GB2234070A

GB2234070A - Analysis of performance during an exercise activity

Info

Publication number: GB2234070A
Application number: GB8913449A
Authority: GB
Inventors: Anthony Alexander Scarisbrick
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-06-12
Filing date: 1989-06-12
Publication date: 1991-01-23
Also published as: GB8913449D0

Abstract

A system (1) for analysing and providing an indication of human or animal performance during an exercise activity comprising means (4a-d) for monitoring performance parameters, electronic processing means (2) for analysing the monitored parameters and indicating means (5) for providing a continually updated real-time indication of performance dependent on the analysis by the electronic processing means, wherein the monitoring means (4a-d) monitor throughout the performance of the activity the interaction between at least one part of the performer's body and at least one contact surface. The monitoring means may comprise four piezoelectric force transducers mounted in a shoe or on a reaction surface, or an accelerometer on a waist belt. <IMAGE>

Description

ANALYSIS OF PERFORMANCE DURING AN EXERCISE ACTIVITY This invention relates to a system for analysing and providing an indication of performance, e.g. human or animal performance, during an exercise activity, the system being of the kind comprising means for monitoring performer parameters during performance of the activity and providing output signals relating thereto, electronic processing means to receive and analyse said output signals from said monitoring means and indicating means for providing a continually updated real-time indication of the performance in dependence on the analysis in the electronic processing means of the output signals from said monitoring means.

The invention also relates to apparatus and a method for performing the system.

A known system of the kind referred to is disclosed in US-A-4571682. This known system relates to a system for human sill enhancement and behaviour modification aru enables e person to modify or adapt his performance as result of the indication, e.g. display, of the indicating means. However this known system is primarily dependent on the measurement of one or more physiological parameters in correspondence with the various physiological processes and functions integral to a person's body, such as heart beat, blood flow, respiration, muscle force and limb or bod position.

The present invention seeks to provide a system for analysing and providing an indication of performance during an exercise activity involving monitoring forces and/or pressures generated during interaction between at least one body part and at least one contact surface.

According to one aspect of the present invention a system of the kind referred to is characterised in that said monitoring means monitor, throughout the performance of the activity, the interaction between at least one part of a performer's body and at least one contact surface to generate said output signals.

A system of the kind referred to is arranged to operate without interruption of, or undue penalty to, any aspect of user performance. The system is intended to indicate by said indicating means directly in real-time how the performer is performing. In addition the indication of performance may be recorded for subsequent use.

Primarily the system is intended to be related to human use, typically by monitoring contact of the user's foot or feet with the ground or some other contact surface(s). However the invention may be adapted to include contact of other body parts, e.g. human hand contact, and may also be used to monitor the performance of an animal, e.g. to determine whether or not a horse is lame.

The monitoring means may monitor the interaction(s) continuously or periodically throughout the performance of the activity. Alternatively the electronic processing means may sample the monitoring means periodically throughout the performance of the activity.

Preferably the electronic processing means analyse different force and time "events" measured by the monitoring means, which typically comprise at least one force or pressure transducer. Conveniently the electronic processing means is able to determine the intervals between successive force events and/or the duration of certain force events, which force events are signalled by transduction, and in this way a substantial analysis of a user's performance can be built up. Force and time events which may be measured and analysed are common to many activities and include, for example, the various forces and timings which are related to the manner in which the foot makes, sustains and breaks contact with a contact surface, e.g.

the ground. One particular application of the invention involves deriving two or more force/time measures for foot/surface contact to derive and display data on the activity being performed. The invention may be related to a very wide variety of activities and contact surfaces including sport and medical applications. In sport, for example, detecting and calculating against time the impact of each heel and forefoot may determine foot action speed and step frequency. In medicine, data on bad posture may be revealed by detecting uneven force/time interactions.

Force transduction may be arranged to measure forces generated between both the front part (or forefoot) of each foot of the user performing the activity and the associated contact surface and the rear part (or heel) of each foot and the associated contact surface. Typically in such an arrangement four transducers are employed - one for each forefoot and heel. Additionally, or alternatively, one or more transducers may be centrally located, e.g. on a waist belt, or be located to measure the forces of one foot only, the force or forces of the other foot being assumed to be equal or to bear some other relationship on which an assumption of force and/or time may be made.

