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Purpose: Endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunting are well-established treatments of obstructive hydrocephalus (HCP) in adult and pediatric patients. However, there is a lack of data with regard to the quality of life (QoL) of these patients during long-term follow-up METHODS: Inclusion criteria were pediatric patients with endoscopic treatment of hydrocephalus at the University Medicine Greifswald between 1993 and 2016. Patients older than 14 years at present were assessed with the Short Form-12 (SF-12) questionnaire. Patients younger than 14 years of age were assessed with the KINDL-R questionnaire that was completed by their parents. Patients' values were compared with the scores of a corresponding age-matched group of the healthy population and with patients who received later shunt treatment. Information about comorbidities, current symptoms, and educational level were gained by an additional part. Comparative analysis between patients with ETV success and failure (defined as shunt implantation after ETV) was performed., Results: A total of 107 patients (53 m, 54f) were included. Fifty-seven/107 patients (53.3%) were considered as ETV success. Mean age at ETV was 6.9 ± 5.9 years. Fifty-four statements of 89 patients that are still alive were gained (response rate 63%). Of these, 49 questionnaires were complete and evaluable (23 m, 26f; mean age 19.8 ± 10.0 years with an average follow-up period of 13.7 ± 7.2 years). Twenty-six/49 patients (53.1%) are considered ETV success. No statistically significant differences could be obtained between patients with ETV success and ETV failure. Patients older 14 years show QoL within normal range, patients younger than 14 years show significantly lower result regarding their environment of peers and social contacts. Patients younger than 6 months at the time of ETV and patients with posthemorrhagic HCP show significantly lower physical QoL. Gait disturbance, fatigue, and seizures are associated with a lower QoL, and educational level is lower than in the normal population., Conclusions: Patients who underwent ETV in childhood do not have a lower health-related QoL in general. Subsequent insertions of ventriculoperitoneal (vp) shunts do not lower QoL. Certain subgroups of the patients show lower results compared to the healthy population., (© 2022. The Author(s).)

As the world's population ages, the prevalence of chronic diseases increases. Sarcopenia and osteoporosis are two conditions that are associated with aging, with similar risk factors that include genetics, endocrine function, and mechanical factors. Additionally, bone and muscle closely interact with each other not only anatomically, but also chemically and metabolically. Fat infiltration, a phenomenon observed in age-related bone and muscle loss, is highly prevalent and more severe in sarcopenic and osteoporotic subjects. Clinically, when individuals suffer a combination of both disorders, negative outcomes such as falls, fractures, loss of function, frailty, and mortality increase, thus generating significant personal and socio-economic costs. Therefore, it is suggested that when bone mineral density loss is synchronic with decreased muscle mass, strength, and function, it should be interpreted as a single diagnosis of osteosarcopenia, which may be preventable and treatable. Simple interventions such as resistance training, adequate protein and calcium dietary intake, associated with maintenance of appropriate levels of vitamin D, have a dual positive effect on bone and muscle, reducing falls, fractures, and, consequently, disability. It is essential that fracture prevention approaches-including postfracture management-involve assessment and treatment of both osteoporosis and sarcopenia. This is of particular importance as in older persons the combination of osteopenia/osteoporosis and sarcopenia has been proposed as a subset of frailer individuals at higher risk of institutionalization, falls, and fractures. This review summarizes osteosarcopenia epidemiology, pathophysiology, diagnosis, outcomes, and management strategies.

