Lateral Dominance Research Articles

小児における手・足・目の利き側に関する研究

小児における手・足・目の利き側に関する研究

A new parameter for characterizing balancing ability on an unstable oscillatory platform

An oscillatory platform can be used as a simple measuring instrument for modelling balancing capacity. We sought (1) to determine the test–retest reliability of the Lehr's damping ratio for characterizing the balancing ability on an unstable oscillatory platform of 20 healthy young and 20 healthy elderly participants and (2) to compare balancing ability on an unstable oscillatory platform between groups. Tests were performed during standing on both limbs and on one limb (dominant or non-dominant). The average of differences of the Lehr's damping ratio was 0.004 ± 0.003 (3.77% ± 3.89%), and tests conducted at different times showed strong correlations (range 0.978–0.998). The average value of the Lehr's damping ratio was significantly smaller for elderly compared to young participants and it was significantly smaller for participants standing on their non-dominant limb compared to when they stood on both limbs or on the dominant limb. Based on this reproducible measuring method, Lehr's damping ratio depends on lateral dominance, and age.

Running Impulse, Functional Strength and Dynamic Balance Asymmetry in Healthy Recreational Runners

Researchers have assumed that normal healthy running is a symmetrical process and gait asymmetry is associated with a pathological condition or injury. However, bilateral asymmetry has been found in healthy individuals during walking and running. The causes of asymmetries remain unclear, but could be the result of lateral dominance. A functional asymmetry hypothesis has been proposed in which the dominant limb (D) provides more propulsion and the non-dominant limb (ND) provides more support during walking. If asymmetry is natural and the lower extremities are responsible for different tasks, then there may be functional strength and dynamic balance asymmetries that could reflect the task demands of each leg. PURPOSE: To test the functional asymmetry hypothesis and asymmetry in functional strength and dynamic balance in healthy, recreational runners. METHODS: Participants (male 14, female 14) were healthy runners (mean ± sd, age 27.39 ± 6.39 years; mass 67.48 ± 9.15 kg; weekly training 37.35 ± 24.51 km; running history 8.88 ± 6.99 years). Vertical impulse (VI) and propulsive impulse (PI) were used to represent the supportive and propulsive function of the lower extremities. Participants ran across a force plate at 3.5 ± 5% m/s, in which VI and PI were measured in the D and ND limb. The Star Excursion Balance Test (SEBT) and Triple hop distance test (THD) were used to test dynamic balance and functional strength, respectively. A two-tailed, paired samples t-test with Bonferonni adjustment was calculated to compare the mean scores between the D and ND limbs in each of the measures. An Absolute Asymmetry Index (ASI) was calculated to determine differences in the test measures, regardless of direction. RESULTS: No significant differences were found between the mean scores of the D and ND limbs in any of the tests. ASI revealed that the participants in this study exhibited some level of asymmetry in all of the measures tested (mean ± sd, SEBT 3.80 ± 3.30%, THD 4.76 ± 4.46%, VI 4.61 ± 4.77%, PI 16.73 ± 15.13%). CONCLUSIONS: Pooling data can hide asymmetries that exist in healthy individuals. Levels of asymmetry can vary greatly between and within individuals in different tests. Lateral dominance may not be a predictor of asymmetries in healthy individuals. However, asymmetries could be the result of individual compensations or individual differences in lateral dominace in varying tasks. Perfect symmetry should not be expected in healthy individuals, and asymmetry does not necessarily implicate a pathological condition. The high ASI of the propulsive impulse in the participants indicates that a functional asymmetry might exist, but is unique for each individual. PRACTICAL APPLICATIONS: Coaches and trainers can address the specific demands of the individual limbs and/or decrease asymmetries, if desired, by having their athletes perform unilateral training, such as single leg squats, single leg dead lifts, multidirectional lunges and low level single leg plyometric exercises. Consequently, the individual kinetics and kinematics of the limbs will more closely replicate that which is performed while running. Researchers should analyze individual participant data and utilize an asymmetry index when making left/right or dominant/non-dominant comparisons.

