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Biomedical subjects

H J Stam

Publications and source records attributed to H J Stam.

At least 73 records · Page 4Linked to original sources
PubMed1996

Measurement of tendon excursion velocity with colour Doppler imaging: a preliminary study on flexor pollicis longus muscle.

PURPOSE: To study the use of colour Doppler imaging (CDI) for the measurement of maximum and mean tendon velocity. Recent studies showed that CDI, normally used for blood flow examinations, can be used for the imaging of tendons at the hand and wrist region. Although other modalities are available for imaging of the muscle-skeletal system, in vivo measurements of the velocity of tendon excursion are not possible. METHODS: The flexor pollicis longus (FPL) tendon of 16 healthy volunteers was measured bilaterally at two levels (wrist and thenar). A splint from the fingers along the proximal lower arm was applied. The thumb was fixed to the splint from the the first phalanx to allow flexion of the interphalangeal (IP) joint only. Pulsed CDI was used for the measurements. The maximum and mean velocities of the FPL tendon were measured at spectrum display mode during continuous voluntary contractions. At least 10 sequential Doppler peaks (cm/s) were recorded at every trial. The measurements were repeated three times. Paired t-test and correlation coefficients were calculated between levels on the same side and the opposite side. RESULTS: No significant differences were found between two levels of the same hand and of the opposite hand. As expected, the data revealed variations in the inter-individual tendon velocities. CONCLUSIONS: The velocity of the excursion of the FPL tendon can be measured with CDI with good reproducibility. It is expected that velocity measurements can be used in the future for the assessment of other tendons affected by various disorders.

Adult↗
PubMed1995

The use of color Doppler imaging for the assessment of sacroiliac joint stiffness: a study on embalmed human pelvises.

PURPOSE: The validity and reproducibility of an instrumented dynamic examination method to measure sacroiliac (SI) joint stiffness was tested in vitro. METHODS: Four embalmed human female pelvises were excitated by a pelvic vibrator. A color Doppler imaging (CDI) scanner was used to image the amplitude of vibrations at different sites of the pelvis. Vibrations were applied to the anterior superior iliac spines unilaterally and were received by CDI all over the ipsilateral SI region. Three different stability conditions were created in the SI joints: no intervention, screwed and ligaments cut. Test results were quantified by taking the minimum threshold levels of the bones. The relative difference of vibration intensity between ipsilateral ilium and sacrum at each stability condition is accepted as the stiffness level for the SI joint. RESULTS: Statistics showed high reproducibility and significant differences between the stability conditions. Dynamic testing based on the use of vibrations provides visible and quantifiable intra- and inter-individual differences between SI joint stiffnesses. CONCLUSIONS: This new method is objective and reproducible. Future in vivo application is promising since there are no technical and safety restrictions.

Aged↗
PubMed1995

The measurements of sacroiliac joint stiffness with colour Doppler imaging: a study on healthy subjects.

RATIONALE AND OBJECTIVES: Primary peripartum pelvic and low back pain is a common complaint of females. The etiologic relation between pain and pelvic stability has been shown in previous studies, but at present there is no objective clinical testing method to evaluate pelvic stability. METHODS: In this study, a dynamic measurement method using sonoelasticity to assess the sacroiliac joint (SI) stiffness was tested in vivo in 14 healthy female volunteers. With the subjects in supine position vibrations were unilaterally applied to the anterior iliac spine. The vibrations were registered by a Colour Doppler Imaging (CDI) transducer over the ipsilateral SI joint. Since the threshold level of the apparatus has a direct relation with the power of the vibrations, the intensity of the vibrations (sonoelasticity) on the sacrum and ilium was measured indirectly in threshold units. The differences between the threshold values were accepted as the power loss of vibrations through the SI joint. One-way analysis of variance-test and T-test for paired samples were applied on the measurement results (P < 0.05). RESULTS: Statistically, the results showed a satisfactory intraindividual reproducibility and inter-individual variability. There was no significant difference between the data derived from the left SI joint and right SI joint. CONCLUSIONS: Based on the promising results on healthy female volunteers, this method will be specifically used in future studies on patients with peripartum pelvic pain.

Adult↗
PubMed1995

Why leg crossing? The influence of common postures on abdominal muscle activity.

