Interaction Technology for Collective and Psychomotor Training in Sports Maiken Hillerup Fogtmann
Kaj Grønbæk
Martin Kofod Ludvigsen
Dept. of Design, Aarhus School of Architecture Nørreport 20 8000 Aarhus C +45 89360000
Dept. of Computer Science, University of Aarhus Aabogade 34 8200 Aarhus N +45 89425636
Dept. of Design, Aarhus School of Architecture Nørreport 20 8000 Aarhus C +45 89360000
maikenhillerup.fogtmann @aarch.dk
[email protected]
[email protected]
ABSTRACT The paper introduces a novel pervasive computing based training concept aimed at elite sports. The concept goes beyond interactive sports equipments that are either individual or multiuser with a common display requiring participant’s focus. These types of equipments are unable to support the kinesthetic empathic elements inherently present within open sports. To put focus on collective training, we draw inspiration from Kinesthetic Empathy Interaction in designing the collective training equipment, TacTowers. The TacTowers prototype is aimed at supporting athletes, particularly team handball players, in honing their psychomotor skills, in particular anticipation and decision making skills, in the one-on-one confrontation. TacTowers is a sensoractuator based system, with LED lights and no screen-based display. It is placed between the players in order to reintroduce the kinesthetic empathic element in the interaction, specific to the sport. We present and discuss results of tests with two elite handball teams. We see prospects for applying the concept for entertaining movement-stimulating games at schools or leisure sports environments.
Categories and Subject Descriptors H.5.2 User Interfaces, H.5.m Miscellaneous
General Terms Design, Human Factors.
Keywords Kinesthetic Interaction, Empathy, Tactics, Sensor-actuator based interaction technology, elite sports training, Collective Interaction.
1. INTRODUCTION In our research project, iSport, at Center for Interactive Spaces our objective was to develop a new type of pervasive computing based training equipment aimed at elite athletes in team sports and in turn for more leisure oriented activity games. We have made empirical studies of team training, and documented training exercises as well as the use of equipments in Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Full presentation, ACE’2011 - Lisbon, Portugal Copyright 2011 ACM 978-1-4503-0827-4/11/11 ...$10.00.
training sessions. We have supplemented these studies with theoretical studies of sports research e.g. [10], [22], kinesthetic interaction [12],[18], kinesthetic empathy interaction [11], and with inspiration from collective interaction [23]. This is the background for the challenge we address: how to build collective computer supported training equipment that supports training of psychomotor skills. Psychomotor abilities refer to the psychological aspect of motor learning, the cognitive part of the motor system. Psychomotor skills results from organized muscle activity in response to stimuli from the environment. Whereas the physical part of motor learning is concentrated around reflex actions that can be trained in relation to strength, psychomotor skills are complex movement patterns that can be practiced with a combination of cognitive and physical means [2],[14],[15]. Psychomotor abilities are key in open sports and can determine success or failure of the individual athlete or a team. Open sports are characterized by having one or more participants confronted by an opponent or a team and stand in contrast to individual sport where the performance isn’t dependent on others e.g. swimming. Within open sports e.g. in tennis, taekwondo, basketball success is not determined merely by how well the individual athletes performs, but is highly reliant on the performance of opponents and possibly teammates as the actions applied are constantly being varied according to what is happing around the performer. We address the challenge by development of a prototype – TacTowers – primarily for elite handball training. In short handball, also known as European handball, is a physical contact game where two teams of seven players pass a ball to throw it into the goal of the other team. But the prototype may also be configured to use for other ballgames where players use their hands e.g. basketball or volleyball [27]. Within elite sports, we face the firm objective that the users have to become better athletes from using training equipment – closer to winning the gold medal. If bodily development fails to appear or it is not apparent to the athletes why the training will prove fruitful, the athletes will quickly loose interest in using the equipment and move on to other and more viable training methods. We thus need to develop for measurable, absolute values, while at the same time create an open sports equipment where the focus is moved away from the performance of a specific skill to the psychomotor skills practiced in the interaction. In this type of interaction the computer should fall into the background and solely function as a facilitator of the interaction, similar to the ball facilitating a soccer game even though it is interaction between players that makes the game.
Setting out from these challenges, the paper is structured as follows: Section 2 review the state of the art of Kinesthetic Interaction related to sports; Section 3 describe out empirical studies of ball sports. Following this, section 4 presents five design parameters for training equipment. Section 5 describes our interactive training equipment, TacTowers. Section 6 summarizes the findings from the evaluation of the prototype in use; and finally in section 7 concludes with a discussion, closing remarks and plans for future work.
