Patent Description:
With the increasing health consciousness of people, walking is gaining popularity. Especially in recent years, with widespread use of smartphones and watches with built-in Global Positioning System (GPS) modules, anyone can easily record walking exercise logs (hereinafter, also referred to as "walking logs"). The use of such walking logs motivates people to continue walking and make it a habit, which is boosting the popularity of walking.

There is a known technology of capturing images of a user's strength training motions with an image capture device and calculating joint positions and angles from the captured images to estimate the training effects (see <CIT>, for example). There is also a known technology of calculating, based on detection results of a stretch sensor that detects stretching and contraction of an attachment part attached to a body part, such as a knee joint, the kinetic energy at the attachment part (see <CIT>, for example).

Furthermore, <CIT> discloses a system and method for determining quantitative gait scores from combinations of gait metrics, termed 'Combined Mobility Score'. Thereby, detected signals are analyzed to determine said 'Combined Mobility Score' for the subject from a combination of metrics in gait categories i-iv, namely: i. daily step count; ii. one or more of gait velocity, step length, stride length, and cadence; iii. one or more of step length asymmetry, step time asymmetry, single support time variability; and iv. walking orientation randomness metric.

Information recorded as a walking log is often information related mainly to the amount of walking, such as walking time and walking distance, and is not necessarily information related to the quality of walking exercise. In this regard, even if the technology of <CIT> is used to evaluate the quality of walking exercise, a special environment in which images of the user's exercise can be captured is required, so that the image capturing cannot be easily performed outdoors by the user himself or herself. Also, even if the technology of <CIT> is used to calculate the kinetic energy, since a dedicated device must be attached to a region that stretches and contracts, it cannot be said that the quality of walking exercise can be easily measured.

The present disclosure has been made in view of such a situation, and a purpose thereof is to provide a technology for measuring the quantity and quality of walking exercise easily and estimating the exercise effects.

To solve the problem above, a gait evaluation system according to one aspect of the present disclosure includes: a quantitative measurement value acquirer that acquires a measurement value of a quantitative parameter indicating an amount of walking, measured by a measurement device worn by a subject; a qualitative measurement value acquirer that acquires at least measurement values of a stride length, of an arm swing angle and a cadence as qualitative parameters indicating a walking form, measured by a measurement device worn by the subject; a quantitative result determination unit that determines an evaluation result regarding an amount of walking, based on a measurement value of a quantitative parameter; a qualitative result determination unit that determines an evaluation result regarding a walking form, based on a predetermined evaluation model that reflects the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved, and a measurement value of a qualitative parameter; and an output unit that outputs walking result information including the evaluation result regarding the amount of walking and the evaluation result regarding the walking form, wherein the qualitative result determination unit (<NUM>) determines the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula for obtaining the sum of a value obtained by adding a weight to the ratio of the subject's stride-height ratio to an average stride-height ratio of a corresponding attributed level, and a value of the ratio of the subject's cadence to an average cadence of the corresponding attributed level, and an evaluation formula set such that a weight is added at least to a measurement value of the arm swing angle.

Another aspect of the present disclosure also relates to a gait evaluation system. The gait evaluation system includes: a quantitative measurement value acquirer that acquires a measurement value of a quantitative parameter indicating an amount of walking, measured by a measurement device worn by a subject; a qualitative measurement value acquirer that acquires at least measurement values of pelvic movement, of an arm swing angle and a cadence as qualitative parameters indicating a walking form, measured by a measurement device worn by the subject; a quantitative result determination unit that determines an evaluation result regarding an amount of walking, based on a measurement value of a quantitative parameter; a qualitative result determination unit that determines an evaluation result regarding a walking form, based on a predetermined evaluation model that reflects the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved, and a measurement value of a qualitative parameter; and an output unit that outputs walking result information including the evaluation result regarding the amount of walking and the evaluation result regarding the walking form, wherein the qualitative result determination unit (<NUM>) determines the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula for obtaining the sum of a value obtained by adding a weight to the ratio of the subject's stride-height ratio to an average stride-height ratio of a corresponding attributed level, and a value of the ratio of the subject's cadence to an average cadence of the corresponding attributed level, and an evaluation formula set such that a weight is added at least to a measurement value of the arm swing angle.

Yet another aspect of the present disclosure relates to a gait evaluation method. The method includes: acquiring a measurement value of a quantitative parameter indicating an amount of walking, measured by a measurement device worn by a subject; acquiring at least measurement values of a stride length, of an arm swing angle and a cadence as qualitative parameters indicating a walking form, measured by a measurement device worn by the subject; determining an evaluation result regarding an amount of walking, based on a measurement value of a quantitative parameter; determining an evaluation result regarding a walking form, based on a predetermined evaluation model that reflects the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved, and a measurement value of a qualitative parameter; and outputting walking result information including the evaluation result regarding the amount of walking and the evaluation result regarding the walking form, wherein the qualitative result determination unit (<NUM>) determines the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula for obtaining the sum of a value obtained by adding a weight to the ratio of the subject's stride-height ratio to an average stride-height ratio of a corresponding attributed level, and a value of the ratio of the subject's cadence to an average cadence of the corresponding attributed level, and an evaluation formula set such that a weight is added at least to a measurement value of the arm swing angle.

