Ambulatory monitoring of mobility-related activities in rehabilitation medicine

Within rehabilitation medicine, as well as in other medical disciplines, there is a need for reliable, sensitive and valid instmments to measure on the level of daily functioning. One of the possible perspectives is to regard daily functioning as a complete range of postures, transitions between postures, and movements, which together are called mobility-related activities. AII/bulatory monitoring enables measurements to be pelformed on persons without being restdcted by space due to use of e.g. instmments, cables, etc. Due to latest technological developments, an ambulatory instmment to measure mobility-related activities could be developed: the Activity Monitor (AM), which is the thread that mns throughout the thesis. The AM is an instrument based on long-term ambulatory accelerometry, and aimed at the measurement of mobility-related activities. Distinction is made between the aspects quantity (which activity is performed, when, how frequent, for how long), quality (how is the activity performed), and physical strain (the physical reaction of the body due to the pelformance of an activity). Activities such as walking, climbing stairs, driving a wheelchair, lying, standing, sitting, and the transitions between these body positions are aimed to be distinguished. The thesis is stmctured to cOlTespond with the three main aspects of mobility-related activities: quantity (chapters 3-8), quality (chapter 9), and physical strain (chapter 10); in chapter 11 all three aspects are studied

To total amount of activity. And beyond: Perspectives on measuring physical behavior

The aim of this paper is to describe and discuss some perspectives on definitions, constructs, and outcome parameters of physical behavior. The paper focuses on the following constructs: Physical activity and active lifestyle vs. sedentary behavior and sedentary lifestyle; Amount of physical activity vs. amount of walking; Detailed body posture and movement data vs. overall physical activity data; Behavioral context of activities; Quantity vs. quality; Physical behavior vs. physiological response. Subsequently, the following outcome parameters provided by data reduction procedures are discussed: Distribution of length of bouts; Variability in bout length; Time window; Intensity and intensity threshold. The overview indicates that physical behavior is a multi-dimensional construct, and it stresses the importance and relevance of constructs and parameters other than total amount of physical activity. It is concluded that the challenge for the future will be to determine which parameters are most relevant, valid and responsive. This is a matter for physical behavior researchers to consider, that is critical to multi-disciplinary collaboration

Outcome measures for complex regional pain syndrome type I: an overview in the context of the international classification of impairments, disabilities and handicaps.

PURPOSE: To determine the availability of relevant and objective outcome measures concerning complex regional pain syndrome type I (CRPS I) for rehabilitation medicine. METHOD: Outcome measures were classified according to the International Classification of Impairments, Disabilities and Handicaps. For each outcome measure a description of concept, operationalization into variables and instrument was given. We performed a PUBMED MEDLINE search (1980-1998) using the following keywords: complex regional pain syndrome, reflex sympathetic dystrophy, impairment, disability, handicap, (long-term) outcome and effect/efficacy. RESULTS: Most outcome measures were concentrated on impairments, whereas measures at the level of disabilities and handicaps, the most relevant levels for rehabilitation medicine, were mentioned in very few studies. Objective outcome measures were merely found at the level of impairment. CONCLUSION: The results indicate a need for the development of relevant outcome measures at the level of disabilities and handicaps that can objectively measure treatment efficacy for CRPS I

Detection of static and dynamic activities using uniaxial accelerometers

Rehabilitation treatment may be improved by objective analysis of activities of daily living. For this reason, the feasibility of distinguishing several static and dynamic activities (standing, sitting, lying, walking, ascending stairs, descending stairs, cycling) using a small set of two or three uniaxial accelerometers mounted on the body was investigated. The accelerometer signals can be measured with a portable data acquisition system, which potentially makes it possible to perform online detection of static and dynamic activities in the home environment. However, the procedures described in this paper have yet to be evaluated in the home environment. Experiments were conducted on ten healthy subjects, with accelerometers mounted on several positions and orientations on the body, performing static and dynamic activities according to a fixed protocol. Specifically, accelerometers on the sternum and thigh were evaluated. These accelerometers were oriented in the sagittal plane, perpendicular to the long axis of the segment (tangential), or along this axis (radial). First, discrimination between the static or dynamic character of activities was investigated. This appeared to be feasible using an rms-detector applied on the signal of one sensor tangentially mounted on the thigh. Second, the distinction between static activities was investigated. Standing, sitting, lying supine, on a side and prone could be distinguished by observing the static signals of two accelerometers, one mounted tangentially on the thigh, and the second mounted radially on the sternum. Third, the distinction between the cyclical dynamic activities walking, stair ascent, stair descent and cycling was investigated. The discriminating potentials of several features of the accelerometer signals were assessed: the mean value, the standard deviation, the cycle time and the morphology. Signal morphology was expressed by the maximal cross-correlation coefficients with template signals for the different dynamic activities. The mean signal values and signal morphology of accelerometers mounted tangentially on the thigh and the sternum appeared to contribute to the discrimination of dynamic activities with varying detection performances. The standard deviation of the signal and the cycle time were primarily related to the speed of the dynamic activities, and did not contribute to the discrimination of the activities. Therefore, discrimination of dynamic activities on the basis of the combined evaluation of the mean signal value and signal morphology is propose

