H. J. G. van den Berg-Emons

Measuring daily behavior using ambulatory accelerometry: the Activity Monitor.

Advanced ambulatory systems that measure aspects of overt human behavior during normal daily life have become feasible, owing to developments in data recording and sensor technology. One such instrument is the Activity Monitor (AM). This paper provides a technical description of the AM and information about its validity and current applications. The AM is based on ambulatory accelerometry, the aim of which is to assess postures and motions for long-term (>24-h) measurement periods during normal daily life. Accelerometers are attached to the thighs, trunk, and lower arms, and signals are continuously stored in a digital portable recorder. In the postmeasurement analysis, postures and motions are detected by means of custom-made software programs. Validity studies performed on different populations showed high agreement scores between the computerized and automatic AM output and the visually analyzed video recordings. The AM has so far been applied in rehabilitation, psychophysiology, and cardiology but has many possibilities in behavioral research.

Platform accelerations of three different whole-body vibration devices and the transmission of vertical vibrations to the lower limbs.

Physical whole-body vibration (WBV) exercises become available at various levels of intensity. In a first series of measurements, we investigated 3-dimensional platform accelerations of three different WBV devices without and with three volunteers of different weight (62, 81 and 100 kg) in squat position (150 degrees knee flexion). The devices tested were two professional devices, the PowerPlate and the Galileo-Fitness, and one home-use device, the PowerMaxx. In a second series of measurements, the transmission of vertical platform accelerations of each device to the lower limbs was tested in eight healthy volunteers in squat position (100 degrees knee flexion). The first series showed that the platforms of two professional devices vibrated in an almost perfect vertical sine wave at frequencies between 25-50 and 5-40 Hz, respectively. The platform accelerations were slightly influenced by body weight. The PowerMaxx platform mainly vibrated in the horizontal plane at frequencies between 22 and 32 Hz, with minimal accelerations in the vertical direction. The weight of the volunteers reduced the platform accelerations in the horizontal plane but amplified those in the vertical direction about eight times. The vertical accelerations were highest in the Galileo (approximately 15 units of g) and the PowerPlate (approximately 8 units of g) and lowest in the PowerMaxx (approximately 2 units of g). The second series showed that the transmission of vertical accelerations at a common preset vibration frequency of 25 Hz were largest in the ankle and that transmission of acceleration reduced approximately 10 times at the knee and hip. We conclude that large variation in 3-dimensional accelerations exist in commercially available devices. The results suggest that these differences in mechanical behaviour induce variations in transmissibility of vertical vibrations to the (lower) body.

Physical fitness, everyday physical activity, and fatigue in ambulatory adults with bilateral spastic cerebral palsy

This study assessed physical fitness and its relationships with everyday physical activity (PA) and fatigue in cerebral palsy (CP). Participants were 42 adults with ambulatory bilateral spastic CP (mean age 36.4 ± 5.8 years; 69% males; 81% with good gross motor functioning). Progressive maximal aerobic cycle tests determined VO2peak (L/min). Objective levels of everyday PA were measured with accelerometry and self‐reported levels of everyday PA with the Physical Activity Scale for Individuals with Physical Disabilities. Fatigue was assessed with the Fatigue Severity Scale. The average aerobic capacity of adults with CP was 77% of Dutch reference values. Participants were physically active during 124 min/day (85% of Dutch reference values), and half experienced fatigue. In women, lower physical fitness was related to lower self‐reported levels of PA (Rp=0.61, P=0.03), and in men to higher levels of fatigue (Rp=−0.37, P=0.05). Other relationships were not significant. Results suggest that ambulatory adults with CP have low levels of physical fitness, are less physically active than able‐bodied age mates and often experience fatigue. We found little evidence for relationships between the level of physical fitness and everyday PA or fatigue.

Energy cost and physical strain of daily activities in adolescents and young adults with myelomeningocele.