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several FIGURES, in which:.

The disclosure will now be described by reference to the preferred embodiments. This does not intend to limit the scope of the present disclosure, but to exemplify the disclosure.

In the following, the present disclosure will be described based on a preferred embodiment with reference to each drawing. In the embodiment and modifications, like reference characters denote like or corresponding constituting elements, and the repetitive description will be omitted as appropriate.

<FIG> illustrates a configuration of a gait evaluation system <NUM>. The gait evaluation system <NUM> includes a wristwatch-type device <NUM>, a waist-mounted device <NUM>, and an information terminal-type device <NUM>, which can be worn by a subject <NUM> who performs walking exercise, and an information management server <NUM>. The wristwatch-type device <NUM>, waist-mounted device <NUM>, and information terminal-type device <NUM> are also collectively referred to as measurement devices <NUM>. The wristwatch-type device <NUM> is a sports watch or a smart watch that can measure position information, motion information, and the like. The waist-mounted device <NUM> is a motion sensor that can be attached to the vicinity of the waist of the subject <NUM> to measure position information and motion information. The information terminal-type device <NUM> is a portable information terminal, such as a smartphone, that can measure position information and motion information while held in a pocket or the like by the subject <NUM>. A measurement device <NUM> is not limited to a device such as the wristwatch-type device <NUM>, waist-mounted device <NUM>, or information terminal-type device <NUM> and may also be a belt-type device that can be worn around the chest, a wrist, the waist, or an arm of the subject to acquire position information and motion information. Further, various other wearable devices may be used as the measurement devices <NUM>.

The subject <NUM> performs walking exercise while wearing at least one or all of the wristwatch-type device <NUM>, waist-mounted device <NUM>, and information terminal-type device <NUM> as the measurement devices <NUM>. Each measurement device <NUM> synchronizes information via communication with the information management server <NUM>. However, the communication means for the wristwatch-type device <NUM> and the waist-mounted device <NUM> among the measurement devices <NUM> is short-range wireless communication; therefore, instead of communicating directly with the information management server <NUM>, the devices synchronize information with the information terminal-type device <NUM> (which also functions as an "information terminal <NUM>" detailed later), and the information terminal <NUM> then synchronizes information with the information management server <NUM>. Thus, since the wristwatch-type device <NUM> and the waist-mounted device <NUM> transmit information to the information management server <NUM> via synchronization to the information terminal <NUM>, it is premised that the information terminal <NUM> is possessed. However, the information terminal <NUM> need not necessarily be worn during walking exercise, and it is sufficient if the synchronization with the information terminal <NUM> can be performed after the exercise. As a modification, after the waist-mounted device <NUM> synchronizes information with the wristwatch-type device <NUM> via near-field wireless communication, the wristwatch-type device <NUM> may further synchronize the information with the information terminal-type device <NUM> (information terminal <NUM>) via near-field wireless communication.

The subject <NUM> performs walking exercise while wearing a measurement device <NUM> and starts measurement and walking log recording by operating a button or the like of the measurement device <NUM> at the start of the walking exercise. During the walking exercise, the measurement device <NUM> measures, as walking time, the elapsed time from the start of recording with a timer and also records position information for each date and time at predetermined time intervals. The measurement device <NUM> also measures the number of steps per unit time with a built-in motion sensor. With the built-in motion sensor, the measurement device <NUM> further measures values of the arm swing angle, pelvic movement, left and right walking tempos, and the like.

When the subject <NUM> wears the wristwatch-type device <NUM> as a measurement device <NUM>, values of the time information, position information, number of steps per unit time, arm swing angle, and the like are measured, and the walking log is recorded. When the subject <NUM> wears the waist-mounted device <NUM> as a measurement device <NUM>, values of the time information, position information, number of steps per unit time, pelvic movement (such as the hip rotation angle, lateral hip tilt, and front-back hip bend), left and right walking tempos, and the like are measured, and the walking log is recorded. When the subject <NUM> wears the information terminal-type device <NUM> as a measurement device <NUM>, values of the time information, position information, number of steps per unit time, and the like are measured, and the walking log is recorded.

After the completion of the walking exercise and the walking log recording, the measurement device <NUM> transmits, to the information management server <NUM>, information such as the walking time, position information, number of steps, arm swing angle, pelvic movement, and left and right walking tempos, as the walking log. Also, the measurement device <NUM> may calculate information such as the walking time, walking distance, and walking speed, based on the time information and position information, and may transmit the walking log including such calculated information to the information management server <NUM>.

The information management server <NUM> is a server computer that is connected to the Internet and transmits and receives data to and from the information terminals <NUM> of multiple subjects <NUM>. The information management server <NUM> acquires, as walking log data of a subject <NUM> received from the corresponding information terminal <NUM>, measurement values of the time information, position information, number of steps per unit time, arm swing angle, and the like, together with identification information and attribute information of the subject <NUM>, and accumulates the walking log data together with various data and evaluation values calculated from the measurement values. In response to a request from an information terminal <NUM>, the information management server <NUM> transmits the accumulated walking log data, evaluation values, and the like to the information terminal <NUM>.