STUDY DESIGN: Abdominal muscle activity is recorded in the supine position, unconstrained standing, and in the sitting position on an office chair with the use of backrest and armrests, with and without crossed legs. OBJECTIVES: To assess the role of oblique abdominal muscles in relation to the stability of lumbar spine and pelvis in commonly adopted unconstrained postures. SUMMARY OF BACKGROUND DATA: Cross-legged sitting is very common for men and women. No solid evidence exists for either a beneficial or a detrimental effect of this posture. No electromyographic study deals with the activity of abdominal muscles in this commonly adopted unconstrained posture. METHODS: In healthy subjects, electromyographic activity of the rectus abdomini and external and internal oblique abdominals was recorded bilaterally during commonly adopted unconstrained postures. RESULTS: The activity of the internal oblique muscle was significantly higher in the sitting position than in supine position. For the external and internal oblique abdominals, the activity was significantly higher in the standing position than in the sitting position. When sitting, the activity of the oblique abdominals is significantly lowered by crossing the legs in the preferred way (either upper legs cross or ankle on knee). In contrast, the activity of the rectus abdominis is not significantly altered by leg crossing. CONCLUSIONS: From these remarkable findings, we conclude that leg crossing is physiologically valuable. It should be studied whether leg crossing can be implemented in the design of the workplace.

Abdominal Muscles↗
PubMed1995

Oblique abdominal muscle activity in standing and in sitting on hard and soft seats.

The activity of the oblique abdominal muscles was investigated with the trunk in unconstrained, symmetrical and static postures. Electromyographic recordings in six healthy subjects revealed that in all subjects the activity of both the internal and the external obliques is significantly higher in unconstrained standing than in supine posture. Activity of the internal oblique was higher than that of the external oblique abdominal. The sacrospinal, gluteus maximus and biceps femoris muscles showed practically no activity in unconstrained erect posture. During unconstrained sitting both oblique abdominals are active. In most subjects the activity of the oblique abdominals was significantly smaller when sitting on a soft car seat than when sitting on an office chair with a hard seat. The possibility is discussed that contraction of the oblique abdominals in unconstrained standing and sitting may help in stabilizing the basis of the spine and particularly the sacroiliac joints. During standing and sitting the oblique abdominal muscles apparently have a significant role in sustaining gravity loads. RELEVANCE: Back pain and pelvic pain are often experienced in prolonged standing and sitting postures. In these postures the oblique abdominals are shown to be active. The present study gains clinical significance by the studies showing relatively small oblique abdominal muscle strength in patients with low back pain. A soft seat may be helpful in treatment and prevention, because it substitutes oblique abdominal muscle activity.

Journal Article↗
PubMed1995

Dimensionality and hierarchical structure of disability measurement.

Since the D-code of the International Classification of Impairments, Disabilities, and Handicaps (ICIDH) in its full form has proven to be impractical, an instrument based on a selection of 28 items is used to measure disability in Dutch patients undergoing rehabilitation. The items are categorized into 5 domains of physical, activities of daily living (ADL), social, psychological, and communicative activity. Measurement is made on a 4-point scale ranging from 0 (not disabled) to 3 (severely disabled). As a result of the ordinal character of the rating, statistical and mathematical manipulations of the scores are complicated. The aim of this study was to obtain more insight in the dimensionality and hierarchical structure of the items, to overcome problems in comparing disability between items, between patients, and within patients between different moments in time. Mokken scale analysis of the disability scores from 1,967 rehabilitation inpatients showed that the 28 items constitute hierarchical scales. However, categorization of the items into the 5 original domains was not replicated. Five other scales or dimensions were investigated, measuring the level of extended ADL, extended psychological, fine motoric, work/leisure, and hearing/seeing activity, respectively. The number of items per dimension ranges from 14 in the extended ADL dimension to 2 each in the work/leisure and hearing/seeing dimensions. Although each disability item may be of importance in clinical case management, a reduced set of extended ADL items suffices to describe the disability level in this dimension for epidemiological research purposes. The other dimensions need further specification to provide reliable and sensitive measuring of disability.

Activities of Daily Living↗
PubMed1995

Characteristics of patients from hospital-based in-patient rehabilitation in The Netherlands.

The University Hospital Dijkzigt in Rotterdam is one of the first hospitals in The Netherlands to have a rehabilitation department providing multidisciplinary, hospital-based-in-patient rehabilitation (HBIR). The main goals of HBIR are to estimate the final optimum level of patient's functioning, to investigate the most appropriate treatment setting to achieve this and to fulfil requirements for discharge from hospital as soon as possible. One of the central issues in rehabilitation in the Netherlands is to obtain more insight into the current daily practice of HBIR. The aim of this study was to describe the characteristics of the patients treated in HBIR in Dijkzigt Hospital. Registered data from 1967 HBIR patients treated between 1988 and 1990 were analysed retrospectively. The patients were on average 53.1 ( +/- 19.7) years old; the men (63%) were significantly younger than the women (mean age of 50.8 and 57.0 years, respectively). The main diagnostic groups were stroke (27%), progressive and regressive neurological conditions (17%), hand injuries (9%), spinal cord lesion (9%), orthopaedic injuries (8%) and amputation of lower extremity (8%). The median duration of HBIR and hospitalization were 13 days and 33 day, respectively. Most patients were discharged home (63%), or to a nursing home (14%) or a rehabilitation centre (8%). The results of this study can be used in policy discussions on HBIR and provides a description of the population which needs to be studied longitudinally in future research on the outcomes of HBIR.

