下肢运动假肢的装配工艺

随着残疾人体育运动的发展．已从早期的康复手殷到近期的竞技阶段。中国截肢运动员穿戴假肢后在国际比赛场上，奋力拼搏、创造佳绩。不仅体现了我国截肢康复和假肢装配的高水平．为国争光．而且也激励着其他截肢克服困难、树立重新开始新生活的勇气和信心。本通过参加两届国际大赛的23名中国截肢运动员装配假肢，并获得优异成绩的实践，提出一些装配下肢运动假肢的有效方法。     

下肢截肢安装假肢患者的运动处方

下肢截肢安装假肢后的系统功能锻炼或康复训练，是提高患者生存质量，为患者早日回归家庭和社会创造条件不可缺少的重要一环，因此，文章针对该类残肢患者制定的相应运动处方，旨在当患者全身情况允许的条件下，为促使其尽早介入系统的功能锻炼提供鉴借。     

下肢截肢安装假肢患者的运动处方

下肢截肢安装假肢后的系统功能锻炼或康复训练,是提高患者生存质量,为患者早日回归家庭和社会创造条件不可缺少的重要一环。因此,文章针对该类残肢患者制定的相应运动处方,旨在当患者全身情况允许的条件下,为促使其尽早介入系统的功能锻炼提供鉴借。     

下肢假肢零部件选择与轻量化

下肢假肢的轻量化问题主要涉及到零部件的重量、性能和截肢的活动性（度）等方面。内论述了截肢的状况、零部件的性能、重量和合理选择三之间的关系，通过对近、现代下肢假肢零部件的发展状况的回顾，从下肢假肢零部件在截肢中实际选择、运用等角度分析了三之间的关系。     

下肢假肢零部件选择与轻量化

下肢假肢的轻量化问题主要涉及到零部件的重量、性能和截肢者的活动性(度)等方面。文内论述了截肢者的状况、零部件的性能、重量和合理选择三者之间的关系,通过对近、现代下肢假肢零部件的发展状况的回顾,从下肢假肢零部件在截肢者中实际选择、运用等角度分析了三者之间的关系。     

下肢假肢步态试验机的设计

实验于2008-03在上海理工大学生物力学与康复工程研究所完成。基于仿生学原理,将人体下肢简化为刚体结构,关节简化为单轴结构,设计出一套下肢假肢步态试验装置。整个步态试验机装置系统由模拟腿、动力和传动装置及测控系统组成,主要部件有躯干、大腿、小腿、脚板和髋关节、膝关节、跑步机以及驱动部分。采集健康青年人常速行走的运动步态参数,以其关节角度数据作为输入信号,以步进电机作为动力驱动实现模拟腿的运动,达到正常人行走步态的模拟。结果显示,对模拟后的输出信号进行采集并与输入信号相比,最大相对误差为5.6%,在工程误差允许范围之内。提示下肢假肢步态试验机能基本模拟人的正常步态。     

储能假肢的原理与临床应用

通过对人体运动的生物力学分析及对储能假肢动态过程的计算机模拟研究，论述了储能假肢的原理。指出储能假肢在动力学方面有更好的仿生特征。这是储能假肢在推动人体前进方面优于传统假肢的特点。根据计算机计算结果还讨论了影响假肢储能性的各种因素。此外还介绍了我国自行研究的储能式小腿运动假肢的临床应用及实验情况．     

使用下肢假肢者的步态训练

下肢假肢使用者由于受到心理因素影响及假肢假脚的限制，其步态与正常步态有较大区别，影响到使用者的生活和社会活动。如能给予适当的指导和训练则可使患步态较接进正常及缩短适应假肢时间。通过对85例下肢截肢患者安装假肢前后进行针对性的心理治疗及步态训练收到了良好的效果。     

下肢假肢装配合的综合康复治疗

近年来由于外伤、感染、肿瘤及周围血管病等因素造成截肢的患者越来越多,据1987年统计全国有肢体残疾者755万人,其中约有45万人需要安装假肢［’j。由此看来此类患者的康复训练显得越来越重要。我科1993年至今共收住院的下肢截肢患者188例,对其中160例装配假肢的患者进行康复训练,收到满意效果。王资料与方法1．l一般资料160例下肢截肢患者来源于西安医科大学第一附属医院假肢装配中心。①选择大腿截肢平面为坐骨结节距残端距离为15～25。m共6O例,男48例,女12例;平均年龄24．5士72岁;装配假肢时间平均3．9月。随机分为大腿康复组与…     

下肢截肢后的假肢训练

下肢截肢后患康复治疗包括全身情况康复和残肢本身康复两个方面。通过有计划地进行假肢训练指导，了解异常步态产生的原因及掌握矫正方法，截肢才能对假肢应用自如。     

Comparative biomechanical analysis of energy-storing prosthetic feet.

