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Biomedical subjects

H J Stam

Publications and source records attributed to H J Stam.

At least 19 recordsLinked to original sources
PubMed2006

Dynamometry of intrinsic hand muscles in patients with Charcot-Marie-Tooth disease.

BACKGROUND: Several problems are associated with manual muscle testing and dynamometry in the hands of patients with Charcot-Marie-Tooth (CMT) disease. OBJECTIVE: To evaluate the efficacy of the Rotterdam Intrinsic Hand Myometer (RIHM) to directly measure intrinsic hand muscle strength in CMT disease. METHODS: We measured hand muscle strength and hand function in 41 patients with CMT disease. RESULTS: RIHM measurement of intrinsic strength had excellent reliability. We found overlapping RIHM strength values in Medical Research Council grades 3 to 5. High grip and pinch strength could be found in patients with severe intrinsic muscle weakness. RIHM measurements were more strongly correlated with fine motor skills of the hand than grip and pinch strength. CONCLUSIONS: The Rotterdam Intrinsic Hand Myometer is a reliable instrument to measure intrinsic hand muscles strength in patients with Charcot-Marie-Tooth disease, providing more detailed information than manual muscle testing and a more direct assessment of intrinsic muscle loss than grip and pinch dynamometers.

Adolescent↗
PubMed2006

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.

Adolescent↗
PubMed2006

Physical capacity in wheelchair-dependent persons with a spinal cord injury: a critical review of the literature.

STUDY DESIGN: Review of publications. OBJECTIVE: To assess the level of physical capacity (peak oxygen uptake, peak power output, muscle strength of the upper extremity and respiratory function) in wheelchair-dependent persons with a spinal cord injury (SCI). SETTING: Erasmus MC, University Medical Centre Rotterdam, The Netherlands. METHODS: Pubmed (Medline) search of publications from 1980 onwards. Studies were systematically assessed. Weighted means were calculated for baseline values. RESULTS: In tetraplegia, the weighted mean for peak oxygen uptake was 0.89 l/min for the wheelchair exercise test (WCE) and 0.87 l/min for arm-cranking or hand-cycling (ACE). The peak power output was 26 W (WCE) and 40 W (ACE). In paraplegia, the peak oxygen uptake was 2.10 l/min (WCE) and 1.51 l/min (ACE), whereas the peak power output was 74 W (ACE) and 85 W (WCE). In paraplegia, muscle strength of the upper extremity and respiratory function were comparable to that in the able-bodied population. In tetraplegia muscle strength varied greatly, and respiratory function was reduced to 55-59% of the predicted values for an age-, gender- and height-matched able-bodied population. CONCLUSIONS: Physical capacity is reduced and varies in SCI. The variation between results is caused by population and methodological differences. Standardized measurement of physical capacity is needed to further develop comparative values for clinical practice and rehabilitation research.

Humans↗
PubMed2006

Responsiveness of isokinetic dynamometry parameters, pain and activity level scores to evaluate changes in patients with capsulitis of the shoulder.

OBJECTIVE: To determine the responsiveness to change of isokinetic dynamometry of the shoulder and to compare this responsiveness with outcome measures of pain and activity level. DESIGN: Responsiveness was evaluated as the change in outcome after intra-articular steroid injection in patients with capsulitis of the shoulder. Effect sizes of all outcome measures, quantified as standardized response means, were compared. Relationships between change scores of shoulder function and activities were assessed. SUBJECTS: Ten patients with unilateral capsulitis of the shoulder. MAIN OUTCOME MEASURES: Muscle strength and active range of motion were measured by isokinetic dynamometry. We then calculated involved/uninvolved ratios of the maximal peak torques of abduction, adduction, external and internal rotation, active range of motion of abduction and external rotation. In addition, pain was scored using the numeric rating scale (NRS-101) and activity level was scored using the Shoulder Disability Questionnaire. RESULTS: The standardized response mean of all outcome parameters was equal to or greater than 0.8, except for active range of motion of abduction. No significant differences between the standardized response means were found. There is a significant correlation between the change scores of NRS-101 and Shoulder Disability Questionnaire. No significant correlations were found between the change scores of NRS-101 and Shoulder Disability Questionnaire on the one hand, and involved/ uninvolved ratios of peak torques and active range of motion on the other. CONCLUSIONS: Responsiveness of all outcome measures is good. Parameters of isokinetic dynamometry may provide additional information as compared with the usual outcome measures of pain and functional level.

