GB2614700A - System and method for coaching a swimmer - Google Patents

Abstract

A system 100 for coaching a swimmer comprises a primary sensing unit 102, a memory unit 104, a processor 106, and a display unit 108. The primary sensing unit 102is positioned between shoulder blades of the swimmer and is configured to sense and measure movement of the shoulder blades during swimming; the processor 106 is configured to analyse the sensed and measured movement of the shoulder blades to determine stroke related data for the swimmer, compare the determined stroke related data with stroke related parameters stored in the memory unit 104 to derive at least one insight, and retrieve a set of instructions from the memory unit 104 based on the derived at least one insight; the display unit 108 is arranged to display a graphical representation of the stroke related data and the retrieved set of instructions in which the retrieved set of instructions are configured to coach the swimmer. The system may also include a secondary sensing unit positioned on a user’s wrist.

Description

SYSTEM AND METHOD FOR COACHING A SWIMMER TECHNICAL FIELD

The present disclosure relates generally to swimming technique analysis; and more specifically, to a system and method for coaching a swimmer 5 for improving a stroke of the swimmer.

BACKGROUND

Swimming is a technique-oriented activity. Swimming in various environments such as competitive sport environments for e.g., in triathlons, or to complete fastest laps possible in a pool of water, or in non-competitive environments such as open water swimming requires different skillsets in terms of stroke technique as they present varying types and degrees of challenges to swimmers. In many cases, a swimmer experienced with swimming in one type of environment may not be aptly, or optimally, skilled and suited to swim in another type of environment.

It is hard for a swimmer to be aware of their stroke and what they are doing wrong.

Receiving lessons or coaching from a swim teacher or coach may be an option, but it is expensive, and the quality of that coaching varies greatly. Moreover, it is sometimes unfeasible to have a physical coach available at all times for correction of strokes made by the swimmer. For example, a coach for providing coaching for a particular type of swim stroke as desired to be learned, may not always be feasible. Regardless of the environment, it may be tedious for the coach as well to efficiently monitor and track the performance of the swimmer from one swimming session to another, as coaches themselves can also struggle to identify stroke faults, prioritise and correct them effectively with their swimmers. Furthermore, even with a coach, it may difficult for the swimmer to access any playback of his or her strokes in order to track and subsequently improve their performance over multiple swimming sessions, especially since filming of video is not allowed in many pools for privacy reasons.

In light of the aforementioned drawbacks, there exists a need of some means for coaching swimmers efficiently and in a cost-effective manner 5 for improving swimming techniques.

SUMMARY

The present disclosure seeks to provide a system for coaching a swimmer. The present disclosure also seeks to provide a method for coaching a swimmer. The present disclosure seeks to provide a solution io to the existing problem of providing a physical coach to a swimmer as it may become cost-intensive yet remain inefficient in that it may be tedious and cumbersome for the coach to monitor the performance of the swimmer during one, or even over multiple, swimming sessions. An aim of the present disclosure is to provide a solution that overcomes, at least partially, the aforementioned problems encountered in prior art, and to provide a system that is cost-effective yet efficient in coaching a swimmer.

In one aspect, the present disclosure provides a system for coaching a swimmer, the system comprising: -a primary sensing unit positioned between shoulder blades the swimmer, the sensing unit is configured to sense and measure movement of the shoulder blades during a swimming session; -a memory unit comprising stroke related parameters stored therein; -a processor in communication with the primary sensing unit and the memory unit, the processor configured to: -analyse the sensed and measured movement of the shoulder blades to determine stroke related data for the swimmer; - compare the determined stroke related data with the stroke related parameters to derive at least one insight; - retrieve a set of instructions from the memory unit based on the derived at least one insight; and -a display unit in communication with the processor, the display unit arranged to display a graphical representation of the stroke related data and the retrieved set of instructions, wherein the retrieved set of instructions are configured to coach the swimmer.

