Biomedical subjects

H J Stam

Publications and source records attributed to H J Stam.

At least 19 recordsLinked to original sources

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↗

PubMed2001

Comparing predictive validity of four ballistic swing phase models of human walking.

It is unclear to what extent ballistic walking models can be used to qualitatively predict the swing phase at comfortable walking speed. Different study findings regarding the accuracy of the predictions of the swing phase kinematics may have been caused by differences in (1) kinematic input, (2) model characteristics (e.g. the number of segments), and (3) evaluation criteria. In the present study, the predictive validity of four ballistic swing phase models was evaluated and compared, that is, (1) the ballistic walking model as originally introduced by Mochon and McMahon, (2) an extended version of this model in which heel-off of the stance leg is added, (3) a double pendulum model, consisting of a two-segment swing leg with a prescribed hip trajectory, and (4) a shank pendulum model consisting of a shank and rigidly attached foot with a prescribed knee trajectory. The predictive validity was evaluated by comparing the outcome of the model simulations with experimentally derived swing phase kinematics of six healthy subjects. In all models, statistically significant differences were found between model output and experimental data. All models underestimated swing time and step length. In addition, statistically significant differences were found between the output of the different models. The present study shows that although qualitative similarities exist between the ballistic models and normal gait at comfortable walking speed, these models cannot adequately predict swing phase kinematics.

Adult↗

PubMed2001

Prevalence of cerebral palsy in The Netherlands (1977-1988).

Children with cerebral palsy (CP) and their families often make strong demands on diagnostic, therapeutic, technical and social facilities. Prevalence estimates are needed to improve treatment and services. As recent Dutch data are not available, the present study aimed to assess the population prevalence of CP in the Netherlands. A representative Dutch area with 1.2 million inhabitants of which 172,000 were born between 1977 and 1988 was studied. To ascertain the children with CP from these birth years, medical practices (such as rehabilitation centres, paediatric and child neurological departments) were consecutively asked to contact their (supposed) CP cases. Next, a parents' organisation and finally regional news media assisted in the ascertainment. In total, 170 'supposed' CP cases underwent an expert examination. Of these 170, 127 children proved to be definite CP-cases, yielding a 'crude' average prevalence of 0.74 per 1,000 inhabitants (95% CI: 0.61-0.87). Under-ascertainment was recognised and quantified. Accordingly, the population prevalence of CP over the birth year period 1977-1988 was calculated as 1.51 per 1,000 inhabitants (average over the 12 birth years). The calculated CP prevalence rose significantly over time: from 0.77 (1977-1979) to 2.44 (1986-1988). This trend is in accordance with other studies.

Adolescent↗

PubMed2001

Determinants of locomotor disability in people aged 55 years and over: the Rotterdam Study.

Locomotor disability, as defined by difficulties in activities of daily living related to lower limb function, can be the consequence of diseases and impairments of the cardiovascular, pulmonary, nervous, sensory and musculoskeletal system. We estimated the associations between specific diseases and impairments and locomotor disability, and the proportion of disability attributable to each condition, controlling for age and comorbidity. The Rotterdam Study is a prospective follow-up study among people aged 55 years and over in the general population. Locomotor disability in 1219 men and 1856 women was assessed with the Stanford Health Assessment Questionnaire. Diseases and impairments were radiological osteoarthritis, pain of the hips and knees, morning stiffness, fractures, hypertension, vascular disease, ischemic heart disease, stroke, heart failure, chronic obstructive pulmonary disease (COPD), depression, Parkinson's disease, osteoporosis, diabetes mellitus, overweight, and low vision. Adjusted odds ratios, etiologic and attributable fractions were calculated for locomotor disability. The occurrence of locomotor disability can partly be ascribed to joint pain, COPD, morning stiffness, diabetes and heart failure in both men and women. In addition in women osteoarthritis, osteoporosis, low vision, fractures, stroke and Parkinson's disease are significant etiologic fractions. In men with morning stiffness, joint pain, heart failure, diabetes mellitus, and COPD a significant proportion of their disability is attributable to this impairment. In women this was the case for Parkinson's disease, morning stiffness, low vision, heart failure, joint pain, diabetes, radiological osteoarthritis, stroke, COPD, osteoporosis, and fractures of the lower limbs, in that order. We conclude that locomotor complaints, heart failure, COPD and diabetes mellitus contribute considerably to locomotor disability in non-institutionalized elderly people.

