Patent Publication Number: US-7901324-B2

Title: Exercise detection apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to exercise detection apparatuses. 
     2. Prior Art/Related Art 
     JP-A-2006-149792 discloses an exercise detection apparatus including a seat on which a human sits. In this apparatus, each of a plurality of members with which parts of a human body will be in contact includes a load cell to which strain gauges are affixed. When a human subject sitting on the apparatus performs plantar flexion for the ankles, the apparatus detects and counts the motion of plantar flexion if the load exerted by one of the femora onto a bar member above the femur is at maximum and if the load exerted by the ankle corresponding to the femur onto another bar member in front of the ankle is within a permissible range. 
     This apparatus involves many members with which parts of a human body will be in contact, so that the mechanical structure is complicated. In addition, it is necessary for human subjects to move their body parts to come into contact with the members of the apparatus, and this makes the use difficult. 
     Accordingly, the present invention provides an exercise detection apparatus with a simple structure that is easy to use. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided an exercise detection apparatus including: a load stage including a load surface onto which a load of parts or all of a human subject is applied; a load measurer for repeatedly or continuously measuring the load on the load surface; a calculator for calculating a difference between adjacent local maximum and minimum in the load varying over time measured by the load measurer repeatedly or continuously; and a detector for detecting a motion of the human subject when the difference calculated by the calculator is within a range. 
     The “motion” to be detected by the present invention includes motions involving change of posture or position of at least part of the body of a human subject, such as a push-up (press-up), a squat, or a forward or backward motion of a push-up or a squat. The “motion” to be detected excludes the motions without change of posture or position, such as the beating of the heart or breathing. 
     The “range” used for detecting the motion in the present invention is a range having an upper limit and a lower limit within which the difference between adjacent local maximum and minimum in the load on the load surface should fall when a human subject performs the motion appropriately. The upper limit will be determined suitably so as to avoid inappropriate detection of the motion when an abrupt impact is imparted to the load surface accidentally or by excessive exercise. The lower limit will be determined suitably so as to avoid inappropriate detection of motion when the motion extent is excessively small or when the human subject does not perform the motion. 
     The exercise detection apparatus according to the present invention does not need many members with which parts of a human body will be in contact, so that the structure can be simple. When using the exercise detection apparatus, the human subject simply imparts a load of parts or all of the human subject, so that the apparatus is easy to use. 
     In an aspect of the present invention, the motion of the human subject is a reciprocating motion including a forward motion and a backward motion, the calculator calculating a first difference between adjacent local maximum and minimum of a first set in the load measured by the load measurer, the detector detecting the forward motion when the first difference calculated by the calculator is within a first range, the calculator calculating a second difference between adjacent local maximum and minimum of a second set in the load measured by the load measurer, the detector detecting the backward motion when the second difference calculated by the calculator is within a second range, the detector detecting the reciprocating motion once the forward motion and the backward motion are detected sequentially. With such a structure, the forward motion can be precisely detected on the basis of the first range dedicated for detection of the forward motion whereas the backward motion can be precisely detected on the basis of the second range dedicated for detection of the backward motion. 
     In this aspect, the exercise detection apparatus may further include: a first range determiner for determining the first range for the human subject on the basis of a load measured by the load measurer; and a second range determiner for determining the second range for the human subject on the basis of a load measured by the load measurer. With such a structure, both the first and second ranges can be determined for particular human subjects. That is, the first and second ranges can be customized, so that the precision of measurement can be improved. 
     In this aspect, the exercise detection apparatus may further include: an information guidance device for providing first guidance for prompting the human subject to rest at a first position, and for providing second guidance for prompting the human subject to rest at a second position, a first load applied onto the load surface when the human subject holds still in the first position being less than a second load applied onto the load surface when the human subject holds still in the second position, in which the load measurer measures the first load and the second load on the load surface when the human subject holds still in the first position and in the second position, in which the first range determiner determines the first range for the human subject on the basis of the first load, and in which the second range determiner determines the second range for the human subject on the basis of the second load. With such a structure, the human subject is guided to take positions for which personal data are collected for determining the first and second ranges for this human subject. 
     The first range determiner may determine the first range for the human subject on the basis of the first load and the second load, and the second range determiner may determine the second range for the human subject on the basis of the first load and the second load. In this case, there is the likelihood that the first and second ranges can be determined more suitably. 
     In another aspect of the present invention, the exercise detection apparatus may further include: an information guidance device for providing guidance for prompting the human subject to stand up and rest on the load surface, so that the load measurer measures a body weight of the human subject when the human subject stands up and rests on the load surface; and a range determiner for determining the range for the human subject on the basis of the body weight measured by the load measurer. With such a structure, the human subject is guided to take a position in which personal body weight is measured for determining the range for this human subject. 
     In another aspect of the present invention, the load surface may include a plurality of metrical regions, each of which receives a regional load which is a part of the load as a whole applied on the load surface. The exercise detection apparatus may further include a regional load measurement processor for measuring the respective regional loads. With such a structure, distribution of load of the human subject can be measured. 