2. KINESTETIC EMPATHY INTERACTION IN SPORTS In any open sports (also known as interactive sport), where two or more participants are competing with and against one another, it is crucial for the players to be able to read, react and build on each other’s actions. Individual performance is no longer solely dependent on ones own performance, but on how well teammates and opponents perform. In these situations, it is not only vital to know how to execute a certain action, but also where and when to apply it [8][30]. To do this athletes utilize their kinesthetic empathy, the empathic part of humans’ innate bodily intelligence, which is the foundation for Kinesthetic Empathy Interaction. KEI [11] builds on existing research on kinesthetic empathy e.g. [13],[31], psychomotor skills [6], and is informed by research in open sports. As shown in the next section, the design of existing interactive systems often gives the system a prominent role in the interaction. The notion of KEI emphasizes that the interactive artifact, installation or environment slides into the background and thereby gives room to the human to human interaction occurring between the participants, as is the case in open sports.
2.1 Levels Of Kinesthetic Empathy In Existing Sports Equipment To give an overview and compare existing examples of sports equipment and interactive technologies we discuss technologies according to their physical setup and the possibility for kinesthetic empathy interaction (see figure 1), i.e. potentials for kinesthetic empathy conveyed by the designs. It highlights the unexplored potential for designing sports training equipments and games that builds on the interpersonal relations exemplified by the open sports. Although individual training equipment does not promote kinesthetic empathy interaction, we include them in this review to give the full picture, since they are the predominant type of training equipment within interactive sports.
Figure 1: The kinesthetic empathy in interaction according to physical setup.
2.2 Individual training Technology has played an important role in advancing sports, for example in the design of new training equipment [1],[7],[19], developing laboratory tests [1] and computerized tracking [16],[20] and in the training of specific skills [27]. These types of technologies are predominantly used in high-level, professional, elite sports, where the difference between winning and loosing is minimal.
The Octopus Trainer [27] is a good example of open sport equipment used by elite athletes to train reaction time and speed, primarily for handball goalkeepers and badminton players. The movements facilitated by the Octopus Trainer are similar to the ones executed when playing the actual sport. But, since the indication of the “ball” comes from lights turning on and off there is no relation to other players, which creates an artificial environment far from the situation in a real match. In a match, the goalkeeper would have the shooter’s movements (and memorized statistical information) to rely on. Makoto is another example of interactive training equipment used by athletes for skill training focusing on reaction time and peripheral awareness/split vision [24]. Three pillars constitute the interaction space and light can shine on each of them. The player(s) should then hit the light to turn it off with e.g. a stick, a kick, a fist or whichever body part or tool is relevant to the athlete’s particular sport. Two players are able to play alongside of each other, but as exercises are fundamentally reactive the players’ attention is mostly on the equipment. Whereas, the other examples mentioned all focus on improving specific physical skills, the IntelliGym™ [21] is a screen-based training system designed to improve the tactical aspects of basketball and hockey. The cognitive training consists of a variety of brain exercises designed to improve performance of psychomotor skills e.g. decision making, anticipation, fast response time, and ‘court sense’. The IntelliGym™ allows the users to train game perception individually in an isolated context by replaying scenarios on the screen with simple mouse-clicks.
2.3 Side by side The side-by-side interaction is typically seen in interactive games and training equipments where large screens and projections are used to mediate the interaction between two or more participants. In the gaming industry, games are becoming more physical and the competitive aspects of sports is drawn in and used for entertainment. With e.g. the Nintendo WiiTM [33], Microsoft’s Xbox Kinect [34] and PlayStation Move [29] the players control the action on the screen by applying different movements, either with a controller or through camera tracking. Sports is used to frame fun, engaging experiences by using the body as a tool for interaction. Though tempting, the problem with directly using the principles of e.g. the Wii in an elite sporting context is that the interaction between the players is controlled or heavily interpreted by the computer and not directly reliant on the players’ precise actions and movement - a key element in any open sport. When the movements have been translated like this, the players are no longer able to feint the opponent because the movement displayed by the avatar on the screen are simplified movements picked up by the Wii remote [33]. Furthermore, the players are only peripherally able to pick up on the opponent’s intentions visible in his movements, since the two players are placed side by side, in order to both look at the shared display. The current development of kinesthetic and casual games is a positive trend introducing new and better forms of interaction to a wider audience. However, related to the elite sport context the interaction does not contribute to the development of skills or physical capabilities compared to other types of training that the athletes could engage in. Playing with an opponent in a shared display setup like the Wii, Kinect or Move, incorporate another human as an unpredictable element. But, the side-by-side setup removes each player’s focus from the opponent to the screen and the simulation. In order to enhance kinesthetic empathy in
interaction players must be positioned in front of each other, so they can observe and react to the actual performed movements.