Functional imaging studies on responders and non-responders to therapeutic interventions in obese children are rare. We applied fMRI before and after a one-year sports therapy in 14 obese or overweight children aged 7-16 years. During scanning, participants observed a set of standardized pictures from food categories, sports, and pleasant and neutral images. We were interested in alterations of the cerebral activation to food images in association with changes in the BMI-standard deviation score (BMI-SDS) after therapy and therefore separated the observation group into two outcome subgroups. One with reduction of BMI-SDS >0.2 (responder group) and one without (non-responder group). Before therapy fMRI-activation between groups did not differ. After therapy we found the following results: in response to food images, obese children of the responder group showed increased activation in the left putamen when compared with the non-responder group. Pleasant images evoked increased insula activation in the responder group. Only the responder group showed enhanced activity within areas known to store trained motor patterns in response to sports images. Both the putamen and the insula are involved in the processing of emotional valence and were only active for the therapy responders during the observation of food or pleasant stimuli. Elevated activity in these regions might possibly be seen in the context of an increase of dopaminergic response to emotional positive stimuli during intervention. In addition, sport images activated motor representations only in those subjects who profited from the sports therapy. Overall, an altered response to rewarding and pleasant images and an increased recruitment of motor engrams during observations of sports pictures indicates a more normal cerebral processing in response to these stimuli after successful sports therapy in obese children., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Force generation during sit-to-walk (STW) post-stroke is a poorly studied area, although STW is a common daily transfer giving rise to a risk of falling in persons with disability. The purpose of this study was to describe and compare strategies for anterior-posterior (AP) force generation prior to seat-off during the STW transfer in both subjects with stroke and in matched controls. During STW at self-selected speed, AP force data were collected by 4 force plates, beneath the buttocks and feet from eight subjects with stroke (>6 months after onset) and 8 matched controls. Subjects with post-stroke hemiparesis and matched controls generated a similar magnitude of total AP force impulses (F(1,71)=0.67; p=0.42) beneath buttocks and feet prior to seat-off during STW. However, there were significant group differences in AP force impulse generation beneath the stance buttock (i.e. the non-paretic buttock in the stroke group), with longer duration (F(1,71)=8.78; p<0.005), larger net AP impulse (F(1,71)=6.76; p<0.05) and larger braking impulse (F(1,71)=7.24; p<0.05) in the stroke group. The total braking impulse beneath buttocks and feet was about 4.5 times larger in the stroke group than in the control group (F(1,71)=8.84; p<0.005). An intra- and inter-limb dys-coordination with substantial use of braking impulses was demonstrated in the stroke group. This motor strategy differed markedly from the smooth force interaction in the control group. These results might be important in the development of treatment models related to locomotion post-stroke., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: Food cues yield different patterns of brain activation in obese compared with normal-weight adults in prefrontal and limbic/paralimbic areas. For children, no mapping studies comparing representation sites for food and other stimuli between obese and normal-weight subjects are available., Design: We used a cross-sectional design of two age-matched subject groups to investigate differences in brain activation in response to visually presented food, pleasant, and neutral pictures between obese/overweight and normal children., Subjects: 22 overweight/obese children were compared with 22 normal-weight children., Measurements: Functional magnetic resonance imaging (of the whole head during perception of visually presented stimuli), psychological testing, and psychophysical measures of heart rate deceleration were assessed., Results: Obese children showed higher activation of the dorsolateral prefrontal cortex (DLPFC) in response to food pictures. In addition, DLPFC activation was negatively correlated with self-esteem. In contrast, normal-weight children showed higher activation of the caudate and hippocampus specific to food pictures, and of the anterior cingulate cortex and thalamus to visual cues in general. In response to food stimuli, obese children showed a heart rate deceleration correlating positively with activation of the ventrolateral prefrontal cortex., Conclusion: Obese children react to food stimuli with increased prefrontal activation, which might be associated with increased inhibitory control.

Objectives: To explore events and describe phases for temporal coordination of the sit-to-walk (STW) task, within a semistandardized set up, in subjects with stroke and matched controls. In addition, to assess variability of STW phase duration and to compare the relative duration of STW phases between the 2 groups., Design: Cross-sectional., Setting: Research laboratory., Participants: A convenience sample of persons with hemiparesis (n=10; age 50-67y) more than 6 months after stroke and 10 controls matched for sex, age, height, and body mass index., Interventions: Not applicable., Main Outcome Measures: Relative duration of STW phases, SE of measurement in percentage of the mean, and intraclass correlation coefficients (ICCs)., Results: Four STW phases were defined: rise preparation, transition, primary gait initiation, and secondary gait initiation. The subjects with stroke needed 54% more time to complete the STW task than the controls did. ICCs ranged from .38 to .66 and .22 to .57 in the stroke and control groups, respectively. SEs of measurement in percentage of the mean values were high, particularly in the transition phase: 54.1% (stroke) and 50.4% (controls). The generalized linear model demonstrated that the relative duration of the transition phase was significantly longer in the stroke group., Conclusions: The present results extend existing knowledge by presenting 4 new phases of temporal coordination of STW, within a semistandardized set-up, in persons with stroke and in controls. The high degree of variability regarding relative STW phase duration was probably a result of both the semistandardized set up and biological variability. The significant difference in the transition phase across the 2 groups requires further study.

The amount of correction from spine deformity surgery that is required to avoid asymmetric and unbalanced sitting is not known, and methods sensitive enough to document moderate changes in pressure distribution over time are few, as the commonly used methods are qualitative or semiquantitative. The aim was to analyse seating pressure distribution with a pressure sensor mat system in patients with nonidiopathic scoliosis and to compare the pressure distribution with that in able-bodied controls. The aim was also to apply the method in a surgically treated scoliosis group before and after the spine fusion. Peak pressure, contact area of the entire and the maximum pressure surface, and three measures of asymmetry were calculated. Patients had higher peak pressure and more asymmetric loading than controls. Significant difference was indicated in contact area. After the spine fusion, all asymmetry indices improved. The method fulfilled clinical needs to detect the differences from normal controls as well as the surgery-dependent changes.