Optionally, the system further comprises at least one secondary sensing unit poisoned on at least one wrist of the swimmer, the secondary sensing unit is configured to sense and measure movement of the at least one wrist of the swimmer during the swimming session and wherein the at least one secondary sensing unit is communicably coupled with the memory unit and the processor.

Optionally, analysing the sensed and measured movement of the shoulder blades and the at least one wrist to determine stroke related data for the swimmer, the processor is further configured to: - log data related to movement of the shoulder blades and the at least on wrist during the swimming session from the primary sensing unit and the at least one secondary sensing unit; - identify start and end of stroke from the logged data using pitch rate criteria; - determine orientations from the logged data and the identified start and end of stroke; -calculate direction of average acceleration over stroke cycle using orientations; - determine positions in space from the logged data, based on the identified start and end of stroke and re-determine orientations based on the calculated direction of average acceleration; and -adjust initial angle between the shoulder blades and the wrist such that the start and end of stroke is in same position.

Typically, "the same position" is considered relative to the position of the 5 swimmer's body.

Embodiments of the present disclosure substantially eliminate or at least partially address the aforementioned drawbacks typically encountered with use of a physical coach, and provide a cost-effective and efficient system for coaching the swimmer. The present disclosure solves the problems most swimmers have of not having a swimming coach. The present disclosure further solves problem of privacy and privacy regulations which in most cases forbid filming and film analysis, video sharing of swimmers between swimmers and coaches, and overcomes complexity, regulations time and resources needed to comply with regulation of video acquisition particularly for under-aged swimmers, which in most countries mean that videoing is not allowed for swimmers aged below 16 to 18 years old.

Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed zo description of the illustrative embodiments construed in conjunction with the appended claims that follow.

It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended 25 claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those skilled in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.

Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein: FIG. 1 is a schematic illustration of a system for coaching a 10 swimmer, in accordance with an embodiment of the present disclosure.

In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description illustrates embodiments of the present zo disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.

The present disclosure is concerned about movement detection, transmission, calculation and correction of swimming techniques that are typical and necessary for a swimming stroke to make a body float and move in water. The disclosed system and method help a swimmer to improve his/her swimming techniques for enhancing health benefits, preventing injuries, all while saving time that may be lost by depending only on a physical swimming coach.

In overview, embodiments of the present disclosure are concerned with a system for coaching a swimmer. The embodiments of the present 5 disclosure are also concerned with a method for coaching the swimmer. The present disclosure relates to a system and a method that can be used to coach a swimmer by analysing movements made by the swimmer during a swimming session for determining stroke related data therefrom and for deriving at least one insight from the analysed movements so 10 that a set of instructions can be provided based on the derived at least one insight for coaching and hence, improving a stroke of the swimmer.

Prior to operation, the system, particularly -a memory unit of the system, is provided with one or more stroke related parameters. The stroke related parameters may comprise position and orientation data for the wrist of an exemplary swimmer at sequential times through a full stroke. They may further comprise corresponding calculated angles and positions of the arm of the exemplary swimmer. The stroke related data may comprise position and orientation data for the shoulder blades of the swimmer being coached at sequential times through a full stroke. They may further comprise corresponding calculated angles and positions of the arm of the swimmer being coached. These stroke-related parameters may be known before-hand e.g., through previously held trial-runs or from an expert swimmer's stroke data. The system, when in operation, performs a plurality of functions: sensing and measuring movement of a wrist of the swimmer during a swimming session, analysing the sensed and measured movement of the wrist to determine stroke related data for the swimmer, comparing the determined stroke related data with the stroke related parameters to derive at least one insight, and retrieving a set of instructions from the memory unit based on the derived at least one insight. Moreover, the system also displays a graphical representation of the stroke related data and the retrieved set of instructions in which the retrieved set of instructions are configured to coach the swimmer i.e., to improve a stroke of the swimmer. In this manner, the swimmer can access a playback of his or her strokes from the system, in particular, a display unit of the system, at any time after a swimming session (e.g., after a lap or a desired block of swim, a single swimming session, or multiple swimming sessions) in order to track their performance, receive the set of instructions and accordingly improve their performance over time.

