Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

While the incidence of injury in cross-country skiing remains relatively low, overuse problems affecting the lumbosacral region may be on the rise, particularly among elite athletes. In this study, a certified "Part A" (Canadian Physiotherapy Association) manual therapist performed lumbosacral physical assessments on 18 elite cross-country skiers and 15 normal subjects. Results indicated sacroiliac (SI) joint dysfunction occurred significantly more often in the skier population (p < 0.007). Incidences of SI joint asymmetry and lumbar spine dysfunction did not differ between groups. The predominant use of asymmetrical ski-skating techniques may play an influential role in the pathogenesis of SI joint dysfunction in elite cross-country skiers.
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PMID:Lumbosacral dysfunctions in elite cross-country skiers. 826 59

Rider peaks are small peaks which are not well resolved from a large and asymmetrical neighbour but sit on its trailing side. The usual case is a large, tailed peak which is eluted just in front of the small peak, although the opposite situation can also occur (a small peak in front of a large peak with fronting). The common integration techniques. i.e. separating the peaks by vertical drop or by a tangent and determining area or height, give erroneous results. We propose a method for their quantification with low error. It is necessary to set up a "two-dimensional" calibration by varying both concentrations, i.e. of the large peak and of the rider. This leads to a series of linear equations which describe the rider size, as found by the integrator, as a function of the size of the large peak. The y-axis intercepts i of these equations show a linear relationship with the concentration x of the rider analyte, whereas the slopes s follow a quadratic relationship. These equations can be used to solve the equation y = s(x) x z + i(x) for x (y and z are the integrated peak size of the rider and the large peak, respectively). The procedure was tested with computer-generated peak pairs as well as with HPLC separations of 2,3-dimethylaniline (large tailing peak) and 2,3-dimethylphenol (symmetrical rider peak).
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PMID:Procedure for the quantification of rider peaks. 1159 98

The aims of this study were to compare the aerobic energy cost of four 'on-snow' skating techniques in cross-country skiing and to examine the relationships between performance and aerobic energy cost. Twelve male skiers from recreational to national standard performed four level skating trials of 6 min duration in random order, each at the same submaximal velocity but with a different skating technique: (1) 'offset' (V1), using a double asymmetrical and asynchronous pole plant as weight is transferred to one ski; (2) 'two-skate' (V2A), where the pole plant is symmetrical; (3) 'one-skate' (V2), where there is a pole plant as weight is transferred to each ski; and (4) 'conventional', without poles. Oxygen uptake (VO2), pulmonary ventilation, the respiratory exchange ratio and heart rate were measured using a K4(b2) portable gas analyser. The aerobic energy cost (VO2/mean speed) and heart rate were higher (P < 0.05) in the one-skate than in the offset condition. This may be explained by the greater and more efficient use of the upper body and the lower variation in centre of gravity velocity in the offset condition. The aerobic energy cost was 5-9% higher (P < 0.01) in the conventional than in the other techniques, probably because of the shorter duration of propulsive forces within a cycle in the conventional skating condition. Moreover, in ski skating, the mechanical efficiency (propulsive forces/total forces) was shown to be higher in the upper than in the lower limbs. The correlation coefficient between performance and aerobic energy cost was significant in the two-skate (r = 0.68, P = 0.02), one-skate (r = 0.72, P = 0.01) and conventional (r = 0.62, P = 0.04) conditions, but not in the offset condition (r = 0.50, P = 0.10). Our results stress the importance of the upper body component in cross-country skiing and that the aerobic energy cost discriminates between skiers of different standards.
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PMID:Energy cost of different skating techniques in cross-country skiing. 1258 86