Survey of Relationship between creativity and Lateral dominance in guidance school students

Survey of Relationship between creativity and Lateral dominance in guidance school students

Specific Factors That Influence Deciding the Takeoff Leg during Jumping Movements

The definition of the dominant leg (lateral dominance) is not clear, and there has been little reporting related to lateral dominance in the legs. To uncover the practical factors influencing which leg to use as the takeoff leg in 1-legged jumping movements, this study aimed to investigate the subjective dominance side of fundamental movements and to examine the lateral dominance of motor functions between the takeoff leg and non-takeoff leg. The subjects consisted of 27 young men who exercised regularly. They had not trained particularly on unilateral jumping. Fifteen men are the athlete group (left-legged jumpers group [LG]) using a left leg and 12 men are the athlete group (right-legged jumpers group [RG]) using a right leg as determined by a preliminary survey related to takeoff leg during high jump. The fundamental motions of the subjective dominant leg were investigated and the differences between the motor functions of takeoff and lead legs, such as sole shapes, single-leg vertical jump, 20-m hopping, ladder hopping, single-leg balance, and isokinetic strength were examined. It was found that many RG subjects (83%) tended to select the right leg for hopping, and many LG subjects (87%) tended to select the left leg for 1-legged balance. It was suggested that skilled movements show right-leg dominance in both takeoff leg groups. In the LG subjects, the left leg showed a higher value than the right leg in sole shape. The RG subjects showed a higher value in the right leg than in the left leg in a single-leg vertical jump. However, marked dominance was not found in the takeoff leg. The lower limbs may not show marked lateral dominance such as in the upper limbs.

Prevalencia de escoliosis, dominancia manual lateral y transporte de material en una población masculina de 6–12 años

This research study evaluated the relationship between scoliosis and a set of variables related to age, motor skills (left-handed or right-handed) and the method of transporting school supplies (backpack or trolley) among a school-aged male population. The final selection of the sample - comprising 682 participants between 6 and 12 years old and residents in Granada (Spain) - was conducted by sampling in response to a natural composition of the groups. Several measurement instruments (such as Edinburgh Handedness Inventory, Adam's test and a questionnaire) were applied in order to collect the selected variables. The results indicated that 9.4% (n = 64) of the boys suffered from scoliosis, 10% (n= 73) were left-handed and 58.2% used a backpack for the transportation of school supplies. No statistically significant difference was found between the deviation of the spine and lateral dominance nor between the transportation of school supplies and deviation of the spine; however the results showed a connection between age and incidence of scoliosis (p= 0.03) as well as between age and the method of transporting school supplies (p= 0.00), mainly due to sociocultural habits. In conclusion, there is no connection between suffering scoliosis and left-handedness, nor between the method of transporting school supplies and the incidence of scoliosis. However, these results could vary at older ages and, therefore, programs aimed at teaching good ergonomic guidelines and preventing the pathology of the spine in schoolchildren and adults are highly encouraged in order to improve their quality of life.

Profiles of Trunk and Thigh Muscularity in Youth and Professional Soccer Players

The present study aimed to examine the influence of lateral dominance for ball kicking on the cross-sectional areas (CSAs) of thigh and trunk muscles in Japanese elite youth and professional soccer players, and to clarify the difference between the 2 groups in the muscle CSAs of the 2 body segments in relation to that in lean body mass (LBM). The CSAs of 4 (rectus abdominis, oblique, psoas major, and erector spinae) and 3 (quadriceps femoris, hamstrings, and adductors) muscle groups located in the trunk and thigh, respectively, were determined in 18 youth players (16.8+/-0.6 years) and 17 professional players (23.7+/-3.1 years) using magnetic resonance imaging. In youth and professional players, no significant effect of lateral dominance was found in the CSA of any muscle group. In all muscle groups except for the erector spinae, the CSAs were significantly greater in the professional players than in the youth players. The CSA of every muscle group was significantly correlated to the two-thirds power of LBM (LBM). In terms of the ratio of CSA to LBM, only the psoas major was significantly greater in the professionals. In conclusion, Japanese youth and professional soccer players did not exhibit bilateral asymmetry in the CSAs of thigh and trunk muscles, and the professional players had more developed psoas major muscle as compared with youth players even when matched for whole-body lean tissue mass. The current results suggest that for soccer players with bilateral asymmetry in the muscularity of the thighs and trunk, personalized strength programs for developing symmetry are recommended, and exercises involving hip flexion should be incorporated progressively into individual strength and conditioning programs.