Further, as movements can be accurately and efficiently sensed and measured in comparison to a physical coach, the system allows the swimmer to take full advantage of the high accuracy and efficiency with which the system operates. Moreover, even if used in conjunction with a physical coach, the system requires minimal to no intervention (e.g., supervision) by the physical coach for coaching the swimmer. Therefore, the system is cost effective as it mitigates the need for a physical coach.

Referring now to FIG. 1, illustrated is a schematic or block representation of a system 100 for coaching a swimmer 200, in accordance with an embodiment of the present disclosure. As shown, the system comprises a primary sensing unit 102, a memory unit 104, a processor 106, and a display unit 108.

The primary sensing unit is positioned between the shoulder blades of the swimmer. The primary sensing unit is configured to sense and measure movement of the shoulder blades during a swimming session.

The swimmer typically moves his or her shoulder and wrist through a sequence of positions (hereinafter also interchangeably referred to as 'modes') during a stroke (hereinafter also interchangeable referred to as 'stroke cycle'). For example, the shoulder and wrist may be sequentially moved from e.g., a catch position towards a pull mode, a push mode, a finish mode before transitioning into a recovery mode (in which the shoulder is moved to a position above the water line), an entry mode, and a press mode to return to the catch position and repeat the stroke cycle.

The system and in particular the primary sensing unit of the system, is 5 implemented by way of a wrist-worn device having a shoulder band that facilitates the swimmer to wear the device between his or her shoulder blades. Additionally, optionally, the primary sensing unit may comprise at least one of: a tri-axial accelerometer, a tri-axial gyroscope, and a magnetic angular rate gravity (MARG) sensor. During operation, the 10 primary sensing unit can sense any axial movement of the shoulder blades in X, Y, and Z-axes. Additionally, the primary sensing unit may also sense any rotational movement i.e., a pitch, a roll, and a yaw of the wrist about the Y, X, and Z-axes.

The primary sensing unit, the memory unit, the processor, and the display unit may altogether reside on the wrist-worn secondary sensing device. That is, the memory unit may be a random-access memory unit residing on the wrist-worn device. In other words, the memory unit may be located together with the primary sensing unit and/or secondary sensing unit, the processor, and the display unit. Optionally, the memory unit may be implemented by way of a remotely located server e.g. a cloud-based storage system. The memory unit comprises stroke related parameters (such as, stroke related parameters) stored therein. These stroke-related parameters include e.g., an expert swimmer's stroke data, or data from previous trial runs of another swimmer that are known before-hand and stored within the memory unit.

The processor disclosed herein may embody a single processor or comprise of multiple microprocessors that are configured to operatively perform functions consistent with the present disclosure (as explained later herein). Numerous commercially available microprocessors can be configured to perform the functions of the processor disclosed herein.

Optionally, the processor could readily be embodied in a general machine microprocessor capable of controlling numerous other functions of a general-purpose machine. That is, the wrist-worn device and/or shoulder-worn comprising the processor may also be used as e.g. a watch or a health tracking device. Some examples of commercially known wrist-worn devices used for such purposes may include fitness trackers such as Fitbit®, or watches sold under the commercial trademarks Apple® or Garmin®. Further, various routines, algorithms, and/or programs can be programmed within the processor for execution thereof. For example, the processor may include a power supply circuitry, a signal conditioning circuitry, and other types of circuitry for performing functions that are consistent with the present disclosure.