2.4 In front remote The research prototypes developed under the label Exertion Interfaces like Table Tennis for Three and Break-out for Two [25] are primarily focused on social interaction, but as they incorporate exertion as a core element, they can be relevantly compared to the technologies we are developing. They differentiate themselves from the standard setup with game-consoles as the opponents have direct visual contact via a videoconference system. Through this visual/audio link the players are able to follow each other’s moves and current state of exertion, as well as talk to and taunt one other in friendly battle. Mueller et al. compares exertion interfaces with standard nonphysically demanding ways of connecting over a distance, and unfolds a range of positive effects of kinesthetic interaction in terms of social connection between the players. However, the focus of our developments has not primarily been on entertainment, social interaction or casual gaming, but on elite sports and on training psychomotor skills [6]. So, when looking closely at the interaction setup of e.g. Break-out for Two it seems like the players will able to anticipate the intent in movements made by the opposing player, but this skill does not seem crucially necessary to win the game to the extend that deceptive moves are required. Break-out for Two is far from playing the actual game of football since the ball is hit against a wall instead being incepted, controlled and played back by another player. Some aspects of the game could possibly be transferred into a training situation as target practice and the other players’ existence would evidently function as a motivating factor. The casual - i.e. not very high demands on specific physical skills other than stamina in the exertion games also underlines a problem of transferability to a particular sport, like an increase in tactical understanding that the player can reposition to his level of expertise in e.g. football. This, of course, has never been the focus of Exertion Interfaces but as it is a significant new development in the HCI-community related to kinesthetic games, it makes a good platform for explaining how our project relates to state-of-the-art and how we build on this to focus on a new domain for interaction design, namely elite sports training of psychomotor skills.
2.5 In front co-located When two participants are placed facing each other, the possibility of designing a space of interaction where the participants action and movements are conditioned by the actions and movement of the other participants, emerges. This setup closely resembles the one-on-one confrontation seen in open sports, e.g. handball, basketball. It is our claim that when players are physically colocated it allows for better communication of movements and bodily signals, compared to side-by-side interaction and in front remote interaction. However, the players are still interacting through a piece of equipment, creating a small distraction in their interaction with each other compared to for example playing the actual sport. We do not see this type of exercise game as a replacement for existing training principals both analog and computationally enhanced but as a new perspective of how to develop exercise game that incorporated aspects inherently present in the open sports. We acknowledge that for training purposes it can be beneficial to isolate a subset of movement patterns or skills rather than playing the full game. In this type of interaction the skills isolated are less definable as the closed skills, e.g. a free throw in basketball or target practice in football.
3. EMPIRICAL STUDIES In order to understand training at highest, elite athletic level, we went through an empirical data-gathering process roughly divided in three main phases; interviews and observations, a participatory workshop, and prototype development involving future users. We will only shortly touch upon the empirical and design process due to the limited amount of space available in this paper. We interviewed seven team coaches and one national team handball coach. Observations were conducted with four sports. In addition to handball we looked into football, taekwondo and basketball. In total we observed six different teams in various depth over a period of four months. The sports were chosen in order to reveal insights in relation to handball – particularly since these four disciplines draw on similar psychomotor abilities and are highly open sports. Furthermore, we included one non-team sport to see if alternative methods were applied. We were interested in comparable types of skills and psychomotor abilities in the various training exercises and how they were conveyed to the athletes. All sessions were reviewed from video recordings afterwards. These observations contributed to the formulation of the five parameters listed in the previous section and specifically two of the parameters emerge from the empirical studies. In order to better understand the differences and similarities across the four sports and to see if training culture and experience might inform one another, we invited a group of elite athletes and coaches to participate in a workshop called SportsCamp. Here they tried exercises from the other sports and, in mixed groups, designed a new training session with completely novel exercises. The participants should focus on the training of psychomotor skills, and mix the insights for the four sports to create exercises that could be shared by all four types of athletes. As an example, all groups took great interest in one particular exercise called ‘One on One’. In this exercise, originating from handball, two people are pitched against one another. Before beginning, the participants are assigned roles; one is defending while the other person is attacking. The person defending has to physically keep the offensive player from getting past him and reach the scoring zone behind him. Should this happen the defensive player immediately must defend a similar zone at the opposite end of the pitch. This exercise requires both athletes to focus closely on the opposite player and his movements, and not merely on performing a specific skill correctly. It is up to the athletes to quickly choose a strategy to solve the given task. At the same time, the possibilities for one athlete to succeed is greatly influenced by how well the opponent performs, and the movements practiced in this exercise can be directly transferred to the actual game of handball. The ‘One on One’ exercise became a key element in the design of all the new exercises in all the participating groups, and also in the further design process in the research project. Generally, the workshop told us that the most engaging drills were competitive, physically challenging, and technically demanding. In the ensuing design process, we invited some of the coaches from the empirical studies to give feedback on a number of design concepts and sketches. This further deepened our understanding of details of the design parameters discussed in the next section.
4. DESIGN PARAMETERS FOR KINESTETIC EMPATHY INTERACTION IN SPORTS In order to provide pragmatic handles in the design process we have crystallized key aspects from the empirical studies and theoretical review into five design parameters. This constitutes a
list of the most relevant aspects of KEI in sports in relation to interaction design and HCI. The first three parameters are directly derived from sports research e.g., [3], [10], [17], [22] and are widely used to describe the skills in open sports. Feedback is included to bridge the sports research and theory to the Industrial Design and HCI community and is focused on the equipment. Finally transferability was stressed by all the interviewed coaches, as the single most important criteria for any exercise to be incorporated in to their professional practice. These parameters have guided the development, and we apply them for evaluation and analysis in Section 6.
