CN1031600A - The living body measurement of body segment's weight and center of gravity thereof - Google Patents

Abstract

The present invention adopts weighing method, the weight size and the centre of gravity place thereof of each link of living body measurement human body.

Measurand can be supported on the dedicated platform of several force-detecting positions one, change the human body desire and survey the position of link, each force-detecting position of mat records the size of power and the relation between each link of human body, utilizes Computing and tries to achieve the weight size and the centre of gravity place of link that human body is surveyed.

Description

The living body measurement of body segment's weight and center of gravity thereof

The invention belongs to the sport biomechanics basic parameter measures.It is the comprehensive means with measurement and mathematical operation, realizes the new method of human body each link (for example: head, trunk, upper arm, forearm, hand, thigh, shank, pin etc.) weight and center of gravity living body measurement thereof.

In researches on exercise biomechanics, in order accurately to analyze the human body characteristics of motion, often need to know this human body basic parameter (as each link weight of health and center of gravity thereof ... Deng).Current, the method for measuring body segment's weight and center of gravity thereof both at home and abroad has three classes.

One, autopsy: because it is few to dissect corpse, and based on middle-aging male, so it is bigger to add up the gained data error in view of the above.

Two, somatometry: common method: 1, water seaoning: desire is surveyed link immerse in the water, obtain link volume, under supposition body density homogeneous condition, try to achieve link weight and centre of gravity place.Therefore, precision is very poor.

2, the human geometry measures and X ray photography conjunction measuring.Because this method needs human body is simplified to the simple geometric figure, thereby error is also bigger.

3, gamma-rays scanning method.This method has many difficulties in using, and easy and absorption object interaction produces secondary γ quantum as beam, needs revise the result.Practicality is relatively poor.

4, CT method of testing.The CT method is to utilize the high-speed computation ability of X ray and robot calculator and the work of image reconstruction principle.Have characteristics such as clear image, resolution height.But there is the equipment complexity, costs an arm and a leg, shortcomings such as testing expense height.Be unsuitable for generally measuring.

Three, human geometry's modeling technique.It is that human body is divided into some links, and replacements such as the regular cylinder of each link, triangle body, hexahedron.Thereby there are shortcomings such as calculation of complex, error be bigger.

Ultimate principle of the present invention is: allow the measured lie (face upward or prostrate) be supported on the platform of several force-detecting positions one.On this platform, determine an origin of coordinate, and represent the residing position of each link of human body with longitudinal and transverse coordinate values.When human body was motionless, the force action line of the active line of human body total centre of gravity and each force-detecting position institute dynamometry coincided, and each force-detecting position to record the power sum be a constant.Change the position that a certain desire of human body is surveyed link if be interrupted, all the other partly all keep motionless human body, then the total centre of gravity position of human body all will change with the size that each force-detecting position records power, but each force-detecting position records the size of making a concerted effort of power constant (because human body weight is constant), and the force action line still coincides with human body total centre of gravity active line.According to the position of each force-detecting position and record the size of power, can calculate make a concerted effort size and force action position, thereby know human total weight and total centre of gravity position.

Again according to the weight of human body total centre of gravity and each link of human body and the relation between centre of gravity place, and try to achieve weight and the centre of gravity place that desire is surveyed link.

As human total weight and total centre of gravity location coordinate value with C ₀; X _c, Y _cExpression, the coordinate of each force-detecting position (for example A, B, three force-detecting positions of D) is A(X _a, y _a); B(X _b, y _b); D(X _d, y _d), it is N that each force-detecting position records power _A, N _B, N _D, when (n), there is following relation then at an arbitrary position:

$X^{\mathrm{(n)}}{}_c=\frac{N^{\mathrm{(n)}}{}_A{X}_a{\mathrm{+\; N}}^{\mathrm{(n)}}{}_B{X}_b{\mathrm{+\; N}}^{\mathrm{(n)}}{}_D{X}_d}{N_A{\mathrm{+N}}_B{\mathrm{+N}}_D}$

$Y^{\mathrm{(n)}}{}_c=\frac{N^{\mathrm{(n)}}{}_A{y}_a{\mathrm{+\; N}}^{\mathrm{(n)}}{}_B{y}_b{\mathrm{+\; N}}^{\mathrm{(n)}}{}_D{y}_d}{N_A{\mathrm{+N}}_B{\mathrm{+N}}_D}$

The upper right footmark of each symbol represents that it locates in the formula.