The processor is configured to analyse the sensed and measured movement of the wrist to determine stroke related data, which may be represented as graphics for the swimmer. Optionally, the processor is configured to analyse the sensed and measured movement using one or more mathematical algorithms e.g., correlation algorithms or recursive algorithms that are beneficially used for predictive analysis in the field of biomechanics. The determined stroke related data comprises a calculated angle and position of at least one arm of the swimmer. Such angle and position may be calculated by simple mechanics from the calculated positions and orientations of the wrist, based on ergonomic information about the human arm and dimensional information on the swimmer. Additionally, or optionally, the determined stroke related data may be combined (i.e. integrally used) with a timing of the movements executed by the wrist of the swimmer during the stroke cycle for analysing the sensed and measured movement and determining stages of motion of the swimmer's arm therefrom. Further, the processor is also configured to compare a graphic of the determined stroke related data with a graphic of the stroke related parameters to illustrate at least one insight, and retrieve a set of instructions and observation of progress from the memory unit based on the derived at least one insight. The processor compares the determined stroke related data, e.g., a position and angle of the swimmer's arm during a cross-over movement with the stroke related parameters e.g. a target position and angle of an expert swimmer's arm during the cross-over movement. The processor 106 compares the determined stroke related data, e.g., a pull-through movement of the swimmer's arm with the stroke related parameters, e.g. a target position and angle of an expert swimmer's arm during the pull-through movement.

The display unit is arranged to display a graphical representation of the stroke related data and the retrieved set of instructions in which the retrieved set of instructions are configured to coach the swimmer. Further, the display unit comprises of a Graphical User Interface (GUI) for displaying the graphical representation of the stroke related data and graphical representation of stroke related parameters, and the retrieved set of instructions and observation of progress. Optionally, the display unit is configured to display a spatial distribution of the determined stroke related data using one of a heat map or tabulation. The display unit is configured to display the spatial distribution of the determined stroke related data e.g., the cross-over movement from several stroke cycles using the heat map. Further, the display unit is also configured to display the retrieved set of instructions using at least one of text, images and video. Also, the display unit is configured to display the retrieved set of instructions using text. Furthermore, the processor is also configured to optionally compute a severity in a deviation of each stroke related data from a corresponding stroke related parameter. The processor may retrieve historical stroke related data of the swimmer over a period of time from the memory unit. Further, the display unit is configured to display a severity of improvement needed based on the historical stroke related data of the swimmer retrieved by the processor from the memory unit.

Optionally, the derived at least one insight comprises two or more insights therein. In such cases, the processor is configured to determine a rank of each insight from the two or more insights using an insight hierarchy determination algorithm and retrieve the set of instructions to 5 provide the retrieved set of instructions in an order of development to the swimmer based on the ranking of each insight from the two or more insights provided by the insight hierarchy determination algorithm. The position in the hierarchy may be influenced by the magnitude of differences between stroke related data and stroke related parameters 10 for a particular insight.

The set of instructions may be selected by the processor from a database of instructions in an extension of the algorithm, where the processing may be based on a look-up table.

Optionally, the method may be implemented using data acquired over an entire swimming session or over a portion of such swimming session. For example, the portion of a swimming session may be defined by a lap, which in turn is defined by the length of a swimming pool. For example, the portion of a swimming session may a given distance swam (for example, 100m or 800m or 1500m) or a given number of strokes as identified by the zero points or a time interval. Such portion may be defined by any factor which is known (namely input or measured) to the system. Optionally, when the method is implemented using data acquired over a portion of a swimming session, alerts may be sent to the swimmer. For example, an alert may be triggered after a number of swimming strokes. For example, such alerts may be sent if the system or the coach identify one or more factors or insights measured or calculated that deviate from a predicted ideal or from the swimmer's average on a particular session or from the swimmer's historical average.

Optionally, the wearable device is equipped with heart rate monitor. 30 Herein, the system 100 may alert the swimmer if the heart rate value drops below a certain level or raises above a defined level. These would help in monitoring the health of the swimmer.

It will be evident that the method relates to coaching the swimmer as described in conjunction with the system herein. The steps of the method herein may be performed by the processor of the system. Therefore, various embodiments and variants disclosed regarding the system above apply mutatis mutandis to the method.