     Each of the metrical regions may include a plurality of measurement sections, each of which receives a sectional load which is a part of the load as a whole applied on the load surface. The exercise detection apparatus may further include a plurality of load sensors provided at the plurality of measurement sections, each of the load sensors converting the sectional load on the corresponding measurement section into an electric signal, in which the load measurer measures the load on the load surface on the basis of electric signals from all of the plurality of load sensors, and in which the regional load measurement processor measures the regional load on each respective metrical region on the basis of electrical signals from load sensors corresponding to the respective metrical region. With such a structure, load sensors can be commonly used for measurement of the load on the load surface and for measurement of the regional loads. 
     The regional load measurement processor may repeatedly or continuously measure the respective regional loads. The exercise detection apparatus may further include a statistical processor for calculating a statistical value for each of the metrical regions on the basis of the corresponding regional load varying over time measured by the regional load measurement processor repeatedly or continuously. With such a structure, the statistical processor can calculate statistical values for respective metrical regions, which will be useful for estimating distribution of muscular force of the human subject. 
     The exercise detection apparatus may further include an information device for informing the human subject or an observer of the number of motions detected by the detector. 
     The exercise detection apparatus may further include an information device for informing the human subject or an observer that the motion has been detected whenever the detector has detected the motion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With reference to the accompanying drawings, various embodiments of the present invention will be described hereinafter. In the drawings: 
         FIG. 1  is a perspective view showing an exercise detection apparatus according to an embodiment of the present invention; 
         FIG. 2  is a schematic view showing a raised position (first position) in reciprocating motions performed on the exercise detection apparatus; 
         FIG. 3  is a schematic view showing a lowered position (second position) in reciprocating motions performed on the exercise detection apparatus; 
         FIG. 4  is a block diagram showing an electrical structure of the exercise detection apparatus of the embodiment; 
         FIG. 5  is a schematic diagram showing a counting process for counting the number of reciprocating motions; 
         FIG. 6  is a flowchart showing an entire operation executed by the exercise detection apparatus; 
         FIG. 7  is a diagram showing an image displayed by a display device of the exercise detection apparatus when the exercise detection apparatus conducts posture adjustment assistance; 
         FIG. 8  is a graph showing an example of change of the total load on a load surface of the exercise detection apparatus during the forward motion of the reciprocating motions; 
         FIG. 9  is a graph showing an example of change of the total load on a load surface of the exercise detection apparatus during the backward motion of the reciprocating motions; 
         FIG. 10  is a flowchart showing a reciprocating motion detection process executed by the exercise detection apparatus; 
         FIG. 11  is a diagram showing an image displayed in the display device of the exercise detection apparatus when the exercise detection apparatus conducts the reciprocating motion detection process; 
         FIG. 12  is a diagram showing an image displayed in the display device of the exercise detection apparatus when the exercise detection apparatus conducts posture adjustment assistance in accordance with a modification of the embodiment; and 
         FIG. 13  is a schematic view showing reciprocating motions performed on an exercise detection apparatus in accordance with a modification of the embodiment. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  is a perspective view showing an exercise detection apparatus according to an embodiment of the present invention. The exercise detection apparatus  100  detects and counts push-ups as reciprocating motions of a human body. More specifically, when the apparatus detects a forward motion and then a backward motion corresponding to the forward motion, the apparatus increases the counted number of push-ups by one. The apparatus outputs information for informing the human subject or an observer of the number of detected push-ups. 
     In this specification, the forward motion of a push-up means lowering the human body H from a raised position (first position), as shown in  FIG. 2 , at which the arms are stretched, to a lowered position (second position), as shown in  FIG. 3 , at which the arms are bent. In contrast, the backward motion of a push-up means raising the human body H from the lowered position at which the arms are bent to the raised position at which the arms are stretched. A push-up is a reciprocating motion constituted of the forward motion and the backward motion. 
     The exercise detection apparatus  100  includes a main body  110  and a display device  120  attached to the main body  110 . The main body  110  is a load stage that includes a load surface  1  onto which a load of parts or all of a human body is applied. A controller inside the main body  110  conducts a total load measurement in which the controller measures the total load exerted onto the load surface  1 . When performing push-ups, the human subject puts both hands on the load surface  1 . 
     When the human subject holds still in the raised position as shown in  FIG. 2 , the total load exerted onto the load surface  1  is less than that when the human subject holds still in the lowered position as shown in  FIG. 3 . In the specification, the total load on the load surface  1  when the human subject holds still in the raised position as shown in  FIG. 2  is referred to as a “lesser static-position load”, whereas the total load on the load surface  1  when the human subject holds still in the lowered position as shown in  FIG. 3  is referred to as a “greater static-position load”. 
     The load surface  1  includes a plurality of (four in the embodiment) measurement sections  1 LF,  1 LB,  1 RF, and  1 RB arranged in two rows and two columns. The measurement sections  1 LF,  1 LB,  1 RF, and  1 RB are provided with load sensors  2 LF,  2 LB,  2 RF, and  2 RB, respectively, so that each load sensor measures the load exerted onto the measurement section beneath which the load sensor is located. The measurement section  1 LF is located in the left column and in the front row. The measurement section  1 LB is located in the left column and in the back row. The measurement section  1 RF is located in the right column and in the front row. The measurement section  1 RB is located in the right column and in the back row. The measurement sections  1 LF,  1 LB,  1 RF, and  1 RB may be structurally separated from one another, or may be formed in an integral body such that they are visually distinguishable from one another. 
