Sprint kinematics of athletes with lower-limb amputations.

OBJECTIVE: To determine and compare the kinematics of the sound and prosthetic limb in five of the world's best unilateral amputee sprinters. SUBJECTS: Five men, all unilateral lower-limb amputee (one transfemoral, four transtibial) athletes. The individual with transfemoral amputation used a Endolite Hi-activity prosthesis incorporating a CaTech hydraulic swing and stance control unit, a Flex-Foot Modular III, and an ischial containment total contact socket. Those with transtibial amputations used prostheses incorporating a Flex-Foot Modular III and patellar tendon-bearing socket, with silicone sheath liner (Iceross) and lanyard suspension. DESIGN: Case series. Subjects were videotaped sprinting through a performance area. Sagittal plane lower-limb kinematics derived from manual digitization (at 50 Hz) of the video were determined for three sprint trials of the prosthetic and sound limb. Hip, knee, and ankle kinematics of each subject's sound and prosthetic limb were compared to highlight kinematic alterations resulting from the use of individual prostheses. Comparisons were also made with mean data from five able-bodied men who had similar sprinting ability. RESULTS: Sound limb hip and knee kinematics in all subjects with amputation were comparable to those in able-bodied subjects. The prosthetic knee of the transfemoral amputee athlete fully extended early in swing and remained so through stance. In the transtibial amputee athletes, as in able-bodied subjects, a pattern of stance flexion-extension was evident for both limbs. During stance, prosthetic ankle angles of the transtibial amputee subjects were similar to those of the sound side and those of able-bodied subjects. CONCLUSION: Prosthetic limb kinematics in transtibial amputee subjects were similar to those for the sound limb, and individuals achieved an "up-on-the-toes" gait typical of able-bodied sprinting. Kinematics for the prosthetic limb of the transfemoral amputee subject were more typical of those seen for walking. This resulted in a sprinting gait with large kinematic asymmetries between contralateral limbs.     

Interface pressures in above-knee sockets

The interface pressures in above-knee sockets of amputee patients were measured during the stance phase of the gait cycle. The pressures were monitored with a pneumatic sensor array that covered the inside of the socket. A pressure map of the socket surface was developed. This map has been related to the fit of the prosthetic socket. The pressures generated by the quadrilateral socket and the Normal Shape Normal Alignment (NSNA) socket were compared. Significant variations were noted in pressure distribution between the two sockets, but the magnitudes of the pressures in well-fitting sockets of both types were similar. Thus, magnitude of pressure in an above-knee socket may provide a more useful guide than distribution for predicting the fit of an appliance.     

Patient preference and gait efficiency in a geriatric population with transfemoral amputation using a free-swinging versus a locked prosthetic knee joint

OBJECTIVE: To investigate patient preference, walking speed, and prosthetic use in a geriatric population with transfemoral amputation using a free-swinging prosthetic knee or a locked knee joint. DESIGN: Before-after trial. SETTING: Ambulatory patients at an amputee rehabilitation facility. PARTICIPANTS: A convenience sample of 14 geriatric individuals with a unilateral dysvascular transfemoral amputation (age range, 61-80y), who were using a prosthesis with a free-swinging knee in the community, 3 months after discharge from an amputee rehabilitation program. INTERVENTION: Change from a free-swinging knee to a locked knee. MAIN OUTCOME MEASURES: Patient preference, distance walked in 2 minutes, and prosthetic use as measured by the Houghton Scale. RESULTS: Eleven of 14 participants preferred the locked knee. Irrespective of preference, the mean 2-minute walk distance was 44.9 +/- 28.9m with the free-swinging knee and 54.4 +/- 35m with the locked knee (P = .001). Prosthetic use was greater with the locked knee (7.8 +/- 2.2) than with the free-swinging knee (6.6 +/- 2.5) (P = .01). CONCLUSIONS: Most geriatric participants with transfemoral amputation preferred locked knees and walked faster and used their prostheses more when using a locked knee prosthesis.     

