Measuring physical activity in patients after surgery for a malignant tumour in the leg. The reliability and validity of a continuous ambulatory activity monitor

Reported Outcome Measures in Studies of Real-World Ambulation in People with a Lower Limb Amputation: A Scoping Review

BACKGROUND

The rapidly increasing use of wearable technology to monitor free-living ambulatory behavior demands to address to what extent the chosen outcome measures are representative for real-world situations. This scoping review aims to provide an overview of the purpose of use of wearable activity monitors in people with a Lower Limb Amputation (LLA) in the real world, to identify the reported outcome measures, and to evaluate to what extent the reported outcome measures capture essential information from real-world ambulation of people with LLA.

METHODS

The literature search included a search in three databases (MEDLINE, CINAHL, and EMBASE) for articles published between January 1999 and January 2022, and a hand-search.

RESULTS AND CONCLUSIONS

98 articles met the inclusion criteria. According to the included studies' main objective, the articles were classified into observational (n = 46), interventional (n = 34), algorithm/method development (n = 12), and validity/feasibility studies (n = 6). Reported outcome measures were grouped into eight categories: step count (reported in 73% of the articles), intensity of activity/fitness (31%), type of activity/body posture (27%), commercial scores (15%), prosthetic use and fit (11%), gait quality (7%), GPS (5%), and accuracy (4%). We argue that researchers should be more careful with choosing reliable outcome measures, in particular, regarding the frequently used category step count. However, the contemporary technology is limited in providing a comprehensive picture of real-world ambulation. The novel knowledge from this review should encourage researchers and developers to engage in debating and defining the framework of ecological validity in rehabilitation sciences, and how this framework can be utilized in the development of wearable technologies and future studies of real-world ambulation in people with LLA.

Maximal Walking Distance in Persons with a Lower Limb Amputation

The distance one can walk at a time could be considered an important functional outcome in people with a lower limb amputation. In clinical practice, walking distance in daily life is based on self-report (SIGAM mobility grade (Special Interest Group in Amputee Medicine)), which is known to overestimate physical activity. The aim of this study was to assess the number of consecutive steps and walking bouts in persons with a lower limb amputation, using an accelerometer sensor. The number of consecutive steps was related to their SIGAM mobility grade and to the consecutive steps of age-matched controls in daily life. Twenty subjects with a lower limb amputation and ten age-matched controls participated in the experiment for two consecutive days, in their own environment. Maximal number of consecutive steps and walking bouts were obtained by two accelerometers in the left and right trouser pocket, and one accelerometer on the sternum. In addition, the SIGAM mobility grade was determined and the 10 m walking test (10 MWT) was performed. The maximal number of consecutive steps and walking bouts were significantly smaller in persons with a lower limb amputation, compared to the control group (p < 0.001). Only 4 of the 20 persons with a lower limb amputation had a maximal number of consecutive steps in the range of the control group. Although the maximal covered distance was moderately correlated with the SIGAM mobility grade in participants with an amputation (r = 0.61), for 6 of them, the SIGAM mobility grade did not match with the maximal covered distance. The current study indicated that mobility was highly affected in most persons with an amputation and that the SIGAM mobility grade did not reflect what persons with a lower limb amputation actually do in daily life. Therefore, objective assessment of the maximal number of consecutive steps of maximal covered distance is recommended for clinical treatment.

Functional Outcome Measurement in Patients with Lower-Extremity Soft Tissue Sarcoma: A Systematic Literature Review

Background

The importance of functional outcome (FO) in the treatment of patients with extremity soft tissue sarcoma (STS) has been increasingly recognized in the last three decades. This systematic review aimed to investigate how FO is measured in surgically treated lower-extremity STS patients.

Methods

A systematic search of PubMed, Web of Science, and Scopus was performed based on the PRISMA guidelines. The methodologic quality of the publications was measured using the MINORS tool. The results from the included studies examining measurement types, measures, and time of FO measurement were compiled. The FO pooled mean and standard deviation were calculated as a weighted average for the groups. The validity of the applied measures is reported.

Results

The literature search found 3461 publications, 37 of which met the inclusion criteria. The measurement types used were clinician-reported outcomes (n = 27), patient-reported outcomes (n = 20), and observer-reported outcomes (n = 2). The most frequently used measures were the Toronto Extremity Salvage Score (TESS) (n = 16) and the Musculoskeletal Tumor Society (MSTS) score 1993 (n = 12). The postoperative FO was relatively good. The pooled mean TESS and MSTS 1993 scores were respectively 83.3 and 86.2 (out of 100). Of the 10 previously reported measures, 3 provide validated FO scores. The methodologic quality of publications was generally low.