Adult↗
PubMed2006

The compangle: a new goniometer for joint angle measurements of the hand. A technical note.

The accuracy of joint angle measurement of the hand may be negatively influenced by joint swelling, deformation and other obstacles. We developed an alternative goniometer with clear ergonomic advantages, especially for the measurement of small joints. This new concept of goniometry is described and preliminary results on the reliability of the measurements are presented. The intraclass correlation coefficients (ICCs) and the standard error of measurements (SEMs) of the alternative goniometer are greater respectively smaller than a conventional goniometer, indicating a better intratester reliability.

Anthropometry↗
PubMed2005

Accuracy and repeatability of the Pedar Mobile system in long-term vertical force measurements.

Portable insole pressure systems can be used to measure the vertical force during long-term (hours) measurements to determine the patient's amount of weight bearing during daily activities in the hospital and at home. Especially for long-term measurements, the amount and duration of loading pressure insoles can have a large influence on the accuracy, as previous studies found a time-dependent behavior after a relatively short period (minutes) of constant loading. Therefore, this study assessed the accuracy and repeatability of a portable capacitive insole system (Pedar, Novel(GmbH)) to measure vertical force during long-term loading. Static loading experiments were performed during which the Pedar insoles were loaded with 5 and 10 N/cm2 for 7 h. Dynamic loading experiments were performed with one Pedar insole which was cyclically loaded with 300, 500 and 1000 N during two sessions of 1200 load cycles. The static and dynamic experiments were repeated 3 days later. Accuracy, due to offset drift, decreased in time during the start of the static experiments (percent error: -1.9% to 0.3% at hour 0; 26.3% to 34% at hour 7). The percent error for the dynamic experiments ranged from -16% to -19%, from -3% to -7% and from -8% to approximately 0% when the insole was loaded with 300, 500 and 1000 N, respectively. The amount of drift ranged from 12 to 62 N for the 500 and 1000 N loads, respectively. The mean day-to-day percentage difference for the static and dynamic experiments ranged from -2.3% to 0.5%, and from -2.9% to 3.0%, respectively. The results indicate that drift correction is necessary for accurate assessment of vertical force by the Pedar Mobile system to determine the amount of weight bearing during long-term measurements.

Humans↗
PubMed2005

Clinical presentation, associated disorders and aetiological moments in Cerebral Palsy: a Dutch population-based study.

PURPOSE: Cerebral Palsy (CP) contains varying clinical presentations, associated disorders and aetiological moments. Quantitative data and trends on these aspects were lacking in The Netherlands. METHOD: Within a population-based study on prevalence, presentation and functioning of Dutch children with CP born in the years 1977-1988, individual history taking, examination and medical file checking was done by experienced clinicians. Clinical subtypes, motor disability, important co-morbidity (mental retardation, visual disability and epilepsy) were recorded, aetiological moments identified if possible. By comparing the four most recent years with the earlier years possible trends were studied. RESULTS: A quarter of children beforehand recorded as CP did not meet inclusion criteria after individual examination. Spastic subtypes accounted for over 90% of all CP cases: bilateral spastic cerebral palsy as a group are the majority although spastic hemiplegia is percentage-wise the largest individual clinical subtype. Epilepsy and mental retardation are common. Clinical patterns and associated disorders remained rather constant comparing earlier to more recent birth years. CONCLUSIONS: An early diagnosis of CP may be challenged. General clinical patterns remained rather constant in following years, as did most studied items. Even if this study revealed a prevalence rise, no aspect stood out as a possible explanation for this prevalence rise. Comparable studies performed elsewhere showed similar findings.

Adolescent↗
PubMed2005

Analysis and decomposition of accelerometric signals of trunk and thigh obtained during the sit-to-stand movement.

