Computerized and fingertip measures of reaction time compared in individuals.

The main purpose of our study was to discover the correlation between the field fingertip and computerized methods of measuring reaction time selectively of the dominant and non-dominant hands for individual, non-trained, healthy young people of senior school age. Forty one, 17 year old, strongly right handed scholars, 21 boys and 20 girls with body mass indices between 18.5 and 25.0, participated in the experiment. The field fingertip method employed a metal metric ruler and the computerized method used the Vienna Test System. The point biserial coefficient of correlation between these two methods was calculated for each individual. The results of demonstrated that the vast majority of participants, 95.2% of males and 85.0% of females for the right hand and 95.2% of males and 95.0% of females for the left hand had a high level of point biserial coefficient of correlation between the two methods. A small number of participants, 3 females and 1 male, did not demonstrate a high level of correlation. We speculate that this fact may be due to differential expression of muscle fibre types between males and females. The portability and ease of use of the field fingertip method are advantageous in the field research and provide a reliable measure of reaction time. It is important to control the initial gap between the thumb and index finger of the person being tested. A metallic metric ruler is adequate experimental instrumentation. The mass of the dropped item does not influence the measurement.

EVALUATION OF BILATERAL ASYMMETRY BETWEEN UPPER LIMB MASSES IN RIGHT-HANDED YOUNG ADULTS OF BOTH SEXES.

The study introduced a novel precise method for measurement and calculation of upper arm mass and to assess the difference between masses of upper limbs on the dominant and non-dominant sides of the body of right-handed participants. Forty healthy untrained male (n = 20; M age = 20.8 yr., SD = 1.2) and female (n = 20; M age = 20.7 yr., SD = 1.3) participants without a history of upper-extremity pathology participated. Kinematic and kinetic data were collected during arm motion. The mass of each arm was calculated. Each participant performed 20 movements with each arm. Most often the dominant arm was more massive than the non-dominant in both sex groups; however, mass was more symmetric for female participants than for male participants. Regression equations related to total body mass were calculated for each arm independently.

Influence of spatial accuracy constraints on reaction time and maximum speed of performance of unilateral movements.

The goal was to study reaction time and maximal velocity of upper limbs of healthy young adults of both sexes during transition from a simple to a more involved task. Performance of dominant and non-dominant arms was recorded. Participants were 43 healthy, right-handed, untrained men (n=22) and women (n=21), 18-22 years old. The simple task required a single jerk-like movement. The involved task required both speed and accuracy where necessity for high speed of performance was emphasized. The effectiveness of transition between tasks was calculated for both reaction time and maximal velocity. No lateral differences were found. Men usually had a shorter reaction time on both tasks and a higher maximal velocity in the simple task. Women were more effective at modifying velocity.

[Relationship between inertial features of the upper extremity and simple reaction time in boys and girls aged 17-18].

The latent period of visual sensor-motor reaction depends, in part, on the sensory and integrative processes in the brain, but is also influenced by the rate of the muscle contraction. There is no clear evidence in the literature whether the rotational inertia of segments of limbs has any direct effect on the reaction time. The aim of our study was to identify this relationship. The study involved 566 right handed students aged 16-17 of both genders beginning their post puberty period. Reaction time was measured during experimental adduction of the forearm and hand, using a special rotating handle and lever connected to a computer that recorded the reaction time (+/- 1 ms). Calculations of the rotational inertia were carried out using regression models by Zatsiorsky and other authors. Each gender group was divided into three subgroups: with high, medium and low values of rotational inertia. It was found that individuals with high values of rotational inertia of forearm and wrist demonstrated significantly longer reaction times. This pattern was apparent in both gender groups. Although males illustrated greater values of rotational inertia than females they demonstrated relatively shorter reaction times. This contradiction can be explained by greater muscle power of young men. We recommend taking into account the amount of rotational inertia of the responsive segment in all kinds of research which require measurement of reaction time.

