zahra safaeepour

The knee joint must adapt to the changes in walking speed to stabilize the stance phase and provide fluency in the swing phase. This study aimed to report a comparison of the gait patterns of transfemoral amputees using a novel mechanical prosthetic knee that can adapt automatically to different walking speeds with 3R60 and 3R15 knee prostheses. In this experimental study, biomechanical data were collected from six unilateral trans-femoral amputees walking with three knee prostheses. Gait data were gathered at slow, normal, and fast walking speeds across a 7-meter walkway using the Vicon motion system. The results revealed a significant difference in knee angular velocity during the swing phase between prosthetic knees across three walking speeds (P-value=0.002). Prosthetic knee flexion decreased significantly by increasing walking speed for the novel mechanical auto-adaptive prosthetic knee (P-value<0.001). A lower value of hip power during early swing was considered when amputees walked with novel knee prosthesis (P-value<0.00). The intact leg ankle plantar flexion angle or vaulting did not significantly change while walking speed increased in the novel knee prostheses compared to walking with the 3R60 and 3R15 knee prostheses (P-value=0.002 and P-value<0.06, respectively).  Based on the results, a novel mechanical auto-adaptive knee prosthesis has advantages compared to the other conventional designs for unilateral trans-femoral amputees walking at different speeds.

Flexible Flat Foot (FFF), a common foot deformity decreasing medial longitudinal arch height is often comorbid with subtalar joint pronation causing physical activity difficulties in this population. Among the orthotic insoles prescribed for improving foot function, foot orthoses with medial heel skive technique have a limited research background. The present study aimed to investigate the effects of the custom-mold insole with medial heel skive technique on physical function in FFF.

Eighteen adults with FFF from the University of Social Welfare and Rehabilitation Sciences students and staff participated in this study. Custom-Mold insole with medial heel skive was fabricated for all research participants. Physical function in the activities of daily living and sports was assessed by the Foot and Ankle Ability Measure (FAAM), Activities of Daily Living (ADL) subscale (ADL-FAAM), and SPORT-FAAM questionnaires at the beginning of the study and 6 weeks after. Paired Samples t-test and nonparametric tests were used to compare the collected results.

After 6 weeks of using the insole with medial heel skive technique, scores in both ADL and SPORTS activities were significantly improved.

Foot function improvement was not found in all of the studies assessing foot function in flat feet after using different orthotic insoles, by different questionnaires or other systems. In this study, foot and ankle function was significantly improved per FAAM questionnaire- which had highly limited use in orthotic interventions in flat feet population- using medial heel skive technique; however, further studies are required to accentuate medial heel skive technique effect on flat feet function by comparing this technique with other positive cast modifications to control the flat foot. According to the present study results, custom-mold insole with medial heel skive may improve physical function in FFF and can be prescribed in this group.

There is no doubt that sporting surfaces are extremely important for every activity. However, there is not sufficient scientific report regarding the effect of the area elastic surface floor with common range stiffness on vertical hopping safety and performance. The aim of this study was to examine the effect of custom area elastic surface with different stiffness on the hopping performance and safety with emphasis on familiarity to the surfaces. Fifteen young and healthy experienced male were volunteered in this study. Kinematic and kinetic data recorded during hopping on four surfaces (300-500 kN/m) using the Motion Analysis System and AMTI force plate. In the data analysis process, leg and joint stiffness, maximum vertical ground reaction force, mechanical energy and power and angular position of joints calculated. The results of this study show that surface stiffness does not effect on the leg and joint stiffness, but after familiarity to the surface, there was a significant increase in 400 kN/m surface positive mechanical energy and power of ankle joint and a significant decrease in negative mechanical energy and power of knee joint (P<0.05). In conclusion, it seems the change in surface stiffness after familiarity to the surface causes an improvement of hopping performance without any change in leg and joint spring stiffness. It can be proposed that deformation following impact also does not enough to significantly reduce the vertical ground reaction force.

This paper describes further improvement and preliminarily evaluation of a novel viscoelastic ankle-foot prosthesis prototype. The objective was to control the ankle hysteresis at slow and normal walking speeds.
Inspired by the ankle biomechanics, in which the hysteresis differs based on the gait speeds, a manually damping control mechanism imbedded in the prosthesis for adjusting the ankle damping at slow and normal walking speeds. The prototype was then preliminarily tested on an able-bodied subject wearing an adaptor which simulates the amputee walking. The ankle joint kinetics and kinematics were measured in a gait analysis lab at different walking speeds.
The results suggest that the viscoelastic ankle foot prosthesis prototype could provide a smooth normal-like walking for most of the measured gait characteristics in slow and normal speeds.
Therefore, it is suggested to apply a controllable damping mechanism based on the gait speeds in the design of new prosthetic feet.