The wearable device may include different graphical user interfaces (GUIs), in accordance with an exemplary implementation of the present disclosure. The wearable device, herein, is a wrist-watch which could be worn on the arm by the swimmer. Which allows the swimmer to start a swim session, and provide inputs related to the swim session including details like "Pool Swim," "Open Water," etc. The processer identifying starting and ending of each stroke from the logged data using pitch rate criteria. Specifically, this involves reading the pitch information from the logged data, and finding the zero points for rate of rotation. It is to be noted that there are usually two zero points for the pitch in each full stroke. Herein, the stroke, i.e. the arms stroke, involving the movement of the arm from one point back to the same point is considered as one cycle. Hence, the start and end point remain constant for the arm stroke. The algorithm employs a pitch rate to define a full stroke (as discussed later in more detail). The pitch rate may be defined as the rate at which the arm of the swimmer pitches. In order to set the start and end points for each stroke, the algorithm assigns a negative value to the underwater portion of the stroke which is measured by the gyroscope sensor and a positive value to the over water portion of the stroke. Therefore, a full stroke is set to start/end when the pitch rate crosses the zero value. It is to be noted that the given scenario is for when the wearable device is worn on the left wrist by the swimmer. When the wearable device is worn on the right wrist instead, the algorithm assigns a positive pitch rate during the underwater stroke and a negative pitch rate on the recovery over the water surface.

The pitch rate is the rate at which the pitch of the swimmer's wrist changes. The pitch rate is measured from the gyroscopic sensor and it is 5 measured in terms of radians per second.

Once the start and end of the stroke has been determined from pitch rate analysis the stroke time can be measured between these two points. However, prior to this determination an estimate of stroke time is required to locate the peak pitch rate for each stroke. It may be io understood that the factors such as, the amount of force applied and technique/position may change, but the stroke time is constrained within known upper and lower bounds. Too long a stroke time and the swimmer starts to drop low in the water, increasing drag and removing their ability to swim effectively. Too short a time and the swimmer cannot complete strokes given the resistance of the water. Hence the stroke time is always within a range that allows the algorithm to accurately identify peak pitch rate. An average stroke time across swimmers is approximately seconds which may be used as a default value.

Since swimming strokes perform the same set of actions of going in and out of water and finally arriving at the same position, the variation in stroke time is generally not large enough to cause inaccuracies in the model. It may be understood that the factors such as, the amount of force applied and technique/position may change, but the stroke time is approximately constant. In fact, in order to swim efficiently, the stroke time should be maintained as a constant; otherwise, the body would not be able to move and glide, and would drag and may sink to some extent. Hence, the swimming of the swimmer may be affected if the stroke time is not maintained constant. In the present embodiments, the stroke time is measured by the wearable device or any another device specifically meant for measuring the stroke time.

As discussed, there are usually two zero points for the pitch in each full arm stroke cycle. It may be appreciated that the peak and the zero point proceeding the same could be easily be easily identified from the graph 800. It may be noted that the second zero point 806 can be confused by movements during the stroke, as in the third cycle shown. From the pitch definition, the negative values correspond to over movements of the wrist, i.e. when the swimmer is pulling on the water. The observed coincidence of pitch movements allows a second criterion to be selected, i.e. that greater than 60% of the negative pitch has occurred between the two significant zero pitch rate measurements. That is, the front of the stroke is considered to occur after 60 percent negative pitch has occurred. Herein, the arrow 808 represents the sixty percent of total negative pitch. It is to be appreciated that the second such zero pitch rate point 804, working backwards along the time axis, is the critical start of the stroke cycle (and end of the proceeding stroke cycle). It is also referred to as the front of the stroke; whereas the rear of the stroke could be thought of as the part of the stroke that the swimmer ceases to apply positive traction against the water. The arm may or may not be still in the water at the rear of the stroke. In order to differentiate the points in circle from zero points, given that positions and angles are known, the points inside the circle would always fall less than 60 percent negative pitch, so those are identified by not being greater than 60 percent negative pitch.

A base set of orientations is determined between the start and end of the stroke cycle identified in using quaternions to represent the orientation vectors. The gyroscope rates of 'pitch', 'roll' and yaw' are integrated over time for the determination of the accurate orientation of the wearable device/arm. Thus, the calculations define vectors to represent each direction through each complete arm stroke cycle.