4.1 Design parameters Anticipation. In team sports, peripheral awareness, also known as split vision [4], is used by the players to orientate themselves around the field. It is important for them to keep a kinesthetic awareness of teammates as well as opponents. Visual information is used to anticipate the actions of an opponent. Anticipation is the ability to make accurate judgment based on e.g. visual information available before definite information is evident. The perceptual ability is inherently linked to deception and the better a player is at anticipating the opponents next moves the more that opponent will need to rely on deceptive actions [22]. Decision-making. In open sports decision-making is the key and is usually only trained when playing the actual game [10]. How well players plan and organize their actions, according to how the game progresses, is determined by the speed of their decisionmaking and thus effect how well they perform [17]. Tactics may change during the game and always depend on what the opponent is doing. It is important for the players to be able adapt their tactics during the game. The players can either choose to disguise movement intent, minimize the accessibility of information or make use of deceptive actions, such as feints. Deceptive actions are cues that signal one action while something else is intended. The aim is to provide misleading information that will encourage opponents to make the wrong judgment [22]. According to Gréhaigne [17] team sports contain four different tactical notions: opposition to opponents, cooperation with partners, attack on the opposing camp, and defense of one’s own camp. Motivation. Top-athletes’ uncompromising commitment stems from their love of the game and the satisfaction they get from setting and achieving goals [3]. Yet, continuously keeping athletes highly motivated is a key challenge in any sport, for any coach. The athletes can either be extrinsically or intrinsically motivated. Extrinsic motivation stems from external factors (e.g. money), whereas intrinsic motivation occurs when athletes are internally motivated to do something because it either brings them pleasure or because they find it important [3]. One key observation, we were surprised to make, was how playful the training approach is, even at the highest elite level. We had expected to see more drills dedicated towards the training of specific skills but, from our observations and written interviews, we were able to conclude that the exercises that the athletes found most motivating were those that hold a competitive element. Feedback. For the players to know whether what they are doing is right or wrong they have to have some type of feedback. Through kinesthetic Empathy Interaction with a system there will be two types of feedback, internal and external [9]. Internal feedback stems from the participants’ senses and is continuously provided, through the interaction, by the other participants. By learning how to read, react and build on the actions of teammates and opponents, the users will slowly reach an understanding of what works and what does not work in a given situation; much in the
same way as an athlete gradually learns which actions work on a given opponent in a given situation [6]. The external feedback is provided by the system that can explicitly tell or show the users how well they are doing by, for example, giving them a score or showing them in which areas they need to improve. Sensors and actuators can be used to give feedback though clues e.g. light, sound, movement. Transferability. Another key element to the success of the design is whether or not the training transfers into the sport as relevant movements, in terms of physical performance and in how movement choices are made. The movements that are provoked through the use of the equipments have to resemble those utilized when playing the actual sport. Because there is no point in training for example reaction time if the physical movements that you are performing are to far from those one otherwise used when playing the sport. Further more, for an equipment to be successful it is important that the equipment is resizable. The physical requirements for male to female players are very different, as they are for junior player and senior players. Section 5 presents the TacTowers training concept and equipment, aimed at supporting Kinesthetic Empathy Interaction.
5. TACTOWERS To meet our objective of creating training equipment that becomes transparent in interaction between athletes, we developed the TacTowers prototype. The design of TacTowers builds on theoretical characteristics of such equipment as well as the empirical studies across four sports including handball. As we have now synthesized these insights into five design parameters, we can now use these to describe the TacTowers prototype. TacTowers consists of four towers each 2,25 meters tall and with eight plastic “balls”. These balls function as sensor-actuator devices that light up in different colors when hit by a player (see figure 2 and http://www.youtube.com/watch?v=LO2BzQkqj_Y for a video of the prototype). The eight plastic balls are connected by a steel structure inside, and each ball is a little larger than an actual handball. The balls afford hitting with flat hands similar to how handballs (and e.g. basketballs) are hit in blocks and dribbles. The TacTowers can be positioned in different formations and with different relative distance. This ensures that the players are pushed to their physical performance limits concerning jump strength and acceleration. It creates and facilitates a playing field of interaction where the user has to focus on the opponent and his/her movements while playing the game. This is to train their anticipation skills. In all exercise games one player’s moves and decision making are closely depending on what the opponent does; how s/he chooses to jump, where s/he hits a ball etc. The opponent’s precise movements are so important that deceptive actions can be made, for example, by pretending to hit the ball in one direction and then in a split-second change direction by a swift turn of the wrist. The elite athlete needs to observe the position, direction and speed of the ball while using his splitvision skills to constantly monitor and anticipate the opponent actions. This closely resembles the interactive play of the one-onone confrontation in the real open sports, thus ensuring a high degree of transferability. The TacTowers can be placed in different distributed patterns, e.g. on a line or half-circle to simulate the interaction space of playing on the edge of the defensive-zone in handball, where moves are executed in a confined space. With respect to equipment feedback given to players, we have chosen an interaction style inspired by TUI [32], where the
physical control and the physical representation is completely integrated in the plastic balls, and the digital state is signaled by the change of color of the light of the ball. Thus every encounter with the sensors on a ball will result in an immediate feedback on the ball. Hitting a ball may in some exercise games make the “ball”-color move sideways to another tower or up and down in the current tower. Hitting a lit ball horizontally can send the light signal in the direction of the hit onto another tower.