Activities of Daily Living↗
PubMed1995

A device for long-term ambulatory monitoring in trans-tibial amputees.

Long-term monitoring of walking in trans-tibial amputees (TTA) is considered important for prosthetic prescription and therapy evaluation. The purpose of this study was to develop a device with the following design criteria: lightweight, easy attachment to the prosthesis, energy and memory capacity for five days and practical in clinical use. The prototype (CAMP: Continuous Ambulatory Monitoring of Prosthetic walking) consists of a cylindrical unit containing an accelerometer, a miniature computer and six batteries. Specifications, data acquisition and processing, instructions for users and first results are presented and discussed. The CAMP prototype proved to be a useful device for measuring relevant aspects of prosthetic use for up to five days.

Amputees↗
PubMed1995

Interobserver agreement on iliac crest pain syndrome in general practice.

OBJECTIVE: To investigate the degree of interobserver agreement on the iliac crest pain syndrome (ICPS) in patients with nonspecific low back pain in general practice. METHODS: Sixty-one patients with nonspecific low back pain were recruited by 11 general practitioners. All patients answered a questionnaire and underwent a standard examination. Each patient was examined by 2 independent observers. RESULTS: Kappa for ICPS was 0.57 (95% CI: 0.34-0.79). For the "localized tenderness" and "typical pain" criteria, kappa was 0.57 (95% CI: 0.40-0.73) and 0.66 (95% CI: 0.48-0.83), respectively. CONCLUSION: The presence of ICPS can be judged with good interobserver agreement. Clear definition of the diagnostic criteria and examining techniques, and multiple training sessions before and during the study are prerequisites. ICPS represents a group of patients with low back pain with the same symptoms and signs. A homogeneous group facilities studies on natural history, prognosis, and therapy.

Adult↗
PubMed1994

Psychosocial impact of laryngectomy mediated by perceived stigma and illness intrusiveness.

In addition to prolonging life, successful treatment by laryngectomy also results in functional disability (loss of speech) and physical disfigurement (stoma). It was hypothesized that these after-effects contribute to perceived stigma which, in turn, compromises quality of life. The hypothesis that the psychosocial impact of perceived stigma operates through illness intrusiveness--illness-induced disruptions that interfere with continued involvements in valued activities and interests--was tested. Data were collected from 51 laryngectomy recipients via standardized interviews. As hypothesized, results indicated that: 1. both perceived stigma and illness intrusiveness are related to psychosocial well-being and emotional distress; 2. illness intrusiveness mediates the relation between perceived stigma and psychosocial outcomes; 3. the psychosocial impact of illness intrusiveness is most devastating in the context of highly stigmatized self-perception; and 4. unique profiles of illness intrusiveness across individual life domains may be associated with specific psychosocial outcomes. Findings are discussed in relation to the hypothesis that illness intrusiveness is a common underlying determinant of the psychosocial impact of chronic illness.

Adaptation, Psychological↗
PubMed1993

The Carleton Skills Training Package for modifying hypnotic susceptibility--a replication and extension: a brief communication.

This study employed the Carleton Skills Training Package (CSTP) to attempt to enhance both objective and subjective components of hypnotic susceptibility. In addition, changes in susceptibility were compared for subjects administered a standard hypnotic induction procedure and for subjects given brief "place yourself in hypnosis" instructions. Results indicated that subjects who were administered the CSTP exhibited significant gains in both objective and subjective susceptibility scores that were maintained at two separate posttests with different scales. No differences were observed between the groups administered the standard induction and those administered the self-induction instructions.

Adult↗
PubMed1993

The long-term consequence of strength deficits after menisectomy.