Objective: To investigate the co-ordination between reaching, ground reaction forces and muscle activity in standing children with severe spastic diplegia wearing dynamic ankle-foot orthoses compared with typically developing children., Design: Clinical experimental study., Subjects: Six children with spastic diplegia (Gross Motor Function Classification System level III-IV) and 6 controls., Methods: Ground reaction forces (AMTI force plates), ankle muscle activity (electromyography and displacement of the hand (ELITE systems) were investigated while reaching for an object., Results: For the children with severe spastic diplegia who were wearing dynamic ankle-foot orthoses, co-ordination between upward and forward reach velocity differed regarding the temporal sequencing and amplitude of velocity peaks. During reaching, these children lacked interplay of pushing force beneath the reach leg and braking force beneath the non-reach leg and co-ordinated ankle muscle activity, compared with controls., Conclusion: The results suggest differences in reach performance and postural adjustments for balance control during a reaching movement in standing between children with spastic diplegia Gross Motor Function Classification System level III-IV, wearing dynamic ankle-foot orthoses compared with typically developing children.

Weight transfer designed to change the area of the supportive base during the performance of three different motor tasks (one-leg stance, tandem stance and gait initiation) was examined both in healthy, physically active elderly people and younger adults. The former two tasks are balance tests used clinically. Our hypothesis was that the elderly subjects would demonstrate age-related changes in their postural adjustments that could be detected by analysis of the ground reaction forces. While 24 healthy elderly adults (65-77 years of age) and 26 younger adults (24-40 years of age) performed these three tasks, the ground reaction forces were recorded from two force plates. Prior to the onset of all three tasks, the elderly placed significantly more weight on the leg that was to provide support (the stance leg), than did the younger individuals. The analyses revealed two distinct phases of weight transfer, i.e., an initial thrust and a subsequent unloading phase. The elderly individuals exhibited a significantly longer unloading phase, as well as a higher frequency of peaks of vertical and lateral forces during this phase. Moreover, the maximal force rate during this phase was achieved at an earlier time point by the elderly. However, both groups generated forces of similar magnitudes and force rates. In conclusion, our findings indicate the presence of age-related differences in the temporal phasing of the ground reaction forces in all three of these tasks involving weight transfer, whereas the magnitude and rates of change of these forces are independent of age.

This paper reports some of the research activities conducted at the Motor Control and Physical Therapy Laboratory aimed to understand the control of the coordination between posture and voluntary actions as reflected in the performance of everyday motor tasks in subject with normal and impaired motor control. Through multi-factorial analysis regarding the kinematics, ground reaction forces and muscle activity patterns (EMG), motor control variables critical for specific task performance are identified. Target-reaching in subjects after stroke and in children with cerebral palsy are discussed in some detail. Further, transfer skills in subjects with spinal cord injury as well as weight shift during gait initiation in young and elderly adults and during clinical balance testing are presented. The research findings are illuminated with respect to clinical implications in neurological rehabilitation, based on the motor control hypothesis.

Sagittal head excursions are frequently used as diagnostic and treatment tools by physiotherapists. Retractions are performed to promote good head-on-body orientation. This study examined the regional contribution of spinal movements to head pro- and retraction in addition to the effect of a more or less restrained sitting position in healthy women. Fourteen healthy women performed seven sagittal head excursions in a more or less restrained sitting position, during which time their kinematic response was measured with an optoelectronic system. Total anterior/posterior head excursion was smaller (P=0.005) in the more restrained sitting position. In both sitting positions, approximately 60% of the total anterior/posterior head excursion originated from the cervical spine, almost 30% from the cervicothoracic spine C7-T4, and approximately 10% from thoracic regions down to T12. Middle thoracic vertical displacement was smaller (p=0.005) in the more restrained sitting position. A high correlation was found between total head excursion and the cervicothoracic unit displacements in both sitting positions (r=0.79, r=0.85, respectively). In each sitting position, the craniovertebral angle, and the tragus-C7-horizontal line decreased in protraction. Movements in the thoracic region contributed to the total head excursion. Therefore, clinicians should recognize the thoracic contribution to sagittal head excursion when using pro- and retraction as a diagnostic and treatment tool.

