Evidence-Based Practices In Competitive Sports

Competitive sports became a very high-tech and cutting-edge field. This happens in elite athletes and also in their young talented counterparts. A lot of records, podium, final, and semi-final spots are granted or lost because of “details.” Hence, athletes and coaches are supported by sport scientists that analyze any major or minor technique detail with the aim of helping the athlete to excel. The same reasoning can be used for clinicians (e.g., sports medicine, rehabilitation, physiotherapy). Diagnosis and prescription are evidence-based practices supported on cutting-edge procedures.

The human movement assessment has the following aims: (i) to enhance the participant’s performance, and (ii) to prevent injuries. It involves four main phases

(Figure 1): (i) preparation of the observation (i.e., understand the theoretical background and the scientific evidence that are the basis of the analysis), (ii) observation of the movement, (iii) diagnosis (i.e., assessment and evaluation of the technique), and (iv) prescription (i.e., delivering feedbacks) to improve the performance [1].

Human movement and technique analysis is a topic especially important in biomechanics, motor learning, and pedagogy. This can be carried out in one of three ways [2]: (i) free observation, (ii) practical observation, or (iii) scientific or systematic observation (Table 1). The scientific or systematic observation seems to be beyond the interest of some practitioners. The equipment, apparatus, and procedures involved in such assessments are often quite complex, time consuming, and less affordable. However, practitioners are currently aware of the importance of the technique analysis to enhance the performance. Free observation might impose a large bias because of intra-participant and inter-participant reliability and accuracy issues. Based on this reasoning, practitioners select less expensive, less time-consuming, and more straightforward procedures to understand the participant’s technique. There are commercially available software and applications (shareware and freeware) to help practitioners in such tasks. Most of those tools are based on the record of the performer, analysis of the movie, and delivery of individual multimedia reports to the participants. These multimedia reports may include pictures (i.e., snapshots), videos, audio, basic 2D kinematic measurements (e.g., angles, distances, and velocities), text, and illustrations to highlight the main points of the motor skill. Hence, these reports are very attractive and an easy way of athletes and patients gathering awareness of their strong and weak points. Analysis can be carried out in both training and competition settings. Athletes and patients might have a briefing with their coaches or physicians who will explain to them the main findings (e.g., causes, consequences, and ways to correct an error or fault). They can bring home those edited videos and do a detailed analysis of their performances.

Multimedia motion analysis tools are used on a regular basis by both academics (for research purposes), sports analysts (for control and evaluation of the athlete), and clinicians (for assessment of their patients) (Figure 2). Advances in information technology have allowed computer scientists and engineers to develop these movement-specific feedback systems in cooperation with biomechanists, physiologists, psychologists, and strength and conditioning experts [3]. In the last couple of years, several research papers were published using this affordable software as measuring tools in several settings, sports, and fields of knowledge. Despite popularity among practitioners, to the best of our knowledge, a review with a critical analysis to these multimedia tools was never published. The closest to the review of affordable motion analysis tools to deliver multimedia feedback to athletes and coaches was more than one decade ago [4], and even so, the focus was in other highly challenging or complex motion capture systems besides different biofeedback ones.

The aim of this paper was to review and summarize the existing affordable multimedia motion analysis tools for human movement, notably for sports technique, including some fundaments about motor learning and visual feedback, main key features, and application fields.

Because long, classical motor behavior theories consider the feedback as a key element to motor learning [5], for example, both Adams and Schmidt theories of motor skill acquisition incorporated concurrent information feedback into closed-loop accounts of motor learning. Information is used in a closed-loop error detection and correction framework. There is a very solid body of knowledge about the fact that feedback is an essential manner to enhance performance [6]. Many research focused on the effect of different types of feedback in the improvement of motor skills.

Feedback (Figure 3) is available to the learner both during the ongoing movement sequence (concurrent feedback) and on completion of the movement sequence (terminal feedback) [7]. Feedback can have origin in intrinsic or extrinsic information. Intrinsic feedback is based on kinesthetic response arising from sensory receptors in the skin, tendons, muscles, and joints, which provides performers with information about their movements, whereas extrinsic feedback (also known as augmented feedback) comes from a second party, that is, an external source, such as the coach, the Physical Education teacher, the clinical practitioner, or some sort of equipment. Convincing experimental evidence exists about performance improvements in the absence of augmented feedback, that is, only with intrinsic feedback [6]. In such cases, performers are able to detect their own errors or faults and correct it themselves. Nevertheless, on the flip side, augmented feedback can benefit performers. Augmented feedback should not be used to substitute the intrinsic feedback but rather to complement it though [6].

A meta-analysis (607 effect sizes and 23,663 observations) suggests that feedback improved performance on average of d = 0.41 [8].

Findings have shown that visual feedback facilitates learning in the practice sequence, after early trials of learning [10]. On top of that, demonstration seems to be more effective in improving performance than information and specific practice on the isolated components of the movement dynamics [10]. The roles of instruction and demonstration in the modeling of the coaching practice were already reviewed and can be found somewhere else [11].