This study was undertaken to investigate the long-term effects of a muscular imbalance of the knee extensors of both legs, resulting from a menisectomy and a subsequent training program. Sixteen subjects were tested at the end of an eight-week training program and again 28 months later. At the end of the training program strength deficits of 13% (maximum isometric torque) and 28% (maximum isokinetic torque) were found. During the 28-month follow-up a significant increase in the mean isometric torque of the operated leg and the mean isokinetic torque of both legs was observed (p < 0.05). This resulted in a symmetrical maximum isometric and isokinetic torque of the knee extensors of both legs. A physical examination and an interview, which formed part of the 28-month follow-up, revealed no indications of knee injury or serious complaints resulting from the strength imbalance present at the end of the training program. It is concluded that the present study does not support the general opinion that a strength imbalance of the knee extensors of both legs will result in further injury to the knee joint. Secondly, it is suggested that the strength of the knee extensors of the operated leg may increase and symmetry may be reached even if the training program is ended and normal activities are resumed.

Adult↗
PubMed1992

A longitudinal study of the development of anticipatory nausea and vomiting in cancer chemotherapy patients: the role of absorption and autonomic perception.

We interviewed 70 cancer patients receiving chemotherapy at home before their second treatment session to obtain baseline measures of absorption, autonomic perception, depression, state-trait anxiety, and basic demographic information. Patients were then interviewed before each of their next six treatment sessions, at which time measures of depression, state anxiety, severity and duration of postchemotherapy nausea and/or vomiting (PCNV), and experience of anticipatory nausea and/or vomiting (ANV) were obtained. Previous findings suggesting that motion sickness, trait anxiety, depression, sex of subject, and age are predictors of the development of ANV were not replicated. Patients with ANV did score significantly higher on measures of absorption and autonomic perception than patients who did not develop ANV. Those variables hypothesized to mediate conditioning (i.e., toxicity of treatment drugs, severity of PCNV, levels of state anxiety) accurately predicted which patients developed ANV. Absorption and autonomic perception added significantly to the prediction.

Adaptation, Psychological↗
PubMed1992

Clinical progress and quadriceps torque ratios during training of meniscectomy patients.

A prospective study of 21 patients after a meniscectomy is presented. During a standardized training program, consisting of static and dynamic exercises five times a week during 8 weeks, the following clinical signs were monitored: pain, swelling and limitation of the range of motion of the knee joint. Furthermore, isometric and isokinetic maximal torque of the knee extensors of both legs was determined in the patient group, as well as in a control group of healthy subjects (n = 11). We found that swelling of the knee joint seems to be the major cause of inhibition of muscle strength, resulting in low torque values in the initial phase of the training program. Mean maximal isometric torque of the operated knee increased from 151 Nm (SD = 50) to 282 Nm (SD = 50). Isokinetic mean maximal torque increased from 77 Nm (SD = 32) to 164 Nm (SD = 28). Isometric and isokinetic mean maximal torque of the nonoperated leg increased 15% and 10%, respectively. In the control group torque output of the knee extensors remained at about the same level. It appeared that the torque differences between both legs are more pronounced in the isokinetic tests than in the isometric tests. At the end of the training program isometric and isokinetic maximal torque of the knee extensors of the operated knee still showed a deficit of 12% and 21%, respectively. Isokinetic testing is more sensitive for small strength differences than isometric testing.

Exercise Therapy↗
PubMed1992

The geriatric prosthesis as metaphor: a clinical note.

This clinical note describes a 96-year-old patient who wears a lengthening prosthesis in connection with the shortening of his leg which occurred after osteomyelitis of his left knee at the age of six years. The prosthesis was made and issued to him when he was twelve years old, and had never been replaced. The considerations that need to be made when replacing the prosthesis of an elderly patient are discussed. In the case described, the prosthesis is replaced by a model that has no fundamental changes from the original. The better fit improves walking considerably and the patient is able to move about safely again using a walking frame.

Age Factors↗
PubMed1991

The relationship between absorption, openness to experience, anhedonia, and susceptibility.

Examination of the absorption (Tellegen Absorption Scale [TAS] of Tellegen & Atkinson, 1974), openness to experience (OTE Inventory of Costa & McCrae, 1978), and anhedonia (ANH Scales of L. J. Chapman, J.P. Chapman, & Raulin, 1976) scales suggested that they might be conceptually related. Given the reliable relationship between TAS and hypnotic susceptibility, the authors were interested in studying OTE and ANH as possible personality correlates of hypnotic susceptibility. 2 studies, 1 involving a community sample and the other a sample of university students, were conducted to assess the relationships between the TAS, OTE, and ANH scales and hypnotic susceptibility. As predicted, in Study 1 (community sample) the TAS and OTE inventories were positively correlated with one another and both were negatively correlated with the ANH scale. This pattern of correlations was replicated in Study 2 (university sample), but only TAS correlated significantly with hypnotic susceptibility. Factor analyses further confirmed these findings. It was concluded that the conceptual relationship among the TAS and the OTE and ANH scales resides in some dimension other than hypnotic susceptibility.

Adolescent↗