正常足与拇外翻足的足底压力研究

目的 对正常足与拇外翻足的足底压力进行测量。方法 运用自行研制的足底生物力学测试系统对３０名健康人６０足,４５例拇外翻患者８９足进行了行走时足底压力的测试。结果 重度拇外翻组３１足和正常组相比,第一跖骨头下压力明显减低,第二跖骨头下明显增另,第三,五跖骨头下压力有增高的趋势。结论正常人前足第一跖骨关下压力最高,并向外侧递减,重度拇外翻足前足第一跖骨头下压力明显减低,第二跖骨头下压力明显增高。     

外翻合并第二跖骨头下疼痛的生物力学定量研究

目的探讨跖骨头下压力变化与(足,母)外翻合并跖骨头下疼痛的关系,并对引起第二跖骨头下疼痛的跖骨头下压力进行定量分析.方法采用由中国中医研究院骨伤科研究所生物力学实验室研制的足底压力测试系统,对58名正常人(116足),32例(45足)(足,母)外翻单纯合并第二跖骨头下疼痛患者,56例(102足)(足,母)外翻无足底疼痛患者进行足底压力测试,将三组跖骨头下压力进行比较.采用病例-对照设计,研究压力与疼痛的关系,并对引起第二跖骨头下疼痛的压力进行定量分析.结果 (1)(足,母)外翻单纯合并第二跖骨头下疼痛组分别与(足,母)外翻无足底疼痛组及正常组比较,第二跖骨头下压力均明显增高(均P＜0.05);(2)第二跖骨头下压力高于正常组与第二跖骨头下压力不高于正常组比较,疼痛的发生率明显增加(P＜0.05,OR＞3,OR 95%CI＞1);(3)(足,母)外翻合并第二跖骨头下疼痛组第二跖骨头下压力占体重的5.20%～7.29%.结论跖骨头下压力异常增高是跖骨头下疼痛的危险因素,第二跖骨头下压力超过体重的5.20%,极易出现跖骨头下疼痛.     

正常足与拇外翻足前足承重比例与跖骨头下压力的研究

目的 从生物力学角度探讨外翻足承重比例及跖骨头下压力的改变情况。方法将测试对象分为正常组(160足)、轻中度(足母)外翻组(100足)、重度(足母)外翻组(56足)三组,运用我所生物力学室研制的足底压力测试系统,对正常足与(足母)外翻足足底压力进行测试,并将结果进行统计分析。结果 轻中度(足母)外翻足前足承重比例较正常足增加,重度(足母)外翻足前足承重比例介于正常足与轻中度(足母)外翻足之间。(足母)外翻足存在着前足压力外移的趋势,这种改变和畸形的程度相关。结论 从生物力学角度证明,(足母)外翻前足承重比例及各跖骨头下压力的变化随(足母)外翻畸形程度增加出现不同程度的变化。     

(足,母)外翻合并第二跖骨头下疼痛的生物力学定量研究

目的探讨跖骨头下压力变化与蹰外翻合并跖骨头下疼痛的关系，并对引起第二跖骨头下疼痛的跖骨头下压力进行定量分析。方法采用由中国中医研究院骨伤科研究所生物力学实验室研制的足底压力测试系统，对58名正常人（116足），32例（45足）拇外翻单纯合并第二跖骨头下疼痛患者，56例（102足）拇外翻无足底疼痛患者进行足底压力测试，将三组跖骨头下压力进行比较。采用病例一对照设计，研究压力与疼痛的关系，并对引起第二跖骨头下疼痛的压力进行定量分析。结果（1）蹲外翻单纯合并第二跖骨头下疼痛组分别与拇外翻无足底疼痛组及正常组比较，第二跖骨头下压力均明显增高（均P〈0．05）；（2）第二跖骨头下压力高于正常组与第二跖骨头下压力不高于正常组比较，疼痛的发生率明显增加（P〈0．05，OR〉3，OR95％CI〉1）；（3）拇外翻合并第二跖骨头下疼痛组第二跖骨头下压力占体重的5．20％-7．29％。结论跖骨头下压力异常增高是跖骨头下疼痛的危险因素，第二跖骨头下压力超过体重的5．20％，极易出现跖骨头下疼痛。     

正常足与外翻足前足承重比例与跖骨头下压力的研究

目的从生物力学角度探讨外翻足前足承重比例及跖骨头下压力的改变情况.方法将测试对象分为正常组(160足)、轻中度外翻组(100足)、重度外翻组(56足)三组,运用我所生物力学室研制的足底压力测试系统,对正常足与外翻足足底压力进行测试,并将结果进行统计分析.结果轻中度外翻足前足承重比例较正常足增加,重度外翻足前足承重比例介于正常足与轻中度外翻足之间.外翻足存在着前足压力外移的趋势,这种改变和畸形的程度相关.结论从生物力学角度证明,外翻前足承重比例及各跖骨头下压力的变化随外翻畸形程度增加出现不同程度的变化.     