being faster and smarter. To gain advantage, deceptive moves are utilized; to for example trick the opponent into thinking the light is in one direction when really it has appeared at the other end of the distributed surface. If performed right, this will give the player a head start and increase their chance of winning the point. In ‘Lights ON’ the players are both defending and attacking at the same time. The players have their own agenda and whoever is the first to turn on 7 lights wins. No more than 3 lights can be lit on each tower (see Figure 3, picture 3). In this game the players can both turn on lights but they can also defend their “camp” by turning off the opponents light. They continuously have to keep an eye on what the opponent is doing, while at the same time concentrating on turning as many light on as possible.
Figure 2: TacTowers prototype in action Finally, TacTowers is designed to motivate players primarily by challenging relevant psychomotor skills, but also by incorporating a strong competitive element in the training. The competitive element in these types of exercises motivates the athletes to perform to their physical maximum. “That’s just how elite players are wired” as one coach commented. The quick loosing and winning in exercises should motivate continued competition.
5.1 Exercise games The exercise games take departure in different tactical notions described by Gréhaigne [17], see Section 4.1. In the games ‘Blocker’ and ‘One on One’ the players are assigned roles and take turns either defending or attacking. ‘One on One’ is designed to be a physically demanding exercise game. Players are placed on the same side of the towers (see figure 3, picture 2). The player closest to and with his back turned to the towers must physically keep the opposing player from reaching the towers behind him and turning off the light. This game resembles the one-on-one confrontation that exists in the real game of handball. ‘Blocker’ has emphasis on tactical understanding. One player (B) controls the “ball” as a red light signal and his objective is to get it into a goal zone (green light signal). The opposing player (A) uses two “blockers” (blue lights) to defend the goal zone and corner his/her opponent (see figure 3, picture 1). In this game the players continually have to anticipate the opponents action, think ahead and plan what to do next to either obstruct the attacking player from reaching the goal or to keep from hitting the blocks placed by the defender. In ‘Extinguish’, the simplest game of the four tested, the players are competing on speed and only have to concentrate on reaching the goal before the opponent. The computer randomly turns on a light on a TacTower and the first player to hit it wins the point (see figure 3, picture 4). In this game there is no way of defending since there is no way to counter act a point that has already been won. The only way of keeping the opponent from winning is by
Figure 3: The four exercise games, ‘Blocker’, ‘One-on-One’, ‘Lights-ON’ and ‘Extinguish’.
5.2 Technical Implementation of TacTowers The interaction and computational elements of the TacTowers prototype (Figure 2) are implemented as described below. Each of the four Towers consists of: a tower controlling board; a USB/serial connection to a controlling PC; six (motorcycle) batteries. Each of the 32 balls consists of: 12 touch sensors placed in 4 bands of 3 sensors; 8 RGB diodes, a controller board. Exercise game engine: C++ game framework that runs on an ordinary laptop PC; special tower hardware drivers; Game menu controller. The exercise game engine features a simple game framework allowing the quick creation and tuning of games. A typical game logic can be written in one page of code. When a game is implemented it is made available in the game menu controller, that let players choose among the exercise games in a selection mode on the actual towers, thus the players select games with the touch sensors, on balls on, one of the towers and multi-ball light feedback immediately signals which game has been chosen, thus the players never have to interact with a traditional computer. The exercise game engine also has mechanisms to measure the time between ball hits and number of ball hits allowing statistics to be reported. Programming of the game engine has focused on simplicity and efficiency, since the reaction time between sensor triggering and actuator reaction is very critical to get the exercise games to flow at the necessary high speed to be realistic. The current implementation, include a full size PC controlling the four towers connected in a cabled network. However, the towers are prepared with Wi-Fi units and small embedded computers allowing each tower to be a self-contained peer in a peer-to-peer
[5] network of towers, that may be dynamically configured in sets of e.g. 2, 3, 4, 6 or 8 towers. Configuration will take place solely through a sequence of hits on a ball on each of the towers indicating with a special hit combination which of the towers will run as the master game engine in the specific setting. The material cost of the current prototype is approximately 60.000 USD (2011 prices), where the electronics is approximately the majority of the price. A mass-produced manufactured version of a set of 4 TacTowers would be expected to be in the price range of 20.000 USD (2011 prices). We thus believe it will be feasible to produce for professional training settings and in the future for colleges, schools and leisure sports environments.
regarding anticipation and decision-making, as the point it to increase ability to make correct decisions while in stressful play. When the players were asked how they used anticipation and tactics most players expressed that they had primarily focused on the TacTowers and the lights turning on and off and not on the other player. However, video analysis showed that not only were they looking closely at the opponent before and during the games, they developed and experimented with feints to cheat the opponents. One possible explanation for their response in the interviews may be that they were not as consciously aware of the decision-making as they were of their explicit reactions to the lights.
