EFFECT OF VISION AND STANCE WIDTH ON HUMAN BODY MOTION WHEN STANDING: IMPLICATIONS FOR AFFERENT CONTROL OF LATERAL SWAY

 EFFECT OF VISION AND STANCE WIDTH ON HUMAN BODY MOTION WHEN STANDING: IMPLICATIONS FOR AFFERENT CONTROL OF LATERAL SWAY 

BY B. L. DAY, 

M. J. STEIGER, 

P. D. THOMPSON AND C. D. MARSDEN 

From the MRC Human Movement and Balance Unit, Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WCIN 3BG 

(Received 12 November 1992) 

SUMMARY 

1. Measurements of human upright body movements in three dimensions have been made on thirty-five male subjects attempting to stand still with various stance widths and with eyes closed or open. Body motion was inferred from movements of eight markers fixed to specific sites on the body from the shoulders to the ankles. Motion of these markers was recorded together with motion of the point of application of the resultant of the ground reaction forces (centre of pressure). 

2. The speed of the body (average from eight sites) was increased by closing the eyes or narrowing the stance width and there was an interaction between these two factors such that vision reduced body speed more effectively when the feet were closer together. Similar relationships were found for components of velocity both in the frontal and sagittal planes although stance width exerted a much greater influence on the lateral velocity component. 

3. Fluctuations in position of the body were also increased by eye closure or narrowing of stance width. Again, the effect of stance width was more potent for lateral than for anteroposterior movements. In contrast to the velocity measurements, there was no interaction between vision and stance width. 

4. There was a progressive increase in the amplitude of position and velocity fluctuations from markers placed higher on the body. The fluctuations in the position of the centre of pressure were similar in magnitude to those of the markers placed near the hip. The fluctuations in velocity of centre of pressure, however, were greater than of any site on the body. 

5. Analysis of the amplitude of angular motion between adjacent straight line segments joining the markers suggests that the inverted pendulum model of body sway is incomplete. Motion about the ankle joint was dominant only for lateral movement in the frontal plane with narrow stance widths (<8 cm). For all other conditions most angular motion occurred between the trunk and leg. 

6. The large reduction in lateral body motion with increasing stance width was mainly due to a disproportionate reduction in the p motion about the ankles and feet. A mathematical model of the skeletal structure has been constructed which offers some explanation for this specific reduction in joint motion.  Page 479.

 站立时视觉和站立宽度对人体运动的影响：对横向摆动的传入控制的影响

 到 B. L. DAY，

 M.J.斯泰格，

 P. D. 汤普森和 C. D. 马斯登

 来自伦敦皇后广场神经病学研究所和国立神经病学和神经外科医院 MRC 人体运动和平衡部门 WCIN 3BG

 (1992 年 11 月 12 日收到)

 概括

 1. 对 35 名男性受试者进行了三个维度的人体直立身体运动的测量，这些受试者试图以不同的姿势宽度和闭眼或睁眼站立。 身体运动是从固定在身体特定部位（从肩膀到脚踝）的八个标记的运动中推断出来的。 这些标记的运动与地面反作用力合力（压力中心）的施加点的运动一起被记录下来。

 2.身体的速度（八个部位的平均值）是通过闭眼或缩小站立宽度来增加的，这两个因素之间存在相互作用，当双脚靠得更近时，视觉更有效地降低了身体速度。 尽管站立宽度对横向速度分量的影响要大得多，但在正面和矢状面中的速度分量也发现了类似的关系。

 3. 眼睛闭合或站距变窄也增加了身体位置的波动。 同样，站距宽度对横向运动的影响比对前后运动更有效。 与速度测量相反，视觉和站立宽度之间没有相互作用。

 4. 放置在身体较高位置的标记的位置和速度波动的幅度逐渐增加。 压力中心位置的波动与放置在臀部附近的标记的波动幅度相似。 然而，压力中心的速度波动比身体任何部位都大。

 5. 对连接标记的相邻直线段之间角运动幅度的分析表明，身体摇摆的倒立摆模型是不完整的。 围绕踝关节的运动仅在窄站立宽度（<8 cm）的额平面横向运动中占主导地位。 对于所有其他情况，大多数角运动发生在躯干和腿之间。

 6. 随着站立宽度的增加，横向身体运动的大量减少主要是由于脚踝和脚的角运动不成比例地减少。 已经构建了骨骼结构的数学模型，为关节运动的这种特定减少提供了一些解释。 第 479 页。