Transduction of force may be used to derive a particular indication of absolute force, e.g. the maximum force of the heel of one foot, or both heels of the different feet, making contact with the ground. Additionally, or alternatively, two or more of such measures may be analysed by said electronic processing means, e.g. to derive an indication of the difference between the heel force and the forefoot force of one foot or the difference between the heel forces of the two different feet.

During the performance of foot contact activities, e.g. running, transduced forces will regularly rise above and then fall (i.e. above and below a certain threshold value), e.g. as a foot makes contact with, and then loses contact with, the ground during each stride. In the analysis of such activities, the length of time between certain events can be calculated and analysed in the electronic processing means to further evaluate the user's performance of the activity concerned. For example, it is possible: (1) to measure the length of time between successive occurrences of a particular transduced force rising above (and/or falling below) a certain threshold value, such as the force or pressure exerted by a person's body weight or another transduced force.

(2) to measure the length of time that a particular transduced force remains above (and/or below) a certain value before next falling below (and/or rising above) a certain value.

(3) to measure the length of time between successive maximum and/or minimum values of a particular transduced force or forces.

t4) to measure the length of time occurring between two or more different transduced forces - e.g. the time between the forefoot and the heel of a foot contacting a surface or the time between each forefoot of the two different feet contacting a surface.

In the monitoring of other activities time intervals may be relative to simultaneous forces. For example, in providing an indication of a skier's performance, the measurement of the skier's balance is important. In this latter case, the electronic processing means may conveniently be designed or programmed to determine successively whether at an instant of time the skier's foot contact forces are equal or unequal between forefoot and heel and/or between the right foot and the left foot.

The invention may be adapted to make use of real-time direct measurement and input of stride length - e.g. heel to heel or forefoot to forefoot distance in running. Such measurements may, for example, be obtained b: (A) analysis of time intervals between activation of foot contact sensors separated by a known distance on a surface. e.g. a running track. Such sensors may be connected to a static electronic processing means and on analysis transmitted by telemetry to the user's said electronic processing means adapted to receive such data.

(B) a transmitting device (or reflector) on one or both of the user's feet or footwear arranged to transmit at, for example, each heel strike on a contact surface, said transmissions being received by a receiving device on, for example, one or both feet or footwear and/or the same foot (via reflector) so that the time delay or other signal characteristic can be analysed by said electronic processing means to derive a distance measurement.

According to another aspect of the present invention apparatus for analysing and providing an indication of performance during an exercise activity comprises means for monitoring, throughout the performance of the activity, the interaction between at least one part of a performer's body and at least one ' contact surface, electronic processing means for receiving and analysing output signals from said monitoring means and indicating means for providing a continually updated real-time indication of the user's performance in dependence on the analysis in the electronic processing means of the output signals received from said monitoring means.

The apparatus according to the invention is intended to be easily portable. In use, the electronic processing means and the indicating means are intended to be carried and/or worn by the user performing the activity. The monitoring means conveniently comprise force or pressure transducers which are typically mounted adjacent the user's feet, e.g. mounted in, or on the sole of, a shoe or on a reaction surface (such as a foot board of a rowing boat or the foot-receiving part of a ski).

According to a further aspect of the present invention a method of analysing and providing an indication of performance during an exercise activity comprises monitoring the interaction between at least one part of a per former'sbody and at least one contact surface throughout the performance of the activity and deriving electric output signals representative of said monitored interaction, supplying the electric output signals to electronic processing means for analysis therein and providing a continually updated real-time indication of the performance in dependence on the analysis of the said electric output signals.

The indication provided may be audible and/or visual.

In the case of an audible indication, the person performing the activity may be equipped with a headset for receiving audible indications throughout the performance of the activity.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawing, the sole figure of which illustrates a system according to the invention for analysing and providing an indication of performance during an exercise activity.

The figure shows a system 1 according to the invention for analysing and providing an indication of a person's performance during an exercise activity, e.g. a foot contact activity. The system 1 comprises an electronic processing unit 2 having an interface 3, at least one monitoring means, e.g. at least one force transducer 4a-d for continuously supplying information to the processing unit 2 via the interface 3, an audio and/or visual system display 5 for displaying or indicating to the person performing the activity his or her performance as evaluated by the processing unit 2 and optionally an additional computer/display apparatus 7. The electronic processing unit 2 also includes a terminal 8, a central processing unit or CPU 9, permanent memory 10, interchangeable memory 11, data memory 12, timers 13 and a battery power supply 14.