The relation between progress in the control of posture (i.e., the achievement of self-sitting posture) and the developmental transition from two-handed to one-handed engagement in infant reaching was investigated. Two groups of 5- to 8-month-old infants, who were either able or yet unable to sit on their own, were videotaped while they reached for objects in four different posture conditions that provided varying amounts of body support. Videotapes of infant reaches were microanalyzed to determine the relative engagement of both hands during reaches. Results demonstrate the interaction between postural development and the morphology of infant reaching. Nonsitting infants displayed symmetrical and synergistic engagement of both arms and hands while reaching in all but the seated posture condition. Sitting infants, by contrast, showed asymmetrical and lateralized (one-handed) reaches in all posture conditions. Results also show that, aside from posture, the perceived spatial arrangement of the object display is a determinant of infant reaching. Combined, these results are discussed as evidence for the interaction between postural and perceptual development in the control of early eye-hand coordination.
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PMID:Self-sitting and reaching in 5- to 8-month-old infants: the impact of posture and its development on early eye-hand coordination. 1497 20

Previous research revealed that shifting patterns of hand preference in the first year of life are linked to infants' sensory-motor experiences as they learn to sit, creep, and walk. In this report, we examine whether new and different forms of locomotion and sensory-motor experiences similarly contribute to alter patterns of hand preference in early development. We examined the cases of three infants with unique developmental histories. Two infants adopted distinctive forms of locomotion in lieu of typical hands-and-knees crawling. One infant scooted using both hands and legs in a coupled fashion, while the other infant performed an asymmetrical, left-biased belly-crawl using only one arm to drag his body. The third infant suffered damage to his left-brain hemisphere shortly after birth and received intense physical therapy to his right arm as a result of it. We followed all three infants on a weekly basis and tracked changes in their reaching behavior, mode of locomotion, and postural achievements. The two infants with unique locomotor patterns displayed changes in hand preference that reciprocated the arm patterns that they used during locomotion. The infant who coupled his body for scooting began to reach bimanually, while the infant who adopted the left-biased belly-crawl developed a strong unimanual, right-hand, preference. The infant with left-hemisphere damage initially displayed a right-hand preference, then a temporary decline in preferred hand use as he began to cruise and walk, and ultimately resumed a right-hand preference in the 2nd year of life. This data is consistent with previous work showing that the development of hand preference in the 1st year of life is highly malleable and sensitive to a variety of new sensory-motor experiences.
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PMID:Plasticity in the development of handedness: evidence from normal development and early asymmetric brain injury. 1688 84

We report a patient who presented with sudden onset instability and diplopia. On neurological examination he had asymmetrical asterixis, predominantly in the left hand, and ocular findings consistent with a pretectal syndrome. He was also unable to stand or even sit up unassisted, with a tendency to tilt his body and rotate his trunk axis to the left. Brain MRI showed a hemorrhage in the right thalamo-mesencephalic junction. This region involves important structures for the control of postural stability, motor control, ocular movements and vestibulo-ocular integration, not yet well understood. To our knowledge, this is the first reported case with the simultaneous combination of astasia, prectectal syndrome and asymmetrical asterixis.
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PMID:Astasia, asymmetrical asterixis and pretectal syndrome in thalamo-mesencephalic hemorrhage. 1963 31

A bucket-type transpelvic socket was fabricated for a man with paraplegia from spinal cord injury, who underwent right partial pelvic amputation and left hip disarticulation. His main problem was inability to sit due to asymmetrical pelvic shape. We prescribed a transpelvic prosthetic socket to enable him to sit again. The socket consisted of a dual structure: a hard frame and soft liner. The main features of the socket were redistribution of pressure to prevent recurrence of pressure ulcer, and a slightly backward tilt to maintain a comfortable sitting position. In addition, the socket had small air holes for ventilation; a big window in the abdominal area for management of stoma and cystostomy; and two straps for donning it independently. In addition, we confirmed the internal pressure distribution in the socket by a pressure mapping system to prevent reoccurrence of skin trouble. Finally, the patient regained independence in activities of daily living, including driving a car, after two months of rehabilitative training.
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PMID:Stabilizing transpelvic prosthetic socket for a patient with spinal cord injury sustaining right partial hemipelvectomy and left hip disarticulation. 2276 24

