Measurement and Analysis of Foot Related Forces During a Golf Swing

• US 20080318703A1
• Filed: 05/08/2005
• Published: 12/25/2008
• Est. Priority Date: 05/06/2005
• Status: Active Grant

• Current Assignee: Brian Francis Mooney
• Original Assignee: Brian Francis Mooney
• Inventors: Mooney, Brian Francis
• Granted Patent: US 7,946,928 B2
• Time in Patent Office: Days
• US Class Current: 473/269
• CPC Class Codes: A63B 2069/367 Detection of balance between both feet, i.e. weight distribution
• CPC Class Codes: A63B 2220/51 Force
• CPC Class Codes: A63B 2220/805 Optical or opto-electronic sensors
• CPC Class Codes: A63B 2220/808 Microphones
• CPC Class Codes: A63B 69/3614 using electro-magnetic, magnetic or ultrasonic radiation emitted, reflected or interrupted by the golf club
• CPC Class Codes: A63B 69/3667 Golf stance aids, e.g. means for positioning a golfer's feet

Abstract

Apparatus (1) comprises a standing surface (2) for the player; a communication means (27); and a plurality of sensors (11) which are operable to measure force. The standing surface (2) comprises two separate foot platforms (3, 4) for the player'"'"'s feet. Each foot platform (3, 4) comprises a supporting structure or supporting members where vertical forces are distributed to a plurality of discrete positions (5). The sensors (11) are located at the discrete positions (5) to which the vertical forces are distributed. The sensors (11) are operable to measure vertical forces. The apparatus also comprises a computing means (26) which is operable to analyse the swing, and includes means to receive and separately process signals from individual or groups of sensors (11); means to determine the relative magnitudes and positions of resultant forces by balance-resolution of forces, including individual forces, measured by the sensors (11) in relation to the discrete positions of the sensors (11); and means to analyse and evaluate numerical data related to the measured positions and magnitudes of the forces.

Claims

1-106. -106. (canceled)

107. Apparatus for measuring and analyzing a player'"'"'s foot related forces during a golf swing or a sports swing similar to a golf swing, comprising a standing surface for the player;

a communication means; and

a plurality of sensor means which are operable to measure force;

the standing surface comprises two separate foot platforms for the player'"'"'s feet, each foot platform comprises a supporting structure which includes a surface or effective surface, where vertical forces on the supporting structure are distributed to a plurality of discrete positions;

the sensor means are located at the discrete positions to which the vertical forces are distributed;

the sensor means being operable to measure vertical forces;

the apparatus also comprises a computing means which is operable to analyse the swing, and includes;

means which is operable to receive and separately process signals from individual or groups of sensor means;

means which is operable to determine the relative magnitudes and positions of resultant forces by balance-resolution of forces, including individual forces, measured by the sensor means in relation to the discrete positions of the sensor means;

means which is operable to analyze and evaluate numerical data related to the measured positions and magnitudes of the forces; and

the computing means is also operable to analyze the swing by determining or evaluating forces from the sensor means against a framework of feature events; and

/or determined positions of the feet; and

a body of information available to the computing means comprising available reference data;

where;

the determination or evaluation related to the framework of feature events comprises mapping out the times of various detectable principal events which are common to all normal swings; and

the determination or evaluation related to the determined positions of the feet comprises statistical analysis of a batch of resultant forces measured by the sensor means where the player shifts weight with the foot in that position; and

the available reference data include;

information related to known swing performance, including criteria which allow different aspects of the performance to be judged or graded against what is considered to be good or bad performance when the available reference data is prepared; and

/or information which is accessible by the computing means from logging means operable to log information concerning previous swings made by the player or information on the player or his or her previous performance; and

/or

information which is accessible by the computing means from co-operating means for co-operating with other apparatus or systems, the co-operating means being operable to receive further information on the swing from the other apparatus or systems.

108. An apparatus according to claim 107, wherein the communication means is operable to communicate directly and/or indirectly with the player and the apparatus is operable to be used by the player in a useful manner without assistance from a skilled third party.

109. An apparatus according to claim 107, wherein the computing means comprises software with training elements;

the communicating means is operable to communicate with a player; and

the computing means and communication means are operable to be used with interactive training processes where the results of the analysis are used to prompt a training element within the computing means software.

110. An apparatus according to claim 107, wherein means to analyze the swing by determining or evaluating forces from the sensor means is against a framework of feature events.

