Dominant-non-dominant asymmetry of kicking a stationary and rolling ball in a futsal context

The aim of this study was to analyse the characteristics of the asymmetries in the dominant and non-dominant limbs when kicking stationary and rolling balls. Ten experienced Brazilian amateur futsal players participated in this study. Each participant performed kicks under two conditions (stationary ball vs. rolling ball) with the dominant and non-dominant limbs (five kicks per condition per limb). We analysed the kicking accuracy, ball and foot velocities, angular joint displacement and velocity. The asymmetry between the dominant and non-dominant limbs was analysed by symmetry index and two-way repeated measures ANOVA. The results did not reveal any interaction between the condition and limb for ball velocity, foot velocity and accuracy. However, kicking with the dominant limb in both kicks showed higher ball velocity (stationary ball: dominant - 24.27 ± 2.21 m · s(-1) and non-dominant - 21.62 ± 2.26 m · s(-1); rolling ball: dominant - 23.88 ± 2.71 m · s(-1) and non-dominant - 21.42 ± 2.25 m · s(-1)), foot velocity (stationary ball: dominant - 17.61 ± 1.87 m · s(-1) and non-dominant - 15.58 ± 2.69 m · s(-1); rolling ball: dominant - 17.25 ± 2.26 m · s(-1) and non-dominant - 14.77 ± 2.35 m · s(-1)) and accuracy (stationary ball: dominant - 1.17 ± 0.84 m and non-dominant - 1.56 ± 1.30 m; rolling ball: dominant - 1.31 ± 0.91 m and non-dominant - 1.97 ± 1.44 m). In addition, the angular joint adjustments were dependent on the limb in both kicks (the kicks with non-dominant limb showed lower hip external rotation than the kicks with the dominant limb), indicating that the hip joint is important in kick performance. In conclusion, the kicks with the non-dominant limb showed different angular adjustments in comparison to kicks with the dominant limb. In addition, kicking a rolling ball with the non-dominant limb showed higher asymmetry for accuracy, indicating that complex kicks are more asymmetric.

Design and test of a custom instrumented leg press for injury and recovery intervention

There is an increasing desire and emphasis to integrate assessment tools into the everyday training environment of athletes. These tools are intended to fine-tune athlete development, enhance performance and aid in the development of individualised programmes for athletes. The areas of workload monitoring, skill development and injury assessment are expected to benefit from such tools. This paper describes the development of an instrumented leg press and its application to testing leg dominance with a cohort of athletes. The developed instrumented leg press is a 45° reclining sled-type leg press with dual force plates, a displacement sensor and a CCD camera. A custom software client was developed using C#. The software client enabled near-real-time display of forces beneath each limb together with displacement of the quad track roller system and video feedback of the exercise. In recording mode, the collection of athlete particulars is prompted at the start of the exercise, and pre-set thresholds are used subsequently to separate the data into epochs from each exercise repetition. The leg press was evaluated in a controlled study of a cohort of physically active adults who performed a series of leg press exercises. The leg press exercises were undertaken at a set cadence with nominal applied loads of 50%, 100% and 150% of body weight without feedback. A significant asymmetry in loading of the limbs was observed in healthy adults during both the eccentric and concentric phases of the leg press exercise (P < .05). Mean forces were significantly higher beneath the non-dominant limb (4–10%) and during the concentric phase of the muscle action (5%). Given that symmetrical loading is often emphasized during strength training and remains a common goal in sports rehabilitation, these findings highlight the clinical potential for this instrumented leg press system to monitor symmetry in lower-limb loading during progressive strength training and sports rehabilitation protocols.

