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- Author or Editor: MW Cornwall x
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The purpose of this study was to describe the velocity of the center of pressure during walking in a sample of young, healthy individuals. The velocity of the center of pressure was recorded in 60 subjects while they walked barefoot over a floor-mounted pressure platform. The results of this study indicate that the velocity of the center of pressure follows a predictable pattern during the stance phase of walking. Intraclass correlation coefficients calculated to measure between-trial reliability for specific parameters of the velocity of the center of pressure ranged from 0.361 to 0.912. These study results suggest that velocity of the center of pressure may be a useful measurement in future gait research.
The purpose of this study was to compare the effects of rigid and soft foot orthoses on forefoot and rearfoot forces in a 20-year-old female runner with a history of tibial and metatarsal stress fractures. The results of this study indicate that a soft orthosis significantly reduced vertical forces through the foot during both walking and running. The authors recommend that proper fabrication materials be considered for those patients with a history of foot or lower extremity problems caused by reduced shock attenuation.
The single-limb sway of 20 individuals with a history of unilateral inversion ankle sprain was compared to that of a control group of 30 individuals without a history of ankle sprain. Using a force platform to obtain center-of-pressure data, the linear distance traveled (mm) and the mean power frequency, (Hz) of postural sway were calculated for each subject. The results of this study showed that postural sway amplitude was significantly greater in the injured group than in the control group. Contrary to previous investigations, this study indicates that individuals with a history of inversion ankle sprain are less stable in single-limb stance compared to a noninjured control group. This decreased stability is evident as much as 2 years following the injury.
The objective of this study was to measure the between-trial variability of the center of pressure pattern integral (COPPI) at the shoe-floor interface and within the shoe. Ten trials of the COPPI were recorded simultaneously at the shoe-floor interface and within the shoe as ten subjects walked over ground in standardized footwear and with two types of foot orthoses. While the results showed that the within-shoe shoe-only and soft orthoses conditions caused the greatest decrease in the COPPI, it was extremely inconsistent-between trials, whether measured at the shoe-floor interface or within the shoe. This suggests that the COPPI is not an acceptable method of assessing the effectiveness of foot orthoses.
This study presents research on typical movement of the rearfoot during walking. The data demonstrate the global nature of foot pronation and supination during gait. Study participants (N = 153) walked along a walkway while the angular displacement of the calcaneus, navicular, and first metatarsal relative to the tibia was measured; three-dimensional movement patterns for all three bones were very similar. This study provides additional information on how the foot functions during walking. This information should help to define and refine clinical management strategies for treating foot dysfunction.
The purpose of this study was to investigate whether the amount of ankle passive dorsiflexion range of motion influences the pattern of frontal plane rearfoot motion during walking. Three-dimensional motion of the rearfoot was measured in two groups of subjects, those with ankle passive dorsiflexion range of motion less than or equal to 10 degrees, and those with ankle passive dorsiflexion range of motion greater than 15 degrees, while they walked along a 6.1-m walkway. The results indicated that the only statistically significant differences between the two groups were in the time to reinversion of the rearfoot and the time to heel-off. Slight-to-moderate limitation of ankle passive dorsiflexion range of motion significantly alters the timing, but not the magnitude, of frontal plane rearfoot motion during walking.
The purpose of this study was to determine the effectiveness of two types of foot orthoses in controlling the magnitude and rate of internal tibial rotation, measured by the tibial pointer device, during walking. Ten subjects between the ages of 23 and 43 years volunteered to participate in the study. Prior to data collection, each subject was issued two types of foot orthoses: a pair of rigid, plastic orthoses with posting in either the forefoot or the rearfoot, and a pair of soft, accommodative, premolded orthoses with no posting. All subjects wore standardized footwear. Following a controlled break-in period for both footwear and orthoses, each subject was asked to walk at a self-selected speed over a 12-m walkway while the movement of internal tibial rotation was recorded with a video camera during five trials. The results indicated that both the rigid plastic and the accommodative foot orthoses significantly reduced the magnitude and the rate of internal tibial rotation. No significant difference was noted between the soft and rigid foot orthoses conditions.
Although three-dimensional movement analysis is the preferred method of assessing rearfoot motion during gait, the high cost of equipment and the time required to use it often make it unreasonable or impractical in a clinical setting. The authors discuss a method of minimizing the variability of rearfoot motion measurements during walking, using two-dimensional analysis when three-dimensional is not available to the clinician.
The purpose of this study was to assess the effectiveness of a semirigid foot orthosis with a varus wedge on forefoot vertical forces in a 24-year-old female with a compensated rearfoot varus deformity. The results of this study indicate that the use of total contact semirigid foot orthoses reduces the forefoot force-time integral during walking, whether a rearfoot varus wedge was or was not used. The authors recommend that total contact construction of the foot orthoses be considered when a reduction of the forces acting on the forefoot is the goal of treatment.
Twelve subjects between the ages of 24 and 35 years walked barefoot over a pressure platform with the following insole materials placed directly on top of the platform: 1) PPT, 2) Spenco, and 3) Viscolas. Maximum vertical force, vertical force-time integral as well as maximum plantar pressure data were collected for the rearfoot, midfoot, and forefoot regions. The results were not significant for maximum vertical force and vertical force-time integral among the three insole materials when compared to barefoot-only walking. There was, however, a significant reduction in forefoot maximum plantar pressure among the three materials compared to barefoot-only walking. In the rearfoot region, a reduction in maximum plantar pressure was seen only with PPT and Spenco.