111. An apparatus according to claim 107, wherein means to analyze the swing by determining or evaluating forces from the sensor means is against a framework of determined positions of the feet.

112. An apparatus according to claim 107, wherein the available reference data include information related to known swing performance, including criteria which allow different aspects of the performance to be judged or graded against what is considered to be good or bad performance when the available reference data is prepared.

113. An apparatus according to claim 107, wherein the apparatus includes a logging means and available reference data include information which is accessible by the computing means from logging means operable to log information concerning previous swings made by the player or information on the player or his or her previous performance.

114. An apparatus according to claim 107, wherein the apparatus includes a co-operating means which is operable to receive further information on the swing from other apparatus or systems, and available reference data include information which is accessible by the computing means from the co-operating means.

115. An apparatus according to claim 107, wherein the sensor means comprises one of the following strain gauge sensors;

each strain gauge sensor comprises two strain gauge elements and a strain member having one surface region which stretches and another surface region which compresses when the sensor is subjected to load with one of the strain gauge elements being connected to each of these regions, so that one stretches and increases in resistance and the other compresses and decreases in resistance, as load is applied to the sensor;

the strain member comprises a beam which is connected at one end to a support member which is cantilevered above the position of the strain gauge elements and is connected at the other end to a support member which is cantilevered below the position of the strain gauge elements, whereby load is applied to the sensor through the support members;

each strain gauge sensor comprises a flexible member whereby load is applied to one of the support members through the flexible member; and

the strain gauge elements are electrically connected in a bridge configuration, such as a balanced Wheatstone bridge configuration.

116. An apparatus according to claim 107, wherein the foot platforms are of rectangular or square shape and are disposed laterally adjacent each other;

optionally, the sensor means are disposed underneath the foot platforms with one sensor means adjacent each corner region of each foot platform; and

optionally, the sensor means are horizontally symmetrically arranged, with the centers of all sensor means to the front of the platforms being disposed laterally co-linearly, the centers of all sensor means to the rear of the platforms being disposed laterally co-linearly, and the centre of each sensor means to the front disposed longitudinally co-linearly with the centre of one corresponding sensor means to the rear.

117. An apparatus according to claim 107, wherein each foot platform comprises two sets of connected rigid elements which support the surface or the effective surface of the foot platform and are substantially disposed in the horizontal plane;

the first set of connected rigid elements comprises two parallel rigid elements, and the second set comprises a plurality of mutually parallel rigid elements which are disposed at an angle, such as a right angle, to the first set, the rigid elements of the second set span, and are supported by, the rigid elements of the first set, which are supported by the sensor means, such that a vertical force applied to the elements of the second set, is transferred to the elements of the first set and then to the sensor means; and

the two sets of rigid elements cooperate so that the foot platform is relatively rigid in directions parallel to the rigid elements and relatively flexible in other directions;

optionally, the foot platform comprises a polymer molding and the rigid elements comprise integral ribs in the molding; and

optionally, the foot platform is supported on a base which has less flexibility than the foot platform in directions where the foot platform is relatively more flexible.

118. An apparatus according to claim 107, wherein the foot platforms are sufficiently larger than the anticipated player'"'"'s foot to allow a choice of foot positions;

and

optionally, the length and width of each foot platform are each between 1.5 and 2.5 times the anticipated length of a player'"'"'s foot.

119. An apparatus according to claim 118, wherein the computing means is operable to determine foot position, or characteristics of foot position, by statistical analysis of a batch of resultant forces measured by the sensor means where the player shifts weight with the foot in that position.

120. An apparatus according to claim 119, wherein the computing means is operable to instruct or require the player to shift weight sufficiently to provide a batch of resultant forces with predefined front-to-back and side-to-side diversity.

121. An apparatus according to claim 119, wherein the batch of resultant forces is provided at the waggle and/or address preceding the swing.

122. An apparatus according to claim 120, wherein the predefined front-to-back required diversity is between 0.45 and 0.55 times the length of the foot, or the assumed length of the foot;

and

optionally, the predefined side-to-side required diversity is between 0.10 and 0.18 times the length of the foot, or the assumed length of the foot.

123. An apparatus according to claim 119, wherein the foot position is represented by no more than two entities which can be expressed in simple mathematical terms.

124. An apparatus according to claim 119, wherein the foot position is represented, or partly represented, by a best-fit line, statistically derived from the batch of resultant forces, and approximately corresponding to a central long axis of the foot;

and

optionally, the statistical derivation of the best-fit line is based on a best-fit line relative to the boundary of the batch of resultant forces.