Gait analysis was performed on eight men who had unilateral traumatic below-knee amputation and on nine control subjects. Each subject was given two prostheses--the Seattle Foot and the Flex Foot--which differed only in the energy-storing foot component. Analysis of subjects consisted of clinical gait observation, forceplate analysis of the ground reaction force (GRF) while using each prosthesis during level walking at the natural cadence, and evaluation of subject preference between the two prosthetic feet. In the control subjects, there was no significant asymmetry in any averaged GRF patterns or parameters. In the subjects with amputations, the amputated limb had a weaker propulsion and the nonamputated limb had a stronger propulsion than controls. This was true for both prostheses. During ambulation with the Flex Foot, there was a pattern of larger late vertical forces but smaller late anteroposterior and mediolateral forces. This is consistent with a medial heel whip, and it was observed when the Flex Foot was used. Three months after the biomechanical studies, four subjects used the Flex Foot exclusively, two used the Seattle Foot exclusively, and two used both, ie, the Flex Foot for sports and the Seattle Foot for work. Application of these results to the choice of prosthetic components is discussed.     

A comparative study of conventional and energy-storing prosthetic feet in high-functioning transfemoral amputees

OBJECTIVE: To compare the results of gait analysis, timed walking tests, and socket comfort for transfemoral amputees wearing initially a Multiflex conventional prosthetic foot and then a Vari-Flex energy-storing prosthetic foot. DESIGN: Experimental crossover trial. SETTING: A regional prosthetic and amputee rehabilitation tertiary referral center in a teaching hospital. PARTICIPANTS: Six established unilateral transfemoral prosthetic users. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Gait analysis, a timed walking test, and a Prosthetic Socket Fit Comfort Score for each amputee wearing the Multiflex foot and then repeated wearing the Vari-Flex foot. RESULTS: Wearing the Vari-Flex foot, our subjects walked faster in the gait lab (1.38 +/- 0.13 m/s, P < .001) and took more equal step lengths at fast speed (1.063 +/- 0.05, P < .05). They also had greater peak ankle dorsiflexion at push-off on the prosthetic side (18.3 degrees +/-4.73 degrees, P<.001) and 3 times as much power from the prosthetic ankle at push-off (1.13 +/- 0.22 W/kg, P < .001). There were no significant changes in temporal symmetry or loading of the prosthetic limb, in the timed walking test with each foot, or in the comfort score. CONCLUSIONS: A transfemoral amputee who wears an energy-storing foot can have a more symmetric gait with regard to some measures of spatial symmetry, kinetics, and kinematics than one who wears a conventional foot. However, in this study important aspects such as more symmetric loading and comfort did not differ significantly between the 2 foot types.     

Energy-storing prosthetic feet

At least six brands of energy-storing prosthetic feet (ESPF) are now commercially available in the US. These are designed to permit lower extremity amputees to participate in a wide variety of activities, such as running and jumping sports, as well as vigorous walking. Although kinesiologic studies of these devices have not been completed, clinical experience suggests that the Flex-Foot provides the highest performance, followed by the Carbon Copy II and the Seattle Foot. The S.A.F.E. Foot, the STEN Foot, and the Dynamic Foot provide less energy storage and may be suitable for less active patients or those with special needs such as walking on uneven ground. All of the ESPF except the Flex-Foot may be attached to a realigned conventional prosthesis. The Flex-Foot incorporates a pylon and foot in one unit and requires special fabrication technologies. The additional cost of most of the ESPF (compared to a Solid Ankle Cushion Heel Foot) may add little to the cost of a finished prosthesis although it provides greatly increased function. The Flex-Foot, however, is significantly more expensive. Advances in kinesiology and materials science are being applied in the design of prosthetic components that are lighter, stronger, and more resilient. Clinicians can now choose from a variety of innovative commercially available devices but have been hampered by a lack of published information. This paper will review the design philosophy, materials, and applications of ESPF, and will supplement the information available from individual manufacturers and the prosthetic literature.     