Based on this framework, coaches, Physical Education teachers, and health practitioners deliver feedbacks to their athletes, students, and patients, respectively, on a regular basis. Although intrinsic feedback should not be disregarded, extrinsic one plays a major role in motor learning. Evidence suggests that demonstration and visual feedback meaningfully facilitates all process. In this sense, affordable multimedia motion analysis software can and should be used. In a very comprehensive and straightforward way, it is possible to deliver useful and informative details to performers. Society, especially in developed and developing countries, is strongly based on IT tools for everyday tasks. Most of the people are familiar with multimedia applications and software in the user perspective. Thus, the use of multimedia motion analysis tool is mainly an extension of such interest with IT

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There are available several (freeware and shareware) multimedia software to analyze human movements. The most cited and selected ones are as follows: (i) TeamPro® (Dartfish, Fribourg, Switzerland), (ii) Kinovea® (v.0.8.15, open source project by Joan Charmant, Bordeaux France), (iii) Quintic video analysis® (v21, Quintic Consultancy Limited, Coventry, UK), (iv) Siliconcoach Pro® (v.7.0, Siliconcoach, Dunedin, New Zealand), and (v) Templo® (v6, Contemplas GmbH, Kempten, Germany).

All multimedia motion analysis softwares currently available have fairly the same structure or modules: (i) database and management, (ii) video capture, (iii) video analysis, and (iv) video report (Figure 4). Database and management are used mainly to key in participant´s personal data and import and export, open, and save files. Video capture is related to the video recording, for example, synchronizing different cameras and configuring the video format (AVI, MPG, MP4, MOV, etc.). Video analysis involves the editing of the movies (cut and paste different sections of the movie, use of filters, insert text, graphics, or some basic 2D kinematic measurements). Video report is an individual multimedia file (including the video, complemented with text and optional audio) of the participant’s performance.

Regarding the video capture, a key feature is the possibility to input several types of video codecs (e.g., DV, DivX, MPEG, AVI) and have live capture using high-definition camcorders (e.g., HDV, AVCHD, MiniDv), high-speed cameras, and even Webcam or network cameras. A very useful feature is to delay the display of live stream by a few seconds. This allows the participants to perform the motor skill and allow the evaluator to analyze it on the screen together. It is also possible to synchronize more than one camera to have different views of the motor skill.

For the video analysis, movies can be displayed in several speeds (i.e., sampling rates) according to the capture settings. It is possible to playback roughly between 1% and 200% of the initial speed or frame by frame. Drawing and text tools allow adding shapes (e.g., lines, arrows, and circles) and short comments about the performance in key frames. A useful tool is the tracking system. It is possible to do a 2D manual or semi-automatic track of an object (e.g., a ball) or anatomical landmarks’ trajectories. Some of the software includes a feature to assess the 2D location of the center of mass of 18-point anatomical models. Basic 2D linear and angular kinematic measurements are also included (distance, angle, speed, and acceleration). For qualitative analysis, an interesting tool is the comparison of different participants or the same participant in different moments. This can be done by either opening the videos side by side or overlaying the videos. Overlaying involves the selection of corresponding frames that calculate video coordinates using advanced image-processing algorithms to combine and blend the content. The software will present a video clip that shows both participants together in one single movie and one single background.

After the analysis and editing, a report can be generated. Reports may include video clip with audio, graphics, text, and measurements. Reports can be exported as snapshots (i.e., one frame) of the video clip, a sequence of snapshots, slideshow, or the edited video. Videos might be saved in several extensions (e.g., AVI, MOV, MPEG, and WMV) so that these can be easily opened in any application. Data can also be exported in spreadsheet formats (XLS, XLSX, CSV, and TXT).

These items of equipment are a suitable way to analyze the technique in competitive sports (Table 2). Some software products (e.g., Templo®) include specific analysis protocols for several sports, such as golf, gymnastics, swimming, martial arts, team games, athletics, skii, and power training. The default protocols provide predefined analysis patterns and parameters to be measured. Research publications with this type of procedures exist since the early 2000s, but the number of papers published seems to boost around late 2012 and early 2013 (N = 8, 47.05% of all papers found in the sports literature). Most of the research aimed to do kinematical analysis of closed motor skills (N = 14, 77.77%). Interestingly, much attention was dedicated to aquatic sports (e.g., water polo and competitive swimming; N = 4, 22.22%) and with no surprise to gait (e.g., running and sprinting; N = 3, 16.66%). Therefore, these tools are used mainly in translational research, bridging basic or fundamental knowledge with useful practical or applied findings that help to enhance human performance or health.

