Effect of Shoe Modifications on Center of Pressure and in-Shoe Plantar Pressures1

Abstract

This study was conducted to determine the effect of footwear modification on patients with neuromusculoskeletal disorders. Two analyses, the center of pressure and the in-shoe plantar pressures, were studied with the help of healthy volunteers so that the effect of shoe modifications could be assessed. The ground force under the sole of the shoe was measured while the subjects were walking, and the plantar pressure at the foot-insole interface and its distribution were measured while the subjects were in both the standing and walking positions, wearing the trial shoes. The trial shoes had three different types of heels-standard heel, Thomas heel, and reverse Thomas heel-and had three different locations for the rocker bar--just under the metatarsophalangeal joint, 1 cm behind the metatarsophalangeal joint, and 1 cm before the metatarsophalangeal joint. The shift change at the center of pressure showed that the Thomas heel generally pushed the center of pressure more laterally and the reverse Thomas heel shifted it medially more than the standard heel did. While the subjects were in a stable standing position wearing the Thomas heel shoes, the medial forefoot and the lateral heel region's pressure showed significant reduction in the plantar pressure and the lateral forefoot and the medial heel showed a tendency to rise, compared with the standard heel condition. When the trial shoes' heels were changed to the reverse Thomas heel, the above changes tended to reverse. Tests at the foot-insole interface showed that the different types of heels and the location of the bar could change not only the pressure distribution but also the duration of the plantar pressure under the lateral area that shifted to the medial area when the subjects walked. This pressure measurement method was very useful for the design and evaluation of such footwear.

Walking Strategy in Diabetic Patients With Peripheral Neuropathy

“…1, healthy subjects show a COP progression that starts from the heel, passes through the metatarsals, reaches the anterior and medial part of the foot, and ends on the hallux. This pattern is consistent with the COP pattern described by Hong et al (11) for healthy barefoot gait. Our data show that diabetic patients with severe neuropathy approach the floor with the most anterior part of the heel and perform their pushoff phase at the metatarsals level, as proven by the reduction of the COP progression along the longitudinal axis.…”

Differences in Plantar Foot Pressure and COP between Flat and Normal Feet During Walking

“…They are also broadly used as a screening tool for diabetic patients to establish the risk of ulceration 17,18) . Plantar pressure evaluation is also used to assess the effectiveness of footwear 19,20) and orthotic interventions 21,22) . Despite the growing use of plantar foot pressure assessments for research and clinical purposes, the factors that contribute to loading patterns of the foot remain poorly understood 23) .…”

Biomechanics of the double rocker sole shoe: Gait kinematics and kinetics

“…Specific shoe design is based on pressure measurements from a floor-reaction imprint; our group has previously demonstrated the effectiveness of this design in relieving midfoot pressures without exacerbating hindfoot or forefoot pressures (Brown, et al, 2004). Other investigations of plantar pressure changes secondary to such modified footwear are widely reported in the literature (Chesnin, et al, 2000;van Schie, et al, 2000;Fuller, et al, 2001;VanZant, et al, 2001), but investigations of changes in joint motion (kinematics) and joint loading (kinetics) are less common (Peterson, et al, 1985;Schaff, et al, 1990;Mueller, et al, 1995;Dingwell, et al, 1999;Xu, et al, 1999). The studies that do exist are generally limited to observational or quantitative two-dimensional analysis.…”

“…Significant changes were also seen in temporal parameters. Xu et al (Xu, et al, 1999) examined COP changes in shoes with medial and lateral support, and found a strong relationship between COP shifting and heel design. Mueller found an 11% reduction in step length with rocker sole use; Peterson (Peterson, et al, 1985) found minimal temporal changes in rocker shoe gait, although most differences occurred with increased walking speed.…”