Study Design: A complex set-up was used to investigate kinematics and ground reaction forces., Setting: Motor Control and Physical Therapy Research Laboratory, Neurotec Department, Karolinska Institutet, Huddinge, Sweden., Objective: To investigate how men and women with spinal cord injury (SCI) perform transfers from table to wheelchair with regard to timing and magnitude of force generation beneath the hands and associated body movements., Methods: A total of 13 subjects (seven men, six women) with thoracic SCI. Kinematics of body movement were recorded (Elite 2000 system) simultaneously with the signals from three force plates (AMTI) placed beneath the buttocks and hands. Temporal and spatial parameters regarding head, trunk and trailing arm displacement, loading amplitudes and loading torque directions of both hands were analyzed for each trial and subject and compared between genders., Results: Men and women used similar amplitudes of head bending and forward displacement of the trailing shoulder, while female subjects had significantly larger trunk rotation. Both genders applied significantly more weight on the trailing hand. Differences between genders were seen in direction and timing of peak torque beneath the hands., Conclusions: The forces beneath the trailing hand were larger than those in the leading, if there is weakness or pain in one arm, this arm should be selected as the leading. To avoid excessive load on the arms, technical aids and environmental factors should be very well adapted., Sponsorship: This project was funded by the Swedish Research Council and the Health Care Science Committee of Karolinska Institutet.

An understanding of age-related changes in motor behaviour is important when considering the design of training programs for fall-prevention in the elderly. Gait initiation is a phase of walking during which falls are often provoked and this study compares strategies employed by healthy older and young adults during gait initiation. Twenty-nine older, physically active subjects (65-79 years) and 28 younger individuals (23-40 years) were instructed to cross a staged road, when a traffic light changed from red to green, leading with a freely chosen or predetermined leg. Electromyography of tibialis anterior (TA) and lateral gastrocnemius (LG) muscles, ground reaction forces exerted and step lengths were recorded. The elderly displayed several striking differences compared to the young individuals. Weight bearing during initial standing was considerably more unequal and reaction time was 46% longer, with identical duration of gait initiation. Swing leg peak posterior force (% BW) tended to be smaller, but the increase of vertical force was larger. Eight elderly and one young subject lacked anticipatory TA onset; however TA anticipation increased with trial number in the elderly group. When the starting leg was predetermined, the deficiency in TA anticipation was no longer apparent. In the stance leg all forces were smaller and LG was recruited later, and unlike the young subjects generally after the swing leg had left the ground. The results revealed that ageing leads to significant alterations in weight bearing and ankle muscle activation in relation to gait initiation. Gait initiation changed significantly when the starting leg was predetermined and, in the elderly, with repetition.

Background: Tandem stance is a clinical measure of standing balance considered to assess postural steadiness in a heel-to-toe position by a temporal measurement. To our knowledge, no studies have evaluated the change of postural steadiness, expressed as force variability, over time. The objective of this paper is to investigate postural steadiness during 30 s of tandem stance in healthy elderly and young adults, and to explore the weight distribution between legs during tandem stance., Methods: A cross-sectional analysis comparing ground reaction forces and muscle activity in 26 healthy elderly adults (mean age 70.6 years) and 27 healthy young adults (mean age 30.0 years). Ground reaction forces beneath both feet and muscle activity of ankle muscles were recorded while the subjects performed 30 s of tandem stance during two conditions., Findings: Two phases were identified in both groups: First a dynamic phase, a decrease in force variability during the first 3-4 s after foot placement, and thereafter a static phase, maintaining a certain level of force variability. Age-related changes were seen in the decrease in force variability (P<0.001) and ankle muscle activity (P<0.001). However, both groups placed more weight on the rear leg (P<0.001)., Interpretation: The first few seconds of tandem stance pose the greatest challenge to postural steadiness and influence the static phase. We suggest that the dynamic phase is the most crucial period of time for assessing balance requirements. Independent of age, tandem stance is not a task for equal weight bearing.

Objective: To investigate postural steadiness during 30 s of one-leg stance in healthy young and elderly adults, by analysing the pattern of the ground reaction force variability., Design: A laboratory set-up was used to analyse the variability of the ground reaction forces in relation to time as a measure of postural steadiness., Background: The one-leg stance test is a measure considered to assess postural steadiness in a static position by a temporal measurement. The common notion is that a better postural steadiness, i.e. less force variability, allows for longer time standing on one leg. However, there is lack of evidence how postural steadiness during one-leg stance changes over time., Methods: Twenty-eight healthy elderly and 28 healthy young adults were tested by means of force plates assessing ground reaction forces while performing one-leg stance., Results: During one-leg stance, two phases could be identified in both groups: First a dynamic phase, a rapid decrease of force variability, and thereafter a static phase, maintaining a certain level of force variability. During the first 5 s of one-leg stance the force variability decreased significantly more in the young group resulting in a lower force variability level during the static phase than in the elderly., Conclusions: The difficulties in maintaining the static position in elderly seems dependent on the reduced initial decrease in force variability and/or musculoskeletal components. We suggest that the first 5 s are crucial when assessing balance during one-leg stance.