Activities of Daily Living↗

PubMed2001

Pelvic pain during pregnancy is associated with asymmetric laxity of the sacroiliac joints.

OBJECTIVE: The aim of this study was to investigate the association between pregnancy-related pelvic pain (PRPP) and sacroiliac joint (SIJ) laxity. METHODS: A cross-sectional analysis was performed in a group of 163 women, 73 with moderate or severe (PRPP+) and 90 with no or mild (PRPP-) PRPP at 36 weeks of pregnancy. SIJ laxity was measured by means of Doppler imaging of vibrations in threshold units (TU). Pain, clinical signs and disability were assessed with visual analog scale (VAS), posterior pelvic pain provocation (PPPP) test, active straight leg raise (ASLR) test, and Quebec back pain disability scale (QBPDS), respectively. RESULTS: Mean SIJ laxity in the PRPP+ group was not significantly different from the PRPP- group (3.0 versus 3.4 TU). The mean left-right difference, however, was significantly higher in the PRPP+ group (2.2 TU) than in the PRPP- group (0.9 TU). In the PRPP- group, only 4% had asymmetric laxity of the SIJs in contrast to 37% of the PRPP+ group. Between the PRPP+ subjects with asymmetric and symmetric laxity of the SIJs significant differences were found with respect to mean VAS for pain (7.9 versus 7.0), positive PPPP test (59% versus 35%), positive ASLR test (85 versus 41%) and mean QBPDS score (61 versus 50). CONCLUSIONS: Increased SIJ laxity is not associated with PRPP. In fact, pregnant women with moderate or severe pelvic pain have the same laxity in the SIJs as pregnant women with no or mild pain. However, a clear relation between asymmetric laxity of the SIJs and PRPP is found.

Adult↗

PubMed2001

Complex regional pain syndrome type I treated with topical capsaicin: a case report.

This report describes the case of a multitrauma patient who underwent an amputation of the left arm and had a complicated left crural fracture with a delayed union. He was treated in an inpatient setting for preprosthetic training for a myoelectric prosthesis and to regain walking abilities. After consolidation of the crural fracture, complex regional pain syndrome type I (CRPS I) developed in the left foreleg, which hindered mobilization. Topical capsaicin .075% was prescribed and a stress-loading mobilization schema was instituted. No other treatment modalities directed at CRPS I were added. After 6 weeks, no signs or symptoms of CRPS I were present and capsaicin was discontinued. Capsaicin is a well-accepted and documented treatment modality in neuropathic pain states such as postherpetic neuralgia. However, it has rarely been described in CRPS I. Capsaicin is discussed within the framework of recent insights in the neurobiology of nociception, and it is concluded that it may provide a theory-driven treatment for CRPS I, especially in the acute stage, that facilitates physical therapy and prevents peripheral and spinal sensitization.

Administration, Topical↗

PubMed2001

Everyday physical activity in adolescents and young adults with meningomyelocele as measured with a novel activity monitor.

We measured the extent of hypoactivity in adolescents and young adults with meningomyelocele with an activity monitor. The activity monitor is based on long-term ambulatory monitoring of signals from body-fixed accelerometers during everyday life and is aimed at the assessment of mobility-related activities. Measurements were performed during 2 consecutive weekdays in 14 patients with meningomyelocele (aged 14 to 26 years) and in 14 matched, healthy subjects. Mean duration of dynamic activities (composite measure) was less in the patients (6.5 +/- 2.3%) than in comparison subjects (12.7 +/- 4.3%, P =.001). Number of walking or wheelchair-driving periods was 122 +/- 48 in the patients and 185 +/- 65 in the comparison subjects (P =.01). Resting heart rate was higher in the patients (70 +/- 7 beats/min vs 64 +/- 5 beats/min, P =.01). Time spent with dynamic activities was correlated with ambulatory status (r(s) = 0.55, P <.05). Adolescents and young adults with meningomyelocele, particularly the nonambulators, are considerably hypoactive.