Piezoresistive accelerometer signals are frequently used in movement analysis. However, their use and interpretation are complicated by the fact that the signal is composed of different acceleration components. The aim of the study was to obtain insight into the components of accelerometer signals from the trunk and thigh segments during four different sit-to-stand (STS) movements (self-selected, slow, fast and fullflexion). Nine subjects performed at least six trials of each type of STS movement. Accelerometer signals from the trunk and thigh in the sagittal direction were decomposed using kinematic data obtained from an opto-electronic device. Each acceleration signal was decomposed into gravitational and inertial components, and the inertial component of the trunk was subsequently decomposed into rotational and translational components. The accelerometer signals could be reliably reconstructed: mean normalised root mean square (RMS) trunk: 6.5% (range 3-12%), mean RMS thigh: 3% (range 2-5%). The accelerometric signals were highly characteristic and repeatable. The influence of the inertial component was significant, especially on the timing of the specific event of maximum trunk flexion in the accelerometer signal. The effect of inertia was larger in the trunk signal than in the thigh signal and increased with higher speeds. The study provides insight into the acceleration signal, its components and the influence of the type of STS movement and supports its use in STS movement analysis.

Acceleration↗
PubMed2005

Validity of the detection of wheelchair propulsion as measured with an Activity Monitor in patients with spinal cord injury.

STUDY DESIGN: Validation study. OBJECTIVES: An accelerometry-based Activity Monitor (AM) has proven to be a valid instrument to quantify mobility-related activities (lying, sitting, standing, walking, cycling, general (noncyclic) movement). The aim of this study was to assess whether, additional to other activities, wheelchair propulsion (hand-rim wheelchair propulsion and handbiking) can be validly detected by the AM in patients with spinal cord injury (SCI). SETTING: Rehabilitation center. METHODS: In all, 10 patients with SCI (aged 19-63 years; five patients with poor triceps strength and five patients with good triceps strength) participated. Patients performed a series of representative daily life activities (involving wheelchair propulsion and nonwheelchair propulsion activities), according to a standard protocol, in a seminatural setting. Continuous registrations of signals from body-fixed accelerometers were made and the AM output (after automatic analysis) was compared with visual analysis of simultaneously made video recordings (reference method). Validity scores (agreement, sensitivity, specificity) between the output of the AM and the video analysis were calculated. RESULTS: Agreement, sensitivity and specificity for the detection of wheelchair propulsion were overall 92 (range, 87-96)%, 87 (76-99)% and 92 (85-98)%, respectively. Sensitivity was smaller in patients with poor triceps strength compared to patients with good triceps strength; 81 (76-89)% and 95 (89-99)%, respectively (P<0.01). Mean overestimation in duration of wheelchair propulsion by the AM was 3.9% (P<0.05). CONCLUSION: Besides already validated other activities, wheelchair propulsion (hand-rim wheelchair propulsion and handbiking) can be validly detected by the AM in patients with SCI, both with good and poor triceps strength. Therefore, the AM offers the possibility to obtain objective and detailed information on all major mobility-related activities performed by patients with SCI. SPONSORSHIP: Stichting Rotterdams Kinderrevalidatie Fonds Adriaanstichting.

Acceleration↗
PubMed2004

Physical training and fatigue, fitness, and quality of life in Guillain-Barré syndrome and CIDP.

Many patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) experience excessive fatigue, which may persist for years and reduce quality of life. The authors performed a 12-week study of bicycle exercise training in 20 patients with severe fatigue, 16 with relatively good recovery from GBS, and 4 with stable CIDP. Training seemed well tolerated, and self-reported fatigue scores decreased 20% (p = 0.001). Physical fitness, functional outcome, and quality of life were improved.

Adult↗
PubMed2004

Validity of the Pedar Mobile system for vertical force measurement during a seven-hour period.