125. An apparatus according to claim 124, wherein the foot position is represented, or partly represented, by a statistical centre, statistically derived from the batch of resultant forces, and approximately corresponding to the position of the resultant force on the foot when the resultant force is centrally balanced on the foot;

and

optionally, the statistical centre is determined as a point lying on the best-fit line, positioned midway between the most forward and most rearward values of the batch of resultant forces.

126. An apparatus according to claim 122, wherein the length of the foot is estimated with reference to the static weight of the player and club determined by the apparatus.

127. An apparatus according to claim 119, wherein the computing means is operable to evaluate the resultant foot force by comparing its position, including its longitudinal or lateral position, to the determined characteristics of the foot position.

128. An apparatus according to claim 124, wherein the computing means is operable to evaluate the position of the resultant foot force relative to two orthogonal axes, one being a line corresponding to a long central axis of the foot, and the other being a line, orthogonal to the long central axis passing through a point which corresponds to a centrally balanced position of the foot;

and

optionally, the line and point are a best-fit line and statistical centre determined from a sample batch of resultant foot forces.

129. An apparatus according to claim 124, wherein the computing means is operable to determine components of the resultant foot force by balance-resolution of the resultant foot force in relation to the determined foot position or characteristics of the foot position.

130. An apparatus according to claim 129, wherein the computing means is operable to determine components of the resultant foot force, for a given foot position, into component forces resolved as co-linear forces with the resultant foot force, and with a common focus position to the rear of the foot;

optionally, the computing means is operable to determine components as toe and heel, or front and rear, components, with their positions co-linear with the resultant force and with a focus point to the rear of the best-fit line, the position of the toe component also lying on a toe line, which is a notional and simplified locus of the most forward positions of the resultant force and the position of the heel component also lying on a heel line, which is a notional and simplified locus of the most rearward positions of the resultant force; and

optionally, the heel line is a straight line, orthogonal to the best-fit line, positioned to the rear of the statistical centre between 0.30 and 0.40 times the anticipated length of a player'"'"'s foot, the toe line is a straight line, at an angle between 45° and

75°

to the best-fit line, positioned forward of the statistical centre between 0.30 and 0.40 times the anticipated length of a player'"'"'s foot and the focus point lies on the best-fit line, at a distance to the rear of the statistical centre, between 0.65 and 1.00 times the anticipated length of a player'"'"'s foot.

131. An apparatus according to claim 107, wherein the computing means is operable to determine the position of the combined resultant force from both of the player'"'"'s feet, by balance-resolution of forces, or characteristics of forces, determined for individual feet in relation to the discrete set positions of the sensor means.

132. An apparatus according to claim 107, wherein the apparatus is operable to measure and analyze foot related forces during a golf swing.

133. An apparatus according to claim 132, wherein the computing means is operable to determine or estimate the times of occurrence of feature events in a golf swing and is operable to use these in the analysis of the golf swing.

134. An apparatus according to claim 133, wherein the computing means is operable to identify particular periods of the golf swing which can be advantageously analyzed in finer time detail than other periods, and is operable to analyze them in finer time detail.

135. An apparatus according to claim 133, wherein the computing means has information available to it of typical or probable sequences and times of occurrence of feature events in golf swings, appropriate to varying circumstances, and is operable to assist the determination or estimation of the times of occurrence of feature events in the golf swing by association of the feature events with the sample information;

and

optionally, the determination or estimation includes restricting the search for a feature event within time limits within the swing, relative to other feature events, or assigning probabilities to finding feature events at different time periods within time limits within the swing.

136. An apparatus according to claim 133, wherein the computing means has record information available to it of details of occurrence of feature events in golf swings previously taken by the player, and is operable to assist the determination or estimation of the times of occurrence of feature events in the golf swing by association of the feature events with the record information;

and

the determination or estimation includes restricting the search for a feature event within time limits within the swing, relative to other feature events, or assigning probabilities to finding feature events at different time periods within time limits within the swing.

137. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the commencement of club backswing by communication with an apparatus which is operable to determine or estimate the time when the club head leaves the address region;

and

including detecting the reinstatement of an electromagnetic beam which is disrupted by the club head when it is in the address region wherein determination or estimation includes associating the time of commencement of club backswing with a time very shortly preceding reinstatement of the beam.

138. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the commencement of backswing, by seeking within the short period following the end of the waggle or address periods, a fluctuation from a period of least change to a period of sustained change across a selected range of variables, including foot, toe and heel force positions and magnitudes on both feet;

and

optionally, detection of change includes the comparison of successive values of the variable when the variable is sampled at regular time intervals.

139. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of transition changeover from backswing to downswing, by determining the time of simultaneous maximum relative difference between toe and heel, or front and back, forces on either or both feet;

and

optionally, determination of relative differences between the two variables includes calculating the difference when the variables are simultaneously sampled at regular time intervals.

140. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of transition changeover from backswing to downswing, by determining the time of reversal of longitudinal or lateral movement, or foot-aligned longitudinal or foot-aligned lateral movement, of the forces on either or both feet, wherein determination of the reversal includes the detection of a positive to negative, or negative to positive change in successive values of the longitudinal or lateral, or foot-aligned longitudinal or foot-aligned lateral, variables when the variables are sampled at regular time intervals;

and

optionally, determination of the reversal includes the detection of a positive to negative, or negative to positive change in successive values of the longitudinal or lateral variables when the variables are sampled at regular time intervals.

141. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of transition from backswing to downswing, by determining a reversal of movement of the positions of the lateral component of combined force on both feet or a change of direction of movement of the lateral or longitudinal components of combined force on both feet;

optionally, determination of the reversal includes the detection of a positive to negative, or negative to positive, change in successive values of the lateral variables when the variables are sampled at regular time intervals; and

optionally, determination of the change in direction includes the detection of an inflective change in the differences between successive values of the longitudinal or lateral variables when the variables are sampled at regular time intervals.

142. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of transition changeover from backswing to downswing, by detecting a fluctuation from a period of sustained change, to a relatively short period of least change and back to a period of sustained change, across a selected range of variables, including foot, toe and heel force positions and magnitudes on both feet;

and

optionally, detection of change includes the comparison of successive values of the variable when the variable is sampled at regular time intervals.

143. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of transition from backswing to downswing, by determining the time of minimum value of force on the front foot, or the beginning of a period of minimum force on the front foot;

and

optionally, determination of the minimum value includes the detection of lowest value when the variable is sampled at regular time intervals.

144. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of transition from backswing to downswing, by determining the time of a significant change in the rate of change of differences in the magnitudes of the force between the left foot and the right foot;

and

optionally, determination of the significant change includes the detection of an inflective change in the rate of change of differences between successive values of the force between the left foot and the right foot when the variables are sampled at regular time intervals.

145. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of the transition from backswing to downswing, by determining the time where recorded cumulative vertical momentum attains zero value;

and

optionally detecting zero value of recorded cumulative vertical momentum includes detecting a zero value in recorded cumulative overall force, relative to the static weight of the player and club at address, at short regular time intervals from the commencement of the swing.

146. An apparatus according to claim 139, wherein the computing means is operable to determine or estimate the time of transition from backswing to downswing, by assessing or averaging the results of any or all of the available indicators of this transition;

and

optionally assessing or averaging includes assigning a weighting to the results of each indicator and taking a weighted average of the results, where weighting is partly dependent on a pre-assessment of the relative importance of the indicators and is partly dependent on an assessment of the strength of the result from each indicator.

147. An apparatus according to claim 139, wherein the computing means is operable to determine or estimate the relative components of the transition from the results of the various indicators;

and

optionally the determination or estimation may be aided by available reference data, available to the computing means.

148. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the times of pre-surge force points in the downswing by detecting changes in the magnitudes of forces on the combination of both feet, or on the left foot or on the right foot, which change either from a minimum value or from a period of relatively constant value from the commencement of the downswing;

and

optionally determination or estimation includes detecting when the minimum value of the magnitude of force occurs by comparison of successive values when it is sampled at regular time intervals.

149. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of peak force points in the downswing by detecting the time when the magnitudes of forces on the combination of both feet, or on the left foot or on the right foot, peak to a maximum value;

and

optionally determination or estimation includes detecting when the maximum value of the magnitude of force occurs by comparison of successive values when sampled at regular time intervals.

150. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the time of impact of the club and ball by communication with an apparatus which is operable to determine or estimate when the club head returns to the address region, including detecting the disruption of an electromagnetic beam by the club head in the address region, or by communication with a microphone which is operable to detect the sound of impact;

and

optionally determination or estimation includes associating the time of impact with a time very shortly following disruption of the beam.