Objective: To explore how the Functional Reach test correlates with the displacement of the centre of pressure and whether the test is a measure of the stability limits in healthy elderly people. Also to explore the performance parameters during the Functional Reach test., Design: Method comparison study., Subjects: Twenty-seven healthy elderly subjects., Methods: Whole body kinematics (ELITE systems), ground reaction forces (AMTI) and muscle activity (EMG) parallel with clinical yardstick measure while performing the Functional Reach test., Results: This study showed a low correlation (r = 0.38) between reach distance and displacement of centre of pressure and a moderate correlation (r = 0.68) between forward rotation of the trunk and reach distance. The movement during the Functional Reach test was characterized by a large forward rotation of the trunk and a small extension in the ankle. The latter constraining centre of pressure forward displacement., Conclusions: The results suggest that the Functional Reach test is a weak measure of the stability limits. Movement of the trunk seems to influence the test more than the displacement of the centre of pressure. When using the Functional Reach test for assessing balance, compensatory mechanisms should be taken into account.

Objective: To quantify differences in the kinematics of lifting between women with low back and/or pelvic pain after pregnancy and women without., Design: Comparison study., Setting: Research laboratory., Participants: Volunteer sample of 7 women with pain (positive pain drawing, no physical examination) and 9 female controls (not matched)., Interventions: Not applicable., Main Outcome Measures: Duration of downward and upward phases, relative instant of box lift-off, joint angles, spatial angles of trunk and pelvis, pelvic angle relative to trunk, and phase angle relationships between joints., Results: The duration of the upward phase +/- standard deviation was longer in the pain group (1731+/-290 ms vs 1489+/-187 ms, P=.031). At box lift-off, this group had less hip joint flexion (101.9 degrees +/-20.8 degrees vs 78.7 degrees +/-12.4 degrees, P=.015) but more backward pelvis tilt relative to the trunk, that is, more lumbar spine flexion (126.3 degrees +/-16.8 degrees vs 109.0 degrees +/-12.3 degrees, P=.031). The pain group showed an immediate transition from lumbar spine flexion to extension, whereas the controls maintained peak flexion for about 600 ms. The peak phase lag between knee and hip joint extension in the upward phase was larger for the pain group (-29.7 degrees +/-8.3 degrees vs -17.2 degrees +/-5.5 degrees, P=.003)., Conclusion: Women with low back and/or pelvic pain after pregnancy showed different kinematics of lifting. Further research is needed to determine the exact relationship between the altered kinematics and the underlying disorder.

Anticipatory postural adjustments (APAs) were studied in a bimanual whole-body lifting task, using a mechanical analysis of the downward movement phase preceding loaded versus unloaded lifts. APAs in the backward ground reaction force were found to lead the perturbing forward box reaction with approximately 400 ms, thus inducing a backward centre of mass momentum. Both the APA onset and magnitude were scaled as a function of the load to be lifted. We conclude that, in this lifting task, the APAs served the generation of an appropriate extending moment of the ground reaction force after box pick-up, rather than the traditionally defined goal of minimising anterior-posterior centre of mass displacements.

Objective: To investigate the coordination among hand movement, ground forces, and muscle activity in standing stroke patients reaching forward and lifting an object from a table., Design: Survey., Setting: Research laboratory., Patients: Eight stroke patients and 8 persons serving as controls., Main Outcome Measure: Symmetry of percentage of body weight (BW) during initial standing, velocity and hand path trajectory, ankle muscle electromyography. Temporal and spatial parameters in percentage of movement time were recorded by using 2 forceplates, 3-dimensional kinematics, and surface electromyography. Motor function, sensory function, and functional performance were also assessed., Results: Weight distribution during initial standing was significantly higher (57.4% +/- 8.1% BW) on the nonparetic leg. All subjects had preserved the preparatory loading phase, and after onset of hand movement loading shifted to the contralateral leg. Ankle muscle activity onset (lateral gastrocnemius [LG]) occurred after loading. In stroke subjects, LG was consistently activated first in the nonparetic leg, regardless of which arm performed the task. During paretic hand task, the reaching phase was significantly longer and the lifting phase significantly shorter compared with that of the nonparetic hand task and with that of the controls. In the paretic task, the hand path velocity was not bell-shaped; the object lifting was., Conclusions: Stroke subjects preserve the coordination between ground forces and hand movement. The lack of spontaneous use of the paretic hand is primarily caused by difficulties of planning the hand trajectory in space, as reflected by temporal and spatial parameters during task performance.