Activities of Daily Living↗

PubMed2001

Functional level of young adults with cerebral palsy.

OBJECTIVE: To acquire insight into the level of functioning of young adults with cerebral palsy (CP). DESIGN: Descriptive cross-sectional study. SETTING: Rehabilitation Centre Den Haag, The Netherlands. METHOD: A structured questionnaire, including the Barthel Index was mailed to 134 young adults (aged 21-31 years) with cerebral palsy. RESULTS: Eighty subjects responded (60%). Of these, 60 (75%) were largely or fully independent in activities of daily living, 72 (90%) moved independently indoors, 56 (70%) outdoors. In 67 (77.5%) of the group the level of communication was adequate for telephone conversation. Twenty-four (30%) lived with their parents, 10 (12.5%) with a partner and 26 (32.5%) lived alone. Almost half lived in an unadapted house. Forty-two (53%) completed some form of secondary education and 29 (36.3%) had paid employment. CONCLUSION: Despite their considerable impairments, the large majority of this group of young adults with cerebral palsy are independent in activities of daily living, mobility and communication. Regarding the level of education, participation in paid employment and sports activities, however, young adults with CP are poorly integrated.

Activities of Daily Living↗

PubMed2001

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.

Activities of Daily Living↗

PubMed2000

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.

Activities of Daily Living↗

PubMed2000

Strains in experimental social psychology: a textual anaylsis of the development of experimentation in social psychology.

A textual analysis of post-World War II social psychology methodology manuals and handbook chapters on "methods" indicates that the introduction of the experimental method was enforced and gradually strengthened through the use of scientific rhetoric and the minimization of alternative research strategies. As a consequence, by the 1960s experimentation had become such an established identifying feature of psychological social psychology that the acceptability of ideas in the field came to depend largely on the ability of authors to couch them in the language of the experiment. Text writers continually shored up the defenses of scientific legitimacy and denigrated all other types of argument. We explore three sources of tension or strains evident as contradictions in these texts: (1) between a rational experimenter's carefully following prescribed, logic-generated scientific practices and the investigator's artfully or intuitively designing research; (2) between social psychologists' missionary activities of proselytizing the experiment as the primary research method and social psychologists' apologies and insecurities expressed about using experiments; and (3) between the treatment of participants as docile and submissive versus portraying them as underhanded and damaging to the outcome of the research. In addition, we briefly reexamine the strain (4) between sober scientific experimentation and a playful "fun and games" approach to experimentation (Lubek & Stam, 1995).

Historiography↗

PubMed2000

Analysis and decomposition of signals obtained by thigh-fixed uni-axial accelerometry during normal walking.

The use of piezo-resistive uni-axial accelerometer signals in gait analysis is complicated by the fact that the measured signal is composed of different types of acceleration. The aim of the study is to obtain insight into the signal from a tangential accelerometer attached to the thigh during walking. Six subjects walk with three different speeds. Simultaneous measurements are performed with accelerometers, footswitches and an opto-electronic system. The components of the accelerometer signal are calculated from the opto-electronic system. A clear relationship is found between the measured and calculated accelerometer signals (range RMS: 0.76-3.69 m x s(-2), range rms: 0.22-0.61). The most pronounced feature is a high positive acceleration peak (> 10 m x s(-2)) at the end of the cycle. The gravitational acceleration during one cycle is characterised by a sinusoidal shape, whereas the inertial acceleration contains higher-frequency components (up to 20 Hz). During the major part of the gait cycle, the gravitational and inertial acceleration make opposing contributions to the signal As a result, the gravitational acceleration influences the amplitudes of the measured acceleration signal, the shape and peaks of which are mainly determined by the inertial acceleration. Because the gravitational and inertial accelerations differ in frequency components, the application for gait analysis remains feasible.