Analysing the favourable effects of physical exercise:Relationships between physical fitness, fatigue and functioning in Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy

Objective: To elucidate the effects of physical exercise in severely fatigued patients with Guillain-Barr syndrome and chronic inflammatory demyelinating polyneuropathy, and to clarify the mutual relationships between 5 domains studied in these patients: physical fitness, fatigue, objectively measured actual mobility, perceived physical functioning, and perceived mental functioning.Design: Case series.Subjects/patients: Twenty patients with Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy.Methods: The patients undertook a 12-week physical exercise program. Relationships between domains were studied in the change scores, and additionally in the baseline data of patients. The percentage of significant relationships between each pair of domains was determined.Results: In the change scores, a small percentage of significant relationships was found between the physical fitness domain and the other 4 domains (2/30, 7%). A higher percentage of significant relationships was found between the domains perceived mental functioning and actual mobility (44%), perceived mental functioning and perceived physical functioning (44%), and between fatigue and perceived physical functioning (33%). Generally, similar patterns were found in the baseline data.Conclusion: Changes in fatigue, actual mobility and perceived functioning seem not to be influenced by changes in physical fitness. This study stresses the presence and importance of additional effects of a physical training program, not directly related to increasing fitness

Upper limb activity over time in complex regional pain syndrome type 1 as objectively measured with an upper limb-activity monitor: an explorative multiple case study.

BACKGROUND: An upper limb-activity monitor (ULAM) has been developed to determine activity limitations in complex regional pain syndrome type 1 (CRPS1). The ULAM is based on 24h ambulatory monitoring of body segment accelerations and enables valid and objective quantification of mobility and upper limb activity in transversal studies. AIMS: To explore upper limb activity over time in acute upper limb CRPS1 a

Objective measurement of upper limb activity and mobility during everyday behavior using ambulatory accelerometry: the upper limb activity monitor.

Ambulatory accelerometry is a technique that allows objective measurement of aspects of everyday human behavior. The aim of our research has been to develop, validate, and apply this technique, which recently resulted in an upper limb activity monitor (ULAM). The ULAM consists of body-mounted acceleration sensors connected to a waist-worn data recorder and allows valid and objective assessment of activity of both upper limbs during performance of also automatically detected mobility-related activities: lying, sitting, standing, walking, cycling, and general movement. The ULAM can be used to determine (limitations of) upper limb activity and mobility in freely moving subjects with upper limb disorders. This article provides a detailed description of its characteristics, summarizes the results of a feasibility study and four application studies in subjects having upper limb complex regional pain syndrome, discusses the most important practical, technical, and methodological issues that were encountered, and describes current and future research projects related to measuring (limitatio

Walking in postpoliomyelitis syndrome: The relationships between time-scored tests, walking in daily life and perceived mobility problems

Objective: To compare walking test results with walking in daily life, and to investigate the relationships between walking tests, walking activity in daily life, and perceived mobility problems in patients with post-poliomyelitis syndrome. Subjects: Twenty-four ambulant patients with post-poliomyelitis syndrome. Methods: Walking tests were performed at self-preferred and maximal speed. Walking activity was measured with an ambulatory activity monitor. Heart rate, step cadence and walking speed in the test and in daily life were compared. Walking speed in daily life was represented by the intensity of walking. Perceived mobility problems were assessed with the Nottingham Health Profile. Results: Heart rate during walking was lower in the test at self-preferred speed than in daily life (mean difference: 11.3 ± 10.4; p = 0.001). Self-preferred walking speed in the test and in daily life correlated significantly (r = 0.55; p = 0.04). In a sub-group with a test performance below the median value, test performance correlated significantly with walking activity. No significant correlation was found between perceived mobility problems and walking activity. Conclusion: Walking in daily life may be more demanding than walking under standardized conditions. Patients with post-poliomyelitis syndrome with the lowest test performance walked less in daily life. Patients do not necessarily match their activity pattern to their perceived mobility problems