     The load surface  1  includes a plurality of (two in the embodiment) metrical regions, i.e., a left metrical region  1 L and a right metrical region  1 R. When performing push-ups, the human subject puts the left hand on the left metrical region  1 L and the right hand on the right metrical region  1 R. The left metrical region  1 L includes the aforementioned plurality of left measurement sections  1 LF and  1 LB whereas the right metrical region  1 R includes the aforementioned plurality of right measurement sections  1 RF and  1 RB. 
     The load surface  1  also includes a plurality of (two in the embodiment) metrical regions, i.e., a front metrical region  1 F and a back metrical region  1 B. The front metrical region  1 F includes the aforementioned plurality of front measurement sections  1 LF and  1 RF whereas the back metrical region  1 B includes the aforementioned plurality of back measurement sections  1 LB and  1 RB. 
     Each of the metrical regions  1 L and  1 R and the metrical regions  1 F and  1 B is a subject for load measurement and is similar to each of the measurement sections  1 LF,  1 LB,  1 RF, and  1 RB, as will be described later. Of course, the metrical regions  1 L and  1 R may be structurally separated from each other, or may be formed in an integral body such that they are visually distinguishable from each other. The same is true for the metrical regions  1 F and  1 B. 
     In the left metrical region  1 L, a symbol G 1  is depicted for instructing the human subject of the position and orientation of the left hand. The symbol G 1  is located over the measurement sections  1 LF and  1 LB. In the right metrical region  1 R, a symbol G 2  is depicted for instructing the human subject of the position and orientation of the right hand. The symbol G 1  is located over the measurement sections  1 RF and  1 RB. 
     On the basis of the respective loads exerted onto the measurement sections  1 LF,  1 LB,  1 RF, and  1 RB and measured by the load sensors  2 LF,  2 LB,  2 RF, and  2 RB, a controller inside the main body  110  executes the aforementioned total load measurement and two regional load measurements. One of the regional load measurements is a process for measuring the respective loads on the left and right metrical regions  1 L and  1 R. This process will be referred to as an “intra-column load measurement”. The other is a process for measuring the respective loads on the front and back metrical regions  1 F and  1 B. This process will be referred to as an “intra-row load measurement”. 
       FIG. 4  is a block diagram showing an electrical structure of the exercise detection apparatus  100 . In addition to the aforementioned display device  120  and the load sensors  2 LF,  2 LB,  2 RF, and  2 RB, the exercise detection apparatus  100  includes a sound emitter  111 , a storage part  112 , and a controller  113 . 
     Each load sensor  2 LF,  2 LB,  2 RF, or  2 RB is located beneath the corresponding measurement section  1 LF,  1 LB,  1 RF, or  1 RB, and converts the sectional load on the corresponding measurement section to an electrical signal. Consequently, the signal output from the load sensor indicates the measured value of the load on the corresponding measurement section. The load sensor may have various structure, e.g., it may include one or more strain gauges. 
     The display device  120  (information guidance device and information device) includes a screen  121  for displaying images as shown in  FIG. 1 . The display device  120  may be a liquid crystal display or any other suitable display device. The sound emitter  111  (information guidance device and information device) includes one or more speakers (not shown). The storage part  112  for storing data written therein includes a rewritable storage region and a nonvolatile storage region. The storage part  112  may have various structures, and in this embodiment, the storage part  112  is an EEPROM (electrically erasable programmable read only memory) of which the storage region is a rewritable and nonvolatile storage region. The controller  113  is, for example, a CPU (central processing unit) which can serve as a timer. 
     The storage part  112  stores standard reference-forward-motion-range data d 1  and standard reference-backward-motion-range data d 2 . The standard reference-forward-motion-range data d 1  indicates a standard reference forward motion range which is a suitable range within which the difference between the maximum and the minimum of the total load to be applied onto the load surface  1  should fall when a standard human subject performs the forward motion of a push-up. The standard reference-backward-motion-range data d 2  indicates a standard reference backward motion range which is a suitable range within which the difference between the maximum and the minimum of the total load to be applied onto the load surface  1  should fall when a standard human subject performs the backward motion of a push-up. The standard reference forward motion range and the standard reference backward motion range can be statistically determined on the basis of measurement results of many the human subjects. 
     The storage part  112  also stores number-of-times data d 3  indicating the number of detections of push-ups performed by the human subject. The initial value of the number of detections is zero. 
       FIG. 5  schematically shows a counting process (reciprocating motion detection) for counting the number of push-ups. The count period starts with the start of push-ups and ends with the end of push-ups. The count period includes one or more reciprocating motion periods. Each reciprocating motion period includes a forward motion period and a backward motion period behind the forward motion period. 
     Referring back to  FIG. 4 , the storage part  112  stores a control program d 4 . The control program d 4  is a computer program executed by the controller  113 . By executing the control program d 4 , the controller  113  serves as a total load measurement processor  114 , a regional load measurement processor  116 , a statistical processor  118  and a detector  119 . 
