Plantar Flexion Of Foot Research Articles

Movement-related Variation in Forces Under Compression Stockings

Objectivescompression therapy is widely used in the treatment of venous leg ulcers, but the efficacy of this treatment is variable. Assessment of variation in compression forces associated with movement may help to elucidate the mechanism of action of compression therapy. The aim of this study was to develop and apply a system to investigate forces under compression stockings during movement.Methodthree sensors were placed on the medial aspect of the left leg on six healthy volunteers to monitor forces under class 2 (Continental European classification) compression stockings. Data were recorded during dorsiflexion and plantar flexion of the left foot and also during short periods of walking.Resultschanges in pressure were observed, associated with dorsiflexion and plantar flexion of the foot. These changes were dependent on sensor position. Changes in pressure during walking were also position-dependent and of variable duration.Conclusionsthe system enables forces associated with compression therapy to be examined during movement and may thus be of value in further understanding its mechanism of action. Foot movement can be associated with clear changes in pressure under compression stockings and rapid changes in pressure may occur during walking.

The effect of calcaneal osteotomy on contact characteristics of the tibiotalar joint

To investigate the effect of calcaneal osteotomy on tibiotalar joint contact patterns in a normal and a flatfoot model, we axially loaded 11 fresh frozen cadaver legs with 700 N and quantified tibiotalar joint contact characteristics using Fuji superlow pressure film. For each testing sequence, the unconstrained foot was loaded in neutral, 10° dorsiflexion, and 10° plantarflexion. Tibiotalar joint loading was performed both with a materials tester (Group 1) and manually using a customized jig (Group 2). After calcaneal osteotomy, the calcaneus was translated medially or laterally by 10 mm, and the testing sequence was repeated. Each of these testing series was then repeated on a flatfoot model simulated by soft-tissue sectioning. Images were analyzed using a Bioquant R Video system for Group 1 and an Orthographics Digitizing Tablet for Group 2. For Group 1, there was no difference in the quantitative tibiotalar joint contact characteristics with the exception of all parameters evaluated with the foot in plantarflexion ( P = 0.062). For Group 2, in the normal foot, a lateral translational osteotomy had no effect, but a medial translational osteotomy was associated with a change in the tibiotalar contact ( P = 0.05). The flatfoot model (Group 2) was associated with a qualitative shift of pressure laterally and a quantitative alteration of the contact area in all positions when compared to the normal ankle ( P = 0.06). A medial translational osteotomy altered this contact area ( P = 0.001). We concluded that hindfoot alignment can adversely affect tibiotalar joint contact characteristics. A calcaneal osteotomy may be a useful alternative to tibiotalar arthrodesis in cases of early tibiotalar arthritis secondary to severe varus or valgus hindfoot deformity.

A Study of Venous Return from the Leg during Exercise

Bi-directional ultrasound velocity detector tracings were made of venous blood flow through the popliteal vein in the following situations: (1) walking normally; (2) walking in place; (3) sitting, foot on floor, with rhythmic plantar and dorsi-flexion; (4) sitting, foot on a treadle device requiring 20 degrees of plantar-flexion and 20 degrees of dorsi-flexion to complete a cycle; (5) using the treadle device while in recumbent position, and (6) pushing the foot in plantar flexion against a pedal equipped with a spring resistance. These studies show that active walking, which consists of both plantar flexion and dorsi-flexion, produces cephalad return of venous blood from the foot and leg. When the walking cycle is accompanied by weight bearing, plantar flexion produces a greater blood velocity. However, when there is no weight bearing, dorsi-flexion produces a greater blood velocity than plantar flexion. Therefore, when not bearing weight on the foot, a full range of dorsi-flexion as well as a full range of plantar flexion is essential to utilizing maximum efficiency of the lower extremity muscle pump.

Effect of the syndesmotic screw on ankle motion.

The purpose of this study was to determine the effect of syndesmotic screw fixation on ankle motion. Eight unpaired osteoligamentous cadaver ankles were tested. The study quantified ankle flexion, talar tilt, ankle drawer, and tibiotalar rotation for each specimen using an MTS biomechanical testing system. Each specimen was tested under a 15-kg and a 70-kg axial load. The testing was repeated after the placement of a syndesmotic screw, a 4.5-mm cortical screw, in accordance with AO technique. There was a statistically significant decrease (P less than .05) in tibiotalar external rotation. There was no statistical difference in ankle flexion. There was a significant decrease in the anterior and the posterior drawer tests with the foot in plantar flexion. These were the most significant results. Syndesmotic screw fixation is used for the internal fixation of certain unstable ankle fractures. Opinions differ as to whether the screw should be removed at 6 weeks (prior to weightbearing) or left in place indefinitely. It was concluded that the syndesmotic screw should be removed prior to the return to full activity. Leaving it in place will contribute to abnormal ankle motion; this may result in local discomfort and a possible fatigue fracture of the screw.

Fundamental Study on Teaching for the Soccer Basic Skill (I)

With five players from the Kansai Student Soccer League and one untrained player as subjects, control of ball speed when kicked at various speed by the instep kick was studied from the point of view of muscle action.Speed of the swinging leg before contact with the ball and subsequent velocity of the ball were measured, and at the same time the activities of 14 muscles in the leg, trunk, and arm on the kicking side were recorded. The kick form was also recorded by 16mm cinematography.With all of this information, the role of skill in the relation between swing speed and ball speed was investigated.1) Correlation between swing speed and ball speed was high in proportion to the level of skill of the player. The more skillfull the player, the steeper the slope of the regression line. This means that the correlation coefficient reflected consistency in skill and the slope of the regression line revealed the level of skill.2) To maximize swing speed, active hip flexion and knee extension during the forward swing appeared to be important factors. Thus the activities of muscles crossing these two joints would control the ball speed.3) Maintaining activity in the knee extensors and hip flexors up to the point of ball impact, and also fixating the foot in plantarflexion, were important in effectively transmitting the momentum acquired during the forward swing into the ball.4) In kicks in which ball speed was relatively low for a given swing speed, the maintenance of muscle activities up to the point of impact was lacking. This was especially prominent in the ankle and knee musculature of the untraind player.5) In the skilled players, the movement of hip flexion was momentarily delayed just as the foot was in impact with the ball. This could be considered a “whipping action” as the momentum of the thigh was transmitted into the forefoot.6) Active knee extension, delay in the hip flexion motion at ball impact, and fixation in ankle plantarflexion were all lacking in the untrained player. After five months of practice, however, the correlation between swing speed and ball speed in this player increased, as well as the slope of the regression line. This player's form and muscle activity also came to more closely resemble that of the skilled players.

Sex differences in the incidence of certain congenital malformations: a review of the literature and some new data.

AbstractPercentages of males with selected congenital malformations reported in a large number of studies have been tabulated and analyzed. Males more often than females have been reported to have congenital hydrocephalus, cleft lip with or without cleft palate, esophageal defects, omphalocele, anorectal defects, polydactyly, syndactyly, reduction deformities, and plantar flexion foot defects. More females have been reported to have anencephaly, spina bifida, cleft palate, simple umbilical hernia, and dorsal flexion and inward rotational foot defects. Down's syndrome has been reported more frequently in males in studies that included older patients and more frequently in females in studies restricted to newborn populations. Sources of data also appear to be related to interstudy variations in sex ratios of anencephaly, cleft lip with or without cleft palate, and isolated cleft palate. It is suggested that unequal sex‐specific risks of death (prenatal in the case of anencephaly) account for the observed variations in the reported sex ratios of these malformations.