Available online at www.sciencedirect.com
Procedia Engineering 60 (2013) 10 – 15
6th Asia-Pacific Congress on Sports Technology (APCST)
The development and application of a live transmitting head
camera for video feedback in rugby decision making
Hayden Crofta*, Daniel Cury Ribeirob
a
b
Otago Institute of Sport and Adventure, Otago Polytechnic, New Zealand.
Centre for Health, Activity, and Rehabilitation Research, School of Physiotherapy, University of Otago, New Zealand
Received 20 March 2013; revised 18 May 2013; accepted 1 June 2013
Abstract
Previous studies have explored the use of head cameras in different scenarios, including sport training [1-4]. Until
recently, athletes had their practice recorded and such recording was used for feedback purposes. This approach is
problematic as it does not allow for immediate feedback and does not provide a similar perspective to those athletes
have when training. To overcome this a head camera was developed to record first-person perspective during real-life
training situation. This camera consisted of 3 main components: a miniature camera with wide angle lens (140
degrees) and transmitter running on a 2.4GHz frequency with a small helical antenna, a video relay device for
increased line of sight between the transmitter and receiver, signal receiver device connected to a laptop computer
with video review software. The camera components were mounted within a protective casing and inserted into a
custom made rugby soft helmet, commonly known as headgear. The vantage point of the wearer is very different to
conventional grandstand camera views and shows that different visual information [5] is presented to an individual
making decisions. Case study: A randomised control trial is to be performed consisting of three groups; a group using
and viewing footage from the head mounted camera, a group viewing coaches’ perspective, side of field footage and
a control group with no video feedback. The players will complete a decision making drill and video feedback will be
reviewed with players observing the movements of their teammates and surrounding opponents. Data will be
recorded throughout the session measuring which video vantage point is associated with improvements in decision
making.
© 2013 The Authors. Published by Elsevier Ltd. Open access under CC BY-NC-ND license.
© 2013 Published
by Elsevier
Ltd. Selection
andSchool
peer-review
underMechanical
responsibility
RMIT University
Selection
and peer-review
under responsibility
of the
of Aerospace,
and of
Manufacturing
Engineering,
RMIT University
Keywords: Head camera; rugby union; decision making; video transmission
* Corresponding author. Tel.: +64 21 760 395.
E-mail address: [email protected].
1877-7058 © 2013 The Authors. Published by Elsevier Ltd. Open access under CC BY-NC-ND license.
Selection and peer-review under responsibility of the School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University
doi:10.1016/j.proeng.2013.07.007
Hayden Croft and Daniel Cury Ribeiro / Procedia Engineering 60 (2013) 10 – 15
1. Introduction
Feedback is used by athletes and coaches for improving performance [6]. The use of feedback allows
athletes and coaches to identify flaws in motor performance and or decision making during a training
session or a competition (references). Different forms of feedback have been used in sports training,
including verbal feedback from coach, and visual feedback through video footage. The use of video
feedback was found to be useful for improving a golf swing in a group of thirty golfers [7]. However, the
positive effects of such type of intervention may take some time to develop [7].
The literature has explored how different feedback characteristics can impact motor performance in
athletes and patients [7-9]. It has been suggested that concurrent feedback (i.e. feedback is provided at the
same time the task is performed) can have detrimental impact on motor performance and learning [10].
On the other hand, the use of delayed feedback may help athletes to improve their motor skills. Based on
previous research, it is clear that the way feedback is provided is crucial to either improve or hinder motor
performance [11]. It is reasonable to assume the same applies for and or decision-making in collective
sports like rugby.
Head cameras have been incorporated into many scenarios in both academic research [1, 2] and sports
practice [3, 4]. Until recently, reviewing the video from the camera has been delayed and ineffective for
immediate feedback. Additionally, the perspective may differ from the one athletes are exposed to when
performing. In sports entertainment, cameras mounted to the umpire have given an interesting first person
perspective of play. However the umpire is required to wear bulky electronics unsuitable for players. The
literature has not extensively explored the impact of the use of video feedback with a first person
perspective on sports decision making. It is possible that, players will improve their decision-making if
they receive video feedback with their own visual perspective during a training session. The aim of this
paper is to report the development of a live transmitting head camera for video feedback in rugby
decision-making.
2. Methods
This is a technical report study with the report of a case study on its use.
2.1 The equipment
The head camera was designed for transmitting live video footage to a viewing laptop for the purpose
of feedback. The head camera that was developed consisted of 3 main components:
1) a miniature camera with wide angle lens (140 degrees) and transmitter running on a 2.4 GHz
frequency with a small helical antenna (Figure 1a);
2) video relay device for increased line of sight between the transmitter and receiver (Figure 1b);
3) a signal receiver device connected to a laptop computer with video review software (Figure 1c).
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a
b
c
Fig. 1. Head camera components: a) head camera embodied inside a protective casing, b) video relay pole, c) video receiver
connected to laptop device.
