Human lateral preferences, such as handedness and footedness, have interested researchers for decades due to their pronounced asymmetries at the population level. While there are good estimates on the prevalence of handedness in the population, there is no large-scale estimation on the prevalence of footedness. Furthermore, the relationship between footedness and handedness still remains elusive. Here, we conducted meta-analyses with four different classification systems for footedness on 145,135 individuals across 164 studies including new data from the ALSPAC cohort. The study aimed to determine a reliable point estimate of footedness, to study the association between footedness and handedness, and to investigate moderating factors influencing footedness. We showed that the prevalence of atypical footedness ranges between 12.10% using the most conservative criterion of left-footedness to 23.7% including all left- and mixed-footers as a single non-right category. As many as 60.1% of left-handers were left-footed whereas only 3.2% of right-handers were left-footed. Males were 4.1% more often non-right-footed compared to females. Individuals with psychiatric and neurodevelopmental disorders exhibited a higher prevalence of non-right-footedness. Furthermore, the presence of mixed-footedness was higher in children compared to adults and left-footedness was increased in athletes compared to the general population. Finally, we showed that footedness is only marginally influenced by cultural and social factors, which play a crucial role in the determination of handedness. Overall, this study provides new and useful reference data for laterality research. Furthermore, the data suggest that footedness is a valuable phenotype for the study of lateral motor biases, its underlying genetics and neurodevelopment.

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Four meta-analyses across 164 studies on atypical footedness prevalence and its relation to handedness.

Context Kinesio taping is commonly used in sports and rehabilitation settings with the aim of prevention and treatment of musculoskeletal injuries. However, limited evidence exists regarding the effects of 24 and 72 hours of kinesio taping on trunk and lower limb neuromuscular and kinetic performance during a vertical jump. Objective The purpose of this study was to analyze the short-term effects of kinesio taping on height and ground reaction force during a vertical jump, in addition to trunk and lower limb muscle latency and recruitment order. Design Single-group pretest-posttest. Setting University laboratory. Participants Twelve male athletes from different sports (track and field, basketball, and soccer). Interventions They completed a single squat and countermovement jump at basal time (no kinesio taping), 24, and 72 hours of kinesio taping application on the gluteus maximus, biceps femoris, rectus femoris, gastrocnemius medialis, and longissimus. Main outcome measures Muscle onset latencies were assessed by electromyography during a squat and countermovement jump, in addition to measurements of the jump height and normalized ground reaction force. Results The kinesio taping had no effect after 24 hours on either the countermovement or squat jump. However, at 72 hours, the kinesio taping increased the jump height (P = .02; d = 0.36) and normalized ground reaction force (P = .001; d = 0.45) during the countermovement jump. In addition, 72-hour kinesio taping reduced longissimus onset latency (P = .03; d = 1.34) and improved muscle recruitment order during a countermovement jump. Conclusions These findings suggest that kinesio taping may improve neuromuscular and kinetic performance during a countermovement jump only after 72 hours of application on healthy and uninjured male athletes. However, no changes were observed on a squat jump. Future studies should incorporate a control group to verify kinesio taping's effects and its influence on injured athletes.

Short-Term Effects of Kinesio Taping on Muscle Recruitment Order During a Vertical Jump: A Pilot Study

Este estudo teve como objetivo determinar a potencia relativa do membro inferior e atividade eletromiografica (EMG) de superficie do gluteo maximo (GM), vasto medial (VM), vasto lateral (VL) e gastrocnemio lateral (GASLAT) durante um salto contramovimento (CMJ) e um salto Abalakov (ABK). No total foram 24 jogadores de volei universitarios divididos em dois grupos iguais, determinados pelo nivel de competicao: o grupo 1 (G1), composto por jogadores de 1a divisao universitaria e o grupo 2 (G2), composto por jogadores de volei de 2a divisao universitaria. Cada um foi submetido a duas avaliacoes simultâneas de potencia e EMG de superficie. Para a potencia foi utilizada um sistema de gravacao 2D, por meio de um segmento do trocânter maior com uma câmara de 250 Fps. Essa gravacao foi submetida a uma medicao por meio de software (TrackerO), para obter os valores de potencia absoluta. A EMG de superficie foi realizada por meio do aparelho de eletromiografia Delsys TrignoO nos musculos GM, VM, VL e GASLAT. Houve diferencas significativas em %PeakRMS do VL (G1=65,210,2; G2=54,0±11,7 %PeakRMS; p 0,05) e ABK (p>0,05).