Acceleration↗

PubMed2000

Assessing joint pain complaints and locomotor disability in the Rotterdam study: effect of population selection and assessment mode.

OBJECTIVE: To assess the prevalence of self-assessed and physician-assessed disability and joint pain, their association, and the effect of cohort reduction and mode of assessment. DESIGN: Cross-sectional population survey. SETTING: General population, age 55 years and older. SUBJECTS: Independently living participants of the Rotterdam Study, including 1,156 men and 1,739 women. OUTCOME MEASURES: Self-reported and physician-assessed joint complaints. Patients' self-assessment of locomotor disability was by response to questions from the Stanford Health Assessment Questionnaire; physicians assessed patients' disability by administering activity tests. RESULTS: Reduction of the study cohort because of nonresponse and missing data had no influence on the frequency and effect measures. The physician-assessed prevalence of pain of the hips, knees, or feet was significantly lower than the self-assessed prevalence, with the percentage agreement being 83% for men and 74% for women, with kappa-values of approximately .40. The prevalence of physician-assessed locomotor disability was also significantly lower than the self-assessed disability, with the percentage agreement being 83% for men and 78% for women, with kappa values of .41 and .47, respectively. The associations of joint complaints with disability were similar for both modes of assessment. CONCLUSION: Cohort reduction caused by nonresponse and missing data had no influence on estimates of frequency and association. Self-assessment gives higher prevalences of joint complaints and locomotor disability than physician assessment, but the associations between complaints and disability were the same.

Aged↗

PubMed2000

Doppler imaging of vibrations as a tool for quantifying first tarsometatarsal joint stiffness.

OBJECTIVE: To assess whether first tarsometatarsal joint stiffness can be measured by Doppler imaging of vibrations and if so, to assess reference values. DESIGN: Repeated in vivo Doppler imaging of vibrations measurements at the first tarsometatarsal joint in healthy persons. BACKGROUND: Clinical hypermobility of the first tarsometatarsal joint is an important factor in a hallux valgus deformity. No objective and non-invasive test is available to quantify first tarsometatarsal joint mobility. Doppler imaging of vibrations, a technique recently developed to measure joint stiffness, might be an effective tool to quantify stiffness of this joint. METHODS: Vibrations were applied to the head of the first metatarsal in 46 feet of 23 healthy subjects and picked up by a transducer at both sides of the first tarsometatarsal joint. A pilot study was performed on three patients with hypermobility of the first tarsometatarsal joint. Measurements are expressed in threshold units related to colour Doppler imaging. RESULTS: The values of the threshold units were found to be very similar in healthy persons, with a good repeatibility; 95% of the healthy persons had a threshold unit below 3.4. No significant difference was found between the left and right foot, or between male and female subjects. Also there was no significant correlation with age or weight of the subjects. In the three patients with first tarsometatarsal hypermobility we found threshold units above 5. CONCLUSIONS: With Doppler imaging of vibrations first tarsometatarsal joint stiffness can be measured in healthy persons in a non-invasive and objective way. In a pilot study, three patients with first tarsometatarsal hypermobility showed lower stiffness values than the healthy subjects. Relevance This study presents a new method for quantification of first tarsometatarsal joint stiffness and provides reference values in healthy persons. First measurements on patients gave promising results to future use of this method for assessment of clinical hypermobility in hallux valgus patients.

Adolescent↗

PubMed2000

Strength of the intrinsic muscles of the hand measured with a hand-held dynamometer: reliability in patients with ulnar and median nerve paralysis.

The aim of this study was to assess the reliability of a technique to measure the strength of the intrinsic hand muscles. Intraclass Correlation Coefficients showed an excellent level of reliability for the comparison of muscle strength between groups of patients. However, for the results of individual patients, the calculated Standard Error of Measurements (10-16%) and the Smallest Detectable Differences for intraobserver (31-36%) and interobserver (37-52%) values indicate that only relatively large changes in strength can be confidently detected with this technique. The results of the present study were compared with those of four previous grip strength studies.

Adolescent↗