Conclusions

Based on this systematic review, several different methods exist for assessing FO in patients with lower-extremity sarcoma. The most frequently used measure is a validated TESS. The postoperative FO of patients with lower-extremity STS seems to increase to the preoperative baseline level during long-term follow-up evaluation.

Functional outcome after surgery in patients with bone sarcoma around the knee; results from a long-term prospective study

Background and Objectives

In a previous conducted study functional outcome of young patients with bone sarcoma located around the knee was longitudinally evaluated during the first 2 years postoperatively. Functional outcome improved significantly over the first 2 years. The purpose of this descriptive study was to evaluate the functional outcome of these patients at long‐term follow‐up of 7 years.

Methods

Functional outcome was assessed with the TESS, MSTS, Baecke questionnaire, and three functional performance tests: time up and down stairs (TUDS), various walking activities (VWA), and the 6‐min walking test (6MWT). Linear Mixed Model has been employed for the repeated measurements.

Results

Twenty patients of the original study (n = 44) participated in the current study. Fifteen limb‐salvage and five ablative surgery patients, median follow‐up 7.4 years (6.8‐8.0) (CI 95%), mean age 22.3 years (18.2‐31.6). Between 2 and 7 years after surgery, 8 limb‐salvage patients (53%) encountered surgery related complications. Questionnaires and functional performance tests showed no significant difference in functional outcome between 2 years and 7 years after surgery (P < 0.05).

Conclusions

Between 2 years and follow‐up at average 7 years after surgery no further improvements were noticed at young patients with a bone sarcoma located around the knee.

Health-related quality of life after treatment for malignant bone tumors: a follow-up study in China

AIM

We conducted the present study to assess health-related quality of life (HRQoL) among bone cancer patients after surgical treatment in one large teaching hospitals in China, and assess the risk factors for improving the physical or mental HRQoL.

METHODS

344 eligible adult patients who were admitted to the hospital with malignant bone tumors during the period of Jun. 2008 to Dec. 2011, and a reference group with 361 health cases was recruited in the same hospital during the same period. All 344 patients were followed up for one year. The HRQoL before treatment and after one year was evaluated with the Medical Outcome Short Form 36 (SF-36).

RESULTS

All 8 domains of HRQoL had the lowest scores greatly improved over the first year after discharge. However, the patients still had significantly lower scores in every domain than the reference group one year after discharge. Age and type of surgery were associated with HRQoL in the mental domain.

CONCLUSION

The HRQoL of patients with malignant bone tumors greatly improved one year after the treatment. This study also highlighted the utility of HRQoL assessment for prognostic evaluation of patients after surgical treatment for bone cancer.

Physical activity assessment in adolescents with limb salvage

OBJECTIVES

To evaluate ambulatory activity differences between youth with limb salvage procedures and typically developing youth (TDY) and assess differences in self-reported activity levels in the 2 groups, to provide a basis for physical activity assessment in patients who had undergone limb salvage surgery and treatment planning that incorporates regaining normal physical and daily living activities.

STUDY DESIGN

In this cohort comparison study, we compared ambulatory and self-reported activity levels in 20 youth (aged 11.7-20.8 years) who had undergone limb salvage surgery and a sex- and age-matched comparison cohort of 20 TDY. StepWatch activity monitor and Activity Scale for Kids data were used to answer these questions.

RESULTS

Significant differences were found between the youth who had undergone limb salvage surgery and the TDY in total time active each day (43% vs 48%; P = .03), median total strides per day (4487 vs 7671; P = .001), and amount of time per day at high activity levels (20 minutes vs 47 minutes; P = .001). Self-reported overall physical activity, locomotion, and standing Activity Scale for Kids subscale scores were significantly lower in the youth undergoing limb salvage surgery compared with the TDY (summary score, 88.3 vs 97.7; P = .001).

CONCLUSION

Patients undergoing limb salvage surgery exhibit reduced physical activity compared with normal age-matched controls.

Estimation of traversed distance in level walking using a single inertial measurement unit attached to the waist

A method for estimating step length during level walking using a single inertial measurement unit is proposed. A combination of an optimally filtered direct and reverse integration technique and a velocity update technique for the initial velocity values identification was implemented to reduce the effects of the acceleration signals drift. The method takes advantage of the cyclic nature of gait. The inertial measurement unit was placed at waist level on the right side and the method was validated on eight subjects walking for 75 m while varying their speed. The traversed distance was estimated with an average error equal to 0.8% of the total walking distance.