Comparing lateral bias in dogs and humans using the KongTM ball test

The KongTM ball test has been used extensively to assess lateral bias in the domestic dog. Implicit in this challenge is the assumption that dogs use their dominant paw to stabilise the ball. This study examined whether or not this is the case. A comparative approach was adopted, exploring limb use in dogs and humans. In Experiment 1, the paw preference of 48 dogs was assessed on the KongTM ball test. Analysis revealed an equal distribution of paw use, although significantly more dogs were paw-preferent than ambilateral. Significantly more male dogs were classified as right-pawed, while more females were ambilateral. There was no significant effect of canine sex or castration status on the dogs’ paw preferences. In Experiment 2, 94 adult humans were assessed on their ability to remove a piece of paper from a KongTM ball with their mouth, using their left, right or both hands to stabilise the ball. 76% of the right-handed people used their left hand, and 82% of the left-handed participants used their right hand, to hold the KongTM steady. It is concluded that dogs, like humans, are most likely using their non-dominant limb to stabilise the KongTM ball and their dominant side for postural support. This has potential applied implications from an animal welfare perspective.

O chute com o membro dominante e não dominante realizado com a bola parada e em deslocamento no futsal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hamstrings-to-quadriceps strength and size ratios of male professional soccer players with muscle imbalance

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assimetria no controle postural em idosos caidores e não caidores neurologicamente sadios e com doenã de Parkinson em diferentes posições estáticas

Individuals with Parkinson's disease (PD) seem to present asymmetric postural control, and the commitment to postural control that is a big factor of falls in this population. However, the asymmetry in the postural control of fallers and non fallers with PD and neurologically healthy elderly is not too much studied. The objective of the study is to analyze the asymmetry in postural control in different static positions of elderly patients with PD and healthy elderly fallers and non fallers. The study included 70 older adults with PD and 70 neurologically healthy (CG). The groups were matched for age, gender, height, weight and cognitive condition. It was evaluated the clinical, cognitive status and incidence of falls among its participants through weekly prospective follow-up of 4 months. Then, for each group, CG and PD, it was selected 12 elderly fallers and 12 elderly non fallers to evaluate postural control. Participants were evaluated through two force platforms in conditions of bipedal support, unipedal and tandem position. It was realized 3 attempts of 30s for each condition. For unipedal and tandem condition it was made 3 attempts for each lower limb. The parameters of interest of the center of pressure (CoP), were analyzed for each condition and compared by MANOVAs with factor group, fall and asymmetry. Post hoc Tukey tests were used to determine the relationships between them. The results show that CG individuals showed greater velocity and CoP area in relation to PD. It was verified that at the control group that non fallers individuals (CGN) had more displacement and RMS in the average lateral direction in the dominant limb when compared to the less affected limb of non fallers with PD (PDN). Faller individuals in the control group (CGF) had larger area in the non dominant limb when compared to the most affected leg of fallers individuals with PD (PDF). Still, the PDF individuals had higher RMS in anteroposterior feeling....

Relacionamento entre as variáveis da corrida de aproximação e da posição de pé de apoio com a velocidade da bola nos chutes com o membro dominante e não dominante

The aim of the study was to analyze the relationship between run-up spatial-temporal variables with ball velocity in the dominant and non-dominant kicks, and to compare the ball velocity between contralateral limbs. Six futsal players (aged 13 and 14 years) participated in the study. The participants performed 4 kicks with maximal velocity in the stationary ball with each limb. Participants’ movements were recorded by 4 digital cameras (120 Hz). Dvideow software was used for kinematic procedures. The variables analyzed were: length and width of the last but one step and last step before ball contact, distance of the support foot to the ball, run-up velocity and ball velocity. The relationship between spatial-temporal variables with the ball velocity was analyzed by linear regressions with ball velocity as dependent variable. Student t test for paired samples was used to compare ball velocity between dominant and non-dominant kicks. For the dominant limb, the ball velocity was predicted only by the run-up velocity in 16.7%, while for the non-dominant limb only the distance of the support foot to the ball was prognostic variable in 11.9%. The ball velocity was greater for the dominant limb. Run-up variables that predictive ball velocity were different between the dominant and non-dominant kicks.