Studies on the Lateral Dominance (Part 4) The Age Difference in the Lateral Dominance as related to the Home Economics Class Work

Studies on the Lateral Dominance (Part 4) The Age Difference in the Lateral Dominance as related to the Home Economics Class Work

Studies on the Lateral Dominance (Part 3)

Studies on the Lateral Dominance (Part 3)

Studies on the Lateral Dominance (Part 2)

Studies on the Lateral Dominance (Part 2)

Lateralidade manual, ocular e dos membros inferiores e sua relação com déficit de organização espacial em escolares

Este estudo teve por objetivos: 1) verificar se existe associação entre lateralidade manual, ocular e dos membros inferiores e déficit de organização espacial em escolares; 2) categorizar as variações de lateralidade nesta população. A amostra foi constituída de 400 crianças na faixa etária de 6 a 10 anos de escolas públicas e privadas da cidade de João Pessoa (PB). A lateralidade e a organização espacial foram avaliadas, respectivamente, por meio do Harris Test of Lateral Dominance e da Bateria de Piaget-Head. Os resultados evidenciaram 23 tipos de lateralidade mão-olho-pé, observando-se maior percentual (48,75%) de destralidade completa (dominância manual, ocular e dos membros inferiores direita). Houve associação significativa (p<0,05) entre sinistralidade completa e déficit de organização espacial. Os resultados atentam para a importância de se inserirem no cotidiano escolar programas de estimulação motora voltados à lateralidade e à organização espacial das crianças, como forma de prevenir distorções no seu processo de aprendizagem.

Does the demand for asymmetric functional lower body postures in lateral sports relate to structural asymmetry of the pelvis?

Pelvic asymmetry has been thought to alter body mechanics and result in increased strain on bony and soft tissues possibly producing asymmetrical skeletal adaptations. The purpose of the present study was to determine if there is a greater prevalence of pelvic skeletal asymmetry in athletes who participate in a sport that requires a lateral dominance combined with increased spinal flexion and rotation. This is a descriptive laboratory study using a cross-sectional design. Sixty healthy female university age elite athletes and non-athletes participated in the study. The height and width of the anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) were measured using an electromagnetic tracking device with stylus. Using these measures a pelvic asymmetry ratio (PAR) was calculated for each athlete based on the difference in slope between the two ASIS and between the two PSIS. PAR was first assessed as a continuous variable to determine any differences in range of asymmetry between groups. All athletes were then assessed for prevalence of asymmetry as defined by a PAR score greater than 0.05. The results showed that there was a significant group effect in the magnitude and prevalence of asymmetry, with the lateral dominant group having significantly more of both. This study demonstrates that potentially there is an association between the asymmetrical nature of lateral dominant sports and pelvic skeletal asymmetry. However, there are possibly two confounding variables in age of initial participation and presence of low back pain that require further exploration.

WUS and STM homologs are linked to the expression of lateral dominance in the acaulescent Streptocarpus rexii (Gesneriaceae)