The purpose of this study was to test the hypothesis whether weight transfer during sit-to-stand (STS) is the result of coordinated ground forces exerted by buttocks and feet before seat-off. Whole-body kinematics and three-dimensional ground forces from left and right buttock as well as from left and right foot were recorded for seven adults during STS. We defined a preparatory phase from onset of the first detectable anterior/posterior (A/P) force to seat-off (buttock forces fell to 0) and a rising phase from seat-off to the decrease of center of mass (CoM) vertical velocity to zero. STS was induced by an increase of vertical and backward directed ground forces exerted by the buttocks that significantly preceded the onset of any trunk movement. All ground forces peaked before or around the moment of seat-off, whereas all kinematic variables, except trunk forward rotation and hip flexion, peaked after seat-off, during or after the rising phase. The present study suggests that the weight transfer from sit to stand is induced by ground forces exerted by buttocks and feet before seat-off, i.e., during the preparatory phase. The buttocks generate the isometric "rising forces," e.g., the propulsive impulse for the forward acceleration of the body, while the feet apply adequate damping control before seat-off. This indicates that the rising movement is a result of these coordinated forces, targeted to match the subject's weight and support base distance between buttocks and feet. The single peaked, bell-shaped profiles peaking before seat-off, were seen beneath buttocks for the "rising drive," i.e., between the time of peak backward directed force and seat-off, as well as beneath the feet for the "damping drive," i.e., from onset to the peak of forward-directed force and for CoM A/P velocity. This suggests that both beginning and end of the weight transfer process are programmed before seat-off. The peak deceleration of A/P CoM took place shortly ( approximately 100 ms) after CoM peak velocity, resulting in a well controlled CoM deceleration before seat-off. In contrast to the view of other authors, this suggests that body equilibrium is controlled during weight transfer.

Background and Purpose: In this study, the rotation of the pelvis was taken into account when assessing the length of hamstrings. A new measure for clinical evaluation was developed to establish reference values of hamstring length in children without movement disabilities for different age groups. Subjects (N = 60) were 3-, 6-, 10- and 14-year-old children (N = 15 for each age group). These values could be helpful in deciding treatment interventions in children with movement disabilities, for example cerebral palsy, when hamstring length is in question., Method: The study was performed with subjects sitting and reaching for a touch control on a wall whilst voluntarily rotating the pelvis forwards. By use of digitized video frames, the spatial angles of the lumbar spine and pelvis, as well as the joint angles of hip and knee, were computed at the initial and end positions of a forward leaning reaching task in sitting (FLRS). The active forward leaning induced a forward rotation of the pelvis, causing stretch on the hamstring muscle with extended knee., Results: The results of spatial and joint angle measurements suggest that the difference of the hip joint angle between initial erect and final forward leaned sitting may be used as reference values for hamstring length. Reference values are based on the mean (+/- SE) of means (mean of 15 children, that is, group and individual means of ten trials)., Conclusions: The age group reference values obtained may indirectly give information as to whether the hamstring length of a child with cerebral palsy is within the normative value of age-related control subjects. The new test developed in this study provides a convenient means for measuring hamstring length and could enhance clinical evaluation.

This study investigated whether sudden rotation of the support surface (platform) triggers motor responses similar to reactions to sudden free fall in infants at very early age (2 to 5 weeks). Ten infants in prone position were exposed to sudden head-down rotation (mimicking the falling phase) and head-up rotation of the platform (mimicking landing phase) of 4 degrees or 6 degrees amplitude and 35 degrees/s velocity while EMGs and kinematics were recorded from the neck, trunk, and right arm. One infant, reassessed at 13 weeks, and one adult were tested for complementary developmental information. Sudden downward acceleration of the platform, induced either during head-down rotation or during the deceleration phase of head-up rotation, indeed mimicked falling and evoked in infants two-peaked EMG responses in the neck, trunk, and arm muscles, lasting in the latter over several hundred milliseconds. The activation pattern showed similarities to the adult and 13-week-old control subjects. The results suggested that the first burst may be ascribed to cutaneous pressure changes at the body and to vestibular signals triggering a startle-like response, whereas the second burst of the pattern in the arm is likely a candidate for an early substrate of the landing response normally seen during later stages of motor development. Head control appeared to be related more to its position with respect to the orientation of the trunk rather than to space in the infants and in the adult and might be due to the experimental paradigm, in which the surface accelerated away from the body and not, as during normal falling, when the body accelerates toward the support surface.