Kinovea® was used to analyze the validity and reliability of an alternative method for measuring the flight time and height of vertical jumping [12], running on a treadmill [13], shot in table tennis [14], and shuttle run [15]. SilliconCoach® was reported as the tool used for the characterization of the temporal aspects of the strongman event “tire flip” [16] and to identify the effect of plyometric training, when added to habitual training regimes, on swim start performance of adolescents [17], and the effect of short-term Swiss ball training on core stability and running economy [18] and water polo swimming patterns [19]. Quintic® was selected to analyze soccer skills [20], swimming starts [21], and Rugby union line-out throw [22]. Templo® was used to assess active drag in swimming [23] and countermovement jump [24]. Dartfish® was selected for the kinematic analysis of the kick in Rugby [25], uphill racewalking [26], start in sprinting [27], and hang power clean [28].

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In clinical settings, these tolls can be used for gait analysis, ergonomics, injury prevention, fitness testing, prosthetics and orthopedics, podiatry, physiotherapy, and physical medicine (Table 3). Most of the research found in the literature goes back to 2006, although a large number of papers were published in the last couple of years (i.e., 2012 and 2013; N = 16, 69.56%). Most of the motor skills assessed are related to daily activities, such as walking, standing, or seating, in a wide variety of diseases, conditions, and syndromes (N = 12, 52.17%). A good share of attention was devoted to the injury prevention of competitive athletes (N = 4, 17.39%) and assessment of the measurement accuracy (N = 4, 17.39%).

Kinovea was used for the analysis of the supination and pronation movements of the forearm assembling jewelry, that is, in ergonomics setting [29], measurement of functional heel pad behavior in-shoe during gait using orthotic embedded ultrasonography [30], or the hyoid and larynx swallowing [31] and mastication [32]. A 2D video analysis using Siliconcoach® was developed and validated to measure core ability in healthy athletes [33] and also to assess dynamic knee joint range of motion [34]. Quintic® motion analysis was reported as the apparatus used to assess the mechanical properties of lower-limb prosthesis technology [35], whole-body vibration training [36], gait in Parkinson’s patients [37], and knee valgus [38]. Templo® was reported to be used for the analysis of a human upper limb robotic system [39,40] and a knee orthosis [41,42]. Podiatry research, such as the effect of foot orthoses on rearfoot motion [43], injury prevention in Cricket [44], knee hyperextension in patients after stroke [45], and knee valgus [46], was evaluated using Siliconcoach®. Dartfish® was reportedly used in several studies in clinical settings to assess joint angles during functional testing [47-48], posture in pregnant women [49], patients with postural backache [50], and the relation between perception and visual-motor skills [51].

These motion analysis tools can be used for the development of observational skills by Physical Education trainee teachers and Sport Science students.

Such tools can also be used in Physical Education classes to give students immediate or delayed visual feedback about a performance or a motor skill and may provide visual feedback in the classroom, which is a straightforward way to become aware of a performance and skill compared with a verbal description by the teacher [52].

For education purposes, some software (e.g., Quintic®) provides comprehensive tutorials, sport-specific questions, and a library of approximately 300 video clips from more than 21 different sports so that a teacher can demonstrate and teach technique, motor skill, and human movement in an interactive manner. Evidence suggests that video feedback may be an effective instructional technology that can be used within the secondary physical education setting to improve the technical aspects of skills and skill performances

[53].

However, the use of these teaching tools is not a standard procedure in most schools even in developed countries [54]. The findings show the high level of enthusiasm of the trainees, university tutors, and school‐based Physical Education teachers for making more use of this technology in teaching and learning Physical Education and their willingness to make changes in their practice to accommodate this. The findings also reveal a severe shortage of participant‐specific professional development and a widespread lack of understanding of needs, which was felt to have contributed to the lack of relevant resources to which most school departments had access [55].

The report of other software and applications falls beyond the aim of this paper. However, tablets and smartphones are very popular IT equipment in some countries. Several developers designed and have commercially available comprehensive apps for educational purposes. As it happens with a personal computer, it is possible to record, save, edit, and analyze motor skills. This might be more convenient in some educational settings because such tablets and smartphones are available to many students. Nevertheless, evidence from pedagogy research to clear out the real effects of these tools in the effectiveness of the teaching-learning process should be carried out in the near future.

Sports, education, and health practitioners have a strong focus on human movement. All of them strive to deliver useful feedbacks to athletes, students, and patients about their performances. Recent developments in information technology boosted the access to affordable and straightforward tools to assess human movement in lab and field settings. Besides that, performers are provided immediately, on the spot, or in a very short period with comprehensive and useful multimedia reports. Concurrent intrinsic and augmented feedback from those reports is expected to help participants to improve the motor skills efficiency and enhance their performances. From an academic point of view, in the last couple of years, the number of papers reporting the use of such tools increased in a very meaningful way, especially in the so-called applied or translational research, both in competitive sports and health sciences fields.

In a society that has become quite advanced in technology, where items of IT and multimedia equipment are available to most people, the easy access to multimedia motion analysis tool might become widespread even more in a near future and become a common practice among researchers and practitioners. This paper highlights the fact that multimedia motion analysis software is a tool for research and a part of the daily practice of sports and health professionals.