Acaulescent species of Streptocarpus Lindl. show unusual patterns of growth, characterized by anisocotyly (i.e. the unequal growth of cotyledons after germination) and lack of a conventional embryonic shoot apical meristem (SAM). A SAM-like structure appears during post-embryonic development on the axis of the continuously growing cotyledon. Since we have shown previously that KNOX genes are involved in this unusual morphology of Streptocarpus rexii, here we investigated the expression pattern of WUSCHEL (WUS), which is also required for the indeterminacy of the SAM, but is expressed independently from KNOX in Arabidopsis thaliana. In A. thaliana WUSCHEL is involved in the maintenance of the stem cell fate in the organizing centre. The expression pattern of the WUS ortholog in S. rexii (SrWUS) strongly deviates from that of the model plant, suggesting a fundamentally different spatial and temporal regulation of signalling involved in meristem initiation and maintenance. In S. rexii, exogenous application of growth regulators, i.e. gibberellin (GA(3)), cytokinin (CK) and a gibberellin biosynthesis inhibitor (PAC), prevents anisocotyly and relocates meristematic cells to a position of conventional SAMs; this coincides with a re-localization of the two main pathways controlling meristem formation, the SrWUS and the KNOX pathways. Our results suggest that the establishment of a hormone imbalance in the seedlings is the basis of anisocotyly, causing a lateral dominance of the macrocotyledon over the microcotyledon. The peculiar morphogenetic program in S. rexii is linked to this delicate hormone balance and is the result of crosstalk between endogenous hormones and regulatory genes.

Does the demand for asymmetric functional lower body postures in laterality dominant sports relate to structural asymmetry of the pelvis?

Introduction: Pelvic asymmetry has been thought to alter body mechanics and put undue strain on some segments of the body contributing to musculoskeletal pain. For athletes, sport participation may already place an increased strain on the body and laterality of sport participation has been linked to asymmetries in bone and muscle girth, as well as flexibility and strength. The purpose of the present study was to determine if there is a greater prevalence of pelvic skeletal asymmetry in athletes who participate in a sport that requires a lateral dominance combined with increased spinal flexion and rotation.

Oscillation parameters for modeling kinesthesis

In order to analyze the kinaesthesis of motion, the author used a ZEBRIS ultrasound-based measuring system with single active markers. The provocation test, when the plate is suddenly swiveled out with a provocation unit, can model the equilibration ability of the person being investigated. In this study the oscillation (swing) characteristics of 45 healthy, young subjects, 11 professional handball players, 24 patients after medial meniscectomy, 20 elderly, healthy subjects, and 20 patients with hip osteoarthritis were identified in terms of provocation. The oscillation (swing) characteristics of provocation were identified by average logarithmic decrement, Lehr’s damping ratio, frequency and own frequency. Kinaesthesis can be described by analyzing the results of the measurements performed. Oscillation parameters depend on lateral dominance, on age, on the grade of sporting, and on orthopaedical diseases.

The effect of gender and lateral dominance on gripping muscle power in young adults

This study aimed to clarify the effect of gender and lateral dominance on grip muscle power. Subjects included healthy young males and females (15 men aged 22.1±0.7 years and 15 women aged 22.4±1.0 years) who were right-hand dominant. Grip muscle power (peak power) was measured in the dominant and non-dominant hands with six different loads ranging from 20% to 70% of maximum voluntary contraction (MVC). The grip muscle power was significantly larger in males than in females and in the dominant hand than in the non-dominant hand. In short, lateral dominance was confirmed. The grip muscle power values increased with increasing loads, and decreased after reaching a maximal value at about 50% MVC in both genders. In contrast, peak velocity decreased with increasing loads. The grip muscle power ratio of the dominant hand to the non-dominant hand was significantly larger in females in all loads. In conclusion, although grip muscle power is superior in males and in the dominant hand, the lateral dominance is more marked in females.

Regional differences in the coupling between resting cerebral blood flow and metabolism may indicate action preparedness as a default state.