     The total load measurement processor  114  conducts the aforementioned total load measurement. That is, the total load measurement processor  114  serves as a load measurer for measuring the total load exerted onto the load surface  1  on the basis of the signals supplied from the load sensors  2 LF,  2 LB,  2 RF, and  2 RB. More specifically, the total load measurement processor  114  sums up the respective loads indicated by the signals supplied from all of the load sensors to obtain the current total load. Then, the total load measurement processor  114  generates a current total load data element d 5  indicating the total load currently obtained, and records it in the storage part  112 . The total load measurement processor  114  repeats the total load measurement periodically (intermittently), but the total load measurement processor  114  may conduct the total load measurement continuously. 
     The regional load measurement processor  116  conducts the aforementioned intra-column load measurement and intra-row load measurement. That is, the regional load measurement processor  116  measures the load (left regional load) exerted onto the left metrical region  1 L on the basis of the signals supplied from the corresponding load sensors  2 LF and  2 LB, generates a current regional load data element d 6 L indicating the load, and records it in the storage part  112 . Similarly, the regional load measurement processor  116  measures the load (right regional load) exerted onto the right metrical region  1 R on the basis of the signals supplied from the corresponding load sensors  2 RF and  2 RB, generates a current regional load data element d 6 R indicating the load, and records it in the storage part  112 . Similarly, the regional load measurement processor  116  measures the load (front regional load) exerted onto the front metrical region  1 F on the basis of the signals supplied from the corresponding load sensors  2 LF and  2 RF, generates a current regional load data element d 6 F indicating the load, and records it in the storage part  112 . Similarly, the regional load measurement processor  116  measures the load (back regional load) exerted onto the back metrical region  1 B on the basis of the signals supplied from the corresponding load sensors  2 LB and  2 RB, generates a current regional load data element d 6 B indicating the load, and records it in the storage part  112 . The regional load measurement processor  116  repeats the set of the four regional load measurements periodically (intermittently), but the regional load measurement processor  116  may conduct this set continuously. 
     The detector  119  detects push-ups performed by the human subject, as will be described in detail. The statistical processor  118  calculates statistical values for respective left metrical regions. 
       FIG. 6  is a flowchart showing an entire operation executed by the controller  113  of the exercise detection apparatus  100 . At step S 1 , the controller  113  guides the human subject into the raised position (first position) shown in  FIG. 2 . More specifically, the controller  113  causes both or either of the display device  120  and the sound emitter  111  to provide guidance for prompting the human subject to take the raised position. Then, the human subject takes the raised position with the hands placed on the symbols G 1  and G 2  on the load surface  1 . The guidance continues for a certain period (for example, five seconds). 
     At step S 2 , the controller  113  conducts posture adjustment assistance. More specifically, the controller  113  causes the regional load measurement processor  116  to repeatedly or continuously perform the intra-column load measurement and the intra-row load measurement, and causes the screen  121  of the display device  120  to sequentially show each value of the regional loads measured as shown in  FIG. 7 . The human subject adjusts the posture viewing the screen  121  until the values are equalized. The posture adjustment assistance continues for a certain period (for example, three seconds). 
     At step S 3 , the controller  113  conducts a greater static-position load determination process, which continues for a certain period (for example, four seconds), for determining the greater static-position load. In the greater static-position load determination process, the controller  113  causes both or either of the display device  120  and the sound emitter  111  to provide guidance for prompting the human subject to rest at the lowered position (second position) after a certain period (for example, three seconds), and then the total load measurement processor  114  repeatedly or continuously perform the total load measurement. The controller  113  determines the greater static-position load on the basis of the measured total load varying over time. By the guidance, the human subject moves from the raised position to the lowered position (performs the forward motion) and rests at the lowered position. 
       FIG. 8  shows an example of change of the total load on the load surface  1  during the forward motion of a push-up. As shown in  FIG. 8 , the total load on the load surface  1  is constant at a value SL min  for the first period T 1  before the human subject starts the forward motion. For the next period T 2  when the human subject is moving, the total load first reduces to the minimum GL min , then rises to the maximum GL max , and finally reduces to a value SL max . For the next period T 3  after the human subject begins to rest at the lowered position, the total load is constant at the value SL max . As in  FIG. 8 , GL min &lt;SL min &lt;SL max &lt;GL max . 
     In the greater static-position load determination process, the total load measured by the total load measurement processor  114  also varies in a similar manner as shown in  FIG. 8 . Accordingly, the total load measured by the total load measurement processor  114  at the period T 3  is the greater static-position load SL max . By the aforementioned guidance, the human subject rests at the lowered position for a certain period (e.g., three seconds) after the guidance, so that the total load on the load surface  1  becomes the value SL max  when the certain period has passed after the guidance. The controller  113  determines the total load SL max  measured lastly in the greater static-position load determination process as the greater static-position load, and records greater static-position load data d 7  indicating the value of the greater static-position load SL max  (second load) in the storage part  112 . 
     At step S 4 , the controller  113  conducts a lesser static-position load determination process, which continues for a certain period (for example, four seconds), for determining the lesser static-position load. In the lesser static-position load determination process, the controller  113  causes both or either of the display device  120  and the sound emitter  111  to provide guidance for prompting the human subject to rest at the raised position (first position) after a certain period (for example, three seconds), and then the total load measurement processor  114  repeatedly or continuously performs the total load measurement. The controller  113  determines the lesser static-position load on the basis of the measured total load varying over time. By the guidance, the human subject moves from the lowered position to the raised position (performs the backward motion) and rests at the raised position. 