Zhànlì shí shìjué hé zhànlì kuāndù duì réntǐ yùndòng de yǐngxiǎng: Duì héngxiàng bǎidòng de chuán rù kòngzhì de yǐngxiǎng

dào B. L. DAY,

M.J. Sī tài gé,

P. D. Tāngpǔsēn hé C. D. Mǎ sī dēng

láizì lúndūn huánghòu guǎngchǎng shénjīngbìng xué yánjiū suǒ hé guólì shénjīngbìng xué hé shénjīng wàikē yīyuàn MRC réntǐ yùndòng hé pínghéng bùmén WCIN 3BG

(1992 nián 11 yuè 12 rì shōu dào)

gàikuò

1. Duì 35 míng nánxìng shòu shì zhě jìnxíngle sān gè wéidù de réntǐ zhílì shēntǐ yùndòng de cèliáng, zhèxiē shòu shì zhě shìtú yǐ bùtóng de zīshì kuāndù hé bì yǎn huò zhēng yǎn zhànlì. Shēntǐ yùndòng shì cóng gùdìng zài shēntǐ tèdìng bùwèi (cóng jiānbǎng dào jiǎohuái) de bā gè biāojì de yùndòng zhōng tuīduàn chūlái de. Zhèxiē biāojì de yùndòng yǔ dìmiàn fǎnzuòyòng lì hélì (yālì zhōngxīn) de shījiā diǎn de yùndòng yīqǐ bèi jìlù xiàlái.

2. Shēntǐ de sùdù (bā gè bùwèi de píngjūn zhí) shì tōngguò bì yǎn huò suōxiǎo zhànlì kuāndù lái zēngjiā de, zhè liǎng gè yīnsù zhī jiān cúnzài xiānghù zuòyòng, dāng shuāng jiǎo kào dé gèng jìn shí, shìjué gèng yǒuxiào de jiàngdīle shēntǐ sùdù. Jǐnguǎn zhànlì kuāndù duì héngxiàng sùdù fènliàng de yǐngxiǎng yào dà dé duō, dàn zài zhèngmiàn hé shǐ zhuàng miàn zhōng de sùdù fènliàng yě fāxiànle lèisì de guānxì.

3. Yǎnjīng bìhé huò zhàn jù biàn zhǎi yě zēngjiāle shēntǐ wèizhì de bōdòng. Tóngyàng, zhàn jù kuāndù duì héngxiàng yùndòng de yǐngxiǎng bǐ duì qiánhòu yùndòng gèng yǒuxiào. Yǔ sùdù cèliáng xiāngfǎn, shìjué hé zhànlì kuāndù zhī jiān méiyǒu xiānghù zuòyòng.

4. Fàngzhì zài shēntǐ jiào gāo wèizhì de biāojì de wèizhì hé sùdù bōdòng de fúdù zhújiàn zēngjiā. Yālì zhōngxīn wèizhì de bōdòng yǔ fàngzhì zài túnbù fùjìn de biāojì de bōdòng fúdù xiāngsì. Rán'ér, yālì zhōngxīn de sùdù bōdòng bǐ shēntǐ rènhé bùwèi dū dà.

5. Duì liánjiē biāojì de xiāng lín zhíxiàn duàn zhī jiān jiǎo yùndòng fúdù de fēnxī biǎomíng, shēntǐ yáobǎi de dàolì bǎi móxíng shì bù wánzhěng de. Wéirào huái guānjié de yùndòng jǐn zài zhǎi zhànlì kuāndù (<8 cm) de é píngmiàn héngxiàng yùndòng zhōng zhàn zhǔdǎo dìwèi. Duìyú suǒyǒu qítā qíngkuàng, dà duōshù jiǎo yùndòng fāshēng zài qūgàn hé tuǐ zhī jiān.

6. Suízhe zhànlì kuāndù de zēngjiā, héngxiàng shēntǐ yùndòng de dàliàng jiǎnshǎo zhǔyào shi yóuyú jiǎohuái hé jiǎo de jiǎo yùndòng bùchéng bǐlì de jiǎnshǎo. Yǐjīng gòujiànle gǔgé jiégòu de shùxué móxíng, wèi guānjié yùndòng de zhè zhǒng tèdìng jiǎnshǎo tígōngle yīxiē jiěshì. Dì 479 yè.