Management of an above-knee amputee with complex medical problems using the CAT-CAM prosthesis

The purpose of this case report is to 1) briefly describe the traditional above-knee (AK) quadrilateral socket, 2) describe the contoured adducted trochanteric-controlled alignment method (CAT-CAM) socket, 3) describe the management of a patient with a temporary CAT-CAM prosthesis, and 4) explain how the CAT-CAM prosthesis approach has resolved a medically complex clinical problem. The 49-year-old patient in this case study received a left AK amputation in 1984 and was provided with a quadrilateral socket. She abandoned this prosthesis after 2 years because of her dissatisfaction with the device (ie, poor fit, awkwardness, excessive energy expenditure) and because of her compromised cardiac condition. The patient was fitted with a CAT-CAM prosthesis in 1988 and reported increased comfort, ease of donning and doffing, and increased gait efficiency with the CAT-CAM prosthesis as compared with the quadrilateral socket. The patient required 19 days of prosthetic training and was discharged independent in ambulation and transfers using two straight canes. We consider the CAT-CAM prosthesis an improvement over the quadrilateral socket for increasing ambulation independence in the individual with AK amputation and other medical complications.     

Amputation rehabilitation and prosthetic restoration. From surgery to community reintegration

PURPOSE: The purpose of this review is to summarize the literature related to the advances that have taken place in the management and rehabilitation care of limb amputation. RESULTS: Prostheses for the lower and upper limb amputee have changed greatly over the past several years, with advances in components, socket fabrication and fitting techniques, suspension systems and sources of power and electronic controls. Higher levels of limb amputation can now be fitted with functional prostheses, which allow more patients to achieve independent life styles. This is of particular importance for the multi-limb amputee. The rehabilitation of more traditional lower limb levels of amputation have also greatly benefited from the technological advances including energy storing feet, electronic control hydraulic knees, ankle rotators and shock absorbers to mention a few. For the upper limb amputee, myoelectric and proportional controlled terminal devices and elbow joints are now used routinely in some rehabilitation facilities. Experimental prosthetic fitting techniques and devices such as the use of osseo-implantation for suspension of the prosthesis, tension control hands or electromagnetic fluids for knee movement control will also be briefly discussed in this paper. CONCLUSION: It is possible to conclude from this review that many advances have occurred that have greatly impacted the functional outcomes of patients with limb amputation.     

Suction socket suspension for below-knee amputees

In this study the current use of suction suspension for below-knee prostheses is examined by means of two questionnaire surveys. The experience of 56 below-knee (B-K) amputees wearing suction socket prostheses is evaluated comparing suction prostheses with previously worn limbs. A high degree of satisfaction was found, with amputees on the whole reporting improved skin condition, diminished pain, and increased activity levels compared to previous prosthetic history. The experience and opinions of 466 certified prosthetist members of the American Orthotist Prosthetist Association are examined in the second survey, including degree of contact, success, and evaluation of problems in using suction suspension for the B-K amputee. This survey indicated limited contact and familiarity with B-K suction suspension, with only 22% stating they had made this type of prosthesis. Prosthetists cited characteristics of the B-K residual limb as the chief deterrent to a successful fitting.     