Efeitos do Kinesio Taping® sobre os marcadores clínicos indiretos de dano muscular induzido pelo exercício excêntrico: ensaio clínico randomizado

Objective: analyze the effect of Kinesio Taping (KT) on the indirect clinical markers of muscle damage induced by eccentric exercises in the elbow flexors in healthy individuals. Materials and methods: It is a randomized controlled trial involving sixty volunteers at age group between 18 and 28 years randomly selected. The sample into three groups with twenty participants: control group (CG) – eccentric protocol without KT, KT group – eccentric with tensioned KT, placebo group – eccentric protocol KT with no tension. The evaluations took place at four moments; the first one was the basis line (AV1), after the second protocol (AV2) and the following two groups 24 (AV3) and 48 hours (AV4) after the intervention protocol. The muscle damage was induced by sixteen maximum eccentric contractions of the elbow flexors from the non-dominant limb, divided in two sets of eight repetitions, at 60º/s, with two minutes interval. The variables analyzed were: the joint amplitude in rest, the level of pain, the joint position sense (JPS) followed of isokinetic checking with electromyographic sign capitation. These data were analyzed in software SPSS 20.0. The normality was identified by Kolmogorov-Smimov examination and then, being used the ANOVA mixed model with significance of 5%. Outcomes: a decrease was observed at joint amplitude moreover, an immediate increase of pain wich increased after 24 and remained until 48 hours at all groups searched. There was not difference at the JPS. The variables peak torque, average peak torque, total work and mean power mean reduced until 48 hours after muscle lesion in all groups. Among the groups, there was no difference in EMG values and for any of the variables. Conclusion: The KT did not influence at the indirect clinical markers of muscle lesion induced by eccentric exercises in the elbow flexors in healthy people.

Efeitos do Kinesio Taping® sobre os marcadores clínicos indiretos de dano muscular induzido pelo exercício excêntrico: ensaio clínico randomizado

Objective: analyze the effect of Kinesio Taping (KT) on the indirect clinical markers of muscle damage induced by eccentric exercises in the elbow flexors in healthy individuals. Materials and methods: It is a randomized controlled trial involving sixty volunteers at age group between 18 and 28 years randomly selected. The sample into three groups with twenty participants: control group (CG) – eccentric protocol without KT, KT group – eccentric with tensioned KT, placebo group – eccentric protocol KT with no tension. The evaluations took place at four moments; the first one was the basis line (AV1), after the second protocol (AV2) and the following two groups 24 (AV3) and 48 hours (AV4) after the intervention protocol. The muscle damage was induced by sixteen maximum eccentric contractions of the elbow flexors from the non-dominant limb, divided in two sets of eight repetitions, at 60º/s, with two minutes interval. The variables analyzed were: the joint amplitude in rest, the level of pain, the joint position sense (JPS) followed of isokinetic checking with electromyographic sign capitation. These data were analyzed in software SPSS 20.0. The normality was identified by Kolmogorov-Smimov examination and then, being used the ANOVA mixed model with significance of 5%. Outcomes: a decrease was observed at joint amplitude moreover, an immediate increase of pain wich increased after 24 and remained until 48 hours at all groups searched. There was not difference at the JPS. The variables peak torque, average peak torque, total work and mean power mean reduced until 48 hours after muscle lesion in all groups. Among the groups, there was no difference in EMG values and for any of the variables. Conclusion: The KT did not influence at the indirect clinical markers of muscle lesion induced by eccentric exercises in the elbow flexors in healthy people.

Análise do efeito da fadiga muscular no senso de posição articular do joelho

Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciada em Fisioterapia

An investigation of lower limb joint powers as a predictive measure of countermovement vertical jump height.