<FIG> is a functional block diagram that shows each configuration in the gait evaluation system <NUM>. The gait evaluation system <NUM> in the present embodiment is constituted by a measurement device <NUM>, an information terminal <NUM>, and the information management server <NUM>. The gait evaluation system <NUM> may be implemented by various hardware configurations and software configurations. For example, the gait evaluation system <NUM> may be constituted only by the information terminal <NUM>, may be constituted by a combination of the information terminal <NUM> and the measurement device <NUM>, or may be constituted by a combination of the information terminal <NUM> and the information management server <NUM>. Also, the gait evaluation system <NUM> may be constituted by a combination of the information terminal <NUM>, the measurement device <NUM>, and the information management server <NUM>, may be constituted by a combination of the measurement device <NUM> and the information management server <NUM>, or may be constituted only by the information management server <NUM>.

For example, on the premise that the walking exercise is measured and recorded as the walking log using a variety of general-purpose devices as the measurement device <NUM>, the gait evaluation system <NUM> may be constituted only by the information terminal <NUM> and the information management server <NUM> or may be implemented as a stand-alone device that includes all software configurations included in the information terminal <NUM> and the information management server <NUM> shown in <FIG>. Therefore, it is sufficient if the gait evaluation system <NUM> includes, regardless of its hardware configuration, at least the software configurations of the information terminal <NUM> and the information management server <NUM> shown in <FIG>.

With regard to each of the measurement device <NUM>, information terminal <NUM>, and information management server <NUM>, <FIG> shows functional blocks implemented by coordination of various hardware configurations and software configurations. Therefore, it will be understood by those skilled in the art that these functional blocks may be implemented in a variety of forms by hardware only, software only, or a combination thereof. The measurement device <NUM> is constituted by a combination of hardware, such as a microprocessor, memory, communication module, positioning module, and motion sensor. The information terminal <NUM> is constituted by a combination of hardware, such as a microprocessor, memory, display, communication module, positioning module, and motion sensor. The information management server <NUM> is constituted by a combination of hardware, such as a microprocessor, memory, display, and communication module. In the following, the functions of each of the measurement device <NUM>, information terminal <NUM>, and information management server <NUM> will be described.

The measurement device <NUM> is, for example, the waist-mounted device <NUM>. The measurement device <NUM> includes a communication unit <NUM>, a time measurement unit <NUM>, a position measurement unit <NUM>, and a motion detector <NUM>. The time measurement unit <NUM> measures the walking start time, i.e., the walking time from the measurement start time, with counting by a timer. The position measurement unit <NUM> measures the current position based on position information received by a Global Positioning System (GPS) module from a satellite positioning system. The motion detector <NUM> detects, with a motion sensor, the number of steps, pelvic movement, and the like in the walking exercise of the subject <NUM>. The measurement values of the number of steps include, besides the number of steps per unit time, the left and right walking tempos. The measurement values of the pelvic movement include the pelvic or hip rotation angle, lateral tilt angle of the pelvis or hips, and front-back bend angle of the pelvis or hips.

As the measurement device <NUM>, the wristwatch-type device <NUM> or the information terminal-type device <NUM> may also be used. When the wristwatch-type device <NUM> is used as the measurement device <NUM>, the motion detector <NUM> of the wristwatch-type device <NUM> detects, with a motion sensor, the number of steps, arm swing angle, and the like in the walking exercise of the subject <NUM>. When the information terminal-type device <NUM> is used as the measurement device <NUM>, the motion detector <NUM> of the information terminal-type device <NUM> detects, with a motion sensor, the number of steps in the walking exercise of the subject <NUM>. The information terminal <NUM> may serve dually as the information terminal-type device <NUM> as the measurement device <NUM>, and, in that case, a single mobile terminal such as a smartphone may have all the functions of both the measurement device <NUM> and the information terminal <NUM>, for example. When the information terminal <NUM> is not used as the measurement device <NUM>, the information terminal <NUM> may be not limited to a smartphone and may also be a tablet terminal or a personal computer owned by the subject <NUM>.

The information terminal <NUM> includes a quantitative measurement value acquirer <NUM>, a qualitative measurement value acquirer <NUM>, an output unit <NUM>, and a communication unit <NUM>. The quantitative measurement value acquirer <NUM> receives, via the communication unit <NUM>, information measured by the measurement device <NUM> worn by the subject <NUM>. Based on the information received from the measurement device <NUM>, the quantitative measurement value acquirer <NUM> acquires a measurement value of a quantitative parameter indicating the amount of walking. The quantitative measurement value acquirer <NUM> includes a time acquirer <NUM>, a distance acquirer <NUM>, and a speed acquirer <NUM>.

The time acquirer <NUM> acquires, as a quantitative parameter indicating the amount of walking, the walking time of the subject <NUM> based on the information received from the time measurement unit <NUM>. The distance acquirer <NUM> acquires, as a quantitative parameter indicating the amount of walking, the walking distance of the subject <NUM> based on the information received from the position measurement unit <NUM>. The speed acquirer <NUM> acquires, as a quantitative parameter indicating the amount of walking, the walking speed of the subject <NUM> based on the walking time and the walking distance.