正常足与Mu外翻足跖骨头下压力与足部负重比例变化的关系

目的：从生物力学角度探讨Mu外翻足前足横弓跖骨头下压力的改变情况。方法：运用本所生物力学室研制的足底压力测试系统，对正常足与Mu外翻足足底压力进行测试，并将结果进行统计分折。结果：随着足部负重比例的增加，Mu外翻足前足中间跖骨头下压力的变化较快，与正常足相比具有显著差异。结论：从生物力学角度证明，正常足前足具有横弓结构，Mu外翻足前足存在横弓塌陷。     

正常足与(*母)外翻足跖骨头下压力与足部负重比例变化的关系

目的 :从生物力学角度探讨外翻足前足横弓跖骨头下压力的改变情况。方法 :运用本所生物力学室研制的足底压力测试系统 ,对正常足与外翻足足底压力进行测试 ,并将结果进行统计分析。结果 :随着足部负重比例的增加 ,外翻足前足中间跖骨头下压力的变化较快 ,与正常足相比具有显著差异。结论 :从生物力学角度证明 ,正常足前足具有横弓结构 ,外翻足前足存在横弓塌陷。     

正常足与(足母)外翻足横弓形态的对比性研究

[目的]比较研究正常足和外翻足横弓的形态,探讨横弓在外翻发生发展中的作用。[方法]对35名外翻患者65只足和30名正常人60只足,在负重位和非负重位足正位X线片和前足轴位X线片上分别测量外翻角(hallux valgus angle,HVA),第1、2跖骨间角(fist intermetatarsalangle,IMA),各跖骨头、籽骨到足底的距离。[结果]外翻足HVA平均30·8±8.9°,第1、2跖骨间角为16.5±2·6°;正常足HVA为10·2±2·0°,第1、2跖骨间角7·9±1·6°。外翻足与正常足比较第1跖骨头向下移位,第2、3跖骨头距足底的距离明显低于正常足。腓侧籽骨向外上方移位,胫侧籽骨向外侧移位。[结论]外翻足横弓塌陷,籽骨脱位,第2、3跖骨头过早、过重负重易产生疲劳性骨折、跖骨痛和足底胼胝体。     

足横弓形态的动态分析与踇外翻关系研究

目的观察正常步态周期中跖骨头平面足横弓的运动形态 ,探讨跖骨头平面足横弓在行走过程中的重要意义及与外翻的关系。方法正常足 13足,外翻足 12足,应用" C"型臂 X线机观察跖骨头平面足横弓在步态周期中的运动形态、空间位置变化,并用录像机记录。电脑工作站与 C＋＋ Builder下精确的计时器相连接,记录足横弓塌陷时间。结果跖骨头平面存在由五个跖骨头构成的足横弓 ,以第一、五跖骨头为底,第二、三跖骨头为顶;在步态周期中,由站立相到推离相时,第二、三跖骨头逐渐塌陷,负重份额渐增加;足横弓指数 Q与外翻角 (HVA)相关, HVA越大, Q值越小,步态周期中第二、三跖骨头下降到地面的时间越短,第二、三跖骨头就越早负重,负重时间延长,导致其过度负重和第二、三跖骨头下疼痛性胼胝体形成。结论跖骨头平面足横弓在正常步态周期中发挥重要作用,由站立相至推离相,随重心前移,第二、三跖骨头的负重增加,跖骨头下移而与地面接触导致足横弓的塌陷。外翻患者中,足横弓塌陷时间早,跖骨头负重时间长,可以导致前足功能紊乱。     