Measuring and tracking athletic performance is crucial to an athlete’s development and the countermovement vertical jump is often used to measure athletic performance, particularly lower limb power. The linear power developed in the lower limb is estimated through jump height. However, the relationship between angular power, produced by the joints of the lower limb, and jump height is not well understood. This study examined the contributions of the kinetic value of angular power, and its kinematic component, angular velocity, of the lower limb joints to jump height in the countermovement vertical jump. Kinematic and kinetic data were gathered from twenty varsity-level basketball and volleyball athletes as they performed six maximal effort jumps in four arm swing conditions: no-arm involvement, single-non-dominant arm swing, single-dominant arm swing, and two-arm swing. The displacement of the whole body centre of mass, peak joint powers, peak angular velocity, and locations of the peaks as a percentage of the jump’s takeoff period, were computed. Linear regressions assessed the relationship of the variables to jump height. Results demonstrated that knee peak power (p = 0.001, ß = 0.363, r = 0.363), its location within takeoff period (p = 0.023, ß = -0.256, r = 0.256), and peak knee peak angular velocity (p = 0.005, ß = 0.310, r = 0.310) were moderately linked to increased jump height. Additionally, the location, within the takeoff period, of the peak angular velocities of the hip (p = 0.003, ß = -0.318, r = 0.419) and ankle (p = 0.011, ß = 0.270, r = 0.419) were positively linked to jump height. These results highlight the importance of training the velocity and timing of joint motion beyond traditional power training protocols as well as the importance of further investigation into appropriate testing protocol that is sensitive to the contributions by individual joints in maximal effort jumping.

Symmetry of in-shoe force signatures in athletes under field conditions : an application for injury prevention

The aetiology behind overuse injuries such as stress fractures is complex and multi-factorial. In sporting events where the loading is likely to be uneven (e.g. hurdling and jumps), research has suggested that the frequency of stress fractures seems to favour the athlete’s dominant limb. The tendency for an individual to have a preferred limb for voluntary motor acts makes limb selection a possible factor behind the development of unilateral overuse injuries, particularly when repeatedly used during high loading activities. The event of sprint hurdling is well suited for the study of loading asymmetry as the hurdling technique is repetitive and the limb movement asymmetrical. Of relevance to this study is the high incidence of Navicular Stress Fractures (NSF) in hurdlers, with suggestions there is a tendency for the fracture to develop in the trail leg foot, although this is not fully accepted. The Ground Reaction Force (GRF) with each foot contact is influenced by the hurdle action, with research finding step-to-step loading variations. However, it is unknown if this loading asymmetry extends to individual forefoot joints, thereby influencing stress fracture development. The first part of the study involved a series of investigations using a commercially available matrix style in-shoe sensor system (FscanTM, Tekscan Inc.). The suitability of insole sensor systems and custom made discrete sensors for use in hurdling-related training activities was assessed. The methodology used to analyse foot loading with each technology was investigated. The insole and discrete sensors systems tested proved to be unsuitable for use during full pace hurdling. Instead, a running barrier task designed to replicate the four repetitive foot contacts present during hurdling was assessed. This involved the clearance of a series of 6 barriers (low training hurdles), place in a straight line, using 4 strides between each. The second part of the study involved the analysis of "inter-limb" and "within foot loading asymmetries" using stance duration as well as vertical GRF under the Hallux (T1), the first metatarsal head (M1) and the central forefoot peak pressure site (M2), during walking, running, and running with barrier clearances. The contribution to loading asymmetry that each of the four repetitive foot contacts made during a series of barrier clearances was also assessed. Inter-limb asymmetry, in forefoot loading, occurred at discrete forefoot sites in a non-uniform manner across the three gait conditions. When the individual barrier foot contacts were compared, the stance duration was asymmetrical and the proportion of total forefoot load at M2 was asymmetrical. There were no significant differences between the proportion of forefoot load at M1, compared to M2; for any of the steps involved in the barrier clearance. A case study testing experimental (discrete) sensors during full pace sprinting and hurdling found that during both gait conditions, the trail limb experienced the greater vertical GRF at M1 and M2. During full pace hurdling, increased stance duration and vertical loading was a characteristic of the trail limb hurdle foot contacts. Commercially available in-shoe systems are not suitable for on field assessment of full pace hurdling. For the use of discrete sensor technology to become commonplace in the field, more robust sensors need to be developed.