Biomedical subjects

E Zinzen

Publications and source records attributed to E Zinzen.

10 recordsLinked to original sources

PubMed2002

Anthropometric fractionation of body mass: Matiegka revisited.

In a group of 699 Belgian nursing professionals, we estimated body composition using the four-component anthropometric model, relying on the equations originally formulated by Matiegka in 1921 and later revised by Drinkwater and colleagues. We estimated muscle mass using the more recent formula proposed by Martin and co-workers. A discrepancy was noted between estimated total body mass and 'assessed' mass, suggesting erroneous estimations of the components.

Adult↗

PubMed2001

The influence of geographic variations on the muscular activity in selected sports movements.

Surface EMG (SEMG) has been used frequently to study motion techniques or skills, body positions, material or equipment used, training-methodology and learning processes in sports and ergonomics. Little if any information is available on the effect of the geographical environment on the neuromuscular control of an athlete or workman during his/her performance or effort. Motions were chosen in Alpine skiing and cycling. Thirty-one certified ski instructors and twelve professional road cyclists participated in the study of geographical variance and its impact on muscle activity. SEMG was measured from the agonists and antagonists of the upper- and lower limb. Skiers were measured on downhill slopes ranging from 19 to 51% while the cyclists performed with different saddle positions on 2, 7 and 12% slope inclinations, respectively. Verification of the variation of muscular intensity (IEMG) over the slope inclination during a simulated giant slalom indicated that the muscular activity increased with increasing slope angle and decreased with decreasing slope angle, while heart rate measured with short-range radio telemetry increased at a constant rate between start and finish independent of the geographical variations. In a direct descent on different slopes % levels the integrated EMG is well related to the inclination (r=0.82) confirming the findings of the giant slalom. In cycling we found that, regardless of the pelvis position, the muscular intensity of lower limb muscles increased with increasing slope inclination, while the muscular intensity of the arms decreased with the same increasing slope inclination. In addition the decreased intensity of the arm muscles remained significantly higher with the pelvis (saddle) fully forward. The geography of the terrain did influence the neuromuscular work and therewith probably the performance also. The influence however, varies with specific circumstances and is coupled with items of variability of the equipment used and the body regions involved.

Adult↗

PubMed2000

Implications of an adjustable bed height during standard nursing tasks on spinal motion, perceived exertion and muscular activity.

Manual handling is a source of occupational stress, particularly for nursing personnel. High levels of biomechanical strain are associated with lifting and transferring patients, especially when the tasks are performed in flexed and twisted positions that induce an increased risk of functional and musculoskeletal problems. The use of adjustable beds in nursing practice has been suggested as a means of influencing working postures and reducing the muscular demands on nurses. The purpose of this study was to investigate the effects on spinal motion, muscular activity and perceived exertion when nurses had the opportunity to adjust bed height. The measures recorded during the conduct of standardized patient handling tasks were the changes in posture (inclination) and in shape (sagittal bending, side bending, axial rotation). Muscular activity was measured using surface electromyography. Perceived exertion was rated using the 15-graded Borg scale. The range of motion was not influenced by the adjustment of bed height, but rather a shift of the time duration histogram was noticed in the direction of the erect, safer position. The time spent in the safe zone of spinal motion near the erect position was significantly increased and was significantly decreased in the potential health-hazardous zones of spinal motion in the extreme positions. No differences in muscular activity or in perceived exertion were found between the two bed height conditions for any of the muscle groups. It was concluded that the quality of spinal motion is enhanced when the opportunity of adjusting the bed height is offered.

Adult↗

PubMed2000

Will the use of different prevalence rates influence the development of a primary prevention programme for low-back problems?

To determine relations to low-back problems (LBP), different prevalence rates are used. The disadvantage of using different selection criteria is that studies are not comparable, except where they provide the same results. The present aim was to establish whether different prevalence selection criteria lead to different answers on a newly formed set of questionnaires. Since this set is new, reliability tests were performed (test-retest and calculations of Cronbach's Alpha, Cohen's Kappa and the intraclass correlation). Results of the questionnaire should form the cornerstones of a primary prevention programme. Altogether 1783 nurses in four Flemish (Belgian) hospitals were questioned. Information was gathered on work circumstances, education, general health, psychosocial factors, leisure activities, family situation and musculoskeletal problems. Four different datasets with variables related to lifetime prevalence LBP, annual prevalence LBP, point prevalence LBP and a set with all related variables were constructed. The variables demonstrating a relation with LBP differed slightly depending on the kind of prevalence used (lifetime, annual, point). A factor analysis on each set of prevalence related data failed due to the lack of homogeneity of the variables. Fear avoidance, coping aspects and musculoskeletal problems in other regions then the lower back were, in all circumstances, the most discriminating variables. Their discriminating power, however, differed depending on the kind of prevalence used. The differences were too small to influence the construction of the prevention programme. It is concluded that in developing a primary prevention programme any of the prevalence rates can be used. The combination of the three types of prevalence rates studied provides the most complete and reliable image.

Adaptation, Psychological↗

PubMed1998

Muscle strength, task performance and low back load in nurses.

Poor muscle strength, relative to the physical demands of specific jobs, is considered a risk factor for low back pain. To gain an understanding of the underlying mechanisms, this study questioned whether muscle strength was related to task performance and low back load in nursing tasks. Trunk extension, elbow flexion and knee extension strength were therefore measured in 17 nurses. The independent effects of muscle strength on task duration, jerkiness of effort and L5-S1 torque were investigated as the nurses performed several patient handling tasks. Despite a large variation in muscle strength within the subject population, no effect of strength on task duration, jerkiness or L5-S1 torques was observed. In conclusion, poor muscle strength was found not to be related to increased low back load. If 'weaker' nurses were to be at a higher risk, it would be due to a reduced capability to withstand the mechanical load, rather than to an increased mechanical load.