Although most functional neuroimaging studies examine task effects, interest intensifies in the “default” resting brain. Resting conditions show consistent regional activity, yet oxygen extraction fraction constancy across regions. We compared resting cerebral metabolic rates of glucose (CMRgl) measured with 18F-labeled 2-fluoro-2-deoxy-D-glucose to cerebral blood flow (CBF) 15O-H2O measures, using the same positron emission tomography scanner in 2 samples (n = 60 and 30) of healthy right-handed adults. Region to whole-brain ratios were calculated for 35 standard regions of interest, and compared between CBF and CMRgl to determine perfusion relative to metabolism. Primary visual and auditory areas showed coupling between CBF and CMRgl, limbic and subcortical regions—basal ganglia, thalamus and posterior fossa structures—were hyperperfused, whereas association cortices were hypoperfused. Hyperperfusion was higher in left than right hemisphere for most cortical and subcallosal limbic regions, but symmetric in cingulate, basal ganglia and somatomotor regions. Hyperperfused regions are perhaps those where activation is anticipated at short notice, whereas downstream cortical modulatory regions have longer “lead times” for deployment. The novel observation of systematic uncoupling of CBF and CMRgl may help elucidate the potential biological significance of the “default” resting state. Whether greater left hemispheric hyperperfusion reflects lateral dominance needs further examination.

Characteristics and Lateral Dominance of Hand Grip and Elbow Flexion Powers in Young Male Adults

This study aimed to clarify the characteristics and the lateral dominance of hand grip power and elbow flexion power. The subjects were 15 healthy young males (mean age 22.1+/-0.7 yr, mean height 171.3+/-3.4 cm, mean mass 64.5+/-4.1 kg). All subjects were right-handed. Peak power was measured by both hands with 6 different loads of 20%-70% of maximum voluntary contraction. The maximum voluntary contraction of hand grip movement and elbow flexion movement was significantly larger in the dominant hand. Peak power of the dominant hand was larger in all loads in hand grip movement and in loads of 20% and 30% of maximum voluntary contraction in elbow flexion movement. In short, lateral dominance was confirmed. Peak power was significantly larger in hand grip movement than in elbow flexion movement in both hands. Peak velocity decreased with increasing loads in both movements, but peak power increased until about 50% of maximum voluntary contraction and then decreased. The peak power ratio of the dominant hand to the nondominant hand was significantly larger in hand grip movement than in elbow flexion movement in all loads and the peak power ratio in elbow flexion movement was more marked in light loads. In conclusion, both powers showed lateral dominance. Lateral dominance is more marked in hand grip power.

The reiterative accuracy of gait determined by simplified gait analysis

Dynamic perception is the perception of the relation of moving body parts to each other. To examine dynamic perception, the reiterative accuracy of well-known movements - for example, gait - is analysed. Simplified gait analysis can be obtained for 50 cycles of gait in this research. The high number of gait cycles analysed provides an opportunity to calculate the average and standard deviation of different temporal (duration of stance phase, swing phase, double support phase) and spatial parameters (step length, stride length, cadence) of each subject investigated. 45 healthy, young subjects, 11 professional hand ball players, 24 patients after medial meniscectomy, 20 elderly, healthy subjects, and 20 patients with hip osteoarthritis are investigated. The average, standard deviation and normalized deviation of parameters of each person are calculated. The normalized deviation of parameters enables modelling of dynamic perception, because it is independent from the value of parameters due to normalization. O ur tests show that the size of the parameter is independent from lateral dominance at healthy subjects. The size of the normalized deviation of parameters depends on age, on the intensity of sports activities, and on orthopaedical diseases.

Anomalous Lateral Dominance Patterns in Women with Eating Disorders: Clues to Neurobiological Bases

Objectives: We tested the hypothesis that there is differential hemispheric functioning in women with eating disorders as compared to controls. Method: A divided visual field paradigm, with a language task [for which we assume left hemisphere (LH) specialization] and a spatial task [for which we assume right hemisphere (RH) specialization]. The participants were 20 healthy women, 17 women with anorexia nervosa (AN), and 18 women with bulimia nervosa (BN). Results: The groups did not differ in accuracy. The latency of responses revealed different asymmetry patterns among the groups. The AN group was indistinguishable from the control group in the spatial task, and showed no evidence of LH specialization for the language task. The BN group revealed evidence for LH specialization in the language task, but no specialization in the spatial task. Discussion: Our results converge with other reports of asymmetric functional deficits in AN and BN, and support the hypothesis that AN involves specific LH dysfunction and BN involves specific RH dysfunction.