Heel-region properties of prosthetic feet and shoes

The properties of the prosthetic components prescribed to amputees have the potential to ameliorate or exacerbate their comfort, mobility, and health. To measure the difference in heel-region structural properties of currently available prosthetic feet and shoes, we simulated the period of initial heel-ground contact with a pendulum apparatus. The energy dissipation capacity of the various prosthetic feet ranged from 33.6% to 52.6% of the input energy. Donning a shoe had a large effect. Energy dissipation of a Seattle Lightfoot 2 prosthetic foot was 45.3%, while addition of a walking, running, and orthopedic shoe increased energy dissipation to 63.0%, 73.0%, and 82.4%, respectively. The force versus deformation response to impact was modeled as a hardening spring in parallel with a position-dependent damping element. A nonlinear least-squares curve fit produced model coefficients useful for predicting the heel-region impact response of both prosthetic feet and shoes.     

Axial and torsional stiffness of pediatric prosthetic feet

BackgroundProsthetic stiffness likely affects the walking biomechanics of toddlers and children with leg amputations, but the actual stiffness values for prostheses are not reported by manufacturers or in standardized testing procedures.AimWe measured axial (k_A) and torsional (k_T) stiffness from four brands of pediatric prosthetic feet (Trulife, Kingsley Mfg. Co., TRS Incorporated, and College Park Industries) over a range of foot sizes.MethodsWe applied forces and torques onto prostheses with a materials testing machine that replicated those exhibited in vivo by using the kinetics measured from four non-amputee toddlers (2–3 years) during walking.FindingsAcross brands, k_A averaged 35.2 kN/m during heel loading, was more stiff during midfoot loading (121.8 kN/m,  P < 0.001) and less stiff during forefoot loading (11.8 kN/m,  P = 0.013). k_A was similar across brands with no statistically significant effect of prosthetic foot size, with the exception of the TRS feet. Plantarflexion torsional stiffness (k_T1), was not statistically different across brands. For every 1 cm increase in foot size, k_T1 increased 0.16 kN·m/rad ( P < 0.001). College Park prostheses had 4.54 kN·m/rad lower dorsiflexion torsional stiffness (k_T2) ( P < 0.001) compared to other brands. For every 1 cm increase in foot size, the k_T2 applied on the foot increased 0.63 kN·m/rad.InterpretationThe axial and torsional stiffness testing methods are reproducible and should be adopted by prosthetic foot manufacturers. Axial and torsional stiffness values of commercially available prosthetic feet should be publically reported to health practitioners to ensure evidence-based decisions and meet the specific needs of each patient with a leg amputation.     

Biomechanical analysis of the influence of prosthetic feet on below-knee amputee walking

Although energy storing prosthetic feet have achieved widespread clinical acceptance, the effect of these components on the biomechanics of below-knee amputee gait is poorly understood. The purpose of this study was to determine the biomechanical adaptations used by the below-knee amputee while wearing a conventional prosthetic foot and to assess the influence of energy storing prosthetic feet on these adaptations. Mechanical power outputs of the lower extremity in five normal and five below-knee amputee subjects using the SACH, Seattle and Flex feet were studied. Ground reaction forces and kinematic data were collected at a walking speed of 1.5 m/s and were used to determine the muscular power outputs of the lower extremity during stance. Consistent patterns of muscular power output at the hip and knee of the residual limb occur. While wearing the SACH foot, negligible energy generation occurs at the prosthetic foot during pushoff. A decrease in energy absorption at the knee during the first half of stance and an increase in energy generation by the hip extensors were the major adaptations noted in the proximal muscle groups. Compared to the SACH foot, the energy storing feet demonstrated increased energy generation during pushoff. Despite the improvements in the performance of the energy storing prosthetic feet, no significant differences were found in the pattern or magnitude of knee and hip power outputs compared to the SACH foot.     

Below-knee amputee gait with dynamic elastic response prosthetic feet: a pilot study

The purpose of this pilot study was to investigate some of the new dynamic elastic response (DER) prosthetic feet compared to the SACH foot and determine if any demonstrated trends of producing the most optimum gait. We investigated the gait of five below-knee amputees while wearing four different DER feet (Flex-Foot, Carbon Copy II, SEATTLE, STEN) and a standard SACH foot. Each subject used each foot for 1 month prior to in-depth gait analysis and energy expenditure testing at the Pathokinesiology Laboratory. Minimal differences in either free or fast walking were noted between the five feet. The Flex-Foot resulted in significantly different gait kinematics at the "ankle" compared to the other four feet, however, this foot did not produce an increased velocity nor an improved energy cost. The results of this pilot study indicated that during free or fast-paced walking on level ground there were no clinically significant advantages of any one of the feet tested. Based on this pilot data, recommendations are made for future studies including appropriate sample size.