The force transducers 4a-d are typically, but not necessarily, all of the same type, e.g. piezoelectric transducers, and are each intended to generate electric output signals representative of the interaction between a person's foot or part thereof and a contact surface. For any particular activity or application there may typically be four force transducers to enable direct output signals to be derived in respect of the forces generated between a contact surface and the right forefoot of the person, the contact surface and the right heel of the person, the (or a different) contact surface and the left forefoot of the person and the (or a different) contact surface and the left heel of the person.However in certain applications less than four force transducers may be used - e.g. it may only be necessary for one or two force transducers to be provided for monitoring the interaction between (e.g.

measuring the forces between) a contact surface and at least one part, e.g. two different parts, of a person's foot (any necessary force/time values of the other foot being assumed) or the forces between both feet of a person and the contact surface(s). In other applications one transducer , e.g. an accelerometer, may be used in a central position, e.g. a waist belt, for measuring the "jolts" occasioned by a person's feet as they contact the ground during running. The electric output signals generated by the transducers 4a-d are received by the interface 3 and are converted into a form suitable for the processing unit. Interface functions are well known in the art and may include preamplification, further amplification, gain adjustment, filtering, voltage to frequency conversion, analogue to digital conversion and/or any other established interface function.Additionally or alternativel interfacing may be provided in the transducers.

The permanent and interchangeable memories 10 and 11 contain data, including data input by a user via, for example, the terminal 8, and instructions defining operations to be performed by the system. Additionally, the interchangeable memory 11 may contain data and information relating to a particular activity or application, e.g.

skiing or running. The data memory 12 stores transduced data received via the interface 3 and data which is the partial or full result of processing in the processing unit 2 including: (a) Data which is the product of processing of the forces measured between the feet and a contact surface or contact surfaces and the duration of and/or between various measured forces in a specific activity which may be selectively displayed to indicate all or some of the data derived from the specific activity.

(b) Data which is the result of a comparison between data derived from a specific activity and data contained in interchangeable memory relating to that activity, to derive and display selected error signals.

(c) Data which is the result of a comparison between data derived from a specific activity b the user or preceding user and a subsequent repeat of similar activity by the user to derive and display selected error signals.

The CPU 9 executes instructions and processes data in order to analyse a person's performance whilst that person performs a particular activity. The CPU interprets and executes the instructions which have been pre-programmed for the particular activity concerned and processes the data continuously being supplied by transduction during the performance of the activity. The timers 13 may be employed for determining the duration of forces monitored or measured by transducers 4a-d and/or the duration between monitored or measured forces for use in analysing the person s performance of the activity.

The terminal 8 provides the user with overall control and input to the system 1 by means of a keyboard (not shown) or similar. The display of information inputted at the terminal may be provided by audio means (e.g. keyclick) and/or visual means (e.g. an LCD display) at the terminal.

Additionally or alternatively the information may be outputted to the system display 5 which may be an audio display, e.g. earphones, and/or a visual display, e.g. an LCD or LED screen.

The processing unit 2 including the terminal 8 may be provided b a portable computer which is intended to be worn or otherwise attached to the person performing the activity to be monitored. The timers 13 will form parx of the conventional computer circuitry. The system display 5 is intended to be positioned so as to be easily audible (in the case of an audio display) and/or easily visible (in the case of a visual display). The force transducers may be arranged to be activated by the feet. For example the force transducers may be positioned in specially adapted footwear, e.g. when monitoring running. Alternatively, the force transducers may be mounted on a reaction surface, e.g. a foot board of a rowing boat.In certain applications, e.g. rowing or skiing, the force transducers may be mounted on a contact surface or in specially adapted footwear. The force transducers 4a-d and system display 5 are suitably connected to the processing unit 2 by wires or cables (not shown) which may be attached to, or integral with, clothing appropriate to the activity being performed.

