P. Van Roy

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.

Arthro-kinematics of the elbow: study of the carrying angle.

The carrying angle of the elbow is usually assessed in full elbow extension, with a protractor goniometer, or derived from X-ray images. Substantial differences in carrying angle values have been reported, possibly explained by methodological differences. Carrying angles tend to show higher values in women than in men. The aim of this study was to confirm the previously described progressive decrease of the carrying angle as a function of increasing elbow flexion. After assessment of the carrying angle with a protractor goniometer and an electromagnetic tracking system (Flock of Birds) in extension, flexion–extension movements with the forearm held in supination were recorded by means of the latter system. Three recordings were averaged in both the left and the right elbows of 20 volunteers without a history of elbow pathology (10 males and 10 females; mean age 25 years). In extension, a mean (± SD) carrying angle of 11.6 ± 3.2° was found in the male and 16.7 ± 2.6° in the female subjects. The carrying angles progressively decreased with flexion, at the end changing into a mean (± SD) varus angle of 1.8 ± 2.9° in men and 1.6 ± 2.3° in women. Significant differences in carrying angles between the sexes were recorded in moving from 0 to 30° of flexion (p < 0.03 for the left and p < 0.01 for the right elbows), but disappeared beyond 30°. No statistically significant differences were found between the results of left and right elbows. Although statistically significant differences (p < 0.05 to p < 0.001) were found along the course of flexion and extension, these differences were small (<0.6°). The mean carrying angles at 0, 30, 60, 90 and 120° of flexion revealed larger standard deviations in the male group than in the female group.

Variations of anatomical elements contributing to subtalar joint stability: intrinsic risk factors for post-traumatic lateral instability of the ankle?

Ankle sprains are frequently followed by chronic lateral instability, often with talar hypermobility. This might be due to subtalar instability. Among intrinsic risk factors, anatomical variants are generally overlooked. In the subtalar region, anatomical variation is particularly frequent. On the talus as well as on the calcaneus, the anterior articular facets may be missing or fused with the medial facets, giving rise to three subtalar joint configurations: a three-joint configuration, a fused configuration with a relatively large anteromedial joint, and a twojoint configuration without anterior joint. Osteometry was performed on these joint facets (134 calcanei, 122 tali), demonstrating significant differences in the surface of these configurations and the existence of a supplementary supporting surface with grossly transverse orientation in the three-joint configuration. There are also several variants of stabilizing ligaments within the sinus tarsi. Some of these configurations might expose to increased risk of associated subtalar lesions, resulting in subtalar instability. A systematic look for these variants is recommended in order to evaluate the associated risk factors, eventually resulting in a better understanding, prevention and cure of sequellae.

Morphological and constitutional comparison of age-matched in-vivo and post-mortem populations

Cadaver studies are often used as a reference in clinical studies and in-vivo Body Composition (BC). However, there is a paucity of comparative information between in-vivo and post-mortem populations. Forty living volunteers for the study (18 males and 22 females, age range 55-92 years) were age-matched with a sample of 26 well-preserved cadavers (13 males and 13 females). Twenty eight anthropometric variables were chosen, i.e. nine circumferences, eight breadths, four lengths, five skinfolds, weight and height. These were measured both in vivo and post-mortem. All measures were taken according to Martin and Saller (1957), Clauser et al. (1969) and Clarys et al. (1984). Normality verification, Variant Analysis (one way Anova) and Mollison transformations were used for the comparative treatment. Data from this study confirm that the in-vivo and post mortem macro morphology are in agreement. The best similarities were found between the female groups. This study confirms that cadaver research is reliable for the validation of in-vivo techniques and as a reference standard in the absence of other direct validation measures.

Magnetic resonance imaging of anatomical variants of the subtalar joint.