The qualitative measurement value acquirer <NUM> also receives, via the communication unit <NUM>, information measured by the measurement device <NUM> worn by the subject <NUM>. Based on the information received from the measurement device <NUM>, the qualitative measurement value acquirer <NUM> acquires a measurement value of at least one of the stride length, cadence, arm swing angle, pelvic movement, difference between the left and right walking tempos, and the like, as a qualitative parameter indicating the walking form. The qualitative measurement value acquirer <NUM> includes a stride length acquirer <NUM>, a cadence acquirer <NUM>, an arm movement acquirer <NUM>, a hip movement acquirer <NUM>, and a tempo acquirer <NUM>.

The stride length acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the stride length of the subject <NUM> based on the information received from the position measurement unit <NUM> and the motion detector <NUM>. The stride length as used herein may be an average value of the stride length per unit time or unit distance. The cadence acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the cadence of the subject <NUM> based on the information received from the motion detector <NUM>. The cadence as used herein may be an average value of the cadence per unit time or unit distance.

The arm movement acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the arm swing angle of the subject <NUM> based on the information received from the motion detector <NUM>. Also, the hip movement acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the pelvic movement of the subject <NUM> based on the information received from the motion detector <NUM>. The measurement values of the "pelvic movement" as used herein may include the pelvic or hip rotation angle, lateral tilt angle of the pelvis or hips, and front-back bend angle of the pelvis or hips. The tempo acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the difference between the left and right walking tempos of the subject <NUM> based on the information received from the motion detector <NUM>. The "difference between the left and right walking tempos" as used herein may be the difference between the cadence interval from the left foot to the right foot and the cadence interval from the right foot to the left foot.

The output unit <NUM> displays, on the screen, the measurement values of the quantitative parameters (walking time, walking distance, and walking speed) indicating the amount of walking acquired by the quantitative measurement value acquirer <NUM> and the measurement values of the qualitative parameters (stride length, cadence, arm swing angle, pelvic movement, and difference between the left and right walking tempos) indicating the walking form acquired by the qualitative measurement value acquirer <NUM>. The output unit <NUM> may display both the measurement values of the quantitative parameters and the measurement values of the qualitative parameters on the screen while the subject <NUM> is performing walking exercise or may display only the quantitative parameters on the screen during the walking exercise. Also, the output unit <NUM> may display the measurement values of the quantitative parameters and the measurement values of the qualitative parameters on the screen after the completion of the walking exercise. The output unit <NUM> transmits the measurement values of the quantitative parameters and the measurement values of the qualitative parameters as the walking log data together with the attribute information of the subject <NUM>, to the information management server <NUM> via the communication unit <NUM>. The output unit <NUM> may transmit, as the walking log, the measurement values of the time information, position information, number of steps per unit time, arm swing angle, and the like acquired from the measurement device <NUM> to the information management server <NUM> or may further transmit, together with the measurement values acquired from the measurement device <NUM>, information such as the walking time, walking distance, walking speed, stride length, and cadence, as the walking log to the information management server <NUM>.

The information management server <NUM> includes a communication unit <NUM>, a log acquirer <NUM>, a quantitative measurement value acquirer <NUM>, a qualitative measurement value acquirer <NUM>, a result determination unit <NUM>, a data storage unit <NUM>, and an output unit <NUM>. The log acquirer <NUM> acquires the walking log data from the information terminal <NUM> via the communication unit <NUM> and accumulates the walking log data in the data storage unit <NUM>.

Based on the walking log data acquired by the log acquirer <NUM>, the quantitative measurement value acquirer <NUM> acquires a measurement value of a quantitative parameter indicating the amount of walking, such as the walking time, walking distance, and the walking speed. The quantitative measurement value acquirer <NUM> includes a time acquirer <NUM>, a distance acquirer <NUM>, and a speed acquirer <NUM>.

The time acquirer <NUM> acquires, as a quantitative parameter indicating the amount of walking, the walking time of the subject <NUM> based on the walking log data. The distance acquirer <NUM> acquires, as a quantitative parameter indicating the amount of walking, the walking distance of the subject <NUM> based on the walking log data. The speed acquirer <NUM> acquires, as a quantitative parameter indicating the amount of walking, the walking speed of the subject <NUM> based on the walking log data.

Based on the walking log data acquired by the log acquirer <NUM>, the qualitative measurement value acquirer <NUM> acquires a measurement value of at least one of the stride length, cadence, arm swing angle, pelvic movement, left and right walking tempos, and the like, as a qualitative parameter indicating the walking form. The qualitative measurement value acquirer <NUM> includes a stride length acquirer <NUM>, a cadence acquirer <NUM>, an arm movement acquirer <NUM>, a hip movement acquirer <NUM>, and a tempo acquirer <NUM>.

The stride length acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the stride length of the subject <NUM> based on the walking log data. The cadence acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the cadence of the subject <NUM> based on the walking log data. The arm movement acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the arm swing angle of the subject <NUM> based on the walking log data. The hip movement acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the pelvic movement of the subject <NUM> based on the walking log data. The tempo acquirer <NUM> acquires, as a qualitative parameter indicating the walking form, the difference between the left and right walking tempos of the subject <NUM> based on the walking log data.