It may be understood that such approach may lead to a phenomenon known as "Gimbal lock." Herein, the gimbal lock is a mathematical problem that leads to a loss of one degree of freedom in a three-dimensional and three-gimbal mechanism. The problems occur when two axes of the three-gimbal mechanisms are parallel to each other making the system neglect one axis and thus turn into a two-dimensional one. Since, the action of swimming is highly repetitive, accumulation of errors may often lead to the gimbal lock. In order to get rid of the gimbal lock, some corrections mechanisms are employed. The gimbal lock problem is prevented by using the quaternion mathematical model on the gyroscope data. The quaternion mathematical model uses numbers that extends the complex numbers. The model is used in particular for calculations involving three-dimensional rotations such as, for multiplication of two quaternions which are parameters of the model. Herein, the two quaternions would be vector quantities as those define the orientation of gyroscope sensor. The two quaternions may also be any directional or positional parameters. Since the quaternions are non-cumulative, hence the gimbal lock type problem is prevented.

The processer further includes calculating direction of average acceleration over stroke cycle using orientations. It may be appreciated that the acceleration is quite complex to calculate because the orientation of the wearable device is continually changing. So, the orientation data has to be applied with the accelerometer data to track the magnitude and direction of the acceleration over time. As may be understood, a time-weighted average of the accelerations results in an acceleration vector, which represents the change in velocity between the initial velocity at the start of the stroke to the end velocity at the end of the stroke. Herein, the calculations are performed using gravity force as the known force (under which only small deviations have been found, but even those deviations are inconsistent). The gravitational force is chosen, since a swim stroke requires an arm to move through a complete stroke cycle, ending at the exact same place and velocity relative to the swimmer's body, the only resulting force would be gravity. Other forces may be assumed to be not present because their presence would deviate the start and end of the stroke. As may be understood, the components of 5 acceleration applied to the watch by the swimmer in vertical directions would not necessarily average out to zero; but if they did, the net acceleration applied to the watch would be the acceleration due to gravity. The other force vectors related to the action of the water and variations by the swimmer, average out very closely to gravity. Thus, the io determination of the direction of gravity provides an orientation fix.

Further, the orientations are rotated so those are facing straight down. Also, the correction of the zero points need to be done via adjusting velocity vectors rather than position. This information is then used as the key directional information for calculating accurate orientation and is position. It may be appreciated that such correction techniques are used in applications such as, video games and aircrafts; however, the determination of the accurate position of the wearable device of the present disclosure may not be replicated in the above-mentioned applications.

The processer further includes determining positions and orientations in space based on the identified start and end of stroke and the calculated direction of average acceleration. This could be calculated from the data obtained by the accelerometer sensor. It may be appreciated that, if the corrections in calculations are not implemented, the accurate position will not be obtained. This is equivalent to collection of different, inaccurate sensor data. The accelerometer data is first converted to velocity data and then converted to position data, such that the stroke always starts and ends at the same place. It may be appreciated that with such data, the positions and orientations in space could be calculated at any given instant of the swimming session.

The difference in position between the start and the end of a stroke (presuming that the forward motion of the swimmer is subtracted) should be in the same direction as the presumed initial velocity. Thus, changing the initial velocity brings the start and end of the stroke into alignment.

The processer further includes, adjusting initial velocity of stroke so that the start and end of stroke is in same place. The processer provides the correction of the distances, thus complementing the correction of the orientations as performed. It may be appreciated that these corrections are necessary because the velocity at the start of the stroke (initial velocity) is unknown, and therefore it is determined to allow the corrections that result in the stroke track resolving back where it started. Potentially, depending on the accuracy of the measurement device, the corrections may also overcome a potential accumulation of measurement errors inherent in the use of the sensors of the wearable device The processer may further include extrapolating the elbow and/or the hand positions. The extrapolation helps in calculation of the elbow and hand positions and accordingly, the improvements on position of the stroke could be recommended. Such extrapolation can be done by any known suitable technique in the art without any limitations.