As an illustration of the application of the present invention reference is made to the Table below which illustrates some of the possible measurements and timings which can be made as a person runs with the feet succes spiel making and breaking contact with the ground (or "contact surface"). Each letter represents a force/time event in the interaction between the heel and forefoot (each of which may have an associated transducer) of each foot and the ground. The force/time events in this illustration are begin, time/peak, end, and associated intermediate forces, (e.g. the "intermediate" time between the peak or maximum of a force application and the end of the force application - i.e. as a foot leaves contact with the ground.Events represented by the letters may be transduced, measured and calculated for force and/or time either individually or in relation to other force and/or time events. In each case, "x" represents an event duration or time interval between events.

TABLE Left Foot Right Foot Heel Forefoot Heel Forefoot Begin Force/Time A x B x C x D x x x x x x x Time/Peak Force E x F x G x H x x x x x o; x End Force/Time I x J x K x L x x x x x x x Intermediate M x N x O x P Forces/Times In the case of this illustration, the time intervals E-F, G-H, E-G, F-H may be established using a timer and calculations of heel-forefoot step speed and step frequency can be calculated; time durations B-J and D-L and/or time ratios B-F/F-J and D-H/H-L will provide time data on the profile of propulsive effort which, with other time related data, such as step speed and frequency, may be used to derive data on stride. The "intermediate" analysis of a force application may give important information concerning the stride of the performer.

Some, all, or more of such time intervals and/or time ratios and profiles may be taken together with force measurements at, for example, F and H and/or with calculations of force ratios such as E/F and G/H to obtain force/time profiles and other data which in itself and/or in comparison with other data will provide indications of a person's running performance. The use of force and time ratios is helpful because they provide relevant data in themselves and, given variations in the environment, will enable comparisons which are more consistent than, for example, simple force comparisons.

As further illustrations of the invention, there now follows three further applications of the invention, namely the use of the system to act as a runner's pacemaker, the use of the system to aid diagnosis and rehabilitation of medical conditions associated with uneven posture and the use of the system to act as an aid to weight distribution in skiing.

1. Running It is well established that runners may benefit from a pacemaker. Some find pace judgement difficult. Many find benefit from being free from some of the mental effort of pace judgement and are more able to concentrate on their own performance. With the aid of a pacemaker they may finely adjust their manner of running or "form" to perform in the most efficient way possible.

Given data on a runner's athletic output (such as may be obtained in the manner illustrated in the Table) this may be compared with, for example, "running data" in interchangeable memory to provide indications of athletic performance which may include an estimate of running speed resulting from assessment of all performance data. Such an assessment may be assisted by input relating to user or environment parameters, which may include: weight, height and foot size; and step frequency and stride length and foot placement at given distances over time. Inputs may be made by the user directly and/or may be the result of data stored during selected athletic performance(s).

Given such indications of athletic performance, the runner maw select a desired level of performance and obtain an error display when that is or is not achieved so that the display (for example, the display or non-display of earphone noise) acts as a pacemaker. The runner may select the meaning of the noise; for example it may represent the sum of the force/time measurements taken, or represent one or more of the measures (for example, the runner may choose to sustain a particular force ratio between heel and forefoot) and the derived data for each foot may be isolated.

2. Medical It will be self-evident that the illustration of the application of the system to running may be adapted to the diagnosis and rehabilitation of medical conditions whose cause or symptoms are concerned with uneven force/time interactions between the feet and ground.

3 Skiing It is well established that in most circumstances skiers must maintain even balance over the skis by neither leaning too far back nor too far forward. This is a vital part of skiing technique which is often difficult to achieve. In skiing, the force/time interaction between the foot/ski and snow may change very rapidly but the force relationship or ratio between the heel and forefoot of each foot at instants of time is, in principle, required to be constantly equal. Using the system as illustrated in the Table, heel and forefoot forces may be compared and an error signal generated when they are unequal and/or a confirmation signal generated when they are equal.The system may be instructed to indicate for the most weighted ski only, and may be further adapted for particular methods of skiing or particular types of skiing equipment which lead to heel and forefoot forces which are necessarily unequal. In this example, force transducers may be located in relation to the foot or ski including bindings, or the ski boot including any flex mechanism or similar device.

The invention described herein derives and displays to a user data arising from the force/time interaction between each foot and any contact surface or surfaces which, in principle, is applicable to any activity and environment where such an interaction exists.