Surface electromyography (EMG) was used to examine lower-extremity myotatic reflex responses following patellar or Achilles tendon taps to normally developing, non-disabled infants and to individuals with cerebral palsy (CP). Reflex irradiation was present in non-disabled infants and infants with CP under two years of age. The only significant differences in myotatic reflex responses between the two groups at this age was the higher amplitude of the directly stimulated muscle of children with CP. After two years the amplitude did not differ between groups. Reflex irradiation, however, was greatly reduced in the non-disabled children but not in the children with cerebral palsy. These findings and those of non-human animal studies indicate the possible neural mechanisms that underlie reflex irradiation of individuals with CP. The potential clinical relevance of these findings is discussed.

F1 progeny of New Zealand Black (NZB) and New Zealand White (NZW) mice spontaneously develop an autoimmune process remarkably similar to human systemic lupus erythematosus. Previous studies have implicated major genetic contributions from the NZW MHC and from a dominant NZB gene on chromosome 4. To identify additional NZB contributions to lupus-like disease, (NZB x SM/J)F1 x NZW backcross mice were followed for the development of severe renal disease and were comprehensively genotyped. Despite a 50% incidence of disease, significant associations between the presence of the NZB genotype and disease were noted on chromosomes 1, 4, 7, 10, 13, and 19. The data indicated that multiple NZB genes, in different combinations, contribute to severe renal disease, and that no single gene is required. To further investigate this NZB contribution, NZB x SM/J (NXSM) recombinant inbred (RI) strains were crossed with NZW mice, and F1 progeny were analyzed for the presence of lupus-like renal disease. Interestingly, nearly all of the (RI x NZW)F1 cohorts studied expressed some level of disease. Five RI strains generated a high incidence of disease, similar to (NZB x NZW)F1 mice, and nearly one-half of the cohorts developed disease at intermediate levels. Only two cohorts demonstrated very little disease, supporting the conclusion that multiple genes are capable of disease induction. Experiments correlating the genotypes of these RI strains with their ability to generate disease revealed that none of the disease-associated loci defined by the backcross analysis were present in all five RI strains that generated disease at high levels. Overall, both the backcross data and RI analysis provide additional support for the genetic complexity of lupus nephritis and uphold the conclusion that heterogeneous combinations of contributing NZB genes seem to operate in a threshold manner to generate the disease phenotype.

There are several controversies concerning the organization and induction of postural adjustments in standing humans. Some investigators suggest the responses are triggered by somatosensory inputs (especially from the ankle in standing subjects), while others emphasize the vestibular input induced by head acceleration. We examined postural responses in sitting subjects in order to describe the muscle activation pattern during various perturbations and to test whether somatosensory or vestibular stimulation elicited the responses. The kinematics and EMG patterns in response to perturbations caused by movements of the support surface were studied in adults. The postural muscle activation following a backward sway was mainly the same, whether it was elicited by a forward translation or a legs-up rotation. This is remarkable, since, except for pelvis rotation, the movements of all body segments including the head differed in the two conditions. Furthermore, a second experiment showed that the direction of the initial head movement could be reversed with retainment of the same postural muscle activation pattern. The results suggest that somatosensory signals derived from the backward rotation of the pelvis, and not vestibular information from the head, trigger postural responses during sitting. There was a slight but consistent difference in the muscle activation pattern, whether the backward sway was elicited by a forward translation or legs-up rotation. The difference seemed to reflect the sensory information from head and other body parts (except the pelvis). This finding allowed us to speculate in a central pattern generator for postural adjustments containing two levels. At the first level, a simple format of the muscle activation would be generated; at the second level, the centrally generated pattern could be shaped and timed by interaction from the entire somatosensory, vestibular, and visual input.

This study examined whether postural responses emerge in children in a predetermined way before independent sitting is achieved, and in what respect postural responses in infants differ from those in adults. Children just able to sit independently and children not yet able to sit were exposed to surface perturbations (translation and rotation) while body movement and electromyographic (EMG) responses were recorded. Perturbations causing a backward sway of the body (i.e., forward translation and legs-up rotation), elicited consistent patterns of muscle activity in ventral hip, trunk, and neck muscles in the independently sitting children. A high tonic EMG background activity in trunk and neck extensor muscles was inhibited at the onset of the ventral muscle activity. Kinematic analysis revealed that backward rotation of the pelvis was the first detectable body movement, while head movements (linear and angular displacement) were irregular and occurred later than the pelvis movement. Perturbations in the opposite direction, causing a forward sway, evoked variable responses in dorsal trunk and neck muscles, suggesting that the excitability level for postural responses was set according to the stability limits of the body. Children not yet able to sit without support were tested when the support around the waist, given by the experimenter's hands, was released prior to the onset of the platform perturbation. Postural responses were elicited in ventral muscles following a backward sway in all children and in about 60% of all trials. Often, only some of the ventral muscles were activated. No distinct responses were evoked during perturbations imposing a forward sway. These results suggest that (1) backward rotation of the pelvis triggers the postural adjustments in the independently sitting children; (2) a basic form of the postural adjustment develops in a predetermined manner before children practice independent sitting; and (3) the basic structure of ventral muscle activation pattern resembles that of adults, while the activation of the dorsal muscles (inhibition) differs in several aspects. These findings are in agreement with a recent model of central pattern generators for postural responses consisting of two operative levels. At the first level, which is triggered by backward rotation of the pelvis, the basic activation pattern is generated. At the second level, the pattern is shaped and fine-tuned by multisensory interactions from all activated sensory systems.(ABSTRACT TRUNCATED AT 400 WORDS)

