Date of Award

2016

Document Type

Thesis - ECU Access Only

Publisher

Edith Cowan University

Degree Name

Doctor of Philosophy

School

School of Medical and Health Sciences

First Supervisor

Dr Sophia Nimphius

Second Supervisor

Dr Jared Porter

Third Supervisor

Dr Ken Nosaka

Abstract

Sprint performance is one of the major determining factors for success in many land-based sports. To improve sprint performance, coaches provide task-oriented verbal instructions to athletes, which could affect how the athlete focuses their attention while sprinting. Adopting an external focus of attention has been shown to enhance a number of motor skills, including sprinting, while an internal focus of attention has been shown to be detrimental to skill performance. However, there is a current gap in the literature regarding how track and field coaches provide internal and external focus instructions to sprint and hurdle athletes during practice and competition. Additionally, there is very little research on how sprint kinematics and kinetics are changed under different attentional focus conditions. Therefore, this PhD research project assessed instructions that coaches provided to sprint and hurdle athletes during practice and competition in study one, followed by evaluating the underlying kinetic, kinematic, neuromuscular and psychophysical components of sprint performance under internal and external attentional focus conditions in comparison to a control condition during sprint acceleration in studies two and three.

In study one, sprint and hurdle coaches (n = 111) completed a questionnaire consisting of a number of questions related to what type of verbal instructions they provide to the athletes they coach. It was found that the coaches provided more internal focus (54%) than external focus instructions (42%) during practice, and provided less internal focus instructions (20%) than external focus instructions (35%) or neutral focus instructions (46%) during competition.

In study two, 12 trained men (age: 22.4 ± 4.0 years; height: 1.8 ± 0.1 m; body mass: 76.6 ± 6.3 kg) performed three sprint sessions separated by at least 48 hours, which included two sets of three 40 m sprints at 100% of maximal effort under control, internal and external focus conditions. Kinetics, kinematics and peak muscle activation (sEMG) were collected at ~10 m, and compared among the three conditions. Sprint times at 10 m, 20 m, 30 m and 40 m were similar between the conditions, but vastus lateralis peak sEMG activity was lower in external focus than control condition (CON: 109.4 ± 29.7%; EXT: 74.6 ± 24.8%, d = -1.28, p < 0.01). Semitendinosus peak sEMG activity was also significantly lower (p < 0.05) in the external (89.2 ± 26.4%) compared to the internal condition (108.5 ± 34.34%). No significant differences between conditions were found for other variables.

In study three, 13 trained male athletes (age: 22.8 ± 3.6 years; height: 1.8 ± 0.1 m; body mass: 76.2 ± 6.6 kg) performed 6 x 10 m sprints in three conditions: control, internal, and external focus conditions, in which kinetics and kinematics from the first and second steps of the sprint acceleration were analysed. No statistical significance or moderate-to-large effect sizes were found for any of the dependent variables measured. It was concluded that simply providing an external focusing instructions to trained athletes may not necessarily result in enhanced key performance indicators or performance measures while sprinting.

Collectively, these studies suggest that coaches provide more internal focus than external focus instructions during training, which may reduce movement efficiency during sprinting. The results of studies two and three did not show improved sprint performance with an external focus of attention. However, the results of study two partially supported the constrained action hypothesis in that adopting an internal focus of attention potentially disrupted the automatisation of sprinting through increasing redundant muscle activation of the semitendinosus potentially causing increased muscular co-contraction, while the external focus condition reduced muscle activation and may have potentially enhanced neuromuscular efficiency. It may be that more global, movement-oriented instructions improves sprint performance more so in trained athletes, as has been shown in previous studies. Thus, further studies are warranted.

Access Note

Access to Chapter 2 of this thesis is not available.

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