Does actively enlarging socket volume during resting facilitate residual limb fluid volume recovery in trans-tibial prosthesis users?

BackgroundResidual limb volume loss is a source of prosthetic socket fit problems in people with lower-limb amputation. The aim of this study was to investigate a novel volume recovery strategy for people with trans-tibial amputation.MethodsTest sockets for people with trans-tibial amputation were created that allowed panels of an adjustable socket and the underlying elastomeric liner to be pulled radially outward, using small motors mounted to the socket. One Control and one Intervention session were conducted with each participant. During Intervention sessions, panel-pull was executed during the sits of a multi-cycle sit/walk protocol. No panel-pull was executed during the Control sessions. Residual limb fluid volume was monitored in anterior and posterior regions using bioimpedance analysis.FindingsResults from 12 participants demonstrated that short-term (12 min after the intervention was applied) median posterior residual limb fluid volume change for Intervention (0.44%) was higher than that for Control (−0.02%) (P = .015). Long-term (40 min after the intervention was applied) median posterior residual limb fluid volume change for Intervention (0.95%) was higher than that for Control (−0.26%) (P = .002).InterpretationIf a panel-pull mechanism that was easy to assemble and operate could be created, then panel-pull may be an effective accommodation strategy to reduce daily limb volume loss in trans-tibial prosthesis users.     

Evolution in prostheses for sprinters with lower-limb amputation]

For about 15 years, technical advances in prosthetic treatment have been the main factor in the increased performance of athletes with lower-limb amputation. For trans-tibial amputation, the prosthesis for sprinting is composed of a gel liner and a socket joined by a locking or virtual vacuum liner. Because of these dynamic properties, the carbon prosthetic foot equipped with tacks ensures outstanding performance. For trans-femoral amputation, a hydraulic swing and a stance control unit are added to the same prosthesis. In comparison with the able-bodied runner, athletes with amputation have smaller loading times in the prosthetic limb and larger ones in the sound limb. The length of the energy-storing prosthetic foot is determined by the "up-on-the-toes" running gait. The sprinting gait with trans-tibial amputation is almost symmetrical. The hip extensor effort is the main compensation of propulsion reduction with lower-limb amputation. With trans-femoral amputation, the lack of knee increases the asymmetry. The total prosthetic knee extension (early in late-swing phase and lasting during total stance phase) compensates with extension of both hips, especially the opposite one. The amputation and sound limb load transfer with lumbar hyperlordosis concern the pelvis, trunk and shoulders. Because of athletes with amputation, research in prosthetic treatment has progressed. The development of orthotics and prostheses for such athletes has benefited non-athletes with amputation.     

残肢与接受腔的三维建模及力学分析

目的：对残肢与接受腔进行三维重建及力学分析，寻求残肢与接受腔间生物力学交互作用，为假肢接受腔的设计提供科学依据。方法：利用CT扫描、图像处理和反求技术重构骨骼、皮肤及接受腔三维模型建立残肢与接受腔的有限元模型．进行有限元受力分析。结果：残肢的主要受力部位是膑韧带、后肌群、胫骨内凸、胫骨远端、腓骨头及腓骨远端；骨骼对力的传递作用显著。结论：残肢受力由穿戴受腔引起，通过骨骼从接受腔传递给软组织，通过改变接受腔形状可以改变残肢的受力分布，残肢与接受腔力学分析是假肢接受腔制定的前提和基础。     

State-of-the-art methods for geometric and biomechanical assessments of residual limbs: a review.

A review is presented on the state-of-the-art methods for geometric and biomechanical assessments of residual limb tissues. Residual limb assessments are needed throughout different stages of prosthetic management, namely preamputation, residual limb maturation, prosthetic design, prosthetic fitting, and subsequent follow-ups. Geometric assessments include the monitoring of the volumetric change as the residual limb matures after amputation. Geometric and biomechanical assessments of the residual limb are important considerations in prosthetic design. Quantitative geometric and biomechanical assessments are becoming more important in the development of a computer-aided system for prosthetic socket design. It is noted that, except for the external shape measurements of residual limbs, most of the instruments used in residual limb assessment are not particularly cost-effective for clinical applications in prosthetics. Further developments are needed to facilitate the incorporation of the internal geometric assessments and biomechanical assessments into the current computer-aided design systems for clinical prosthetics.     

Review of secondary physical conditions associated with lower-limb amputation and long-term prosthesis use

Musculoskeletal imbalances or pathologies often develop into secondary physical conditions or complications that may affect the mobility and quality of life of people with lower-limb amputation. Using one or more prostheses causes people with amputation to alter the biomechanics of their movement. For example, people with lower-limb amputation often favor and stress their intact lower limb more during everyday activities. This can lead to degenerative changes such as osteoarthritis of the knee and/or hip joints of the intact limb. Since people with amputation spend less time on their residual limb, osteopenia and subsequent osteoporosis often occur secondary to insufficient loading through the long bones of the lower limb. A proper prosthetic fit increases the probability of equal force distribution across the intact and prosthetic limbs during ambulation, thus decreasing the risk of osteoarthritis. People with limb loss commonly complain of back pain, which is linked to poor prosthetic fit and alignment, postural changes, leg-length discrepancy, amputation level, and general deconditioning. We review the literature on secondary complications among people with lower-limb loss who are long-term prosthesis wearers.     