[Characteristics of the latent period of sensorimotor reactions in middle-aged and elderly outpatients with asthma during long-term treatment with inhaled glucocorticosteroids].

AIM: To study a relationship of the characteristics of simple and complex visual sensorimotor reactions to asthma controllability in middle-aged and elderly outpatients during disease-modifying antirheumatic drug therapy with beclomethasone, fluticasone, or budesonide in average and high daily doses. SUBJECTS AND METHODS: Eighty middle-aged and elderly patients with asthma were examined. The level of asthma control, the main parameters of external respiratory function, and the characteristics of simple and complex visual sensorimotor reactions were assessed. RESULTS: Uncontrolled asthma was observed in more than 50% of the asthmatic patients in the outpatient setting. Moderate linear relationships were found between the main physiological parameters and the level of the standard asthma control test. CONCLUSION: In the patients with controlled asthma, the latent periods of simple and complex visual sensorimotor reactions were significantly shorter than in those with poorly controlled asthma.

Reaction time and movement duration influence on end point accuracy in a fast reaching task.

In labor and sport physiology a great deal of interest concerns the conceptual model of governance of both rapid and precise target-directed movements. Widely known in the theory of motor control, Fitts' paradigm determines the time of motion, calculated from the distance to the target and the diameter of the target. However this paradigm does not take into account the time of preparation for movement, which can have a significant impact on accuracy. In addition, the literature highlights little evidence of temporal and spatial asymmetry in the production of fast and accurate movements. The aim of our work was to investigate the influence of the duration of the preparatory phase (reaction time - T(R)) and duration of protractile motion of the arm (T(M)) on the speed and accuracy of movement. Also, the in-dividual asymmetry of the temporal characteristics and accuracy of performance of movements were studied. We measured three aspects of translational motion of the arm to the computerized target: reaction time (T(R), s), time of motion of the arm (T(M), s), and error in the achievement of the target (deltaL, mm). The group of participants consisted of 12 healthy, right-handed, untrained girls, each of whom completed 5 series of 10 discrete movements by each of the left and right arms. Mathematical analysis of the results revealed the existence of five models of performance. Each model was represented in the participant's performance with different probability. The combination of high speed and high precision when the arm moved towards the target was found only in model 5, which combines a long period of preparation for the movement (T(R)) and a short time of motion (T(M)). The probability of its occurrence in the untrained subjects was very low (2-3%). We suggest that it may be possible to develop special methods of training, geared towards the ability to increase the probability of appearance of this model. Asymmetry of motor action appeared clearly evident only in the parameter of accuracy (right arm committed the least errors), especially when the reaction time (T(R)) and movement time (T(M)) were close to average values of the sample. This result enables us to recommend this method for the determination of "handedness". The results allow us to conclude that in the process of development of new motor skills which include both precise and rapid movements we must take into account the initial values of reaction time. We also think that Fitts' existing formula should be modified by including the parameter of reaction time.

Toward effective forecast of professionally important sensorimotor cognitive abilities of young soccer players.

Development of skill in young soccer players relies on progressive improvement in different professionally important sensorimotor cognitive abilities. Development of seven leading abilities was based on the results of 23 tests provided for experimental and control groups. 600 elite young soccer players of both sexes, ages 11 to 19 years, were assessed over a period of 4 years. Experimental groups were given different exercises to aid development of selected abilities. At the end of the monitoring period, the experimental groups demonstrated a significant improvement in contrast to the control groups, and the greatest improvements in different test performances were observed in the 11- to 13-year-olds. The test-retest ata show the testing process to be reliable. The study provides standard pedagogical models and data for trainers, coaches, and researchers working with young soccer players. Future research on talent identification and selection should adopt amultidimensional approach.

Age-related changes in force and power associated with balance of women in quiet bilateral stance on a firm surface.