Apparatus for performing the system described is intended to be portable so that it can be worn or carried b a person performing an activity. In particular, one or more force transducers or other monitoring means may be located in close proximity to at least one body part, e.g.

one or each foot and/or associated lower leg area adjacent to footwear of various kinds. At least one similar transducer or monitoring means may also or alternatively be located in or on the related environment; for example, in or on various footwear or snow skis. Signals are generated relating to levels of force at measurable instants of time.

An on-line real-time or effectively real-time computer, which will accept user data input, calculates a number of different force and time measures (including force and/or time ratios and profiles) of two or more transduced signals in accordance with permanent computer memory and interchangeable computer memory for specific applications. The computer generates data for a real-time or effectively real-time audio and/or visual display, and stores some or all derived data for further display and/or analysis, or other use by the user including comparisons with repeat activities.

In events such as a rowing eight, the provision of additional computer facilities may correlate the force/time interactions of the crew. A system according to the invention may include an additional computer and display, which may be static and off-line during the activity (or on-line linked b telemetry) to obtain more powerful data processing.

The invention may also be adapted for use with animals. For example, to discover the force/time relationships of the feet of a horse which is possibly lame but is not, as may be the case, displaying clear symptoms.

The invention may be arranged to make use of only one monitoring means or transducer, e.g. located in relation to one foot or centrally located as on a waist belt, or be used in conjunction with other systems which employ different transduction or monitoring functions. The invention may also be adapted to replace all or some fixed links with telemetry.

Data on the environment may also be derived by the system. For example, the affects of hard and soft running surfaces or the affects of different footwear on posture.

Use may also be made of transducers in or on an environment distinct from the user; for example, a treadmill or a jumper's point of take-off.

Claims

1. A system for analysing and providing an indication of performance, e.g. human or animal performance, during an exercise activity comprising means for monitoring performer parameters during performance of the activity and providing output signals relating thereto, electronic processing means to receive and analyse said output signals from said monitoring means and indicating means for providing a continually updated real-time indication of the performance in dependence on the analysis in the electronic processing means of the output signals from said monitoring means, characterised in that said monitoring means monitor, throughout the performance of the activity, the interaction between at least one part of a performer's body and at least one contact surface to generate said output signals.

2. A system according to claim 1, including recording means for recording performance parameters for subsequent use.

3. A system according to claim 1 or 2, in which the monitoring means monitors the interactions(s) continuously or periodically throughout the performance of the activity.

4. A system according to claim 1 or 2, in which the electronic processing means samples the monitoring means periodically throughout the performance of the activity.

5. A system according to any one of the preceding claims, in which the electronic processing means analyse different force and time "events" measured by the monitoring means.

6. A system according to claim 5, in which the monitoring means comprise at least one force or pressure transducer.

7. A system according to claim 5 or 6, in which the electronic processing means determines the intervals between successive force events and/or the duration of certain force events, which force events are signalled by transduction, in order to provide a substantial analysis of a user's performance,

8. A system according to claim 6 or claims 6 and 7, in which force transducers are arranged for measuring forces generated between both the front part (or forefoot) of one or each foot of the user performing the activity and the associated contact surface and the rear part (or heel) of one or each foot and the associated contact surface.

9. A system according to claim 6, claims 6 and 7 or claim 8, in which one or more transducers is substantially centrally located, e.g. on a waist belt.

10. A system according to any one of claims 6 to 9, in which the processing means derives a particular indication of absolute force, e.g. the maximum force of the heel of one foot, or both heels of the different feet, each time the feet make contact with the ground.

11. A system according to any one of claims 6 to 11, in which the electronic processing means analyses, during the performance of foot contact activities, the length of time between certain events to further evaluate the user's performance of the activity concerned.

12. A system according to claim 12, in which the electronic processing means analyses at least one of the following: (1) the length of time between successive occurrences of a particular transduced force rising above (and/or falling below) a certain threshold value; (2) the length of time that a particular transduced force remains above (and/or below) a certain value before next falling below (and/or rising above) a certain value; (3) the length of time between successive maximum and/or minimum values of a particular transduced force or forces; (4) the length of time occuring between two or more different transduced forces.

13. A system according to any one of the preceding claims, including foot contact sensors separated by a known distance on a surface, a static electronic processing device arranged to analyse the intervals between activation of said foot contact sensors by a performer and means for transmitting by telemetry output signals from said electronic processing device to said electronic processing means.