Bilateral step length estimation using a single inertial measurement unit attached to the pelvis

BACKGROUND

The estimation of the spatio-temporal gait parameters is of primary importance in both physical activity monitoring and clinical contexts. A method for estimating step length bilaterally, during level walking, using a single inertial measurement unit (IMU) attached to the pelvis is proposed. In contrast to previous studies, based either on a simplified representation of the human gait mechanics or on a general linear regressive model, the proposed method estimates the step length directly from the integration of the acceleration along the direction of progression.

METHODS

The IMU was placed at pelvis level fixed to the subject's belt on the right side. The method was validated using measurements from a stereo-photogrammetric system as a gold standard on nine subjects walking ten laps along a closed loop track of about 25 m, varying their speed. For each loop, only the IMU data recorded in a 4 m long portion of the track included in the calibrated volume of the SP system, were used for the analysis. The method takes advantage of the cyclic nature of gait and it requires an accurate determination of the foot contact instances. A combination of a Kalman filter and of an optimally filtered direct and reverse integration applied to the IMU signals formed a single novel method (Kalman and Optimally filtered Step length Estimation - KOSE method). A correction of the IMU displacement due to the pelvic rotation occurring in gait was implemented to estimate the step length and the traversed distance.

RESULTS

The step length was estimated for all subjects with less than 3% error. Traversed distance was assessed with less than 2% error.

CONCLUSIONS

The proposed method provided estimates of step length and traversed distance more accurate than any other method applied to measurements obtained from a single IMU that can be found in the literature. In healthy subjects, it is reasonable to expect that, errors in traversed distance estimation during daily monitoring activity would be of the same order of magnitude of those presented.

Quality of life, functional ability and physical activity after different surgical interventions for bone cancer of the leg: A systematic review

PURPOSE

To systematically review published studies comparing Quality of Life (QoL), functional ability and/or physical activity between different surgical interventions due to a malignant bone tumour of the leg.

METHODS

A systematic literature search, covering the years 2000-2010 was performed using the PubMed, Embase, Web of science and Cochrane databases. Studies were included if they described and statistically compared QoL, functional ability and/or physical activity of at least two surgical interventions for lower extremity bone cancer. In addition, the methodological quality of the selected studies was evaluated by using a 24-point scale. Where appropriate, a qualitative analysis or meta-analysis was performed.

RESULTS

The search strategy resulted in a list of 246 citations. Based on titles and abstracts 50 full-text articles were selected, of which 13 articles describing 12 studies, were finally included. Overall, the methodological quality of the studies was moderate. Studies were heterogeneous with respect to their categorisation of surgical interventions, average age of patients and average duration of follow-up. Overall, results regarding differences between ablative and limb-sparing surgery varied largely. Meta-analysis was considered to be not appropriate due to clinical heterogeneity, methodological differences and flaws.

CONCLUSION

Twelve studies comparing the outcomes of QoL, functional ability and physical activity between limb-sparing and ablative surgery groups were identified, with an overall moderate methodological quality. Their largely varying outcomes suggest that no general conclusions on the advantage of either limb-sparing or ablative surgery in patients with malignant bone tumours of the lower extremity can be drawn.

Quantity versus quality of gait and quality of life in patients with osteoarthritis

PURPOSE

This study investigated the relationship between the quality of life, quality of gait and the quantity of gait in patients with impairments in the lower extremities.

METHODS

Twenty-six subjects (age 58.6+/-13.4 years) suffering from knee or hip osteoarthritis were investigated before implantation of an endoprosthesis. Quality of life was assessed using the SF-36 survey. The quality of gait was assessed with a six camera motion analysis system in combination with two force plates. For evaluation of the quantity of gait, two monitors were applied: (a) the accelerometer-based DynaPort activity monitor measured locomotion and posture for 1 day and (b) The Step-Activity-Monitor, a small microprocessor-operated acceleration sensor, measured the number of gait cycles in 1-min intervals for 1 week. Spearman correlation coefficients were calculated between quantity of gait, quality of gait and quality of life.

RESULTS

The patients showed typical gait impairments caused by osteoarthritis. Locomotion accounted for 10.5+/-5% of the daily recorded time, 4782+/-2116 gait cycles were counted per day. The sub-categories of the SF-36 showed limited physical functioning and general health with 38 and 56 out of 100 points, respectively. Computation of Spearman-rho revealed no relevant correlations between quality and quantity of gait but moderate correlations between quality of life and quantity of gait.