X in following formula _a, y _a; X _b, y _b; X _d, y _dBe known constant, N ⁽ⁿ⁾ _A, N ⁽ⁿ⁾ _B, N ⁽ⁿ⁾ _DCan directly record, so can try to achieve X ⁽ⁿ⁾ _c, Y ⁽ⁿ⁾ _c

In addition: (be made as m link, its weight is respectively with G for health total centre of gravity and each link weight ₁, G ₂, G ₃G _mShow it) and center of gravity (its respective seat is marked with X ⁽ⁿ⁾ _1c, y ⁽ⁿ⁾ _1c; X ⁽ⁿ⁾ _2c, y ⁽ⁿ⁾ _2c; X ⁽ⁿ⁾ _3c, y ⁽ⁿ⁾ _3c; X ⁽ⁿ⁾ _Mc, y ⁽ⁿ⁾ _McShow it) and surveying instrument impost (with G ' table) and center of gravity thereof (with X ^{' (n)} _c, y ^{' (n)} _cShow it) between, when (n), there is following relation at an arbitrary position:

$X^{\mathrm{(n)}}{}_c=\frac{G_1{X}^{\mathrm{(n)}}{}_{\mathrm{1\; c}}{\mathrm{+\; G}}_2{X}^{\mathrm{(n)}}{}_{\mathrm{2\; c}}{\mathrm{+\; G}}_3{X}^{\mathrm{(n)}}{}_{\mathrm{3\; c}}{\mathrm{+\dots \dots +G}}_m{X}^{\mathrm{(n)}}{}_{\mathrm{m\; c}}{\mathrm{+G\; \prime X}}^{\mathrm{\prime (n\; )}}{}_c}{G_0\mathrm{+G\; \prime }}$

$Y^{\mathrm{(n)}}{}_c=\frac{G_1{y}^{\mathrm{(n)}}{}_{\mathrm{1\; c}}{\mathrm{+\; G}}_2{y}^{\mathrm{(n)}}{}_{\mathrm{2\; c}}{\mathrm{+\; G}}_3{y}^{\mathrm{(n)}}{}_{\mathrm{3\; c}}{\mathrm{+\dots \dots +G}}_m{y}^{\mathrm{(n)}}{}_{\mathrm{m\; c}}{\mathrm{+G\; \prime y}}^{\mathrm{\prime (n\; )}}{}_c}{G_0\mathrm{+G\; \prime }}$

For a specific people, between each link center of gravity and its proper length certain relation is arranged.(establishing its coordinate is X from shoulder as an arm ₀, y ₀, Z ₀) (its coordinate is X to ancon ₀₁, y ₀₁, Z ₀₁) be a regular length l ₁, this part distance of centre of gravity l ₁Starting point (shoulder) is l _1c; (establish its coordinate is X to ancon to wrist ₁₂, y ₁₂, Z ₁₂) be a regular length l ₂, this part distance of centre of gravity l ₂The distance of starting point (ancon) is l _2c, pushing is l ₃, its distance of centre of gravity wrist is l _3c, the long l of m link in like manner _m, its distance of centre of gravity l _mStarting point is l _Mc, with α ⁽ⁿ⁾ ₁, α ⁽ⁿ⁾ ₂... α ⁽ⁿ⁾ _m; γ ⁽ⁿ⁾ ₁, γ ⁽ⁿ⁾ ₂... γ ⁽ⁿ⁾ _mRepresent the Space Angle when each link length at an arbitrary position.Accompanying drawing shows each parametric relationship with three links, X among the figure ₀, y ₀, Z ₀It is the starting point coordinate of first link; X ₀₁, y ₀₁, Z ₀₁Being the terminal point coordinate of first link, also is simultaneously the point coordinates that rises of second link; X ₁₂, y ₁₂, Z ₁₂Being the terminal point coordinate of second link, also is simultaneously the point coordinates that rises of the 3rd link.X _1c, y _1c, Z _1cIt is the coordinate of the first link center of gravity; X _2c, y _2c, Z _2cIt is the coordinate of the second link center of gravity; X _3c, y _3c, Z _3cIt is the coordinate of the 3rd link center of gravity.l ₁, l ₂, l ₃Be respectively the first, the second, the 3rd link length size; l _1c, l _2c, l _3cThe center of gravity that is respectively first, second, third link is to the length scale of link starting point separately.