Adult↗

PubMed1997

Is ergonomic intervention alone sufficient to limit musculoskeletal problems in nurses?

This study retrospectively surveyed 1,216 nurses at hospitals in Belgium and The Netherlands. Data concerning workloads, musculoskeletal symptoms, work loss and psychosocial factors were collected by questionnaire. Lifetime prevalence rates for musculoskeletal problems and low back trouble were significantly lower in the Dutch hospitals than the Belgian hospitals, but a significantly higher proportion of Dutch nurses had 'heavy' workloads. Overall, symptoms and work loss in the previous 12 months were not related to workload, nor was the perception that work was causative; a change of duties because of symptoms was rare (< 3%). The Dutch nurses differed strikingly from Belgian nurses on the psychosocial variables; they were less depressed and significantly more positive about pain, work and activity. It is proposed that ergonomic interventions alone may be sub-optimal in controlling musculoskeletal problems among nurses. The additional provision of psychosocial information to challenge misconceptions and encourage self-management is proposed.

Adaptation, Psychological↗

PubMed1994

The influence of triazolam and flunitrazepam on isokinetic and isometric muscle performance.

The influences of two benzodiazepines (triazolam 0.25 mg and flunitrazepam 2 mg) on isokinetic and isometric muscle performance and on cardiovascular parameters were examined after a standard period of sleep. A randomized and double-blind test procedure was used (n = 15). Triazolam had no significant (p < 0.05) influence on either of the test conditions. Administration of flunitrazepam significantly lowered values for maximal isometric force and for the cardiovascular parameters. It was concluded that triazolam does not influence performance. On the other hand, flunitrazepam does influence a number of strength characteristics and cardiovascular parameters in effort situations.

Adult↗

PubMed1994

Post-mortem limitations of body composition analysis by computed tomography.

Few of the indirect methods for measuring body composition have every been validated against direct human cadaver evidence. Computed tomography (CT), like NMR, has proved to be an important diagnostic tool and they appear to be the techniques of the future for body composition studies. The purpose of the present study (Cadaver Analysis Study III), undertaken at the Vrije Universiteit Brussel in a joint venture with the University of Göteborg, Sweden, was to validate tomographic measurements of volumes and areas from different tissues using data from CT-scanning of unembalmed deep-frozen cadavers and data collected by dissection of the same cadavers. Six Belgian adults were extensively measured and dissected. The body was divided into several slices for comparison of the CT image with photography of the same slice and comparison of tissue-volumes per segment for the whole body. Due to post-mortem changes and the frozen state of the cadavers, the CT measurements were greatly affected by artefacts disturbing adipose tissue (AT) and muscle area determinations. Only the bone area measurements were similar between the two techniques. However, when the volumes (per segment) of the same tissues were considered, no apparent difference was found between CT and dissection data for the muscle volume.

Aged↗

PubMed1994

Ergonomic analyses of downhill skiing.

The purpose of this study was to provide electromyographic feedback for (1) pedagogical advice in motor learning, (2) the ergonomics of materials choice and (3) competition. For these purposes: (1) EMG data were collected for the Stem Christie, the Stem Turn and the Parallel Christie (three basic ski initiation drills) and verified for the complexity of patterns; (2) integrated EMG (iEMG) and linear envelopes (LEs) were analysed from standardized positions, motions and slopes using compact, soft and competition skis; (3) in a simulated 'parallel special slalom', the muscular activity pattern and intensity of excavated and flat snow conditions were compared. The EMG data from the three studies were collected on location in the French Alps (Tignes). The analog raw EMG was recorded on the slopes with a portable seven-channel FM recorder (TEAC MR30) and with pre-amplified bipolar surface electrodes supplied with a precision instrumentation amplifier (AD 524, Analog Devices, Norwood, USA). The raw signal was full-wave rectified and enveloped using a moving average principle. This linear envelope was normalized according to the highest peak amplitude procedure per subject and was integrated in order to obtain a reference of muscular intensity. In the three studies and for all subjects (elite skiers: n = 25 in studies 1 and 2, n = 6 in study 3), we found a high level of co-contractions in the lower limb extensors and flexors, especially during the extension phase of the ski movement. The Stem Christie and the Parallel Christie showed higher levels of rhythmic movement (92 and 84%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Electromyography↗

PubMed1994

Effect of individually chosen bed-height adjustments on the low-back stress of nurses.

OBJECTIVES: The effects of height-adjustable beds in hospitals on the subsequent prevalence of low-back problems among nurses depend on the capacity to reduce low-back stress by bed-height adjustment. This capacity was investigated in the present study. METHODS: Professional nurses performed patient-handling tasks at a standard and an individually chosen bed height. Peak values and time integrals of spinal compression and shear forces were estimated with dynamic biomechanical modeling. RESULTS: The bed-height adjustment led to lower values of time-integrated compression (average 8.8% lower), peak shear force (average 9.3% lower), and time-integrated shear force (average 18.1% lower). No significance was found for the effect on peak compression, nor for the results for each individual task. This finding can be explained by the minor adjustments made in comparison with the standard height or by the application of different criteria for bed-height adjustment. CONCLUSIONS: The decreasing time-integrated forces and peak shear force, without a concomitant rise of peak compression, speak in favor of the use of height-adjustable beds in nursing.

Adult↗