The processer may further include displaying the results in a system device (such as, a phone) and/or a wearable device (such as, a smartwatch). In some examples, the output of the process as described above may be checked by comparing with video recordings. This may be done to test if the results are correct for a particular distance and body measurements. It may be appreciated that this step may be automated using image processing techniques as known in the art. As discussed, all the necessary calculation for the process as described above may take place at the wearable device itself or the system device, or in a cloud server without departing from the spirit and the scope of the present

disclosure.

The present disclosure provides a system and a method for improving swimming techniques, which result in health benefits, prevents injuries and saves time for swimming coaches. The wearable device worn by a swimmer, preferably a wrist-worn device (such as, an Apple® Watch) in connection with an app connected to the wearable device and optionally to a system device is utilized for calculation movement deviation and recommendation of movement correction for swim related activities. The system and the method of the present disclosure is advantageous, as there is no need for direct measurements of force or position. Rather positioning is accurately determined using the data obtained from the gyroscope sensor. This eliminates the need of measuring positions by video or other special positions. Hence, the problem of privacy and privacy regulations which in most cases forbid filming and film analysis, and video sharing of swimmers between swimmers and coaches is solved.

The invention also solves the particular problem of complexity, regulates time and resources needed to comply with regulation of video acquisition particularly for under-aged swimmers, which in most countries mean that videoing is not allowed for swimmers aged below 16 to 18 years old.

It may be understood that, the present disclosure relates to the movement detection, transmission, calculation and correction of swimming needs. Herein, the movements are the ones that are typical and necessary for a swimming stroke to make a body float and move in water. It may be understood other movements may not be related to the present disclosure. For instance, the present disclosure cannot be applied in other application models because only for swimming the start and end of the stroke is at same position and is replicated (generally, every 2 seconds). In other sports, such as, tennis golf, each stroke starts and end on different positions. Similarly, in running, or any other movement sports, the steps or repeated movements follow other parameters, notably different actions or even terrain variations.

Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present disclosure are intended to be construed in a nonexclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

Claims (3)

1. CLAIMS1. A system for coaching a swimmer, the system comprising: - a primary sensing unit positioned between shoulder blades the swimmer, the sensing unit is configured to sense and measure movement 5 of the shoulder blades during a swimming session; - a memory unit comprising stroke related parameters stored therein; - a processor in communication with the primary sensing unit and the memory unit, the processor configured to: -analyse the sensed and measured movement of the shoulder blades to determine stroke related data for the swimmer; -compare the determined stroke related data with the stroke related parameters to derive at least one insight; -retrieve a set of instructions from the memory unit based on the derived at least one insight; and - a display unit in communication with the processor, the display unit arranged to display a graphical representation of the stroke related data and the retrieved set of instructions, wherein the retrieved set of instructions are configured to coach the swimmer.
2. 2. The system according to claim 1, wherein the system further comprises at least one secondary sensing unit poisoned on at least one wrist of the swimmer, the secondary sensing unit is configured to sense and measure movement of the at least one wrist of the swimmer during the swimming session and wherein the at least one secondary sensing unit is communicably coupled with the memory unit and the processor.
3. 3. The system according to any of claims 1 or 2, wherein, for analysing the sensed and measured movement of the shoulder blades and the at least one wrist to determine stroke related data for the swimmer, the 30 processor is further configured to: - log data related to movement of the shoulder blades and the at least on wrist during the swimming session from the primary sensing unit and the at least one secondary sensing unit; - identify start and end of stroke from the logged data using pitch rate criteria; - determine orientations from the logged data and the identified start and end of stroke; - calculate direction of average acceleration over stroke cycle using orientations; -determine positions in space from the logged data, based on the identified start and end of stroke and re-determine orientations based on the calculated direction of average acceleration; and - adjust initial angle between the shoulder blades and the wrist such that the start and end of stroke is in same position.