6. EVALUATION
In the exercise games ‘Extinguish’ and ‘Lights-ON’, the lights and equipment, requires the players’ attention and immediate interaction and kinesthetic dependency between the players are secondary. In ‘Lights-ON’, it is even questionable whether it is present at all. Our video analysis showed that players developed a strategy before starting the game and stuck to it without being aware of or affected by the opponent’s actions. Probably the game-design gave too much emphasis on speed at the expense of psychomotor skills. So, in contrast to ‘Blocker’ too much physical stress removes focus on anticipatory and decision-making-skills. ‘Extinguish’ resemble ‘Lights-ON’ in that the players are defending and attacking at the same time and also require the players to focus on the equipment. However, in ‘Extinguish’ the players have to search the distributed surface for where the next light is going to appear. In this case, video analysis made it clear that players also kept a keen eye on the opponent’s actions. Players often responded to opponent’s sudden acceleration and not because they have spotted the light. This game makes it lucrative to use and train deceptive movements.
We have conducted two tests of TacTowers, with national level professional handball teams. Each test lasted approximately an hour with 5-6 players each time. It included a short introduction to each exercise game and a tournament, best of three, followed by an evaluation with coaches and players. Both test were recorded on video primarily in order to evaluate the player’s use of anticipation and decision-making, while the remaining parameters were evaluated based on a combination of video recordings and interviews. Video analysis was conducted by looking through each play-situation from two angles in slow motion. In order to track players’ movements and intentions focus was on each player’s direction of gaze, eye contact and with the other player.
6.1 Anticipation and decision-making ‘Blocker’ is the most tactically challenging of the four exercise games. The game calls for the use of deceptive movements by the attacking player who is trying to gain headway and reach the goal (green light) without the defending player obstructing him. Likewise the defending player needs to efficiently anticipate the opponents next move to win. In figure 4 a play sequence from ‘Blocker’ exemplifies how anticipation was observed. Frame 1 shows the defending player (A) already in motion and on his way to obstruct the forthcoming attack. Before the opponent has acted out his intention the defending player has anticipated what he is going to do and is already on the move. This buys him enough time to place a block (blue light) on the next tower where he anticipates the opponent is going to hit the “ball” (red light) to next (see figure 4, frame 3). In this case, however, he was tricked by the attacking player, who instead of hitting the ball in a horizontal line, made a diagonal pass thus passing by the block and making it easy to hit the ball up into the goal.
Figure 4: Anticipation in the exercise game ‘Blocker’. The video analysis showed that the tactical element incorporated into the game slowed down the player’s movements, thus players were not adequately physically challenged. This definitely is a problem and will have to be changed to ensure transferability beyond the development of psychomotor skills. Lack of physical stress in the exercise games, reduces the learning potential
In the exercise game ‘One-on-One’ the physicality of the interaction also encourages the use of deception by the attacking player. In frame 2 (in figure 5) it is possible to see how the attacking player is looking to his left and slightly moving in that direction and then within a split second changes direction (frame 3) and accelerates in the opposite direction. If not caught by the opponent this will give him a little extra time and possibly ensures that he is able to reach is goal. Training decision-making and anticipation in sports with interactive equipment requires tremendous attention to detail when it comes to both physical setup and digital definitions of game-play. The exercises need to induce adequate physical stress while also putting demand on the psychomotor skills of decision-making and anticipation.
Figure 5: Video snapshots of the ‘One-on-One’ game. The sequence illustrates how the game affords the use of deception.
6.2 Feedback When a sensor is activated, players receive feedback from a light turning on, as well as a physical indication when the hand meets the equipment. In the tests we found that the 5x5 cm sensors were
too small and detected less than 95% of the hits. This interrupted the players’ flow, as one player explained; “when the light signal does not react, I have to stop and look at the ball”. This corresponded well with the video analysis where the players were already focusing on the next ball to hit and had planned the movement unconsciously to that effect. However, when a sensor did not detect a hit properly the next preliminary movement is cancelled. This was observed several times in the two tests. So, especially when designing this type of training equipment it is important that all relevant actions are registered by the system because even a small inconsistency will remove focus from the skill training aimed for - even at this prototype-level of development. Feedback also needs to be consistent and preferably perceptible at an unconscious level that does not obstruct the game itself.