Foot and ankle problems are common complications in rheumatoid arthritis disease. Gait pattern such as normal foot and ankle rocker is impaired in patients with rheumatoid arthritis. Rocker sole as an external shoe modification is commonly prescribed in this pathology. The aim of this study was to investigate the effect of rocker shoe on vertical ground reaction force parameters during walking in patients with rheumatoid arthritis. Sixteen female participants with rheumatoid arthritis were recruited in this study. All patients were prepared with a pair of high-top, heel-to-toe rocker shoe and were asked to wear the shoes for one month. Ground reaction force parameters including peak forces and peak force times were evaluated in the first session, and after seven days and thirty days follow up were carried on. first maximal vertical force was significantly increased with rocker shoe compared to barefoot after 7 days follow up. Walking with rocker shoe reduced the minimal vertical force after 7 days. The second maximal vertical force showed to be statistically lower with rocker shoes than barefoot after 7 and 30 days. Furthermore, stance time decreased with rocker shoe after one month. Results of this study revealed that vertical ground reaction force parameters changed in rheumatoid arthritis patients with heel-to-toe rocker shoe, both immediately and after one month follow up. This might suggest the effectiveness of rocker shoes in improving gait in rheumatoid arthritis patients.

Rheumatoid arthritis is a chronic inflammatory disease which causes structural and functional changes in foot joints and results in alteration of plantar pressures. Therefore, the aim of this study was to investigate the immediate effect of insole with medial longitudinal arch support and metatarsal pad on plantar pressure distribution in females with rheumatoid arthritis. This was a quasi-experimental study in which 15 volunteer females with rheumatoid arthritis were recruited using no-probability simple sampling method. Plantar pressures were assessed using Pedar-X system in four anatomical foot region in two conditions of walking with and without foot orthosis. Average maximum pressures (Kilopascal) were calculated in each region. Foot orthosis with medial longitudinal arch support and metatarsal pad reduced plantar pressure in heel (P< 0.015), metatarsal heads (P< 0.03) and increased pressure in mid-foot area (P< 0.00). However, no significant differences in average maximum pressure were observed between two assessed conditions in the toe area. The findings of the present study revealed that the orthosis with medial longitudinal arch support and metatarsal pad corrects increased pressure on heel and metatarsal heads in rheumatoid arthritis. It could increase plantar pressure in mid-foot while decrease it in metatarsal heads and heel regions. Therefore, this orthosis is recommended to be used as a treatment in this pathology in order to re-distribute the foot pressures more normally.

Hallux Valgus is one of the most foot deformities which increase plantar pressure beneath big toe and first metatarsal. The aim of this study was to assess the effect of foot orthosis on plantar pressure distribution in subjects with mild and moderate Hallux Valgus. Method & Materials: in this quasi-experimental study، females 16 with Hallux Valgus were recruited. Plantar pressure in 8 area of foot was measured by Pedar-X insole when wearing standard shoe only; shoe with foot orthosis and shoe with foot orthosis after a month of using orthosis. Data were analyzed by repeated measure analysis of variance test. using foot orthosis for a month leaded to decrease pressure in the big toe (p<0/019); first metatarsal and 3-5 metatarsals (p<0/001) and also increased pressure in medial mid foot (p<0/001). Foot orthosis decreased peak pressure in fore foot and increased it in medial mid foot. Therefore redistribute plantar pressure to the more normal pattern in Hallux Valgus subjects. So it could be one of the effective methods to prevent the progression of this deformity in its initial steps of formation.

Prosthetic foot is an essential element of lower limb prosthesis، which plays an important role in the amputee gait. There is a growing trend towards development of energy storing prosthetic feet considering the amputee needs during walking. Several researches have focused on kinetics and kinematics of energy storing feet، however little is known about the mechanical properties of these commercial feet. Assess the mechanical properties of Flex-foot using its force-deformation curve and a linear elastic model. This was a case study in which gait of a healthy subject was analysed and maximum force of 800 N was defined as applied load on the prosthetic foot. Load-deformation test was performed on heel and forefoot regions of Flex-foot using a testing machine. A linear elastic behaviour was assumed، and thus the slope of the force-deformation curve was defined as the stiffness. The linear elastic model was found relatively appropriate (R2 > 0. 9). The stiffness in heel and forefoot was found to be 88. 85 and 74. 54 N/mm، respectively. The results of this study show that a linear elastic model could predict mechanical behaviour of this foot adequately. The higher stiffness in heel compared to forefoot is an indicator of greater storing capacity in this region.

The flatfoot might be caused complications and pain within upper joints and also change distribution of plantar foot pressure in flatfoot patients. One of the current treatments for this problem is longitudinal arch support insole which might be used for decreasing the related complications of this disorder. This foot orthosis maybe help to improve the medial longitudinal arch and redistribute of foot plantar pressure. Assessing the distribution of plantar foot pressures within flexible flatfoot patients and the effects of longitudinal arch support insole on distribution of plantar foot pressures were the aims of this study. This was a quasi-experimental study with participation of 12 young men with bilateral flexible flat foot (age: 18- 28). The plantar pressures measurement insole (Pedar) was used for measuring the foot plantar pressures as an instrument which it includes five different sizes of insoles with 99 sensors. Each trial included three direct walk ways (nine meters) with normal speed and 50 Hz. There were two types of tests with/without foot orthoses. There was a significant decrease of plantar pressure in medial hindfoot and a significant increase of plantar pressure in midfoot foot by using the longitudinal arch support insole in contrast of without orthoses condition (with shoe). There was also an increasing contact area in the medial part of midfoot foot by using of foot orthosis in comparison of using the shoe only. The results of this study shows that the foot orthoses might be caused to transfer the pressures from other adjacent areas include hindfoot and forefoot to midfoot foot which support the previous studies. Also، significant decrease pressure in hindfoot by using the foot orthoses confirms that insole may help the foot to compensate the function of medial longitudinal arch.