基于先进制造平台的假肢接受腔计算机辅助制造系统

目的：为了克服手工制作假肢接受腔的缺点,将计算机辅助制造技术用于加工假肢接受腔,提高接受腔的质量和加工效率,减少对操作者知识和经验的要求。方法：基于先进制造平台建立假肢接受腔计算机辅助制造系统,进行系统的硬件设计和软件实现。先进制造平台的主要部件包括工控机,运动控制卡,松下全数字交流伺服控制系统,丝杠导轨,铣刀主轴电机,变频器,开关电源,限位开关及接近开关。软件主要包括参数设置、测试机器及开始加工 3 个功能模块。通过设置不同的指令脉冲输入和驱动器参数,调试出不同的电机转速。结果：实验结果显示,电机不仅有着自我保护的最高转速限制,而且即使在极低速运转的情况下,电机的运转现象仍然非常平稳,不会出现振动现象,更符合假肢接受腔的加工特点,可以加工出满足残疾人需要的高质量假肢接受腔。结论：基于先进制造平台的假肢接受腔计算机辅助制造系统可以克服手工制作的缺点,确保产品质量,降低成本。可以把优秀假肢制作师长期积累的经验编入计算机设计程序,减少对操作者知识和经验的要求,提高假肢接受腔一次制作成功率,降低接受腔的质量不确定性,从根本上改变了过去依靠手工设计、测量、取型、修型等落后的生产模式。     

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.     

Amputation rehabilitation and prosthetic restoration. From surgery to community reintegration

Purpose:?The purpose of this review is to summarize the literature related to the advances that have taken place in the management and rehabilitation care of limb amputation.

Results:?Prostheses for the lower and upper limb amputee have changed greatly over the past several years, with advances in components, socket fabrication and fitting techniques, suspension systems and sources of power and electronic controls. Higher levels of limb amputation can now be fitted with functional prostheses, which allow more patients to achieve independent life styles. This is of particular importance for the multi-limb amputee. The rehabilitation of more traditional lower limb levels of amputation have also greatly benefited from the technological advances including energy storing feet, electronic control hydraulic knees, ankle rotators and shock absorbers to mention a few. For the upper limb amputee, myoelectric and proportional controlled terminal devices and elbow joints are now used routinely in some rehabilitation facilities. Experimental prosthetic fitting techniques and devices such as the use of osseo-implantation for suspension of the prosthesis, tension control hands or electromagnetic fluids for knee movement control will also be briefly discussed in this paper.

Conclusion:?It is possible to conclude from this review that many advances have occurred that have greatly impacted the functional outcomes of patients with limb amputation.     

Tensile strength and impact resistance properties of materials used in prosthetic check sockets, copolymer sockets, and definitive laminated sockets

Prosthetic sockets serve as the interface between people with amputations and their prostheses. Although most materials used to make prosthetic sockets have been used for many years, knowledge of these materials' properties is limited, especially after they are subjected to fabrication processes. This study evaluated tensile and impact properties of the current state-of-the-art materials used to fabricate prosthetic check sockets, copolymer sockets, and definitive laminated sockets. Thermolyn Rigid and Orfitrans Stiff check socket materials produced significantly lower tensile strength and impact resistance than polyethylene terephthalate glycol (PETG). Copolymer socket materials exhibited greater resistance to impact forces than the check socket materials but lower tensile strengths than PETG. The heated molding processes, for the check socket and copolymer materials, reduced both tensile strength and elongation at break. Definitive laminated sockets were sorted according to fabrication techniques. Nyglass material had significantly higher elongation, indicating a more ductile material than carbon-based laminations. Carbon sockets with pigmented resin had higher tensile strength and modulus at break than nonpigmented carbon sockets. Elongation at yield and elongation at break were similar for both types of carbon-based laminations. The material properties determined in this study provide a foundation for understanding and improving the quality of prosthetic sockets using current fabrication materials and a basis for evaluating future technologies.     

Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

ABSTRACT: BACKGROUND: Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user's nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. METHODS: We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step intersubject variability of these profiles by calculating variance-to-signal ratios. RESULTS: We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. CONCLUSION: Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee's nervous system.     

Amputation rehabilitation and prosthetic restoration. From surgery to community reintegration

Purpose: The purpose of this review is to summarize the literature related to the advances that have taken place in the management and rehabilitation care of limb amputation.

