (beats/min) increased with a higher walking speed and a more proximal amputation. Data on metabolic costs of other activities were limited. The poor quality of the studies and the relatively healthy participants limited generalizability of the results of the meta-analysis.

Predicting ambulatory energy expenditure in lower limb amputees using multi-sensor methods

Purpose

To assess the validity of a derived algorithm, combining tri-axial accelerometry and heart rate (HR) data, compared to a research-grade multi-sensor physical activity device, for the estimation of ambulatory physical activity energy expenditure (PAEE) in individuals with traumatic lower-limb amputation.

Methods

Twenty-eight participants [unilateral (n = 9), bilateral (n = 10) with lower-limb amputations, and non-injured controls (n = 9)] completed eight activities; rest, ambulating at 5 progressive treadmill velocities (0.48, 0.67, 0.89, 1.12, 1.34m.s^-1) and 2 gradients (3 and 5%) at 0.89m.s^-1. During each task, expired gases were collected for the determination of V˙O2 and subsequent calculation of PAEE. An Actigraph GT3X+ accelerometer was worn on the hip of the shortest residual limb and, a HR monitor and an Actiheart (AHR) device were worn on the chest. Multiple linear regressions were employed to derive population-specific PAEE estimated algorithms using Actigraph GT3X+ outputs and HR signals (GT3X+HR). Mean bias±95% Limits of Agreement (LoA) and error statistics were calculated between criterion PAEE (indirect calorimetry) and PAEE predicted using GT3X+HR and AHR.

Results

Both measurement approaches used to predict PAEE were significantly related (P<0.01) with criterion PAEE. GT3X+HR revealed the strongest association, smallest LoA and least error. Predicted PAEE (GT3X+HR; unilateral; r = 0.92, bilateral; r = 0.93, and control; r = 0.91, and AHR; unilateral; r = 0.86, bilateral; r = 0.81, and control; r = 0.67). Mean±SD percent error across all activities were 18±14%, 15±12% and 15±14% for the GT3X+HR and 45±20%, 39±23% and 34±28% in the AHR model, for unilateral, bilateral and control groups, respectively.

Conclusions

Statistically derived algorithms (GT3X+HR) provide a more valid estimate of PAEE in individuals with traumatic lower-limb amputation, compared to a proprietary group calibration algorithm (AHR). Outputs from AHR displayed considerable random error when tested in a laboratory setting in individuals with lower-limb amputation.