14. A system according to any one of claims 1 to 12, including a transmitting device on one or both of the user's feet or footwear arranged to transmit output signals on foot strike contact on a contact surface, a receiving device on one or both feet or footwear for receiving said output signals, the said electronic processing means analysing the time delay or other signal characteristic between said received output signals for deriving a distance measurement.

15. A system for analysing and providing an indication of performance substantially as herein described with reference to, and as illustrated in, the accompanying drawing.

16. Apparatus for analysing and providing an indication of performance during an exercise activity comprising means for monitoring, throughout the performance of the activity, the interaction between at least one part of a performer's body and at least one contact surface, electronic processing means for receiving and analysing output signals from said monitoring means and indicating means for providing a continually updated real-time indication of the user's performance in dependence on the analysis in the electronic processing means of the output signals received from said monitoring means.

17. Apparatus according to claim 16, in which the monitoring means comprise force or pressure transducers.

18. Apparatus according to claim 17, in which at least some of said transducers are mounted adjacent the user's feet.

19. A method of analysing and providing an indication of performance during an exercise activity comprising monitoring the interaction between at least one part of a performer's body and at least one contact surface throughout the performance of the activity and deriving electric output signals representative of said monitored interaction, supplying the electric output signals to electronic processing means for analysis therein and providing a continually updated real-time indication of the performance in dependence on the analysis of the said electric output signals.

20. A method according to claim 18, in which the indication is audible and/or visual.

21. A method of analysing and providing an indication of performance during an exercise activity substantially as herein described, with reference to, and as illustrated in, the accompanying drawing.

Amendments to the claims have been filed as follows

1. A system for analysing and providing chosen indications of human performance during a selected exercise activity comprising means for monitoring throughout the activity performance parameters relating to the force(s) and time(s) of the interactions between at least one part of the performer's body and at least one contact surface and providing output signals relating thereto, electronic processing means to receive and analyse said output signals from said monitoring means, and indicating means for providing a continually updated real-time indication of the performance to the performer in dependence on analysis in the electronic processing means of the output from said monitoring means, characterised in that said moitcrin means and said electronic processing means are arranged to provide comparative analysis of said performance parameters or said performance parameters and/or other data including data relating to the selected exercise activity, data relating to the performance environment and/or data relating to characteristics of the performer.

2. A system according to claim 1, including recording means for recording performance parameters for subsequent use including comparative analysis with repeat performances

5. A system according to any one of the preceding claims, in which the electronic processing means analyse different force and time events measured by the monitor ing means.

6. A system according to claim 5, in wnich the monitoring means comprise at least one force or pressure transducer.

7. A system according to claim 5 or 6, in which the electronic processing means determines the intervals between successive force events and/or the duration of certain force events, which force events are signalled by transduction, in order to provide a substantial analysis of a user's performance.

A A system according to claim 6 or claims t and 7, in which force transducers are arranged for measuring forces generated between both the front part (or forefoot) of one or each foot of the user performing the activity and the associated contact surface and the rear part (or heel) of one or each foot and the associated contact surface.

10. A system according to any one of claims 6 to i, in which the processing means derives a particular indication of absolute force, e.g. the maximum force of the heel of one foot, or both heels of the different feet, each time the feet make contact with the ground.

12. A system according to claim 12, in which the electronic processing means analyses at least one of the following: (1) the length of time between successive occurrences of a particular transduced force rising above (and/or falling below) a certain threshold value; (2) the length of time that a particular transduced force remains above (and/or below) a certain value before next falling below (and/or rising above) certain value; (3) the length of time between successive maximum and/or minimum values of a particular transduced force or forces; (4) the length of time occuring between two or more different transduced forces.

17. Apparatus according to claim 16, in which the monitoring means comprise force or pressure transducers mounted adjacent to at least one body part.

19. A method of analysing in a comparative manner and providing an indication of performance during an exercise activity comprising monitoring the interaction between at least one part of a performer's body and at least one contact surface throughout the performance of the activity and deriving electric output signals representative of said monitored interaction, supplying the electric output signals to electronic processing means for comparative analysis therein and providing a continually updated realtime indication of the performance in dependence on the analysis of the said electric output signals.

20. A method according to claim 19, in which the indication is audible and/or visual.