Janet Hughes

The importance of the toes in walking

The importance of well-functioning toes has long been recognised but has not previously been assessed in biomechanical studies. We have examined the weight-bearing function of the foot in 160 normal subjects by use of the pedobarograph. The function of the toes was assessed by reference to the time they were in contact with the ground and the peak pressures they exerted individually in comparison with other parts of the foot. The toes were in contact for about three-quarters of the stance phase of gait and exerted peak pressures similar to those of the metatarsal region. When the foot was bearing the second peak of total force, the area in contact with the ground (the metatarsal heads and toes) was decreasing.

Foot pressure measurement: a review of clinical findings.

In this review, a description of what is known about plantar pressure distribution in standing and in gait is followed by sections on clinical findings. Two major clinical areas are treated extensively, namely the diabetic foot and the foot in rheumatoid arthritis. Other applications, including the assessment of surgical procedures for orthopaedic corrections are also included. A large variety of different techniques for foot pressure measurement have been used; interpretation of the results has to be made on the basis of a firm understanding of the technique employed. Often, quantitative results from different pieces of apparatus are difficult to compare, indicating a need for accurate calibration and a standardized presentation. An up-to-date summary of pressure measurement systems reported over the past five years is included.

A Comparison of Two Studies of the Pressure Distribution under the Feet of Normal Subjects Using Different Equipment

There is growing interest in the use of foot pressure measurement both clinically and in the study of normal subjects. A number of systems are now commercially available, but comparison of the results is complicated by the different techniques employed. This paper compares the results of two studies. The first examined a large group of normal subjects using the dynamic pedobarograph. The second was identical to the first except that the EMED F system was used. The second study was carried out in order to verify existing results and to assess the clinical significance of the expected differences. Comparison of the results from the two studies showed that the median peak pressures demonstrated similar patterns with the highest pressure in the forefoot under the second/third metatarsal heads and the toes taking gradually reduced pressure from the first to the fifth toe. The EMED F showed higher peak pressures than the dynamic pedobarograph under the heel, the medial four metatarsal heads, and the great toe and showed lower peak pressures and shorter contact times under the lateral four toes. The pattern of loading across the metatarsal heads was further analyzed using an objective method of splitting the subjects into groups. Four groups were isolated from both sets of results, and this has confirmed that only a proportion of normal subjects demonstrate highest loading under the first metatarsal head whereas the remainder show highest loading centrally within the forefoot.

A Clinician's View of Foot Pressure: A Comparison of Three Different Methods of Measurement

The measurement of the pressure distribution under the foot can provide permanent records which can be used to monitor patients progress and the effects of surgical operations. It can be utilized in the assessment of foot disorders and the results of treatment. It is also of value in the study of the function of the normal foot. Three commercially available systems have been compared by measuring ten “normal” subjects with these different techniques. The results are not directly comparable but are described to show the differences between the equipment and the results and help investigators interested in foot problems to choose the best system for their particular needs.

Metatarsal head excision for rheumatoid arthritis. 4-year follow-up of 68 feet with and without hallux fusion.

Thirty-four painful deformed rheumatoid feet treated by excision of all five metatarsal heads were compared with 34 similar feet in which the lesser metatarsal heads were excised and the first metatarsophalangeal joint was arthrodesed. In the latter group, one third had failure of fusion of the hallux, and this produced the worst results. Metatarsalgia and plantar callosities were more common after excision arthroplasty, but shoe fitting and correction of deformity were better in this group. However, the results were more variable in the fusion group, and the complication and reoperation rates were higher. For this reason, excision arthroplasty, rather than fusion of the hallux, is recommended when the lesser metatarsal heads are removed.

A COMPARISON OF WILSON AND HOHMANN OSTEOTOMIES IN THE TREATMENT OF HALLUX VALGUS

In a retrospective study we compared the results of 31 Wilson and 31 Hohmann osteotomies of the first metatarsal in the treatment of hallux valgus. There were no differences between the two operations in terms of patient satisfaction, pain relief, appearance, footwear and walking ability. First metatarsal shortening was the same after both operations, and the degree of shortening was unrelated to either the clinical or the pedobarographic findings. Although the long-term radiographic changes after the Hohmann osteotomy were more worrying, the pedobarographic patterns tended to be worse after the Wilson osteotomy. There were no poor results and the numbers of feet with the same final grade were identical in each group. However, there was abnormal loading of the lateral metatarsal heads after both osteotomies when compared with the normal foot, and hallux-contact time during the stance phase was also significantly reduced after osteotomy.

The pattern of pressure distribution under the weightbearing forefoot

Abstract The pressure characteristics found commonly under the forefeet in a healthy asymptomatic population have been described. 160 subjects have been recorded walking over the pedobarograph. The foot pressure data have been analysed in three ways. The first has examined the whole group and documents the results for peak pressure and for contact time as a proportion of stance phase under the metatarsal heads compared to the hindfoot and toes. The second used image analysis to plot the pressure distribution across the forefoot. The third has utilised methods of pattern recognition of the distribution of pressure across the weightbearing forefoot. The four common patterns observed in this group are described and confirmed by cluster analysis.

A gait analysis system in clinical practice

A gait analysis system using a transduced walkway, monitored by microcomputer to measure the time and distance factors of gait, has been in regular clinical use for over two and a half years. The results are easy to understand and have provided objective data which has been found useful in a number of clinical situations. Some of the ways in which the system has been used are described.

A study of the effect of wear on the pressure-relieving properties of foot orthosis

There is little comparative data available to assist choice of materials for the manufacture of orthoses, and there have been few objective studies comparing insole designs. This study has compared two materials, PPT and SPENCO, and assessed one design of insole together with a commonly used variation of that design. Both materials and designs have been tested for effectiveness against each other and against themselves following a period of continuous wear. The pedobarograph was used to measure the changes in pressure. n nSeven subjects, with a high pressure pattern under the second metatarsal head of one foot, wore a series of four insoles in random order for 1 month each. The four insoles were made to the same pattern for each patient, two of PPT and two of SPENCO, each with a Ud plantar metatarsal pad. In one insole of each material, the U-shaped cut-out was filled with sponge. Pedobarograph recordings were taken, barefoot and with the insole taped to the foot, at issue and after 1 month of wear for each insole. n nResults show that all the insoles were effective in reducing pressure and force under the areas measured (P < 0.0001). There were no significant differences in pressure relief between new and old insoles, but the insoles with a sponge button had different characteristics from those without.

The assessment of patients with foot problems using the pedobarograph

Pressure measurement is becoming recognised as a clinically useful method of analysis of foot problems. The number of centres using the pedobarograph to do this is increasing. There are no established standards with which to compare patients recordings and analysis depends largely upon the experience of the operator and the clinician in the interpretation of results. The author has used this equipment in both its simple and computerized forms over a period of several years. A technique of studying the results has evolved. This is described with examples recorded on the pedobarograph using the Sheffield system of computerized analysis. 1