6.3 Motivation In a matter of minutes the players were excited, sweating, shouting and cheering for each other. Victories were elaborately celebrated (see figure 6, frame C) and losing were followed by visible disappointment (see figure 6, frame B). The different exercise games intrinsically motivated players through physical engagement and spoke to their competitive instinct. And if a game hadn’t been won, there was always the possibly of launching a surprise attack and just tackling the opponent after the game to regain the lost pride. The immediate feedback, provided by the system, was also a motivating factor. All the exercise games are relatively short and the players quickly found satisfaction in wining points or would strive at doing better when a tactical notion failed them or a feint deceived them. Our tests showed that TacTowers was able to motivate the players through physical engagement and the competitive elements of exercise games. Adding a competitive element is an easy way to immediately motivate athletes. However, in post-interviews our users argued that adding measurability would be a prerequisite for maintaining long-term engagement with the training equipment.
actual handball well. Although a training setup will always be artificial, TacTowers requires users to react to the opponent’s moves and not merely computer-based outputs. This ensures transferability of the psychomotor skills we aimed for. This conclusion is based on the expert reflections of the players and coaches. Actual proof of the efficiency of the TacTowers training can only be secured by prolonged tests with athletes at high enough level. Something we aim for in future studies.
Figure 7: Frame A illustrates a snapshot of the exercise game 'One-on-One’. Frame B is a photo from a handball match.
7. FUTURE WORK As we have been getting experts’ advise on the development of the TacTowers from e.g. national level coaches, we have seen that the simple and dynamic setup that the TacTowers provide could be useful in other contexts beyond handball. Several different sports have the same need for training fast movements in a defined space moving quickly between high and low positions. Depending on the exercise games executed by TacTowers there are multiple possibilities of establishing relevant and transferable training to a range of sports e.g. badminton, volley and squash. The competitive and engaging – playful and entertaining – aspects of the TacTowers’ use indicate that the equipment could also be used for less elite oriented training activities, e.g. educational or leisure. In such contexts the requirements for games effectively directed towards specific skills are not as high, but TacTowers might be an engaging alternative to introducing more exercise and physical activity in everyday context. This is an avenue of future work that we are currently considering.
8. CONCLUSION Figure 6: Three examples where players physically express engagement in the exercise games and the competition.
6.4 Transferability As mentioned in section 4, transferability can be achieved either through the movements performed or the way movement choices are made. TacTowers facilitates transferability to real handball with e.g. the bodily postures and movements in the exercise game ‘One-on-One’ as illustrated by frame B (see figure 7). The players are using physical strength to push each other and thereby moving the other person, to either get around or as the defending player to keep the opponent from slipping by and scoring a point. In the other exercises the movements used are not as directly transferable to handball. Transferability is instead reached in a combination of the training of basic skills like strength, acceleration and speed in combination with the psychomotor skills of decision-making and anticipation. As mentioned in section 6.1 exercises should demand that players not merely engage these psychomotor skills casually, but that they are mentally challenged while under physical pressure and competitive stress. Our observations showed that by having two players in an in-front co-located setup, TacTowers create a training setup that resembles
We have developed an interactive collective training concept that goes beyond existing training techniques and support the athletes in focusing on the psychomotor skills, anticipation and decisionmaking. By placing the equipment in between the athletes/players, we have observed from test sessions that the athletes use split vision in order to support decision-making, and that they often look directly at each other in close encounters to make their choice of actions based on the opponent behavior or expected behavior. To our knowledge, no existing training equipment affords such transparency and kinesthetic empathy in interaction. Our tests show it is possible to design physical training equipment that trains perceptual skills. This type of training can thus be integrated in the physical training. When asked, both coaches and players agreed that TacTowers could be used outside team training, comparable to a piece of weight-lifting equipment. Thus it is possible to integrate TacTowers in daily training without abandoning existing session. One of the strength of TacTowers is that is it can be used without a coach with a part of the team only. The paper shows how it is possible to design physical training equipment that trains psychomotor skills, such as anticipation and decision-making. Based on video analysis of the test sessions, it is possible to conclude that both anticipation and decision-making is not only used by the athletes in the training but in the exercise games that work the best, ‘One-on-One’ and ‘Extinguish’, it is
evident how these skills are essential to participation and winning. Effective game-design is an important factor when deciding which skills are trained while keeping games fast-paced and competitive, and challenge the players’ physical abilities.
[13] Foster, Susan Leigh, 2008. Movement’s contagion: the kinesthtic impact of performance. In The Cambridge Companion to Performance Studies, edited by Tracy C. Davis. Cambridge: Cambridge University Press.
With the empathic aspect in the kinesthetic interaction, we emphasize the collective interaction space where decisions made by one participant continually depend on how others choose to engage. The interaction space affords a shared kinesthetic consciousness that is associated with but not necessarily present in social and collective interaction. This as a general concept that may we believe will develop beyond elite sports and into school and leisure settings as well as inspire domains beyond sports.
[14] Fredens, K. Det nervoese grundlag for informations forarbejdning og laering (in Danish). Klinisk Sygepleje. 5 (1989).
9. ACKNOWLEDGEMENTS
[17] Gréhaigne, J.F., Godbout, P. and Bouthier, D. The Foundations of Tactics and Strategy in Team Sports. Journal of Teaching In Physical Education, 1999, 18, 159-174.
We would like to thank our colleagues from Center for Interactive Spaces as well as Active Institute and Dept. of Sports Science both Aarhus University. We are also grateful for the help provided by TeamDanmark and the players and coaches from BSV and Aarhus Handball teams.