α ₁, γ ₁It is the Space Angle of first link; α ₂, γ ₂It is the Space Angle of second link; α ₃, γ ₃It is the Space Angle of the 3rd link.

If the part of surveying has m link, and except that this m link, all the other weight of health are G _M+1, its centre of gravity place is X _{(m+1) c}, y _{(m+1) c}(this centre of gravity place is constant in measuring process), then in arbitrary position, the center of gravity coordinate can be expressed as:

X ^（n） _c＝〔G ₁（X ₀+l _1ccosγ ^（n） ₁sinα ^（n） ₁）+G ₂（X ₀+l ₁cosγ ^（n） ₁sinα ^（n） ₁+l _2ccosγ ^（n） ₂sinα ^（n） ₂……+G _m-1（X ₀+l ₁cosγ ^（n） ₁sinα ^（n） ₁+l ₂cosγ ^（n） ₂sinα ^（n） ₂+……+l _m-2cosγ ^（n） _m-2sinα ^（n） _m-2+l _（m-1）ccosγ ^（n） _m-1sinα ^（n） _m-1）+G _m（X ₀+l ₁cosγ ^（n） ₁sinα ^（n） ₁+……+l _m-1cosγ ^（n） _m-1sinα ^（n） _m-1+l _mccosγ ^（n） _msinα ^（n） _m）+G _m+1X _（m+1）c+G′X ^′（n） _c〕÷（G ₀+G′）

Y ^（n） _c＝〔G ₁（y ₀+l _1ccosα ^（n） ₁cosγ ^（n） ₁）+G ₂（y ₀+l ₁cosγ ^（n） ₁cosα ^（n） ₁+l _2ccosγ ^（n） ₂cosα ^（n） ₂）+……+G _m（y ₀+l ₁cosγ ^（n） ₁cosα ^（n） ₁+l ₂cosγ ^（n） ₂cosα ^（n） ₂+……+l _m-1cosγ ^（n） _m-1cosα ^（n） _m-1+l _mccosγ ^（n） _mcosα ^（n） _m）+G _m+1y _（m+1）c+G′y ^′（n） _c〕÷（G ₀+G′）

In the formula: G ₀=G ₁+ G ₂+ ... + G _m+ G _M+1, G ' is the surveying instrument impost.

L in the following formula ₁, l ₂..., l _m; α ⁽ⁿ⁾ ₁, α ⁽ⁿ⁾ ₂... α ⁽ⁿ⁾ _m; γ ⁽ⁿ⁾ ₁, γ ⁽ⁿ⁾ ₂... γ ⁽ⁿ⁾ _m; X ⁽ⁿ⁾ _c; Y ⁽ⁿ⁾ _c; G ' and X ₀, y ₀, X ^{' (n)} _c, y ^{' (n)} _cBe detectable known number.And G ₁, G ₂G _m, G _M+1; l _1c, l _2c... l _Mc, X _{(m+1) c}, y _{(m+1) c}Be 2m+3 unknown number altogether, because G ₀=G ₁+ G ₂+ ... + G _m+ G _M+1, therefore, simply change m+1 fixed position as long as the human body desire is surveyed partly (be made as m link, for example hand, foot respectively are 3 links, i.e. m=3), just can draw 2m+2 secondary equation with many unknowns formula.

So with the known quantity that records, the input computing machine utilizes certain program of working out, finds the solution top secondary equation with many unknowns group, can make things convenient for the weight size and the centre of gravity place of trying to achieve the link of surveying exactly.

Claims (3)

1, a kind of method of measuring each link weight size of human body and centre of gravity place thereof is characterized in that utilizing the living body measurement of weighing method.

2, living body measurement according to claim 1 when it is characterized in that utilizing each limbs of measurand to change position, concerns between the numerical values recited of its corresponding each force-detecting position and each limbs weight and center of gravity and tries to achieve.

3, living body measurement according to claim 1 is characterized in that utilizing computing machine that the system of equations of setting up according to last measuring principle is found the solution.