       FIG. 9  shows an example of change of the total load on the load surface  1  during the backward motion of a push-up. As shown in  FIG. 9 , the total load on the load surface  1  is constant at a value SL max  for the first period T 4  before the human subject starts the backward motion. For the next period T 5  when the human subject is moving, the total load first rises to the maximum BL max , then reduces to the minimum BL min , and finally rises to a value SL min . For the next period T 6  after the human subject begins to rest at the raised position, the total load is constant at the value SL min . As in  FIG. 9 , BL min &lt;SL min &lt;SL max &lt;BL max . 
     In the lesser static-position load determination process, the total load measured by the total load measurement processor  114  also varies in a similar manner as shown in  FIG. 9 . Accordingly, the total load measured by the total load measurement processor  114  at the period T 6  is the lesser static-position load SL min . By the aforementioned guidance, the human subject rests at the raised position for a certain period (e.g., three seconds) after the guidance, so that the total load on the load surface  1  becomes the value SL min  when the certain period has passed after the guidance. The controller  113  determines the total load SL min  measured lastly in the lesser static-position load determination process as the lesser static-position load, and records lesser static-position load data d 8  indicating the value of the lesser static-position load SL min  (first load) in the storage part  112 . 
     In an alternative embodiment, after the lesser static-position load determination process, the greater static-position load determination process may be conducted. 
     As shown in  FIG. 8  and  FIG. 9 , usually GL min &lt;BL min  whereas GL max &lt;BL max . It is not limited that BL min −GL min  is equal to GL max −BL max . Accordingly, in the illustrated embodiment, a personal reference forward motion range and a personal reference backward motion range are separately used for detecting the forward motion and the backward motion, as will be described later. 
     Referring back to  FIG. 6 , at step S 5 , the controller  113  conducts a personal reference-motion-range determination process in which the controller  113  serves as a first range determiner for determining a personal reference forward motion range (first range) for the particular human subject and serves as a second range determiner for determining a personal reference backward motion range (second range) for the particular human subject. In the personal reference-motion-range determination process, by an arithmetic process on the basis of the standard reference-forward-motion-range data d 1 , the standard reference-backward-motion-range data d 2 , the greater static-position load data d 7 , and the lesser static-position load data d 8 , the controller  113  determines the personal reference forward motion range having its upper and lower limits and the personal reference backward motion range having its upper and lower limits. The controller  113  generates personal reference-forward-motion-range data d 9  indicating the determined personal reference forward motion range and personal reference-backward-motion-range data d 10  indicating the determined personal reference backward motion range, and records the personal reference-forward-motion-range data d 9  and the personal reference-backward-motion-range data d 10  in the storage part  112 . 
     The arithmetic process for determining the personal reference forward motion range and the personal reference backward motion range is not limited. For example, the personal reference forward motion range (first range) may be determined on the basis of the standard reference-forward-motion-range data d 1  and the lesser static-position load data d 8 , whereas the personal reference backward motion range (second range) may be determined on the basis of the standard reference-backward-motion-range data d 2  and the greater static-position load data d 7 . In an another example, the personal reference forward motion range (first range) may be determined on the basis of the standard reference-forward-motion-range data d 1 , the greater static-position load data d 7 , and the lesser static-position load data d 8 , whereas the personal reference backward motion range (second range) may be determined on the basis of the standard reference-backward-motion-range data d 2 , the greater static-position load data d 7 , and the lesser static-position load data d 8 . 
     The personal reference forward motion range indicated by the personal reference-forward-motion-range data d 9  is a suitable range within which the difference between adjacent local maximum and minimum of the total load on the load surface  1  falls when the human subject performs the forward motion of push-ups. That is, the personal reference forward motion range is a suitable range of the forward motion for this particular human subject, and is different from the standard reference forward motion range indicated by the standard reference-forward-motion-range data d 1  since the standard reference forward motion range is a suitable range of the forward motion for an imaginary standard human subject. 
     As will be understood from  FIG. 8 , the maximum value GL max  and the minimum value GL min  for the forward motion have relation to the value SL min  (indicated by the lesser static-position load data d 8 ), so that the personal reference forward motion range (first range) can be determined on the basis of the value SL min . In addition, as will be understood from  FIG. 8 , the maximum value GL max  and the minimum value GL min  for the forward motion have relation to the value SL max  (indicated by the greater static-position load data d 7 ) and the value SL min  (indicated by the lesser static-position load data d 8 ), so that the personal reference forward motion range (first range) can be more precisely determined on the basis of the values SL max  and SL min . 
     The personal reference backward motion range indicated by the personal reference-backward-motion-range data d 10  is a suitable range within which the difference between adjacent local maximum and minimum of the total load on the load surface  1  falls when the human subject performs the backward motion of push-ups. That is, the personal reference backward motion range is a suitable range of the backward motion for this particular human subject, and is different from the standard reference backward motion range indicated by the standard reference-backward-motion-range data d 2  since the standard reference backward motion range is a suitable range of the backward motion for an imaginary standard human subject. 