The result determination unit <NUM> includes an attribute acquirer <NUM>, a reference value calculation unit <NUM>, a quantitative result determination unit <NUM>, a qualitative result determination unit <NUM>, and a condition judgment unit <NUM>.

The attribute acquirer <NUM> acquires the attribute information of the subject <NUM> from the data storage unit <NUM>, based on the walking log data or the identification information of the subject <NUM> related to the walking log data. The attribute information includes, for example, information such as the age, gender, and height of the subject <NUM> and information on a level regarding physical strength or health to which the subject <NUM> belongs. The physical strength level is based on measurement values obtained by comprehensive measurement of muscle strength, flexibility (the ranges of motion of the hip joints and the shoulder joints), grip strength, leg strength (sit-to-stand test), balance strength (one-leg standing with eyes closed), endurance, and the like. The physical strength level may also include other physical strength levels evaluated for measurement items in physical strength evaluation commonly used. The health level is based on measurement values of, for example, indices used in medical examinations (height, weight, BMI, blood pressure, blood indices) and a stress index.

The reference value calculation unit <NUM> calculates average measurement values for each attribute or level to which the subject <NUM> belongs, as reference values to be compared with various measurement values of the subject <NUM>. The reference value calculation unit <NUM> may calculate average measurement values for each generation, gender, physical strength level, and health level, for example.

The quantitative result determination unit <NUM> determines an evaluation result regarding the amount of walking, based on the measurement values of quantitative parameters acquired by the quantitative measurement value acquirer <NUM>. The quantitative result determination unit <NUM> may determine the evaluation result based on the measurement values of quantitative parameters such as the walking time, walking distance, and walking speed, in comparison with the average values thereof for each attributed level. For example, the case where the walking time is longer than the corresponding generation's average thereof may be evaluated as "a larger amount of exercise", and the case where the walking time is shorter than the corresponding generation's average thereof may be evaluated as "a smaller amount of exercise".

The qualitative result determination unit <NUM> determines an evaluation result regarding the walking form, based on the measurement values of qualitative parameters acquired by the qualitative measurement value acquirer <NUM> and a predetermined evaluation model that reflects the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved. As the predetermined evaluation model that reflects the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved, an evaluation formula can be considered, for example, in which, in the case where a better value of a specific qualitative parameter leads closer to an ideal form for a higher exercise effect, the weighting factor for the specific qualitative parameter is made larger so that the qualitative parameter is reflected more in the evaluation. Also, a different value may be set as the weighting factor for each qualitative parameter so as to be proportional to the magnitude of contribution to the exercise effect.

The qualitative result determination unit <NUM> determines the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula set such that a weight is added at least to the measurement value of the stride length. The qualitative result determination unit <NUM> may determine the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula for obtaining the sum of a value obtained by adding a weight to the ratio of the stride-height ratio of the subject <NUM> to the average stride-height ratio of the corresponding attributed level, and the value of the ratio of the cadence of the subject <NUM> to the average cadence of the corresponding attributed level. The qualitative result determination unit <NUM> may also determine the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula set such that a weight is added at least to the measurement value of the pelvic movement. The qualitative result determination unit <NUM> may also determine the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula set such that a weight is added at least to the measurement value of the arm swing angle. The evaluation model or the evaluation formula will be described later.

The condition judgment unit <NUM> judges whether or not at least one of the evaluation result regarding the amount of walking or the evaluation result regarding the walking form has satisfied a predetermined target achievement condition. In recent years, a method called gamification has been used to continue exercise habits for the purpose of improving health through exercise. For example, a game-like method can be considered in which, in addition to the calculation of energy consumption based on the walking distance and the number of steps taken and to the estimation and display of the amount of body fat reduction, a specific game is made to progress each time a certain condition is met, and discount tickets or points are issued based on the degree of achievement of the game. Thus, the condition judgment unit <NUM> judges whether or not any of multiple types of target achievement conditions, presented as such game-like elements to the subject <NUM>, has been satisfied.

A target achievement condition judged by the condition judgment unit <NUM> may be, for example, a condition of awarding <NUM> point for each time the walking distance reaches <NUM>, or a condition of awarding <NUM> point for each time the number of steps reaches <NUM> steps. Also, while the point award rate is usually one times, it may be increased to <NUM> times or the like for each time a favorable result is obtained as the evaluation result regarding the walking form. Other target achievement conditions may be, for example, "to walk for <NUM> minutes or longer five times", "to obtain a favorable result as the exercise effect on the thighs five times", "to walk <NUM> or longer once", "to walk at an average walking speed of <NUM>/h five times", "to obtain a favorable result as the exercise effect on the vicinity of the waist five times", "to obtain a favorable result as the exercise effect on the upper arms five times", "to walk <NUM> once", "to perform walking exercise <NUM> times", and so on. Also, these various target achievement conditions may be displayed in a 3x3 matrix on the screen such that the game is cleared when targets for the squares of any of the horizontal, vertical, or diagonal rows are achieved, just like a bingo game.