Quantitative assessment of the fluctuations of the body centre of mass (CM) while in a stationary bilateral stance on a firm surface is an important criterion of the functional state of human motor-vestibular and sensory apparatus. From analysis of the literature we conclude that more objective characteristics of human balance in quiet standing may be the amount of energy used to maintain the CM in a constant position. Further analysis of the references showed that these characteristics have not been investigated in neurological practice. In this study, the displacement of CM in participants standing in a normal anatomical position was analysed. Forty-five healthy women in three age groups: 18-24, 45-55 and over 60 years participated in the experiments, which consisted of recording changes in partial body weight on the force platform (under one leg) in situations with opened and closed eyes. The specific power of oscillation of body sway and force of lateral swing of CM were calculated. Results indicated that the maximum specific power of oscillation and force of lateral swing were observed in the group of women older than 60 years, especially in the absence of vision. Minimum values occurred in the group of 18-24 years. We also found a considerable variability in all indices in all age groups. This indicates that the stability of the vertical posture in humans depends also on the individual biological characteristics of the central nervous and muscular systems.

Behavior of dominant and non dominant hands during ballistic protractive target-directed movements.

The purpose of this study is to investigate the asymmetry of dominant and non-dominant arms regarding reaction time (RT), velocity, force and power generated during ballistic target-directed movements. Fifty six, right-handed young males performed protractile movements with both arms separately by pushing a joystick towards a target-line as quickly and as accurately as possible. Participants performed 21 repetitions with each hand. The temporal, spatial, kinetic and kinematic parameters were computed. All movements were grouped regarding their accuracy (when joystick fell short, stopped precisely or overreached the target). Each group of movements was analyzed separately and the data obtained was compared across groups. The results showed that although the left arm was less accurate than the right one, it reached the target significantly faster, developing greater average force and power. The forces of acceleration and deceleration of the left arm were greater too. We did not observe a significant lateral difference in RT in situations when the arm fell short of the target, or stopped precisely on the target. It was only when the target was overreached that the left arm displayed a significantly greater RT than the right one. We explain the results from the asymmetry of motor behavior in favor of the influence of both hemispheres in this process.

Intermanual temporal differences in bimanual simple isometric coupling by instructions.

To study intermanual temporal and force differences during contractions of adductor thumb muscles, the force-time history during isometric contraction of both hands was recorded and analysed for temporal phases including initiation of force, moments of maximum acceleration and velocity of force development, and period to peak force. 36 strongly right-handed young participants (18 women, 18 men) were instructed to use their thumbs to push buttons bimanually in response to 20 separate 35-db sound signals in each of four sessions. Sessions 1 and 2 were preceded with a "strong" instruction to "react as strongly as possible" (Strong Reaction task). Sessions 3 and 4 were preceded with a "speed" instruction to "react as quickly as possible" (Speed Reaction task). Lateral differences between magnitudes of forces developed by left and right thumbs and asynchrony between defined temporal parameters in bilateral force-time histories were significantly greater for Strong Reaction tasks. This departure from bilateral correlation observed between identical phases of isometric pushing action may suggest that participants' thumbs operate more independently under instructions that focus attention on force. Thus, specific instructions given to participants may have a profound effect on performance. It was also found that intermanual temporal differences for women were significantly smaller than for men, especially on Strong Reaction tasks. This phenomenon may be partly explained by a lower lateralization in women.

A possible anatomical and biomechanical explanation of the 10% rule used in the clinical assessment of prehensile hand movements and handed dominance.