The camera device was positioned on the players head as it enabled capture of video images from the
perspective of the player and due to its live transmission it enabled immediate review of practice footage.
The vantage point of the wearer was very different to conventional grandstand camera views and showed
that different visual information [5] was presented to the individual making decisions.
2.1.1 Camera
The miniature camera used in this device was SupersunTM SM-539 CCTV CCD camera, which was
compact and light weight. It produces standard definition video images which were deemed suitable from
this application. A 140 degree, horizontal and vertical field of view (FOV), board lens was attached to the
camera giving a FOV suitable for the given application.
The captured pictures are transmitted via a 24mm by 28mm by 7mm, 2.4 GHz, 500mV analogue
transmitting device which only weighed 10 grams, which made it ideal for a head mounted application.
The transmitter utilised a 0dbi gain, right hand polarised, quarter wave, helical antenna enabling even
transmission in all directions and orientations. As it was only 10mm long it did not pose an injury risk to
the participants.
The camera components were mounted within a protective casing (Figure 2a) and inserted into a
custom made rugby soft helmet, commonly known as headgear (Figure 2b). This casing provided
protection to the electronics from impacts and water damage while it also provided protection to the
players by being encased within a soft foam rugby headgear. This head gear was specially constructed
with a cavity which the protective casing sat inside.
Hayden Croft and Daniel Cury Ribeiro / Procedia Engineering 60 (2013) 10 – 15
a
.
b
.
Fig. 2. Front and rear views of a) camera components mounted inside a protective casing prior to being fitted into, b) rugby
headgear.
2. 1.2. Video relay
As analogue transmission requires line-of-sight, for disruption free transmission, a high mounted video
relay device was used to improve line of sight between the transmitter and receiver (Figure 1b). The relay
was positioned up to 4 meters off the ground and received the 2.4 GHz signal sent from the players head.
The signal was then re-transmitted via a 5.8 GHz frequency, to avoid disruption between the 2 signals, to
a receiving device at the side of the practice area. In pilot trials, this was shown to improve signal quality.
2.1.3. Receiver and laptop
To capture and display the relayed video signal a receiver device was connected to a laptop computer
with video review software (Figure 1c). The receiving device captured the 5.8 GHz signal from the video
relay and converted it into a video stream which was connected to the laptop via a USB input. The video
stream was then captured and displayed by Silicon Coach – Timewarp 4TM software, enabling the coaches
and players delayed review and various other replay functions.
2.2 Procedures for use
Although there are many ways this technology could be applied its initial design was to allow players
to review video of their practice in-between trials. Players could work on a group activity, normally
involving a decision, while one person in the group wears the head camera. At the completion of a trial,
or a number of trials, the group would walk over to the viewing laptop at the side of the practice area and
review the practice trials. This can be done by replaying the footage in slow motion or by freeze framing
it then discussions about the kinematic, temporal and spatial cues exhibited by the opposition can be had.
Once this review is finished the players practice more trials in an attempt to improve their performance.
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3. Case study
A pilot randomised control trial is to be performed to assess the effectiveness of the use of this head
camera as a feedback instrument for rugby training purposes. The intervention will consist of three
participant groups: (1) one group will review footage from the head mounted camera; (2) another group
will review footage from the coaches’ perspective; (i.e. side of field footage); and (3) a control group will
receive no video feedback.
The players will be organised in groups of 3 attackers and 2 defenders, set out in grid formation with
limited attacking space. The defensive players will run various predetermined defensive patterns,
unknown to the attackers, and the attacking team will attempt to “breach the defence” and execute the
correct play so a try can be scored.
The drill will be repeated five times, and then the two video feedback conditions will review their
video footage observing the movements of their teammates and surrounding opponents. This will be
repeated for a minimum of 5 times, giving a total 25 samples for each group. Data will be recorded
throughout the session, measuring which video vantage point is associated with improvements in decision
making. This will be defined by the number of times attackers were capable of breaching the defence.
Ball
Defenders
15m
Attackers
Goal line
25m
Fig. 3. Grid formation of decision making task between attaching and defending players.
4. Conclusion
The technology featured in this paper provides important visual feedback to players, which helps them
identify what important visual cues look like. These cues help them make correct decisions and improve
their chances of success.
The components used to create this technology appear to be effective capturing, transmitting and
displaying standard definition video, of the wearers perspective during the execution of the decision
making task. With the advent of new digital wireless technologies further research is required into
improvements that could be made. Digital technology has the ability to transmit high definition video
footage and remove issues with momentary loss of line of sight, which is a requirement of this papers
Hayden Croft and Daniel Cury Ribeiro / Procedia Engineering 60 (2013) 10 – 15
analogue technology. High definition footage would provide players with greater detail and allow the
identification of less obvious visual cues.
Acknowledgements
The authors would like at acknowledge Insight Sport Technology for providing information about the
construction of the head camera.
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