The output unit <NUM> outputs walking result information including the evaluation result regarding the amount of walking and the evaluation result regarding the walking form, to the information terminal <NUM> via the communication unit <NUM>. The output unit <NUM> outputs the walking result information including information regarding whether or not at least one of the evaluation result regarding the amount of walking or the evaluation result regarding the walking form has satisfied a predetermined target achievement condition, to the information terminal <NUM> via the communication unit <NUM>. By allowing the output unit <NUM> to display the information regarding whether or not a target achievement condition has been satisfied on the screen of the information terminal <NUM>, the subject <NUM> can be motivated to exercise and also encouraged to continue the exercise.

The output unit <NUM> outputs the walking result information including information regarding the exercise effect on each body part based on the evaluation result regarding the amount of walking and the evaluation result regarding the walking form, to the information terminal <NUM> via the communication unit <NUM>. For example, the output unit <NUM> may display, on the screen of the information terminal <NUM>, an object indicating the type and magnitude of the exercise effect on each body part on an image of a human body model to express the exercise effect on each body part.

<FIG> shows relationships between the walking speed, stride length, and muscle activity level. The muscle activity level is an example of a qualitative evaluation value for walking exercise estimated by the qualitative result determination unit <NUM> with a predetermined evaluation model. It can be said that the larger the amount of muscle activity in each body part, the higher the exercise effect on each body part. For example, in the case of the so-called cadence type, of which the cadence is relatively large, it can be said that the range of motion of the legs is relatively narrow, the leg muscles are not sufficiently stretched, and the amount of muscle activity is relatively small. Conversely, in the case of the so-called stride type, of which the stride length is relatively large, it can be said that the range of motion of the legs is relatively wide, the leg muscles are sufficiently stretched, and the amount of muscle activity is relatively large. Accordingly, it is considered that the load on the leg muscles is greater in walking with a larger range of motion and a smaller number of repetitions than in walking with a smaller range of motion and a larger number of repetitions. Therefore, with reference to <FIG>, the muscle activity level of which the relationship with the stride length was particularly evaluated greatly will be described.

<FIG> shows the results of interval walking performed by the subject <NUM>, in which walking at a speed increased to a point where it is not regarded as running (also called fast walking) and walking at a slower speed were repeated alternately about every <NUM> minutes. Such interval walking is known to provide exercise effects comparable to those of running, while placing less strain on the legs than running. In the graph of <FIG>, the horizontal axis represents the walking time [minutes]. Also, the right vertical axis represents the stride length [cm], and the left vertical axis represents the walking speed [km/h] and the muscle activity level estimate.

In the graph of <FIG>, the line of walking speed <NUM> indicates an average walking speed for each minute. The line of walking speed <NUM> increases to about <NUM>-<NUM>/h during fast walking and decreases to about <NUM>-<NUM>/h during slow walking in the intervals, showing such an increase and decrease in speed repeated about every <NUM> minutes. The line of stride length <NUM> indicates an average stride length for each minute. The line of stride length <NUM> indicates walking with a large stride length of about <NUM>-<NUM> immediately after the start and, over the walking time, the stride length gradually decreasing to about <NUM>. The line of muscle activity level estimation <NUM> indicates an average muscle activity level estimate for each minute. The line of muscle activity level estimation <NUM> indicates that the muscle activity level estimate increases to around <NUM> immediately after the start and, while increasing and decreasing along with the increase or decrease of the walking speed <NUM>, gradually decreases to about <NUM> to <NUM> over the walking time.

The qualitative evaluation values for walking exercise can be divided into multiple types of evaluation values for each body part, and the exercise effect can be measured for each body part. This also enables measurement of an exercise effect in terms of dieting focusing on a specific target body part, which may also be called "localized slimming". In the following, a method for estimating an evaluation value for each body part will be described.

The line of muscle activity level estimation <NUM> in the graph of <FIG> indicates an evaluation value of the muscle activity level in the buttocks and thighs. Normally, the amount of activity of the buttock and thigh muscle groups, such as the gluteus maximus, hamstrings, and rectus femoris, is proportional to the walking speed. The walking speed is thought to be more influenced by the stride length than by the cadence. The muscle activity level in the buttocks and thighs can be estimated from the two variables of the stride length and the cadence. A muscle activity level estimate y per minute is determined by the qualitative result determination unit <NUM> using the following estimation formula. <MAT> where a represents the stride-height ratio per minute, b represents the cadence per minute, A represents the average stride-height ratio of the corresponding generation, and B represents the average cadence of the corresponding generation. The "stride-height ratio" indicates the ratio of the stride length to the height of the subject <NUM>. For the weighting such that the degree of contribution of the stride length becomes greater than that of the cadence, the weighting factor for the stride length may be set to <NUM>, and the weighting factor for the cadence may be set to <NUM>, for example.

For example, if the measurement values of the stride length and the cadence are equal to the corresponding generation's averages thereof, a/A and b/B will be both <NUM> and hence y = <NUM>, which corresponds to the reference value. In the graph of <FIG>, the scale of "<NUM>" located in the middle of the left vertical axis indicates the reference value, and, when the evaluation value is positioned above the reference value, i.e., when the estimate y is greater than <NUM> as the reference value, the muscle activity level in the buttocks and thighs of the subject <NUM> can be evaluated as high. When the evaluation value is positioned below the reference value, i.e., when the estimate y is smaller than <NUM> as the reference value, the muscle activity level in the buttocks and thighs of the subject <NUM> can be evaluated as low.