Results: Prostheses for the lower and upper limb amputee have changed greatly over the past several years, with advances in components, socket fabrication and fitting techniques, suspension systems and sources of power and electronic controls. Higher levels of limb amputation can now be fitted with functional prostheses, which allow more patients to achieve independent life styles. This is of particular importance for the multi-limb amputee. The rehabilitation of more traditional lower limb levels of amputation have also greatly benefited from the technological advances including energy storing feet, electronic control hydraulic knees, ankle rotators and shock absorbers to mention a few. For the upper limb amputee, myoelectric and proportional controlled terminal devices and elbow joints are now used routinely in some rehabilitation facilities. Experimental prosthetic fitting techniques and devices such as the use of osseo-implantation for suspension of the prosthesis, tension control hands or electromagnetic fluids for knee movement control will also be briefly discussed in this paper.

Conclusion: It is possible to conclude from this review that many advances have occurred that have greatly impacted the functional outcomes of patients with limb amputation.     

Le chaussage de la prothèse chez le sujet amputé âgé

Medical advancement over the last 20 years has deeply changed the epidemiological data concerning lower limb amputation: henceforth, it mainly affects elderly subjects suffering from arteritis. The aim of prosthetics, as well as reeducation is to restore the most complete functional independence for these patients, often impaired with multiple pathology. The dependency towards fitting the prosthesis should be considered in this context. Indeed, this is a common problem concerning two thirds of the patients aged over 70. The choice of an appropriate prosthesis and the involvement of the whole medical and paramedical team in the teaching process are the bases that will help the patient recover his or her autonomy. These concepts apply to both the transfemoral amputee, in which the use of a socket as an interface is clearly established, and the transtibilal amputee.     

Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system.     

Bone overgrowth in the adult traumatic amputee

Bone overgrowth of the residual limb after an amputation is a well documented complication in the pediatric amputee population. Bone overgrowth can cause pain, problems with skin breakdown, and poor prosthetic fit. There have been few reports of bone overgrowth in the adult amputee. Two cases of traumatic transfemoral amputations after extensive tissue damage are presented. Both patients successfully completed an in-patient amputee rehabilitation program and achieved functional ambulation with their prostheses. However, each developed distal residual limb pain within a year after their amputations that significantly limited the amount of time they could wear their prostheses and the distance they could walk. Radiographs demonstrated additional bone growth from the residual femur into adjacent soft tissues in both patients. These case examples demonstrate that bone overgrowth should be considered in the differential diagnosis of residual limb pain in the adult amputee.     

Influence of different types of sockets on the range of motion of the hip joint by the transfemoral amputee

PurposeTo compare the individual influence of different types of socket designs on the hip's range of motion in transfemoral amputees.Patients and methodsWe studied the kinematic parameters of the hip joint for patients with transfemoral amputation under four experimental conditions: without a socket, with a quadrilateral socket, an ischial containment socket, an ischial-ramal containment socket. An opto-electronic system was used to record the movements in the frontal and sagittal planes for a 3D movement analysis.ResultsThe hip's range of motion is always significantly restricted with the sockets, regardless of their type, compared to the situation without a socket (P < 0.05). The adduction and extension movements are the most restricted. The global amplitude (i.e., the sum of all the ranges of motion) is significantly higher for the ischial-ramal containment socket (139.5°) compared to the ischial containment socket (125.4°, P = 0.002) and the quadrilateral socket (127.3°, P = 0.01). No comparable study exists in the literature, especially for the ischial-ramal containment socket.ConclusionThe ischial-ramal containment socket seems to be the most interesting type of socket in terms of the criterion studied. It still remains to identify the possible functional improvements that this design would provoke during gait and during daily activities.     