10. REFERENCES [1] Bideau, B. et al. Virtual reality applied to sports: do handball goalkeepers react realistically to simulated synthetic opponents. In Proc. of SIGGRAPH 04. ACM Press (2004), 210-216. [2] Boucher, M., Kinetic Synaesthesia: Experiencing Dance in Multimedia Scenographies. Contemporary Aesthetics (2002), vol. 2. Directory of Open Access Journals, ejournal [3] Burton, D., Raedeke, T.D. Sports Psychology for Coaches. Human Kinetics, Il, USA, 2004. [4] Bjurwill, C., Perceptual-Motor Behavior In Sport: The Double Reaction. Perceptual and Motor Skills, 1991 72, 137138. [5] Christensen B.G., Kristensen M.D., Hansen F.A., Bouvin N.O. (2008): Enabling Co-located Learning over Mobile Ad Hoc P2P with LightPeers. In the Journal of Network (JNW) Volume 3 Issue 2, February 2008. ISSN 1796-2056 [6] Czajkowski, Z. The Essence and Importance of Timing (sense of surprise) in Fencing. Kinesiology 2006, 16(33), pp. 35-42. [7] DARTFISH™. http://www.dartfish.com/en/index.htm [8] Davis et al. Physical Education and the Study of Sport, second ed., Mosby, Spain, 1994. [9] Fadde, P. J., 2010. Training Complex Psychomotor Performance Skills: A Part-Task Approach. In Silber, K.H. & Foshay, W.R., ed. Handbook of Improving Performance in the Workplace. Volume 1: instructional design and training delivery. A publication for The International Society for Performance Improvement. New York: Pfeiffer [10] Flyn, R. Anticipation and Deception in Squash. Presented to the 9th Squash Australia/PSCAA National Coaching conference. 1996, Australian Institute of Sport, Canberra. [11] Fogtmann, M.H. Kinesthetic Empathy Interaction Exploring the Possibilities of Psychomotor Abilities in Interaction Design. In proc. of 2nd Workshop on Physicality, 2-3 Sep. 2007, Lancaster University, UK [12] Fogtmann, M.H., Fritsch, J. and Kortbek, K.J. Kinesthetic Interaction – Revealing the Bodily Potential in Interaction Design. OZCHI ’08, ACM Cairns, Australia, 2008.
[15] Fredens, K. Hvad er motorik? Motorrikkens betydning for den kognitive udvikling (in Danish). Tidsskrift for idræt. 3 (1987). [16] GoalRef™. http://www.goalref.com
[18] Grønbæk, K., Iversen, O.S., Kortbek, K.J., Nielsen, K.R., Aagaard, L. Interactive Floor Support for Kinesthetic Interaction in Children Learning Environments (2007). In proceedings of INTERACT 2007, September 10-14, Rio de Janeiro, Brazil. Springer Verlag [19] Hämäläinen, P. Interactive Video Mirrors for Sports Training. In Proc. Norwich ´04, ACM Press (2004). [20] Hawk-Eye™. http://www.hawkeyeinnovations.co.uk [21] Intelligym, ACE - Applied Cognitive Engineering. http://www.intelligym.com [22] Jackson, R. F., Warren, S. and Abernethy, B. Anticipation Skill and Susceptibility to Deceptive Movements. Acta Psychologica, 2006, 123, pp. 355-371. [23] Krogh, P. G., and Petersen, M. G., 2008. Collective Interaction – Let’s join forces. In proceedings of COOP’08, May 20-23 2008, Carry-le-Rouet, France, 193-204. [24] Makato. http://www.makoto-usa.com/new/index.html [25] Mueller, F., Agamanolis, S. and Picard, R. Exertion Interfaces: Sports over a Distance for Social Bonding and Fun Proceedings of the SIGCHI conference on Human factors in computing systems, ACM, Ft. Lauderdale, Florida, USA, 2003. [26] Mueller, F., Gibbs, M.R. and Vetere, F. Design Influence on Social Play in Distributed Exertion Games. CHI 2009, ACM Press (2009), 1539-1548. [27] Ludvigsen, M., Fogtmann, M. H., and Grønbæk, K., 2010. TacTowers: An Interactive Training Equipment for Elite Athletes. In Proceedings of the 8th ACM Conference on Designing Interactive Systems (DIS '10). ACM, 412-415. [28] Octopus Trainer™. http://www.octopustrainer.dk/sprog_en [29] Playstation® Move. http://us.playstation.com/ps3/playstation-move/ [30] Poulton, E.C. One prediction in skilled movements. Psychological Bulletin (1957) 54, 467-478. [31] Schachtel, Ernest G., 1967. Experiential Foundations of Rorschach’s Test. London: Tavistock Publications. [32] Ullmer, B. and Ishii, H. 2000. Emerging frameworks for tangible user interfaces. IBM Syst. J. 39, 3-4 (Jul. 2000), 915-931. [33] WII™. http://us.www.wii.com [34] Xbox Kinect™. http://www.xbox.com/en-US/kinect