Normally, the amount of activity of the muscle groups around the waist, such as the rectus abdominis muscles and oblique abdominal muscles, is increased by rotating the pelvis greatly during walking. The muscle activity level in the vicinity of the waist can be estimated from the two variables of the pelvic rotation angle and the cadence. The muscle activity level estimate y per minute is determined by the qualitative result determination unit <NUM> using the following estimation formula. <MAT> where c represents the average pelvic rotation angle per minute, b represents the cadence per minute, C represents an average pelvic rotation angle, and B represents the average cadence of the corresponding generation. For the weighting such that the degree of contribution of the pelvic rotation angle becomes greater than that of the cadence, the weighting factor for the pelvic rotation angle may be set to <NUM>, and the weighting factor for the cadence may be set to <NUM>, for example.

For example, if the measurement values of the pelvic rotation angle and the cadence are equal to the corresponding generation's averages thereof, c/C and b/B will be both <NUM> and hence y = <NUM>, which corresponds to the reference value. When the estimate y is greater than <NUM> as the reference value, the muscle activity level in the vicinity of the waist of the subject <NUM> can be evaluated as high. When the estimate y is smaller than <NUM> as the reference value, the muscle activity level in the vicinity of the waist of the subject <NUM> can be evaluated as low.

While the pelvic rotation angle has a high degree of contribution to the estimation of the muscle activity level in the vicinity of the waist, the measurement values of the lateral hip tilt and the front-back hip bend have no direct effect on the estimation of the muscle activity level in the vicinity of the waist and have a relatively low degree of contribution. However, the measurement values of the lateral hip tilt and the front-back hip bend may be added, as variables with relatively low weighting factors, to the evaluation formula for the muscle activity level in the vicinity of the waist so that the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved can be measured more accurately.

Normally, the amount of activity of the upper arm muscle groups, such as the biceps and triceps brachii muscles, is increased by swinging the arms greatly during walking. The muscle activity level in the upper arms can be estimated from the two variables of the arm swing angle and the cadence. The muscle activity level estimate y per minute is determined by the qualitative result determination unit <NUM> using the following estimation formula. <MAT> where d represents the average arm swing angle per minute, b represents the cadence per minute, D represents an average arm swing angle, and B represents the average cadence of the corresponding generation. For the weighting such that the degree of contribution of the arm swing angle becomes greater than that of the cadence, the weighting factor for the arm swing angle may be set to <NUM>, and the weighting factor for the cadence may be set to <NUM>, for example.

For example, if the measurement values of the arm swing angle and the cadence are equal to the corresponding generation's averages thereof, diD and b/B will be both <NUM> and hence y = <NUM>, which corresponds to the reference value. When the estimate y is greater than <NUM> as the reference value, the muscle activity level in the upper arms of the subject <NUM> can be evaluated as high. When the estimate y is smaller than <NUM> as the reference value, the muscle activity level in the upper arms of the subject <NUM> can be evaluated as low.

<FIG> illustrates a screen example for displaying the muscle activity level estimate. A screen <NUM> shows the contents displayed on the screen of the information terminal <NUM>. In a first frame <NUM>, the number "<NUM>" is displayed as the muscle activity level estimate determined by the qualitative result determination unit <NUM>. In a second frame <NUM>, the ratio of the stride length to the average stride length of the corresponding generation is represented by a stick figure object indicating the magnitude of the muscle activity level with the skeleton of a person performing walking exercise. As shown in <FIG>, a first stick figure <NUM> representing the subject <NUM> is displayed at a skeletal position such that the magnitude of the muscle activity level is different from that of a second stick figure <NUM> representing the corresponding generation's average, thereby visually indicating that the subject <NUM> exceeds the generation's average. The first stick figure <NUM> and the second stick figure <NUM> may be displayed in animated forms performing walking exercise, and, in that case, the magnitude of each of the arm swing, leg movement, and hip sway on the left and right sides may be expressed by the magnitude of the skeletal movement in the animation. Also, in the first stick figure <NUM>, part of the body parts mainly evaluated for the muscle activity level may be emphasized with a specific color. In a third frame <NUM>, the measurement value of the arm swing angle is displayed with a level indicator <NUM> and a text <NUM>. As shown in <FIG>, the level indicated by the level indicator <NUM> is the sixth of the total eight levels, which visually indicates that the measurement value is greater than a standard value as an intermediate value.

On the screen shown in <FIG>, the arm swing angle is displayed as being mainly evaluated, thereby indicating that the muscle activity level estimate displayed in the first frame <NUM> and the second frame <NUM> is based mainly on the evaluation of the muscle activity level in the upper arms. In another aspect, when the muscle activity level in the buttocks and thighs is mainly evaluated, it may be indicated in the third frame <NUM> that it is mainly the result of evaluation of the stride length, for example. Also, in another aspect, when the muscle activity level in the vicinity of the waist is mainly evaluated, it may be indicated in the third frame <NUM> that it is mainly the result of evaluation of the average pelvic rotation angle, for example.