1. Anticipatory postural adjustments were studied in children (6-14 yr of age) walking on a treadmill while pulling a handle. Electromyographs (EMGs) and movements were recorded from the left arm and leg. 2. Postural activity in the leg muscles preceded voluntary arm muscle activity in all age groups, including the youngest children (6 yr of age). The latency to both leg and arm muscle activity, from a triggering audio signal, decreased with age. 3. In older children the latency to both voluntary and postural activity was influenced by the phase of the step cycle. The shortest latency to the first activated postural muscle occurred during single support phase in combination with a long latency to arm muscle activity. 4. In the youngest children, there was no phase-dependent modulation of the latency to the activation of the postural muscles. The voluntary activity was delayed during the beginning of the support phase resulting in a long delay between leg and arm muscle activity. 5. The postural muscle activation pattern was modified in a phase-dependent manner in all children. Lateral gastrocnemius (LG) and hamstring muscles (HAM) were activated during the early support phase, whereas tibialis anterior (TA) and quadriceps (Q) muscles were activated during the late support phase and during the swing phase. However, in the 6-yr-old children, LG was also activated in the swing phase. LG was activated before the HAM activity in the youngest children but after HAM in 14-yr-old children and adults. 6. The occurrence of LG activity in postural responses before heel strike suggests an immature (nonplantigrade) gating of postural activity.(ABSTRACT TRUNCATED AT 250 WORDS)

1. The ability of the CNS to coordinate several motor tasks was studied in humans walking on a treadmill while pulling on a handle. Subjects were instructed to respond to an audio signal that was presented in different phases of the step cycle. Electromyograph (EMG) and movements were recorded from the left arm and leg. 2. The activity of the arm muscle was preceded by postural activity in the leg muscles. The pattern of the anticipatory postural activity differed in the various phases of the step cycle. Lateral gastrocnemius and hamstring muscles were activated during responses occurring in the early support phase whereas tibialis anterior and quadriceps muscles were activated when the pull was exerted during the late support phase and during the swing phase. In the middle of the support phase the combination of both muscle activity was present. 3. The temporal sequencing and the spatial distribution of the anticipatory muscle activity changed gradually. Early during the support phase the hamstring muscles were activated before the gastrocnemius muscle, whereas the order was reversed during midstance. The EMG amplitude of the hamstring and gastrocnemius muscles was largest in the beginning of the support phase and then gradually decreased, whereas the amplitude of the tibialis anterior and quadriceps muscles increased during the later parts of the support phase. 4. The anticipatory responses to pulls exerted during the first part of the support phase reduced the ankle flexion during the single support phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Electromyographic and kinematic data were collected during treadmill locomotion by normal infants and infants with cerebral palsy. Locomotor patterns of the infants with cerebral palsy were similar to those of normal infants during the stage of supported locomotion, but as they matured, some of the characteristics of the infant stepping pattern, such as synchronous muscle activity with excessive muscular co-contraction and short-latency reflexes at foot contact, were retained. The normal plantigrade features of adult gait did not develop in these children.

Neonatal neuronal exuberance and its retention following neonatal brain damage have been demonstrated in a number of species but not in humans. The purpose of the present ongoing study is to determine if there is any evidence of neonatal neuronal exuberance and its retention following damage to the CNS in the human. Of equal concern is the determination of the neurological mechanisms underlying abnormal movement and reflex development in children with cerebral palsy.

Experiments were performed to determine whether spinal and supraspinal components of reciprocal inhibition (a neural mechanism responsible for the prevention of muscular co-ordination during voluntary movement) were present in groups of non-disabled children and children with cerebral palsy. Changes in the gastrocnemius-soleus H reflex were examined during voluntary dorsiflexion and plantarflexion of the ankle and during a vibration applied to the anterior tibial tendon. The results indicate that children with cerebral palsy have impairments in reciprocal inhibition, both before and during voluntary movement. These deficits, which involve damage to supraspinal centres, contribute to their inability to perform smooth, co-ordinated movements.