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Potencia y actividad electromiográfica en voleibolistas universitarios

A literature review of the application of kinesio taping in the prevention of professional dancers' injuries indicated frequent dance-related and overuse injuries and a lack of organized information about this issue. This study aimed to assess the impact of kinesio taping on the musculoskeletal system of dancers, based on scientific research data from 2015-2017. The analysis revealed that kinesio taping can effectively reduce muscle spasms, rebuild muscle strength of the injured extremity, improve static and dynamic balance and ease pain, due to its ability to improve proprioception of joints and regulate muscle tone. These effects reduce muscle imbalance and joint instability, thus increasing treatment efficacy and shortening the physical load limitation. Kinesio taping significantly reduces the risk of overuse syndromes and dance-related injuries during dance training and strenuous exercises of people with chronic musculoskeletal diseases. Therefore, kinesio taping has broad utility in primary and secondary prevention of dance-related injuries.

Possibilities of kinesio taping to prevent injuries of professional dancers.

Background Despite the high prevalence of anxiety among chronic stroke survivors and evidence of its negative effects on postural control in healthy subjects, it is unclear whether anxiety also affects postural control in these patients. Recent evidence of improved postural control of healthy subjects by distracting the attention using an external focus (EF) or cognitive task, raises the question of whether similar benefits would be observed in stroke survivors. Thus, the current study aimed to investigate the effects of anxiety and distracting the attention on postural control of chronic stroke survivors in terms of both postural sway measures and neuromuscular regulation. Methods Postural sway measures and ankle muscle activity of chronic stroke survivors with the high and low level of anxiety (HA-stroke (n = 17), and LA-stroke (n = 17), respectively) and age-, sex-, height-, and weight-matched healthy subjects (n = 17) were assessed while standing on rigid and foam surfaces under following conditions: baseline, internal focus (IF), EF, simple and hard cognitive tasks (SC and HC, respectively). Results Stroke survivors, particularly HA-stroke participants, showed greater postural sway measures (i.e. postural instability) and enhanced co-contraction of ankle muscles (i.e. stiffening of the neuromuscular system) compared with healthy subjects. As opposed to baseline and IF conditions, postural instability and neuromuscular stiffening significantly reduced in EF condition and decreased more in cognitive task conditions, particularly HC condition. Conclusions The results suggest that anxiety enhances stroke-induced postural instability promoting improper neuromuscular control of posture with stiffening strategy, which can be alleviated by EF and cognitive tasks.

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Overload of anxiety on postural control impairments in chronic stroke survivors: The role of external focus and cognitive task on the automaticity of postural control.

Objective: To examine the effect of kinesio tape compared to no tape on vertical jump height and triceps surae electromyographic (EMG) muscle activity in healthy varsity athletes. Design: One group pre-test post-test design. Methods: Twenty healthy varsity athletes (15 females and 5 males) between the ages of 18 and 30 (20.45 years ± 1.36) participated in this study. Each participant was a member of a varsity university basketball, volleyball and/or track and field team. After consent was obtained, the participant completed a Physical Activity Readiness Questionnaire (PAR-Q) and the Waterloo Footedness Questionnaire. The participant then completed a brief warm up and three practice trials of each jump technique. The jumping techniques included the countermovement vertical jump and static vertical jump. The skin at each sensor site was prepped and cleaned and a Delsys Trigno Wireless EMG System was attached to the lateral and medial gastrocnemius, and soleus muscles. After insuring that the EMG sensors were firmly attached, the individual performed a maximal vertical jump and the height of the vertical jump measured using a Vertec device. The participant performed three trials of a one-footed take off using only his/her dominant foot and a two-footed take off maximal countermovement vertical jump and static vertical jump. Each of these jumps were performed with a one footed take off using the dominant leg only, and then a two footed take off using both legs. Kinesio tape was then applied to the dominant leg using a combined taping technique (facilitatory and mechanical corrective). The maximal countermovement vertical jump and static vertical jump height was then re-tested. The mean rectified average EMG signal intensities and vertical jump heights were analyzed. A paired samples t-test was used to analyze the data comparing baseline to post-taping values with an alpha level set at p<.05. Results: There was a significant increase in mean vertical jump height (t(19)=-4.091, p=0.01) for the one legged static jump with the application of tape. The mean one legged static jump height without tape was 26.29 cm ± 9.12, while with tape it was 28.72 cm ± 7.37. There was no significant difference in the vertical jump height for the one legged static, one legged countermovement, or two legged countermovement jumps. There was also no significant difference in the EMG activity across the four jump types for the gastrocnemius or soleus muscles with and without tape. Conclusions: The findings of this study have shown that the application of an Achilles tendinopathy kinesio taping technique increased the vertical jump height during a one legged static vertical jump. A trend of minor improvement was evident in all of the vertical jumps that were performed with tape. It was found that kinesio tape had no effect on EMG activity of the gastrocnemius or soleus muscles. The improvement in vertical jump height demonstrates that the application of kinesio tape may provide an individual with an athletic advantage in sports such as volleyball and basketball where jump height may be advantageous in certain sport specific situations.

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Ian MacDowall

Papers

The Effect of Kinesio Taping on Vertical Jump Height and Muscle Electromyographic Activity of the Gastrocnemius and Soleus in Varsity Athletes