UNLABELLED: A current doctrine in the dynamometric approach to determine lateralization of hand function states that in 10% of cases, the non-dominant hand will be stronger than the dominant hand. In this study, a novel MRI based modelling approach was applied to the first dorsal introsseus muscle (FDI), to determine whether the 10% rule may be applied to the FDI and may be partially explained by the arrangement of the anatomical components of the FDI. METHODS: Initially the force generated by the thumb segment during an isometric pushing task in the horizontal plane was measured from 25 strongly right-handed young males. Nine of these participants then had structural magnetic resonance imaging (sMRI) of the thumb and index osseous compartment. A modelling technique was developed to extract the muscle data and quantify the muscle line of action onto to the first metacarpal bone segment in order to quantify the muscle force at the point of momentary rotation--equilibrium. RESULTS: Eight of 25 subjects exhibited stronger force from the left hand. Six out of nine subjects from the MRI possessed significantly greater angles of attachment of the index osseous compartment on the left (non-dominant) hand. These six subjects also generated greater maximal isometric forces from the FDI of the left side. There was a significantly greater muscle volume for the right FDI muscle as compared to the left as measured from the reconstructed MRI slice data. CONCLUSIONS: The calculated force produced by the muscle is related to the angle of attachment of the muscle to bone in the index osseous compartment. The MRI findings indicate that the 10% rule may be anatomically and biomechanically explained.

Relationship between simple reaction time and body mass index.

The aim was to establish the relationship between simple reaction time in motor response in young adults in relation to their body physique, as represented by body mass index. Forty-five young male participants were allocated to one of three anthropometric groups, based on their body mass index. Participants performed 100 reaction-time trials with instructions to move a joystick, as quickly as possible, as soon as they detected a single star appearing in the centre of a monitor. All data were statistically selected into seven intervals and data from the mode frequency interval were precisely analysed. Participants from the group with greater body mass index reacted significantly slower than others. We did not record group lateral differences based on simple reaction time in each selected group. We recommend for future researchers the importance of identification of the level of body mass index of participants prior to testing them for effectiveness of simple sensori-motor reactions.

Acquisition of the lateral inconsistency in involuntary behaviour of upper limbs in 12-year-old children during walking at moderate speed.

The aim of this work was to investigate possible lateralisation in the behaviour of periodic motion of the human upper limb, during normal walking at a comfortable speed of locomotion. Ten healthy pre-adolescent, strongly right-handed, 12-year-old males participated in the experiment. Participants were walking on a treadmill with a standardised velocity of 1.1m/s (comfortable speed for all of them). A video analysis system with Silicon software was used to synchronically measure various angles of arms and forearms. The initial, final and interim angular positions of both arms and forearms in 10 cycles of each participant were compared in terms of variations (cycle to cycle) between both upper extremities at corresponding phases of each cycle for distal and proximal segments, respectively. We compared the coefficients of variation in relation to the spatial and temporal data of both limbs and their angular velocities. In addition we investigated the level of cycle-to-cycle regularity (constancy) of behaviour in relation to various positions, periods and velocities of movement of upper extremities (specifically arms and forearms) using the Eta non-linear method of correlation. All participants exhibited a lower level of regularity for the distal segments. The spatial and temporal variations in the dominant limb were also greater than the non-dominant limb for all participants. This may be due to a larger contribution from the right-sided muscles that are considered to be the main contributing factor to the motion of the dominant upper limb during walking, rather than simply gravity force acting alone. A possible practical application of this information may be useful in the objective clinical identification of the level of dominance of the upper extremity (arm plus forearm), in addition to 'traditional' handedness.

How close to a pendulum is human upper limb movement during walking?

The aim of this work was to investigate how close to pendulum-like behaviour the periodic motion of the human upper limb (or upper extremity) is, during normal walking at a comfortable speed of locomotion. Twenty-five healthy young persons (males and females) participated in the experiment. Biomechanical testing was undertaken (mass and centre of mass of each segment of the total upper extremity). Participants were walking on a treadmill with a standardised velocity of 1.1 ms(-1) (comfortable speed for all of them). A video analysis system with Silicon software was used to measure the different angles of the arm and forearm. The theoretical period of motion and maximal angular velocity were computed for the centre of mass of the total upper limb from the measured phases of the arm swing and associated positional potential energies. Actual measured periods of motion, in comparison, represented a level of similarity to a lightly damped simple pendulum. Using this assumption, the "damping factor" was calculated from the ratio between theoretical and measured values. A vast majority of people exhibited an actual angular velocity exceeding the expected theoretical angular velocity calculated for a virtual pendulum of similar mass and length characteristics. This may be due to muscle forces that are contributing to the motion of the upper limb during walking rather than simple gravity force acting alone. The observed positional potential energy of the dominant limb was greater than that of the non-dominant limb for the vast majority of participants.