CONCLUSION

The findings underline that a patient's level of mobility cannot be reliably estimated from quality of gait or from quality of life. Instead, adequate methods should be chosen to measure the quantity of gait in daily life.

Validity of the prosthetic activity monitor to assess the duration and spatio-temporal characteristics of prosthetic walking

The prosthetic activity monitor (PAM) is an instrument to assess over the long-term the duration and spatio-temporal characteristics of walking of amputees, during normal daily life. In this study, the validity of PAM-derived measurements was investigated. Twelve transtibial amputees performed an activity protocol, consisting of stationary and walking activities, and activities associated with nonlocomotor movements. The protocol also included potential sources of error and activities assumed to be prone to misdetection. Measurements consisted of the PAM and video recordings. Agreement between video analysis and PAM output was the main outcome measure. The PAM generally correctly classified stationary activities (100% inactive, 0% active, 0% locomotion), nonlocomotor activities (45% inactive, 55% active, 0% locomotion) and walking activities (0% inactive, 1.8% active, 98.2% locomotion). When walking, the number of strides taken was slightly underestimated (-1.0%). The underestimation of distance travelled (-6.2%) and walking speed (-5.8%) was greater. The agreement with video output decreased when the PAM was misaligned, when persons walked at a speed below the defined minimum speed, and when persons walked with crutches. The PAM provides valid data on activity classes and number of strides. Although the majority of the distance data was satisfactory, in some cases considerable differences were found between the PAM and the video data. The impact of alignment, walking speed, and use of assistive devices on the PAM's operation should be considered.

Equal quality of life after limb-sparing or ablative surgery for lower extremity sarcomas

This study investigated quality of life (QoL) and function of 124 patients with lower extremity sarcoma who underwent either amputation or limb-salvage surgery (LSS) in order to assess potential differences in subjective treatment outcome. The results reflect similar QoL in both treatment groups. However, in contrast to patients with LSS, who described QoL in terms of a high physical performance status with sports and recreational activities, amputees' QoL was strongly associated with their social acceptability. High QoL in amputees brings into question the expectations held with time-consuming advanced technical skills for LSS by physicians.

Daily physical activity and heart rate response in people with a unilateral transtibial amputation for vascular disease

OBJECTIVE

To study the activity level and heart rate response, objectively measured during normal daily life, of persons with a unilateral transtibial amputation for vascular disease.

DESIGN

Case comparison.

SETTING

General community, daily life in the Netherlands.

PARTICIPANTS

Nine subjects with a unilateral transtibial amputation for vascular disease (convenience sample) and 9 control subjects without known impairments (matched for sex, age, social situation, employment).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Duration of dynamic activities, body motility (the intensity of body movement, measured with accelerometry), and heart rate (on 2 consecutive days).

RESULTS

Persons with an amputation were less active than the comparison subjects (4.3% vs 11.4% of a 48-h period, P=.007). Body motility during walking was lower in the amputee group (.111 g vs.147 g, P=.003). No differences between groups were found in normalized heart rate during walking. In the amputee group, a strong relationship was found between body motility during walking and the percentage of the day that the subject walked (r=.88, P=.002). No relationship was found between the percentage of the day that persons with an amputation were active and data from disability questionnaires.

CONCLUSION

Persons with a unilateral transtibial amputation for vascular disease were considerably less active than persons without known impairments. Heart rate response during walking of the amputee group did not differ from the response in the comparison group.

Correlations between the step activity monitor and the DynaPort ADL-monitor

OBJECTIVE

This study was performed to evaluate correlations between the DynaPort activity of daily living monitor and the step activity monitor.

DESIGN

Experimental study with repeated measures.

BACKGROUND

Physical activity becomes more important to assess quality of life, e.g. after clinical interventions such as joint replacement surgery.

METHODS

Nine subjects wore both devices simultaneously for two days. Limitations and technical problems caused by the devices were assessed by a questionnaire. Correlation coefficients were calculated between parameters derived from both instruments.

RESULTS

Only small limitations and problems were reported. Significant correlations were found between the number of steps (step activity monitor) and the percentage of locomotion (DynaPort) (r=0.95), between the number of steps and the physical activity index (DynaPort) (r=0.71) and between the physical activity index and the percentage of locomotion (r=0.76). Wilcoxon-tests between the first and second measurement of each subject did not reveal significant differences but correlation coefficients were poor (r=0.16-0.36).

CONCLUSIONS

After one day of simultaneously wearing both devices, the percentage of locomotion can be obtained using only the step activity monitor for additional days. Poor correlations between the first and the second measurements of each subject underline the necessity to record further days to acquire the level of human physical activity.