The asymmetrical weight-bearing distribution of individuals with hemiparesis rising from a chair might be used to produce similar muscular efforts at the lower limbs. The aim of this study was to determine if individuals with hemiparesis have symmetrical levels of effort at the knee during spontaneous sit-to-stand transfers. Nineteen subjects with hemiparesis and 16 healthy controls participated. Their weight-bearing (WB) distribution during sit-to-stand was assessed with a force platform setup while the knee effort distribution was quantified using electromyographic (EMG) data normalized to maximal EMG values then expressed relative to the sum of the bilateral efforts. The healthy individuals presented symmetrical weight-bearing and knee effort distributions during the sit-to-stand transfer. The participants with hemiparesis, classified in three subgroups based on knee extensors' strength asymmetries (mild, moderate and severe), yielded different results. The mild group (n = 6) behaved like the controls, with almost symmetrical WB and knee efforts. The moderate group (n = 7) had similar WB and effort asymmetries while the severe group (n = 6) exhibited a WB distribution difference between sides but had almost symmetrical knee effort. These results for the severe group suggest that a control is exerted on the levels of effort when rising from a chair, which might be required when a certain threshold of effort is reached on the nonparetic side.
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PMID:Knee efforts and weight-bearing asymmetry during sit-to-stand tasks in individuals with hemiparesis and healthy controls. 2318 67

This paper presents a general method to estimate unmeasured external contact loads (ECLs) acting on a system whose kinematics and inertial properties are known. This method is dedicated to underdetermined problems, e.g. when the system has two or more unmeasured external contact wrenches. It is based on inverse dynamics and a quadratic optimization, and is therefore relatively simple, computationally cost effective and robust. Net joint loads (NJLs) are included as variables of the problem, and thus could be estimated in the same procedure as the ECL and be used within the cost function. The proposed method is tested on human sit-to-stand maneuvers performed holding a handle with one hand, i.e. asymmetrical movements with multiples external contacts. Three sets of measured and unmeasured contact load components and three cost functions are considered and simulated results are compared to experimental data. For the population and movement studied, better results are obtained for a least-square sharing between actuated degrees-of-freedom of the relative motor torques (motor torques normalized by the maximal torque production capacity). Moreover, the number of unknown ECL components does not significantly influence the results. In particular, measuring only the vertical force under the seat lead to a relatively correct estimation of the ECL and NJT: not only the values of R% were small (about 10% for the feet ECL and 20% for the NJT), but the influence of an experimental parameters (the Seat Height) was also correctly predicted.
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PMID:Estimation of external contact loads using an inverse dynamics and optimization approach: general method and application to sit-to-stand maneuvers. 2389 11

Sit-to-stand transfer is a common prerequisite for many daily tasks. Literature often assumes symmetric behavior across the left and right side. Although this assumption of bilateral symmetry is prominent, few studies have validated this supposition. This pilot study uniquely quantifies peak joint moments and ground reaction forces (GRFs), using a Euclidian norm approach, to evaluate bilateral symmetry and its relation to lower limb motor-dominance during sit to stand in ten healthy males. Peak joint moments and GRFs were determined using a motion capture system and inverse dynamics. This analysis included joint moment contributions from all three body planes (sagittal, coronal, and axial) as well as vertical and shearing GRFs. A paired, one-tailed t test was used, suggesting asymmetrical joint moment development in all three lower extremity joints as well as GRFs (P < .05). Furthermore, using an unpaired two-tailed t test, asymmetry developed during these movements does not appear to be predictable by participants' lower limb motor-dominance (P < .025). Consequently, when evaluating sit-to-stand it is suggested the effects of asymmetry be considered in the interpretation of data. The absence of a relationship between dominance and asymmetry prevents the suggestion that one side can be tested to infer behavior of the contralateral.
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PMID:Leg dominance may not be a predictor of asymmetry in peak joint moments and ground reaction forces during sit-to-stand movements. 2467 26


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