The measurement and lateral comparison of the peak torque caused by the fast abduction exercise of stretched upper extremities in normal and trained adults.

The maximal torque effect of the middle portion of action of the deltoid muscle while raising an out-stretched upper limb was measured from left and right sides of normal untrained young adults and of the same age elite athletes. Seventeen strongly right-handed untrained males and females and 10 elite tennis players were tested. All participants were required to raise (abduct) one arm (right and then left, or vice versa) as fast as possible with maximal amplitude while standing on an electronic platform scale which measured to 0.001 kg. An assumed force at the centre of mass of the entire upper limb was considered. The force consisted of two components, namely static weight force of the upper limb and a dynamic force component created by upward acceleration of the limb. Using regression equations and scaling methods the static weight of the upper limb was derived and combined with the dynamic component to produce the total force, applied to the centre of mass of the limb. The total force multiplied by the distance from the centre of mass to point of rotation of the limb equated to the torque produced by deltoid muscle. Using video system analyses the angle of abduction was measured for each individual exercise. The additional anthropometrical tests identified proportionality and body mass indices for each participant. There was no significant difference in dynamic force and torque between left and right limb from the three groups. Sportsmen demonstrated greater lateral abduction when performing the exercise from the dominant side of the body. Sportsmen also demonstrated greater range of abduction, bigger dynamic force and torque on both sides in comparison to untrained adults. Remarkably, the absolute and relative length of arms of athletes were shorter in comparison to untrained males, but the radius of gyration from the stretched upper limb (from its centre of gravity to the shoulder joint) were greater. This phenomenon may be due to distal shifting of the gravity center of the entire upper limb in elite athletes, perhaps, because greater investment of the distal portion of the limb with skeletal muscle tissue.

Lateralized regular spatial patterns in oscillating drawing arm movements of right-handed young women.

There is a lacuna in literature with reference to the spatial lateral difference in fast rhythmical movements produced by the whole dominant and nondominant whole arm, where spinal regulation has a significant role. Based on a fast oscillating zigzag drawing task, this study focused on (a) creation of a specific model of the task based on the intermittencies of coupled vectors of the fast motion, (b) identification of the spatial patterns that triggered these vectors, and (c) identification of quantified lateral differences between the spatial rhythmical patterns. 12 strongly right-handed young women performed 9 to 11 trials drawing zigzag lines. Each participant was required to extend her arm and perform this task using the left and right arm selectively on a frontally positioned graphic design system. The spatial patterns produced on each trial were identified in terms of five constant combinations of horizontal (X) and vertical (Y) projections of each line on the zigzag drawings. The dominant arm differed from the nondominant arm in preferred patterns. Because the duration of each line in the zigzag was highly restricted in time, the appearance of the patterns with different block schemes of movement could be explained as being associated with lower levels of the central nervous system. Initiation of fast movement of the total upper arm is probably associated with selection of the block scheme of motor control appropriate to each arm. Each block scheme is grounded on the coupled vectors of motion organised with particular muscle groups. Some block schemes seemed linked specifically to the dominant arm.

Are temporal characteristics of fast repetitive oscillating movement invariant?