第1跖趾关节融合术后前足评分与足底压力的分析

[目的]分析第1跖趾关节融合术后对前足功能影响,以及对推进期足底压力的影响.[方法]15例患者共18足,行第1跖趾关节融合术后2年以上,根据AOFAS评分系统,对第1跖趾关节功能评分,并与正常对照组进行足底压力测试.测量前足底推进期的(足母)趾下、第1～5跖骨下共6处的峰值压强、峰值压力、压强-时间积、压力-时间积四个参数.[结果]融合术后AOFAS第1跖趾关节评分满意,术后组的(足母)趾下四项参数均明显小于正常人组.与时间相关的参数在(足母)趾下,以及第2、4、5跖骨头下小于正常人组,并具有明显差异.第1跖骨头下的峰值压强与峰值压力与对照组没有统计学差异.[结论]第1跖趾关节融合术后患者在推进期,前足跖骨头的足底压力分布与正常人基本相同.术后前足功能改善.术后(足母)趾下压力减少,但是对前足压力分布没有影响.     

Plantar pressure distribution in normal,hallux valgus and hallux limitus feet

Selected dynamic plantar pressure measurements of 30 control, 30 hallux valgus and 30 hallux limitus subjects, using an EMED-SF system and a two-step method of data collection, were analysed for significant differences, with a one-way analysis of variance being performed with P<0.05. In comparison to normal control subjects, those with hallux valgus feet demonstrated significant medial plantar peak and mean pressures under the first, second and third metatarsal heads. In contrast, hallux limitus feet showed significantly high mean pressure under the hallux, lesser toes, third and fourth metatarsal heads, indicating a more lateral forefoot load.     

Force, pressure, and motion measurements in the foot: current concepts

Modern foot-pressure measurement studies have successfully debunked the tripod theory; on the contrary, the highest peak loads under the forefoot occur as often as not under the third metatarsal head and not the first and fifth. This does not necessarily mean that the first metatarsophalangeal joint does not sustain the highest pressures; calculations based on the measured pressures under the metatarsals and digits show that it does. One must bear in mind that the hallux consistently bears significantly more pressure than any of the other toes. It is likely that the pressure borne by the first metatarsal head and hallux combined consistently exceed that for the other four metatarsal heads and their respective digits. In other words, the first ray probably has the consistently highest load in normal feet, even when the second or third metatarsal head achieves a greater peak pressure than the first metatarsal head. Three lines of evidence suggest the role that pressure plays in forefoot pathology. First, metatarsalgia is commonly associated with hallux valgus. It often arises following or is exacerbated by hallux valgus surgery (especially arthroplastic procedures). Patients with hallux valgus demonstrate increased peak pressure under the lateral metatarsal heads that actually increases following the Keller procedure. Second, the peak pressure under callosities are, on the average, higher than normal. Third, diabetic plantar ulcers occur at sites of high pressure. The correlations between peak loads on the lateral column and both age and weight merit some attention, since it is common experience that the prevalence of symptomatic foot lesions is higher in older populations. The correlation with body weight may be unexpected. One would expect that, on the average, body weight would correlate with the weight-bearing surface area of the foot and, therefore, the pressure would be relatively constant. The increased pressure under the medial column suggests a relative instability of the medial column with advancing age and weight. Pressure should not be construed as the only factor. The large overlap in peak pressures found under diabetic ulcers and intact skin in both normal and diabetic feet makes this apparent. However, while peak pressures have been extensively studied, there has been no attempt to measure the duration or frequency of loading on a day-to-day basis. According to Brand, it is not the absolute loads applied to a part but repetitive pressure that is responsible for tissue breakdown, especially when such repetitive loads are applied without any interim period for the tissues to recover.(ABSTRACT TRUNCATED AT 400 WORDS)     

Axial radiographic evaluation in hallux valgus: evaluation of the transverse arch in the forefoot

To quantitatively evaluate the shape of the transverse arch in the forefoot with hallux valgus, a method for axial imaging and analysis of the forefoot has been developed. A foot was imaged at 30° of flexion. A two-dimensional coordinate system was established by drawing a vertical line on the X-ray image through the lowest point of the head of the second metatarsal. The origin was set at the intersection between the plane of the base of the foot and this vertical line. A control group of 51 feet from 29 normal subjects and a test group of 59 feet from 34 subjects with hallux valgus were examined. Compared with the normal group, the heads of the first, second, and third metatarsal bones were lower in the hallux valgus group, and their sesamoids were shifted outward with a rotational deviation. There was a statistical correlation between the degree of outward dislocation of the fibular sesamoid bone and the hallux valgus angle. The position of the fibular sesamoid bone become higher than the head of the first metatarsal when the angle of the hallux valgus exceeded 25°.     