151. An apparatus according to claim 133, wherein the computing means is operable to evaluate foot positions by comparing detected particular characteristics of foot positions, to available reference data available to the computing means, the particular characteristics including distance between foot positions;

alignment of the combined lateral axis of the feet with the target direction;

alignment angles of individual feet; and

longitudinal and lateral distance of the feet from the ball position; and

optionally the available reference data may be pre-programmed and includes ranges of values of particular characteristics, appropriate to circumstances, judged in relation to graded achievement and the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

152. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate characteristics comprising durations between feature events in the swing, and relative relationships of durations between feature events in the swing, by comparing these characteristics with available reference data available to the computing means, the characteristics including absolute values of durations of backswing;

downswing;

total swing;

portion of downswing from start to pre-surge point;

portion of downswing from pre-surge point to peak point;

portion of downswing from peak point to impact; and

/or the ratio of these absolute values to each other; and

optionally the available reference data is pre-programmed and includes ranges of absolute values and ratio values, appropriate to circumstances, judged in relation to graded achievement and the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

153. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate the smoothness or regularity of changes in the position of specified forces over specified periods of the swing, including the following forces and periods:

—

Left foot, and right foot, toe and heel forces during the backswing;

Left foot, and right foot, toe and heel forces during the downswing;

Left foot, and right foot, lateral foot forces during the backswing;

Left foot, and right foot, lateral foot forces during the downswing;

Left foot and right foot forces during the backswing;

Left foot and right foot forces during the downswing;

Combined left and right foot force during the backswing;

Combined left and right foot forces during the downswing; and

detection of change includes the comparison of successive values of the position when the position is sampled at regular time intervals and smoothness or regularity is determined by the relative maximum magnitude of the differences in changes, and the frequency of occurrence of such changes, compared to available reference data available to the computing means, including pre-programmed available reference data and the computing means matches the player'"'"'s performance to available reference data and associates a corresponding graded achievement.

154. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate the player'"'"'s pelvis related movement by determining the degree of transfer of force from the heel to the toes on the left foot and from the toes to the heel on the right foot, in the backswing, and the degree of transfer of force from the toes to the heel on the left foot and from the heel to the toes on the right foot, in the downswing, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes ranges of ratios of toes/heel force values at the beginning and end of the backswing and the beginning and end of the downswing, appropriate to circumstances, judged in relation to graded achievement and the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

155. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate the timing, direction and magnitude of overall weight transfer towards the target or intended direction, by means including checking the direction and magnitude of the combined force on both feet at relevant instances during the swing, and comparing the values to available reference data available to the computing means, the relevant instances including the point in time close to the end of the backswing, the point in time associated with transition between the backswing and the downswing, and points in times at intervals through the downswing;

and

optionally, the available reference data is pre-programmed and includes, for the relevant instances, ranges of directions and magnitudes, appropriate to circumstances, judged in relation to graded achievement and the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

156. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate the magnitudes and timing of the pre-surge force points and peak force points, relative to each other and to the determined magnitudes and timing of corresponding forces at the beginning and end of the downswing, and compare these to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes ranges of ratios of force magnitude and position values for individual feet and for the combination of both feet, appropriate to circumstances, judged in relation to graded achievement and the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

157. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate the player'"'"'s foot-aligned-longitudinal, or longitudinal, balance throughout the swing, across each foot and across the combination of feet, by checking toe and heel forces on each foot, and the relative relationship between them, against relevant criteria across each stage of the swing, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes ranges of ratios of toes/heel force values for individual feet and for the combination of both feet, at the address, at the beginning and end of the backswing and the beginning and end of the downswing, appropriate to circumstances, judged in relation to graded achievement and the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

158. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate lateral balance across the combination of both feet, by checking the lateral position of the combined resultant force relative to the positions of the feet, across each stage of the swing, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes ranges of ratios of lateral left/right force values for the left and right feet, at the address, at several points through the backswing and downswing, including the beginnings and ends, appropriate to circumstances, judged in relation to graded achievement and whereby the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