<FIG> illustrates a screen example for displaying measurement values as qualitative parameters. The screen <NUM> shows the contents displayed on the screen of the information terminal <NUM>. On the screen <NUM>, a fourth frame <NUM>, a fifth frame <NUM>, and a sixth frame <NUM> are arranged. In the fourth frame <NUM>, a third stick figure <NUM> with arrows, which indicate hip rotation, is displayed, together with a level indicator <NUM> that indicates the hip rotation level, and with a text <NUM> that indicates the measurement value of the hip rotation angle (a numerical value such as "<NUM> degrees", for example). In the fifth frame <NUM>, the third stick figure <NUM> is displayed with arrows indicating hip sway on the left and right sides, the level indicator <NUM> indicates the sway level, and the text <NUM> indicates the measurement value of the lateral pelvic tilt angle (a numerical value such as "<NUM> degrees", for example). In the sixth frame <NUM>, the level indicator <NUM> indicates the level of the difference between the left and right cadences, and the text <NUM> indicates the measurement value of the difference between the left and right cadences (a numerical value such as "<NUM> milliseconds", for example). In the same way as shown in <FIG>, the measurement value of the arm swing angle, the measurement value of the front-back bend angle of the pelvis, and the measurement value of the stride length or cadence may be further displayed.

<FIG> illustrates a screen example for displaying exercise effects divided based on a quantitative parameter and a qualitative parameter. The screen <NUM> shows the contents displayed on the screen of the information terminal <NUM>. In the graph of <FIG>, the horizontal axis represents the quantity of exercise, i.e., the walking time as the amount of walking, and the vertical axis represents the quality of exercise, i.e., the muscle activity level. In the matrix of the graph, a first effect object <NUM> located on the upper right is a large flame mark representing complete combustion, which indicates that both the quantity and the quality of exercise are high. A second effect object <NUM> located on the upper left is a small flame mark representing complete combustion, which indicates that the quantity of exercise is low but the quality of exercise is high. A third effect object <NUM> located on the lower right is a large flame mark representing incomplete combustion, which indicates that the quantity of exercise is high but the quality of exercise is low. A fourth effect object <NUM> located on the lower left is a small flame mark representing incomplete combustion, which indicates that both the quantity and the quality of exercise are low. On the actual screen, one of the first effect object <NUM>, second effect object <NUM>, third effect object <NUM>, or fourth effect object <NUM> is displayed to visually indicate the quantity and quality of exercise such as to be grasped at a glance.

<FIG> illustrates a screen example for displaying an exercise effect on each body part. The screen <NUM> shows the contents displayed on the screen of the information terminal <NUM>. In the screen example of <FIG>, a human body model <NUM> is displayed in the center of the screen, and a flame mark object is displayed for each body part. For example, a fifth effect object <NUM> and a sixth effect object <NUM> are displayed at positions corresponding to the left and right upper arms. The fifth effect object <NUM> and the sixth effect object <NUM> are large flame marks representing incomplete combustion, similar to the third effect object <NUM> shown in <FIG>. This visually indicates that, with regard to the left and right upper arms, the exercise effect was high in the quantity of exercise but low in the quality of exercise. Also, a seventh effect object <NUM> is displayed at a position around the waist, for example. The seventh effect object <NUM> is a large flame mark representing complete combustion, similar to the first effect object <NUM> shown in <FIG>. This visually indicates that, with regard to the vicinity of the waist, the exercise effect was high in both the quantity and the quality of exercise. Also, an eighth effect object <NUM> and a ninth effect object <NUM> are displayed at positions of the left and right thighs, for example. The eighth effect object <NUM> and the ninth effect object <NUM> are large flame marks representing complete combustion, similar to the first effect object <NUM> shown in <FIG>. This visually indicates that, with regard to the thighs, the exercise effect was high in both the quantity and the quality of exercise. Further, when the quantity of exercise is low, an effect object similar to the second effect object <NUM> or the fourth effect object <NUM> shown in <FIG> may be displayed on the target body part. This allows the effect in the quantity and quality of exercise for each body part to be grasped at a glance.

Claim 1:
A gait evaluation system (<NUM>), comprising:
a quantitative measurement value acquirer (<NUM>, <NUM>) that acquires a measurement value of a quantitative parameter indicating an amount of walking, measured by a measurement device (<NUM>) worn by a subject;
a qualitative measurement value acquirer that acquires at least measurement values of a stride length, of an arm swing angle and a cadence as qualitative parameters indicating a walking form, measured by a measurement device (<NUM>) worn by the subject;
a quantitative result determination unit that determines an evaluation result regarding an amount of walking, based on a measurement value of the quantitative parameter;
a qualitative result determination unit (<NUM>) that determines an evaluation result regarding a walking form, based on a predetermined evaluation model that reflects the degree of approximation to a form tendency with which a walking exercise effect is likely to be achieved, and measurement values of the qualitative parameters; and
an output unit that outputs walking result information including the evaluation result regarding the amount of walking and the evaluation result regarding the walking form,
wherein the qualitative result determination unit (<NUM>) determines the evaluation result regarding the walking form using, as the predetermined evaluation model, an evaluation formula for obtaining the sum of a value obtained by adding a weight to the ratio of the subject's stride-height ratio to an average stride-height ratio of a corresponding attributed level, and a value of the ratio of the subject's cadence to an average cadence of the corresponding attributed level, and an evaluation formula that is set such that a weight is added at least to a measurement value of the arm swing angle.