Forces under the hallux valgus foot before and after surgery.

Abnormalities in the hallux valgus foot and changes after surgery were investigated by measuring the distribuiion of load on the foot in walking. Hallux valgus was associated with reduced load imposed on the toes, and on the medial side of the forefoot, compared with a large sample of healthy feet. Abnormalities correlated with the degree of the deformity. Both Keller's operation and a wedge displacement osteotomy of the first metatarsal not only failed to restore normal loading but increased the abnormalities of loading seen preoperatively. A large decrease in the angle between first and second metatarsals as a result of surgery minimized this increase. A silastic arthroplasty did not carry high loads when used to treat hallux valgus, but near normal loads were imposed on it when used for hallux rigidus. Considerable variability was found in the loading distribution on the healthy feet. The distribution between first and second metatarsal heads was partially dependent upon their protrusions, relative to the direction of walking. The changes in the relationships between the loadings on the forefoot and skeletal shape in response to surgical operations are important for our understanding of treatment of the hallux valgus foot.     

Forefoot reconstruction: Effectiveness of Stainsby operation in treating disclocated lesser toes

BackgroundDeformity of the forefoot is a common disabling problem especially in chronic rheumatoid arthritis. The most common deformities are hallux valgus and dorsally dislocated clawed lesser toes.ObjectiveThis paper assesses results of forefoot reconstruction with emphasis on the effectiveness of Stainsby's procedure in treating severely clawed lesser toes with irreducible dislocation at the metatarsophalangeal joint. The purpose of this procedure is to remove the deforming forces causing depression of the metatarsal head, and restore the dorsally displaced plantar plate of the MTP joint and the related part of the plantar fat pad to their correct position beneath the metatarsal head.MethodSeventy-four patients were operated on between 1998 and 2003. Sixty-nine patients (94 feet) were available for review at an average of 32 months (range 10–67) post surgery. American Orthopaedic Foot and Ankle Scores (AOFAS) were measured and footprints were obtained. Patients were asked about overall satisfaction and whether they would recommend the operation to a family member.ResultsEighty-nine of the 94 feet (95%) had severe or moderate pain preoperatively under the dislocated metatarsal head; only 19 (20%) had significant pain at review. Tender plantar callosities were reduced from 76 feet preoperatively (81%) to 31 feet (33%) at review, these were mainly under un-operated metatarsal heads. Footprints showed a normal loading under 63% of operated metatarsal heads. AOFAS scores were increased from a mean of 19 preoperatively to 52 at review. Residual valgus of the big toe of more than 25° persisted in 33 feet (35%). Corrective osteotomy of 44 first metatarsals resulted in significant residual valgus in 16 feet (36%).ConclusionsStainsby operation was effective in relieving pain and skin callosities from under dislocated lesser metatarsal heads, and in reducing shoe problems, but the osteotomy performed by the authors was unreliable in correcting valgus of the big toe.     

Mechanics of the Hallux Valgus Foot and the Effect of Keller's Operation

Using a system for measuring the load distribution under the foot, patients with hallux valgus were compared, before and after undergoing Keller's operation, with a group of normal subjects. Preoperatively the patients showed reduced loading under all their toes and increased loading under their lateral metatarsal heads; the decrease under the hallux was found to correlate with an increase in hallux valgus angle. Postoperatively there was a further decrease in loading under the hallux and an increase under the first metatarsal head.     

Precise anatomic configuration changes in the first ray of the hallux valgus foot

To detect precise anatomical configuration of the first ray in feet with hallux valgus, a two-dimensional coordinate system was devised for evaluation of a weight-bearing dorsoplantar radiograph. The radiographs, taken from 229 feet of 114 patients with symptomatic hallux valgus and 94 normal feet, were investigated. A comparative study showed the first metatarsal head of a foot with hallux valgus was located on the medial side of that of the normal foot and the base of the proximal phalanx of the hallux valgus foot was located on the same point of that of the normal foot. Lateral translation of the base of the proximal phalanx occurred only in cases with overlap toes. Our study shows that subluxation of the metatarsophalangeal joint in hallux valgus is primarily caused by metatarsus primus varus. This study indicated that first metatarsal osteotomies should be given the first priority in consideration for bunion surgery, because these procedures could move the first metatarsal heads laterally in a more normal position.