     As will be understood from  FIG. 9 , the maximum value BL max  and the minimum value BL min  for the backward motion have relation to the value SL max  (indicated by the greater static-position load data d 7 ), so that the personal reference backward motion range (second range) can be determined on the basis of the value SL max . In addition, as will be understood from  FIG. 9 , the maximum value BL max  and the minimum value BL min  for the backward motion have relation to the value SL max  (indicated by the greater static-position load data d 7 ) and the value SL min  (indicated by the lesser static-position load data d 8 ), so that the personal reference backward motion range (second range) can be more precisely determined on the basis of the values SL max  and SL min . 
     At step S 6 , the controller  113  initializes the number-of-times data d 3  (i.e., renew the number-of-times data d 3  to zero) and deletes all of the total load data elements d 5  and regional load data elements d 6 L, d 6 R, d 6 F, and d 6 B stored in the storage part  112 . In addition, the controller  113  causes both or either of the display device  120  and the sound emitter  111  to provide guidance for instructing to start push-ups. 
     Thereafter, the controller  113  repeats a reciprocating motion detection process, i.e., a counting process (step S 7 ). As shown in  FIG. 5 , the count period starts with the start of the first reciprocating motion period. The count period ends with the end of the final reciprocating motion period. 
       FIG. 10  is a flowchart showing the reciprocating motion detection process (step S 7 ). In the reciprocating motion detection process, the controller  113  conducts a forward motion counting process at step S 71  for determining whether or not a suitable forward motion is detected. On the basis of change in the total load varying over time measured by the total load measurement processor  114 , the controller  113  can determine the start and the end of the actual forward motion since the load reduces, rises and then reduces during the forward motion as shown in  FIG. 8 . 
     In the forward motion counting process, the controller  113  determines at step S 710  whether or not the forward motion has ended. If the forward motion has ended, the controller  113  serves as a calculator at step S 711  for calculating the first difference between adjacent local minimum and maximum of a first set in the total load varying over time measured by the total load measurement processor  114 . More specifically, the controller  113  chooses the local minimum and the local maximum among the total load values indicated by the total load data elements d 5  sequentially generated by the total load measurement processor  114  during the last forward motion, and calculates the first difference therebetween. Then, the controller  113  serves as a comparer for comparing the first difference with the personal reference forward motion range indicated by the personal reference-forward-motion-range data d 9  and serves as the aforementioned detector  119  for determining whether or not the first difference falls within the personal reference forward motion range at step S 712 . Thus, the detector  119  detects a suitable forward motion when the first difference is within the personal reference forward motion range (first range). 
     If the determination at step S 712  is negative, the process proceeds to step S 72 . If the determination at step S 712  is affirmative, the process proceeds to step S 713  in which the controller  113  sets a first flag, which means a suitable forward motion has been detected, and then the process proceeds to step S 72 . 
     Thus, the controller  113  finishes the forward motion counting process and conducts a backward motion counting process at step S 72  for determining whether or not a suitable backward motion is detected. On the basis of change in the total load varying over time measured by the total load measurement processor  114 , the controller  113  can determine the start and the end of the actual backward motion since the load rises, falls, and then rises during the backward motion as shown in  FIG. 9 . 
     In the backward motion counting process, the controller  113  determines at step S 720  whether or not the backward motion has ended. If the backward motion has ended, the controller  113  serves as a calculator at step S 721  for calculating the second difference between adjacent local maximum and minimum of a second set in the total load varying over time measured by the total load measurement processor  114 . More specifically, the controller  113  chooses the local maximum and the local minimum among the total load values indicated by the total load data elements d 5  sequentially generated by the total load measurement processor  114  during the last backward motion, and calculates the second difference therebetween. Then, the controller  113  serves as a comparer for comparing the second difference with the personal reference backward motion range indicated by the personal reference-backward-motion-range data d 10  and serves as the aforementioned detector  119  for determining whether or not the second difference falls within the personal reference backward motion range at step S 722 . Thus, the detector  119  detects a suitable backward motion when the second difference is within the personal reference backward motion range (second range). 
     If the determination at step S 722  is negative, the process proceeds to step S 73 . If the determination at step S 722  is affirmative, the process proceeds to step S 723  in which the controller  113  sets a second flag, which means a suitable backward motion has been detected, and then the process proceeds to step S 73 . 
     Thus, the controller  113  finishes the backward motion counting process and conducts an information output process at step S 73 . In the information output process, the controller  113  serves as the detector  119  for counting up push-ups. If the first and second flags are set, the detector  119  renews the number-of-times data d 3  so as to increase the number of detections of push-ups by one, and the controller  113  causes both or either of the display device  120  and the sound emitter  111  to inform the human subject or an observer of the number of detected push-ups. Thus, the detector  119  counts up the number of detected push-ups if the determinations at steps S 712  and S 722  are affirmative. Otherwise, the detector  119  does not count up the number of detected push-ups. In other words, the detector  119  detects the reciprocating motion once the forward motion and the backward motion are detected sequentially at steps S 712  and S 722 . 
     After step S 73 , the controller  113  resets the first and second flags (not shown) at step S 74 , and the process returns to step S 71  for repeating the reciprocating motion detection process. 