Comparison of Ischial Containment and Subischial Sockets Effect on Gait Biomechanics in People With Transfemoral Amputation: A Randomized Crossover Trial

ObjectiveTo compare gait biomechanics of the Northwestern University Flexible Sub-Ischial Vacuum (NU-FlexSIV) Socket to the ischial containment (IC) socket.DesignRandomized crossover trial with 2, 7-week periods.SettingPrivate prosthetic clinics and university research laboratory.ParticipantsA total of 30 enrolled (n=30); 25 participants completed the study with full (n=18) or partial data (n=7).InterventionsTwo custom-fabricated sockets (IC and NU-FlexSIV), worn full-time for 7 weeks, with testing at 1, 4, and 7 weeks after socket delivery.Main Outcome MeasuresGait analyses were conducted at 1, 4, and 7 weeks post socket delivery. Differences between sockets in selected gait variables related to hip motion and coronal plane socket stability were assessed.ResultsFor participants with data for both sockets at week 7 (n=19), there were no significant differences in any gait variables between sockets at self-selected normal walking speed. However, when all participants and all study time points were assessed (n=25), there was a significant main effect of socket (P=.013), with prosthetic side sagittal plane hip range of motion being significantly greater for the NU-FlexSIV Socket at self-selected normal walking speed. There were no other significant effects.ConclusionsThe results suggest that, compared to the IC socket, the NU-FlexSIV Socket did not alter gait biomechanics related to hip motion and coronal plane socket stability in people with unilateral transfemoral amputation.     

计算机辅助设计与制作大腿假肢的应用研究

目的 研究一套临床应用快捷、可行的计算机辅助接受腔设计与制作系统.方法 对基于三维扫描与逆向工程方法 的计算机辅助设计与制作假肢接受腔和传统手工制作的假肢接受腔的生物力学进行比较.结果 3例患者穿戴计算机辅助设计与制作接受腔假肢比传统手工制作假肢在静力学参数、步行动力学参数、残肢-接受腔界面压力显现相似或更好的指数.结论 计算机辅助设计与制作接受腔方法 可以满足患者使用假肢需求.     

Does increased prosthetic weight affect gait speed and patient preference in dysvascular transfemoral amputees?

OBJECTIVES: To determine if increased prosthetic weight affects gait speed in dysvascular transfemoral amputees and to see if there is any patient preference for lighter versus heavier prostheses. DESIGN: Randomized prospective double-blind crossover trial. SETTING: Outpatient, tertiary care, amputee clinic in Ontario, Canada. PARTICIPANTS: A convenience sample of 10 subjects with unilateral transfemoral amputations because of peripheral vascular disease. All subjects were independent community ambulators over 50 years old. INTERVENTION: Seemingly identical weights of 150g (placebo weight), 770g, and 1625g were added to the prosthesis 14cm below the knee joint. MAIN OUTCOME MEASURES: Two-minute walk test (2MWT) and subject preference. RESULTS: The 2MWT results were not significantly influenced by weight added (mean, 53.4+/-28.4m, 55.1+/-28.9m, and 52.8+/-26.7m for 150g, 770g, and 1625g of added weight, respectively). Subject preference revealed that more than half preferred a weighted prosthesis over the "placebo" weight (5 subjects preferred 770g added, 4 subjects preferred 150g added, 1 preferred 1625g added). CONCLUSIONS: Short-term intervention with increased prosthetic mass had no significant adverse affect on gait speed, and more than half of the subjects preferred an added mass condition.     

脱细胞异体真皮组织补片在智齿拔除中的应用

背景：使用J-1型脱细胞异体真皮组织补片覆盖拔牙创口的报告较少。目的：探讨异体脱细胞组织补片置入拔牙窝对预防拔牙后并发症的影响。方法：将400例阻生智齿拔除患者随机分为2组,实验组智齿拔除后拔牙窝内放置医用组织补片;对照组智齿拔除后不放置医用组织补片。分别观察拔牙后组织补片脱落率、肿胀发生率、拔牙窝内血凝块存留和食物残渣残留情况、牙龈是否红肿、对拔牙后出血的影响以及干槽症的发生率。结果与结论：拔牙后出血的百分比,血凝块留存率,拔牙窝内食物残渣残留百分比,干槽症发生率实验组均明显低于对照组。放置组织补片对术后肿胀和牙龈红肿无明显影响。所有放置在拔牙窝内的组织补片与拔牙创周围组织附着紧密,未见脱落。