The aim of this study was to assess the energy cost and physical strain of daily activities in adolescents and young adults with myelomeningocele (MMC) compared with peers without a disability. Eighteen participants with MMC aged between 16 and 30 years (13 males, five females; mean age 21y 4mo [SD 4y 8mo]) and 18 age‐ and sex‐matched non‐disabled participants performed several standardized activities. Energy cost was assessed by oxygen uptake expressed per unit time (all activities) and per metre (walking and wheelchair use at preferred speed). Physical strain was calculated by dividing energy cost by aerobic capacity. For all activities no difference was found in energy cost per unit time between ambulatory participants with MMC and comparison participants. Energy cost per metre walking at preferred speed in participants with MMC was 0.26ml/kg/m (SD 0.08), and in comparison participants was 0.20ml/kg/m (SD 0.03); p=0.08. Non‐ambulatory participants with MMC had lower energy cost (per unit time and per metre) during wheelchair use than comparison participants during walking (p<0.05). For most activities, physical strain was 1.4 to 2 times higher in participants with MMC than in comparison participants (p<0.05). In conclusion, energy cost per unit time of daily activities was not increased in participants with MMC. However, energy cost per metre during walking at preferred speed and physical strain were higher than in peers without disability.

Effects of a rehabilitation programme on daily functioning, participation, health-related quality of life, anxiety and depression in liver transplant recipients

Purpose. Fatigue is a chronic problem in liver transplant recipients and may influence daily functioning and health-related quality of life (HRQoL). This study aimed to evaluate the effects of a fatigue-reducing physical rehabilitation programme on daily functioning, participation, HRQoL, anxiety and depression among liver transplant recipients. Method. Eighteen fatigued liver transplant recipients (mean age 51 years, 10 men/8 women) participated in a 12-week rehabilitation programme, which included supervised exercise training and daily physical activity counselling. We assessed pre- and post-programme health-related daily functioning, participation, HRQoL, anxiety and depression using questionnaires. Results. After the programme, patients showed improvements in daily functioning (23.6%, p = 0.007), the participation domain ‘autonomy outdoors’ (34.1%, p = 0.001), and the HRQoL domains ‘physical functioning’ (11.5%, p = 0.007) and ‘vitality’ (21.5%, p = 0.022). Anxiety and depression were unchanged post-programme. Conclusions. Rehabilitation using supervised exercise training and daily physical activity counselling can positively influence daily functioning, participation and HRQoL among fatigued liver transplant recipients.

Cognitive functioning of adolescents and young adults with meningomyelocele and level of everyday physical activity

Purpose. To explore whether cognitive functioning in patients with meningomyelocele (MMC) is related to level of everyday physical activity. Method. In a cross-sectional study in 14 patients with MMC (aged 14 – 26 years) a neuropsychological test battery was administered to each patient. Everyday physical activity of the patients was measured with an accelerometry-based Activity Monitor (AM), and compared to 14 healthy comparison subjects. Results. Intellectual ability of 10 patients was in the normal range. For memory and verbal learning, executive functioning, divided attention and reaction speed subnormal scores were present in six or more patients. Time spent on dynamic activities was low in patients with MMC as compared to healthy subjects. After controlling for intellectual ability, we found that in patients with MMC (i) executive functioning was positively related, and (ii) word production was negatively related to everyday physical activity. Conclusion. We found some indication that specific impairments in executive functioning might be related to everyday physical activity of adolescents and young adults with MMC.

Effect of wearing an activity monitor on the amount of daily manual wheelchair propulsion in persons with spinal cord injury.

Study design:An experimental study.Objectives:To assess the effect of reactivity related to wearing a multi-sensor activity monitor (AM) on the amount of manual wheelchair propulsion during daily life in wheelchair-bound persons with spinal cord injury (SCI). In addition, to establish the subjectively experienced burden of wearing the AM.Setting:Rehabilitation centre and home-based study.Methods:In 10 persons with SCI, during a 7-day period, the daily amount of manual wheelchair propulsion was measured by means of a rotation counter. During this period, an AM was worn for 1 day (AM+ day) by the participants. Experienced burden was measured by a questionnaire based on visual analogue scale scores.Results:The overall median of the number of rotations per minute was 1.38 (range 0.63–1.83). No significant difference was found in the amount of daily manual wheelchair propulsion between AM+ and AM− days (P=0.33, median difference: −0.06 rotations per minute). Experienced burden was not different between subgroups that differed in reactivity.Conclusion:The results seem to indicate that wearing the AM of this study does not systematically influence the amount of daily manual wheelchair propulsion. Although low to moderate burden was experienced when wearing the AM, this does not seem to affect the amount of manual wheelchair propulsion.