Validation of the proportional duration model was attempted using very fast single-joint repetitive horizontal abductive-adductive movements of the stretched upper extremity with minimal cognitive input. Participants drew oscillating horizontal lines during 20 sec. over relatively short distances as quickly as possible without visual feedback. Spatial, temporal, and kinetic parameters were analysed. The amplitude and the time spent accelerating, decelerating, and reversing in both directions of each experimental line were recorded and related to the centre of gravity of the upper extremity. The accelerations of the centre of mass of the upper extremity were calculated and used to calculate the forces involved. The ratios of durations were compared and intercorrelated for the two fastest, two average, and two slowest cycles from each participant. Results exhibited significant standard deviations and variability of temporal and kinetic parameters within individual trials. The number of significant coefficients of correlation within individual trials was small despite the controlling influence of the same generalised motor program. The proportional duration model did not hold for our data. Peripheral factors (probably the length-tension relationship rule for skeletal muscles and viscosity of muscle) may be important in this type of action.

Lateral difference in reaction times to lateralized auditory stimuli.

Evidence suggests that Reaction time (RT) is affected by human behaviour in that stimuli are processed and conducted faster and more accurately when they are presented directly to the specialised hemisphere and responded to more quickly when stimulus and response are mediated by the same hemisphere. The purpose of the current study was to investigate the effect of laterality using one parameter-reaction time (RT) on ipsilateral reactions to monuaural latralized stimuli. Twenty-four undergraduate polytechnic students and 10 representative level Rugby players participated in the study by reacting unilaterally to single and choice RT using simple and complicated sensor motor reactions (SMR). Results Shorter reaction times by the dominant hand while testing simple and complicated audio SMR, without reference to sex and sport skills results have been explained in terms of specialisation of left hemisphere in different aspects of information processes mechanisms, geared towards programming of the movement.

A new conceptual model of asymmetry in motor performance for bidimensional fast-oscillating movements in selected variants of performance.

Spatial characteristics and lateral differences between two upper extremities were investigated in unilateral graphical tasks involving fast oscillating movements in the vertical plane based on the model of restricted (less than 10 degrees) horizontal abduction adduction in the shoulder joint. The spatial locations of reversal points were used to identify two groups of motor performance: with big angles and gross vertical vectors (stretched accordion group), and small projectile angles with small vertical vectors (compressed accordion group). Both groups appeared in right and left arm performance. The former group had a strong pattern of distribution of big and small projectile angles which reflects a particular variant of execution with a significant difference between angles and intermittent big and small angles (BB). Two other variants of execution relating to specific angular patterns of performance were identified in the compressed accordion group: one (Bs) showed a big difference between big and small angles but without intermittance; the other (ss) had only small differences between magnitudes of angles. The Bs variant of execution was observed only in left-handed performance, whilst ss was typical of both extremities. The performances affiliated to the stretched accordion group with the BB variant of execution mostly operated with reciprocal cooperation between alterations of X and Y vectors for the right arm. Performance related to the same group with the Bs variant of execution used concurrent collaboration involving alteration of these vectors for the left arm. The compressed accordion group which deployed the ss variant of execution mostly displayed concurrent alteration of vectors irrespective of the side of performance. It is suggested that the spatial movement strategies might reflect several different schemes of motor control wherein coupling of oscillators controls vertical and horizontal movements. It is also proposed that specific subunits of the functional system of nervous elements responsible for the expression of spatial derivatives of motor programmes may exist at lower levels of the CNS and might be initiated by the left brain or by the cooperative activity of the left and right hemispheres.

Spatial coordination in a bimanual task related to regular switching of movement vectors.

The spatial aspect of cooperation between the two upper extremities was investigated using a bimanual task involving drawing simultaneous zig-zag lines on a vertical surface. In 62 trials by 31 strongly right-handed subjects three performance types were identified; Type I involved alternation of dominance in sideways and vertical movement components, in Type II a constant vertical movement was superimposed upon sideways movement, and Type III showed no consistent pattern across the two hands. These performance types differed significantly on the measure of spatial coordination, with Type I having the best, and Type III the poorest. These results suggest that on this bimanual task better spatial symmetry in limb movement is achieved when both hands employ similar within-hand strategies, involving switching between vectors for all muscle groups.