Objective measurement of weight bearing during a long-term period can give insight into the postoperative loading of the lower extremity of orthopedic patients to avoid complications. This study investigated the validity of vertical ground reaction force measurements during a long-term period using the Pedar Mobile insole pressure system, by comparing it with a Kistler force platform. In addition, the validity of a new sensor drift correction algorithm to correct for offset drift in the Pedar signal was evaluated. Ground reaction force data were collected during dynamic and static conditions from five healthy subjects every hour for 7 h. A mean offset drift of 14.6% was found after 7 h. After applying the drift correction algorithm the Pedar system showed a high accuracy for the second peak in the ground reaction force-time curve (1.1 to 3.4% difference, p>0.05) and step duration (-2.0 to 4.4% difference, p>0.05). Less accuracy was found for the first peak in the ground reaction force-time curve (5.2 to 12.0% difference; p<0.05 for the first 3 h, p>0.05 for the last 4 h) and, consequently, in the vertical force impulse (5.5 to 11.0% difference, p>0.05). The Pedar Mobile system appeared to be a valid instrument to measure the vertical force during a long-term period when using the drift correction program described in this study.

Adult↗
PubMed2004

Tetraplegia Hand Activity Questionnaire (THAQ): the development, assessment of arm-hand function-related activities in tetraplegic patients with a spinal cord injury.

STUDY DESIGN: Development of Tetraplegia Hand Activity Questionnaire (THAQ). SETTING: Patients and spinal cord injury (SCI) professionals from five rehabilitation centres in the Netherlands and Belgium. OBJECTIVE: To construct a disease-specific questionnaire to evaluate interventions to the arm-hand of tetraplegics in terms of gained and lost activities relevant to the patient. METHODS: All arm-hand function-related activities were inventoried by examining existing scales and interviewing spinal cord injury patients and professionals in the field. Subsequently, item reduction was achieved; first, in the technical construction by incorporating all activities in an item list, then reducing the list by selecting the items most likely to be sensitive to change after surgical or functional electro stimulation interventions on the arm-hand as judged by an expert panel, using a Delphi method. RESULTS: The arm-hand-related activity inventory comprised 652 activities. The technical construction of the items and the Delphi procedure resulted in a questionnaire with 153 items. The experts considered many of the 'new' activities more relevant for the evaluation of hand function interventions than those found in scales studied in the literature. This is reflected in a relatively large proportion of new activities (69%) for the item list of the THAQ, and even more in the domains work/admin/telecom (88%) and leisure (100%). CONCLUSION: The questionnaire constructed to assess hand function-related activities contains relevant activities to evaluate arm-hand function-related interventions for tetraplegic SCI patients.

Activities of Daily Living↗
PubMed2003

Traumatic brain injury: classification of initial severity and determination of functional outcome.

PURPOSE: The aim of the present manuscript is to review current methods for classifying initial severity and final outcome in traumatic brain injury (TBI) and to suggest a direction and form of further research. METHOD: The literature on valid and reliable measurements used in TBI-research for classifying initial severity and final outcome was reviewed. RESULTS: Classifying initial severity in patients with head injury according to clinical condition or CT-parameters is valid. Classifying outcome according to measurement tools of disability showed adequate validity and reliability. CONCLUSIONS: Future research in TBI outcome, particularly in rehabilitation medicine, should focus on determinants of outcome, identifying those patients who will have the greatest chance of benefiting from intensive rehabilitation programmes. More research is needed to determine the long-term functional outcome in TBI, the long-term socio-economic costs, and the influence of behavioural problems on family cohesion. Finally, validation of outcome measures is required in the TBI-population; the relative value of various outcome measures needs to be determined, and the usefulness and applicability of measures for health related quality of life in TBI should be established.

Brain Injuries↗
PubMed2003

Techniques for measuring weight bearing during standing and walking.