Pituitary dysfunction after aneurysmal subarachnoid haemorrhage: Course and clinical predictors-the HIPS study

Objective We describe the occurrence and course of anterior pituitary dysfunction (PD) after aneurysmal subarachnoid haemorrhage (SAH), and identify clinical determinants for PD in patients with recent SAH. Methods We prospectively collected demographic and clinical parameters of consecutive survivors of SAH and measured fasting state endocrine function at baseline, 6 and 14 months. We included dynamic tests for growth-hormone function. We used logistic regression analysis to compare demographic and clinical characteristics of patients with SAH with and without PD. Results 84 patients with a mean age of 55.8 (±11.9) were included. Thirty-three patients (39%) had PD in one or more axes at baseline, 22 (26%) after 6 months and 6 (7%) after 14 months. Gonadotropin deficiency in 29 (34%) patients and growth hormone deficiency (GHD) in 26 (31%) patients were the most common deficiencies. PD persisted until 14 months in 6 (8%) patients: GHD in 5 (6%) patients and gonadotropin deficiency in 4 (5%). Occurrence of a SAH-related complication was associated with PD at baseline (OR 2.6, CI 2.2 to 3.0). Hydrocephalus was an independent predictor of PD 6 months after SAH (OR 3.3 CI 2.7 to 3.8). PD was associated with a lower score on health-related quality of life at baseline (p=0.06), but not at 6 and 14 months. Conclusions Almost 40% of SAH survivors have PD. In a small but substantial proportion of patients GHD or gonadotropin deficiency persists over time. Hydrocephalus is independently associated with PD 6 months after SAH. Trial registration number NTR 2085.

OPTImal CArdiac REhabilitation (OPTICARE) following Acute Coronary Syndromes: Rationale and design of a randomised, controlled trial to investigate the benefits of expanded educational and behavioural intervention programs

The majority of cardiac rehabilitation (CR) referrals consist of patients who have survived an acute coronary syndrome (ACS). Although major changes have been implemented in ACS treatment since the 1980s, which highly influenced mortality and morbidity, CR programs have barely changed and only few data are available on the optimal CR format in these patients. We postulated that standard CR programs followed by relatively brief maintenance programs and booster sessions, including behavioural techniques and focusing on incorporating lifestyle changes into daily life, can improve long-term adherence to lifestyle modifications. These strategies might result in improved (cardiac) mortality and morbidity in a cost-effective fashion. In the OPTImal CArdiac REhabilitation (OPTICARE) trial we will assess the effects of two advanced and extended CR programs that are designed to stimulate permanent adaption of a heart-healthy lifestyle, compared with current standard CR, in ACS patients. We will study the effects in terms of cardiac risk profile, levels of daily physical activity, quality of life and health care consumption.

Fatigue in persons with subacute spinal cord injury who are dependent on a manual wheelchair

Study design:Cross-sectional.Objectives:To determine the prevalence and severity of fatigue in persons with subacute spinal cord injury (SCI), assess whether demographic and lesion characteristics are related to fatigue and determine the relationship with physical fitness and physical behavior.Setting:Measurements were performed 2 months before discharge from inpatient rehabilitation.Methods:Thirty-six persons with subacute SCI, dependent on a manual wheelchair, mean age 43±15 and 83% men, completed the Fatigue Severity Scale (FSS). FSS scores >4 indicated fatigue. We recorded age and lesion characteristics, measured body mass index, measured peak power output and peak oxygen uptake during a maximal handcycling test and determined physical behavior using an accelerometer-based activity monitor. T-tests were used to test for differences in fatigue between subgroups based on age and lesion characteristics, and regression analyses to assess the relationship with physical fitness and physical behavior.Results:Mean FSS was 3.3±1.3. Fatigue, including severe fatigue, was prevalent in 31% (95% confidence interval: 16–46) of participants compared with 18% in the general population. Furthermore, mean fatigue was significantly higher in persons with incomplete compared with complete lesions (t=2.22, P=0.03). Mean scores between other subgroups did not differ significantly. Of the physical fitness and physical behavior measures, only peak oxygen uptake tended to be related to more fatigue (B=−1.47, P=0.05).Conclusion:Fatigue was prevalent and is of concern in persons with subacute SCI. Those with incomplete lesions seem to be at higher risk. Because fatigue is known to persist among persons with SCI, interventions to reduce fatigue seem necessary.