     The reciprocating motion detection process may end when a predetermined time period has passed from the start of the reciprocating motion detection process. In an alternative embodiment, the reciprocating motion detection process may end when the human subject or the observer manipulates an interface (not shown) for having the process end. In another alternative embodiment, the reciprocating motion detection process may end when the human subject takes the hands off from the load surface  1  and the total load measurement processor  114  measures nothing. 
     During the reciprocating motion detection process, the controller  113  serves as the aforementioned statistical processor  118  (see  FIG. 4 ) for conducting a statistical process (step S 75 ) in which the statistical processor  118  calculates a statistical value for each of the left and right metrical regions  1 L and  1 R on the basis of the regional load varying over time measured by the regional load measurement processor  116  repeatedly or continuously. The statistical processor  118  repeats the statistical process at regular time intervals. 
     For example, in the statistical process, the statistical processor  118  calculates a left muscular force which is, in this embodiment, the average of the left regional load values applied on the left metrical region  1 L on the basis of the left regional load data elements d 6 L stored in the storage part  112 . The statistical processor  118  also calculates a right muscular force which is, in this embodiment, the average of the right regional load values applied on the right metrical region  1 R on the basis of the right regional load data elements d 6 R stored in the storage part  112 . 
     At step S 76 , the controller  113  causes the display device  120  to show the statistical values for respective metrical regions.  FIG. 11  shows an image displayed by the display device  120 , in which the statistical values for respective metrical regions are displayed. Accordingly, the human subject or the observer is informed of the right and left distribution of muscular force of the human subject. 
     Additionally or alternatively, the statistical processor  118  may calculate a statistical value for each of the front and back metrical regions  1 F and  1 B on the basis of the regional load varying over time measured by the regional load measurement processor  116  repeatedly or continuously. In this case, the human subject or the observer is informed of the front and back distribution of muscular force of the human subject. 
     In this embodiment, the calculated statistical value is the average of regional load values. However, it is not intended to limit the present invention to this. The calculated statistical value may be another statistical value which is suitable for evaluating partial muscular force of the human subject, e.g., the average of local maximums of regional load values, the average of local minimums of regional load values, or the sum of regional load values. 
     As has been described above, in accordance with the exercise detection apparatus  100 , as long as the human subject performs push-ups within suitable load ranges, the number of detections of push-ups is incremented by one. The human subject or the observer is informed of the number of detections of push-ups and of the statistical values of respective regional loads on respective metrical regions. 
     MODIFICATIONS 
     While the present invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as claimed by the claims. Such variations, alterations, and modifications are intended to be encompassed in the scope of the present invention. Examples of such variations, alterations, and modifications will be described below. 
     In a modification, at the posture adjustment assistance (step S 2 ), the controller  113  may cause the display device  120  to show each value of the sectional loads on the measurement sections  1 LF,  1 LB,  1 RF, and  1 RB as shown in  FIG. 12 , rather than the regional loads. 
     In the above-described embodiment, the load surface  1  includes four measurement sections  1 LF,  1 LB,  1 RF, and  1 RB. However, the number of measurement sections may be less than four or greater than four. 
     In an modification, it is not necessary that the load surface  1  include the left and right metrical regions  1 L and  1 R. 
     In another modification, it is not necessary that the load surface  1  include the front and back metrical regions  1 F and  1 B. 
     The load surface  1  may include three or more metrical regions aligned in one direction. 
     Each metrical region may include a single measurement section or three or more measurement sections. 
     Different metrical regions may include different numbers of measurement sections. 
     In the above-described embodiment, each of steps S 1  through S 4  in  FIG. 6  continues for a certain period. However, the period of each or either of these steps may be variable. For example, in the posture adjustment assistance (step S 2 ), the controller  113  may calculate the difference between the left and right regional loads obtained by the intra-column load measurement and may compare the difference with a predetermined range. The controller  113  may also calculate the difference between the front and back regional loads obtained by the intra-low load measurement and may compare the difference with a predetermined range. If both of the differences are within the ranges, the posture adjustment assistance (step S 2 ) may end. 
     In a modification, at the greater static-position load determination process (S 3 ), the controller  113  may measure a time period in which the repeatedly or continuously measured total load is within a reference range. If the time period reaches a threshold, the controller  113  may calculate a statistical value (e.g., the average) of the repeatedly or continuously measured total load values, and determines the statistical value to be the greater static-position load. 
     In the above-described embodiment, the human subject or the observer is informed of the right and left distribution of muscular force of the human subject, the front and back distribution of muscular force of the human subject, or both. However, such report of the distribution of muscular force may be omitted. 
     In a modification, both or either of the display device  120  and the sound emitter  111  may be omitted. Instead, an outside information guidance device, such as a television set, may perform the role of information guidance. In another modification, a set of light emitting devices, such as light emitting diodes, may be used as an information guidance device. 
     In the above-described embodiment, all of the load sensors  2  are commonly used for the regional load measurement and the total load measurement. In a modification, it is possible to provide a plurality of load sensors for the regional load measurement and to provide one or more load sensors for the total load measurement. In another modification, it is possible to provide one or more load sensors only for the total load measurement. 