OBJECTIVE: To classify and assess techniques for measuring the amount of weight bearing during standing and walking. BACKGROUND: A large variety of weight bearing measuring techniques exists. This review describes their advantages and limitations to assist clinicians and researchers in selecting a technique for their specific application in measuring weight bearing. METHODS: A literature search was performed in Pubmed-Medline, CINAHL, and EMBASE. Measurement techniques were classified in 'clinical examination', 'scales', 'biofeedback systems', 'ambulatory devices' and 'platforms', and assessed on aspects of methodological quality, application, and feasibility. RESULTS: A total of 68 related articles was evaluated. The clinical examination technique is a crude method to estimate the amount of weight bearing. Scales are useful for static measurements to evaluate symmetry in weight bearing. Biofeedback systems give more reliable, accurate and objective data on weight bearing compared to clinical examination and scales, but the high costs could limit their use in physical therapy departments. The ambulatory devices can measure weight bearing with good accuracy and reliability in the hospital and at home. Platforms have the best methodological quality, but are mostly restricted to a gait laboratory, need trained personnel, and are expensive. CONCLUSIONS: The choice of a technique largely depends upon the criteria discussed in this review; however the clinical utilisation, the research question posed, and the available budget also play a role. The new developments seen in the field of 'ambulatory devices' are aimed at extending measuring time, and improved practicality in data collection and data analysis. For these latter devices, however, mainly preliminary studies have been published about devices that are not (yet) commercially available.

Feedback↗
PubMed2002

Ambulatory measurement of upper limb usage and mobility-related activities during normal daily life with an upper limb-activity monitor: a feasibility study.

The aim of this research was to assess the ability of an upper limb-activity monitor (ULAM) to discriminate between upper limb usage and non-usage in healthy and disabled subjects during normal daily life. The ULAM was based on ambulatory accelerometry and consisted of several acceleration sensors connected to a small recorder worn around the waist. While wearing this ULAM, four healthy and four disabled subjects performed an activity protocol representing normal daily life upper limb usage or non-usage. The motility feature (derived from the raw acceleration signals) was used as a measure of the extent of upper limb usage. Agreement scores between ULAM output and videotape recordings (reference method) were calculated. ULAM data that were of special interest for rehabilitation were detected satisfactorily (overall agreement 83.9%). There were no systematic differences in the agreement percentages between healthy and disabled subjects for mobility-related activities (p = 0.345) and the different forms of upper limb usage or non-usage (p= 0.715). The ULAM can be used in future studies in subjects with upper limb disorders to discriminate between upper limb usage and non-usage during performance of mobility-related activities to determine activity limitations.

Activities of Daily Living↗
PubMed2001

Reliability and validity of the active straight leg raise test in posterior pelvic pain since pregnancy.

STUDY DESIGN: A cross-sectional analysis was performed in a group of women meeting strict criteria for posterior pelvic pain since pregnancy (PPPP). The scores on the Active Straight Leg Raise Test (ASLR test) were compared with the scores of healthy controls. OBJECTIVES: To develop a new diagnostic instrument for use in patients with PPPP. The objectives of the present study were to assess the validity and reliability of the ASLR test. SUMMARY OF BACKGROUND DATA: Various diagnostic tools are used to diagnose PPPP, but there is still a need for simple tests with high reliability, sensitivity, and specificity. METHODS: Reliability of the ASLR test was assessed in a group of 50 women with lumbopelvic pain of various etiologies and various degrees of severity. Sensitivity was assessed in 200 patients with PPPP and specificity in 50 healthy women. Sensitivity and specificity of the ASLR test were compared with the posterior pelvic pain provocation test (PPPP test). RESULTS: The test-retest reliability measured with Pearson's correlation coefficient between the two ASLR scores 1 week apart was 0.87. The intraclass correlation coefficient (ICC) was 0.83. Pearson's correlation coefficient between the scores of the patient and the scores of a blinded assessor was 0.78; the ICC was 0.77. In the patient group, the ASLR score ranged from 0-10; in the control group it ranged from 0-2. The best balance between specificity and sensitivity was found when scores 1-10 are designated as positive and zero as negative. With this cut-off point sensitivity of the test was 0.87 and specificity was 0.94. The sensitivity of the ASLR test is higher than the sensitivity of the PPPP test; an advantage of the ASLR test is the simplicity of measuring the score. CONCLUSION: The ASLR test is a suitable diagnostic instrument to discriminate between patients who are disabled by PPPP and healthy subjects. The test is easy to perform; reliability, sensitivity, and specificity are high. It seems that the integrity of the function to transfer loads between the lumbosacral spine and legs is tested by the ASLR test.

Adult↗