ObjectiveTo evaluate MRI with thin slices to depict anatomical variations of the subtalar and talocalcaneonavicular joints.Methods and materialsAnkle MRI was performed in 51 patients. The articular configurations were differentiated on sagittal T1-weighted and three-dimensional (3D) DESS images. Multiplanar reconstructions were performed. The variation in curvature of the posterior facet of the calcaneus and talus was analysed. 3D surface-rendered images of the calcaneus were obtained. All images were studied by an experienced physical therapist.ResultsAnalysis revealed that 18 (36.7%) of the subjects had 3 distinct facets on the calcaneus. A missing anterior facet was revealed in five (10.2%) of subjects. Twenty-six (53.1%) subjects showed a fusion of the anterior and middle facets. In four cases, an articulation was found between the talus and the cuboid bone. At the posterior talocalcaneal articulation, variations were observed of the curvature of the medial side of the joint.ConclusionsThe configuration of the facets of the talocalcaneal joints can be analysed on MR images. On 3D images, an articular connection was seen between the talus and the cuboid bone, as well as variations in the curvature of the posterior talocalcaneal joint. These anatomical variations may have implications for mobility and stability of the ankle.

Measurement of three-dimensional intra-articular kinematics: methodological and interpretation problems.

Intra-articular kinematics evaluates joint motion in terms of the configuration of the joint. Therefore data are needed concerning joint kinematics as well as joint configuration. We have developed accurate measurement methods for both in vivo and in vitro evaluation. Interpretation of the processed data is more complex than simply setting up a coordinate system based on the joint configuration. Although the description of intra-articular motion in terms of Euler–Cardan or helical angles may be complete, the therapeutic interpretation may be doubtful. Using the the ulno-humeral joint during flexion–extension as an example, we found the combination of helical angles in the directions of extension/external rotation/varus. In the case of the Cardan angles, inconsistent patterns of rotation resulted from a different choice of sequence order and were different from the helical angles. The finite helical axis (FHA) provides a functional representation of the joint movement, i.e. pathways of motion, whereas the sequence dependency of Euler–Cardan angles produces problems in the therapeutic interpretation of the movement. Therefore we believe that an FHA approach should be used in intra-articular kinematics research.

Lack of impairment of kinaesthetic sensibility in cervicogenic headache patients

To compare the cervical kinaesthetic sensibility of cervicogenic headache (CEH) patients and asymptomatic controls, the head repositioning accuracy of 10 CEH patients and 23 asymptomatic controls was measured. Should an impaired kinaesthetic sensibility be demonstrated, its assessment could be of diagnostic value in the evaluation of patients with suspected CEH. Additionally, specific exercises to improve cervical kinaesthesia could be prescribed. Kinaesthetic sensibility was assessed using a head repositioning task: subjects were asked to relocate their heads as accurately as possible to a previously memorized head position following an active movement (flexion, extension and left and right rotations). The repositioning error was registered using a validated magnetic tracking device (Flock of Birds). No significant differences were found between the asymptomatic controls and the CEH patients (independent-samples T-test, P < 0.05). We conclude that cervical kinaesthetic sensibility is not impaired in non-traumatic CEH. The use of kinaesthetic assessment and treatment in this patient group seems to be limited.

Forefoot deformation during stance: Does the forefoot collapse during loading?

This study presents a specific description of forefoot deformation during the stance phase of normal human walking based on the combined analysis of pressure and three-dimensional optoelectronic measurements. Forefoot deformation is measured in forty healthy subjects using (1) a six-camera motion capture system (sampled at 250 Hz) tracking five reflective skin markers attached to the forefoot, (2) a pressure platform (sampled at 500 Hz) and (3) a forceplate (sampled at 1250 Hz). Forefoot deformation is characterized by the forefoot width, the mediolateral metatarsal arch height and the plantar pressure under the metatarsal heads. Using this setup, a typical pattern of forefoot motion is described during stance phase: From a flexible, compliant configuration at the beginning of stance phase, characterized by a decrease in mediolateral metatarsal arch height and a controlled increase in forefoot width, the forefoot turns into a stable configuration during midstance. Subsequently, the increase in mediolateral arch height and the decrease in forefoot width describe the transformation into a tight configuration during final stance. This transfer from a compliant into a rigid configuration through stance phase rejects the idea of the forefoot as a collapsing structure under increased loading.

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 Cronbachs Alpha, Cohens 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.