     In the above-described embodiment, the forward and backward motions are detected on the basis of the personal reference forward motion range and the personal reference backward motion range for the particular human subject, which are determined on the basis of a test applied to the human subject. In a modification, the forward and backward motions may be detected on the basis of the standard reference forward motion range and the standard reference backward motion range. 
     In the above-described embodiment, the lesser and greater static-position loads are used for determining the personal reference forward motion range and the personal reference backward motion range. Additionally or alternatively, the total body weight of the human subject may be used by the controller  113  (range determiner) for determining the personal reference forward motion range and the personal reference backward motion range. In this case, both or either of the display device  120  and the sound emitter  111  may provide guidance for prompting the human subject to stand up and rest on the load surface  1  for measuring the body weight, and then the total load measurement processor  114  measures the body weight of the human subject. In addition, the exercise detection apparatus  100  may estimate the energy consumption of the human subject per push-up on the basis of the body weight of the human subject, and/or may estimate the energy consumption of the human subject during a plurality of push-ups on the basis of the body weight of the human subject and the number of detected push-ups. 
     In the above-described embodiment, the exercise detection apparatus  100  detects push-ups in which both hands of a human subject are put on the load surface  1 . In a modification, an exercise detection apparatus may detect another motion of a human subject in which the load of all of a human subject is applied onto a load surface. For example, such an exercise detection apparatus may detect push-ups in which both feet of a human subject are placed onto a load surface. 
     In another example, such an exercise detection apparatus  101  may detect squats when both feet of a human body H are placed onto a load surface whereby the load of all of a human subject is applied onto the load surface as shown in  FIG. 13 . For squats, when the human subject holds still in the standing position (first position) with the legs stretched, the total load exerted onto the load surface is less than that when the human subject holds still in the crouching position (second position) with the legs are bent. For squats, the aforementioned personal reference forward motion range may be usually the same as the personal reference backward motion range, and therefore either of the greater static-position load determination process (S 3 ) or the lesser static-position load determination process (S 4 ) may be omitted. For squats, at the posture adjustment assistance (S 2 ), the intra-row load measurement can be omitted since it is usually meaningless to check the front and back distribution of load of the human subject (differently from push-ups). 
     In the above-described embodiment, the length of the period required for both the forward motion and the backward motion is not limited in advance. In a modification, in advance of the exercise, it is possible to fix the limit of length of both or either of the forward motion and the backward motion. For example, the human subject may freely set the length. In this modification, when the detector does not detect a suitable forward motion within a forward motion limit period or when the detector does not detect a suitable backward motion within a backward motion limit period, the detector does not detect or count the reciprocating motion corresponding to the forward or backward motion. In this modification, preferably, both or either of the display device  120  and the sound emitter  111  may inform the human subject of the start and/or end of each of a forward motion limit period, a backward motion limit period, or a reciprocating motion limit period. 
     In a modification, it is possible to settle an upper limit for the number of detected reciprocating motions and to instruct the human subject of the end of exercise when the number of detected reciprocating motions reaches the upper limit. This upper limit (target number) may be freely set by the human subject. In another modification, it is possible to settle the length of the count period. This length of the count period (target length) may also be freely set by the human subject. 
     In the above-described embodiment, the human subject or an observer is informed of the number of detected reciprocating motions. Additionally or alternatively, both or either of the display device  120  and the sound emitter  111  may inform the human subject or an observer of the number of one or both of suitably detected forward motions and backward motions. Additionally or alternatively, whenever at least one of a forward motion, a backward motion, or a reciprocating motion is detected suitably, both or either of the display device  120  and the sound emitter  111  may inform the human subject or an observer that a suitable motion has been detected, by emitting, for example, a sound, such as beep. 
     In the above-described embodiment, the exercise detection apparatus detects reciprocating motions (push-ups or squats). However, it is possible for the exercise detection apparatus to detect only forward motions or backward motions. 
     In a modification, various data indicating one or more of the first and second differences, the date of exercise, the number of detected motions, and the distribution of muscular force may be recorded in the storage part  112  or any other suitable information storage medium. The human subject can be informed of the recorded information with the information device, such as the display device  120 , when the human subject so desires. Thus, the human subject can be aware either or both of the history and the degree of development of the muscles of the human subject. 
     In the above-described embodiment, the total load data elements d 5  are used for determining adjacent local maximum and minimum in the total load on the load surface  1 , and then if the difference therebetween falls within a suitable range, the number of detected motions is counted up. The total load data elements d 5  indicating change in the total load may be used for another purpose, for example, for calculating the motion speed which is the number of detected motions per unit of time. Based on the motion speed and the exercise load, a value indicating degree of exercise burden, e.g., the momentum, may be calculated. The exercise load may be the difference between the global or local maximum and the global or local minimum in the total load on the load surface  1 . 
     The momentum is more appropriate for estimating the effect of exercise, although the number of detected motions also indicates the effect of exercise. This is because the heavier the body weight, the greater the momentum even if the numbers of the detected motions are equal. In addition, the exercise load that is the difference between the maximum and the minimum in the total load is smaller for a lighter human subject than that for a heavier human subject. Furthermore, although the exercise loads are equal, the momentum is greater for quick motions. If the controller  113  of the exercise detection apparatus calculates the momentum, the human subject can be aware of the effect of exercise more precisely. The controller  113  may cause the display device  120  to show the momentum.