159. An apparatus according to claim 133, wherein the computing means is operable to determine and evaluate foot-aligned-lateral, or lateral, rolling of the player'"'"'s left or right feet, by checking foot-aligned-lateral, or lateral, positions of the resultant forces on each foot relative to that foot, across each stage of the swing, and comparing the values to available reference data available to the computing means;

and

optionally the available reference data is pre-programmed and includes ranges of ratios of foot-aligned-lateral or lateral left/right force values for the left and right feet, at the address, at several points through the backswing and downswing, including the beginnings and ends, foot-aligned-lateral or lateral left/right force values for individual left and right feet, at the address, at the beginning and end of the backswing and the beginning and end of the downswing, appropriate to circumstances, judged in relation to graded achievement and in which the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

160. An apparatus according to claim 133, wherein the computing means is operable to determine or estimate the duration between the end of pelvis related backswing and the end of club backswing, and relative delays at the changeover from backswing to downswing, by statistical analysis of the duration and magnitude of least change across a selected range of variables which are known to typically reduce their rate of change at the time of changeover, including foot, toes and heel force positions and magnitudes on both feet, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes ranges of absolute values and ratio values, appropriate to circumstances, judged in relation to graded achievement and wherein the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

161. An apparatus according to claim 133, wherein the computing means is operable to determine if the player lifts a foot off the standing surface, by checking if the magnitude of the resultant force reduces to zero value or close to a zero value, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes varying fault grading for the occurrence in the period prior to backswing, the period of backswing and downswing, and the period of follow-through and wherein the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

162. An apparatus according to claim 133, wherein the computing means is operable to determine if the player slides or rotates a foot to a different position on the standing surface, by checking if the position of the resultant force moves outside the resultant boundary limits established for the foot position, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes varying fault grading for the occurrence in the period prior to backswing, the period of backswing and downswing, and the period of follow-through, the boundary limits are calculated in a predefined relationship to characteristics defining the position of the foot and wherein the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

163. An apparatus according to claim 133, wherein the computing means is operable to determine if the player rotates a foot on the standing surface, by checking if the magnitude of the heel component force or the toes component force reduces to zero value or close to a zero value, and comparing the values to available reference data available to the computing means;

and

optionally, the available reference data is pre-programmed and includes varying fault grading for the occurrence in the period prior to backswing, the period of backswing and downswing, and the period of follow-through and wherein the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

164. An apparatus according to claim 151, wherein the computing means is operable to determine and evaluate the relative consistency of different swings by determining differences in relevant characteristics between different swings and comparing the values of these differences to available reference data available to the computing means, the relevant characteristics comprising any measured or determined characteristics which are relevant to required measures of consistency and include any value or characteristic which is compared to available reference data available to the computing means;

and

optionally, differences in relevant characteristics are expressed as dimensionless entities, such as ratios, and the available reference data is pre-programmed and includes varying grading for consistency, appropriate to circumstances and wherein the computing means matches the player'"'"'s performance to the available reference data and associates the corresponding graded achievement.

165. An apparatus according to claim 133, wherein the computing means is operable to selectively assign lower importance, in accordance with available reference data available to the computing means, to force measurements from a very lightly loaded foot than to those from a relatively heavily loaded foot, when determining or estimating likely times of feature events or player performance based on changes, on individual feet, of toes, heel or resultant forces;

and

optionally, the available reference data is pre-programmed and indicate an assignment of lower importance on a very lightly loaded foot where unusual toes, heel or resultant forces are detected.

166. An apparatus according to claim 133, wherein the computing means additionally receives and processes signals from sensors which measure horizontal forces on the foot platforms.

167. A method of measuring and analyzing a player'"'"'s foot related forces during a golf swing or a sports swing similar to a golf swing, by standing the player with each foot on a foot platform and distributing the vertical forces generated to a plurality of discrete positions;

measuring the vertical forces generated at the discrete positions;

determining the relation, magnitudes and positions of resultant forces by balance resolution of forces including individual forces measured at the discrete positions;

analyzing and evaluating numerical data related to the measured positions and magnitudes of the forces; and

analyzing the swing by determining or evaluating forces against a framework of feature events; and

/or determined positions of the feet; and

a body of available information comprising available reference data;

where;

the determination or evaluation related to the framework of feature events comprises mapping out the times of various detectable principal events which are common to all normal swings; and

the determination or evaluation related to the determined positions of the feet comprises statistical analysis of a batch of measured resultant forces where the player shifts weight with the foot in that position; and

the available reference data include;

information related to known swing performance, including criteria which allow different aspects of the performance to be judged or graded against what is considered to be good or bad performance when the available reference data is prepared; and

/or

information concerning previous swings made by the player or information on the player or his or her previous performance; and

/or

further information on the swing from other apparatus or systems.