State-of-the-art research in lower-limb prosthetic biomechanics-socket interface: a review

Scientific studies have been conducted to quantify attributes that may be important in the creation of more functional and comfortable lower-limb prostheses. The prosthesis socket, a human-machine interface, has to be designed properly to achieve satisfactory load transmission, stability, and efficient control for mobility. The biomechanical understanding of the interaction between prosthetic socket and the residual limb is fundamental to such goals. The purpose of this paper is to review the recent research literature on socket biomechanics, including socket pressure measurement, friction-related phenomena and associated properties, computational modeling, and limb tissue responses to external mechanical loads and other physical conditions at the interface. There is no doubt that improved biomechanical understanding has advanced the science of socket fitting. However, the most recent advances in the understanding of stresses experienced at the residual limb have not yet led to enough clinical consensus that could fundamentally alter clinical practice. Efforts should be made to systematically identify the major discrepancies. Further research should be directed to address the critical controversies and the associated technical challenges. Developments should be guided to offer clinicians the quantification and visualization of the interaction between the residual limb and the prosthetic socket. An understanding of comfort and optimal load transfer as patterns of socket interface stress could culminate in socket design expert systems.     

Temperature measurement and control system for transtibial prostheses: Single subject clinical evaluation

The snug fit of a prosthetic socket over the residual limb can disturb thermal balance and put skin integrity in jeopardy by providing an unpleasant and infectious environment. The prototype of a temperature measurement and control (TM&C) system was previously introduced to resolve thermal problems related to prostheses. This study evaluates its clinical application in a setting with reversal, single subject design. The TM&C system was installed on a fabricated prosthetic socket of a man with unilateral transtibial amputation. Skin temperature of the residual limb without prosthesis at baseline and with prosthesis during rest and walking was evaluated. The thermal sense and thermal comfort of the participant were also evaluated. The results showed different skin temperature around the residual limb with a temperature decrease tendency from proximal to distal. The TM&C system decreased skin temperature rise after prosthesis wearing. The same situation occurred during walking, but the thermal power of the TM&C system was insufficient to overcome heat build-up in some regions of the residual limb. The participant reported no significant change of thermal sense and thermal comfort. Further investigations are warranted to examine thermography pattern of the residual limb, thermal sense, and thermal comfort in people with amputation.     

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.     

Socket size adjustments in people with transtibial amputation: Effects on residual limb fluid volume and limb-socket distance

BackgroundSmall intermittent adjustments of socket size using adjustable sockets may be a means for people with transtibial amputation to better maintain residual limb fluid volume and limb position while using a prosthesis.MethodsSocket size, limb fluid volume, and distance from the limb to the socket, termed “sensed distance,” were recorded while participants with transtibial amputation walked on a treadmill wearing a motor-driven, cabled-panel, adjustable socket. Researchers made frequent socket size adjustments using a mobile phone app to identify participants' acceptable socket size range. Limb fluid volume and sensed distance were then monitored as incremental adjustments were made to the socket.FindingsProsthesis users in this study (n = 10) accepted socket sizes between −5% and +5% of their neutral socket volume. There was a rapid increase in limb fluid volume and sensed distance upon socket enlargement, and a rapid decrease upon reduction. Subsequently, there were gradual changes in fluid volume and sensed distance. While visually monitoring limb fluid volume data in real time, researchers were able to adjust socket size to maintain consistent limb fluid volume within a −0.7% to +0.9% volume change for 24 min.InterpretationParticipant residual limbs compensated to socket size adjustment. Using socket-mounted sensors to monitor limb-socket mechanics, an automatic adjustable socket that maintains limb fluid volume may be possible and may improve socket fit in instances where fit deteriorates during use.     

小腿假肢接受腔-残肢生物机械系统三维重构

目的：建立小腿假肢接受腔-残肢生物机械系统三维几何模型。方法：以一名25岁男性小腿截肢患者为对象，采用三维坐标测量和核磁共振成像获得原始数据，利用软件MIMICS、SURFACER、SOLIDWORKS等实现了接受腔和残肢的三维重构．并根据接受腔修型模式等完成了系统装配。结果：数字化三维模型较精确的反映了接受腔-残肢系统的几何特征。结论：这种低成本方法可用于假肢数字化设计、有限元分析和计算机辅助制造。     

The Trinity Amputation and Prosthesis Experience Scales and quality of life in people with lower-limb amputation

OBJECTIVES: To undertake preliminary research into quality of life (QOL) for a group of people with a lower-limb amputation and to investigate what aspects of the "prosthetic experience" are most strongly associated with QOL using the Trinity Amputation and Prosthesis Experience Scales (TAPES). DESIGN: Cross-sectional survey. SETTING: Prosthetic limb fitting center. PARTICIPANTS: Sixty-three people older than 18 years with unilateral lower-limb amputation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The TAPES and the World Health Organization Quality of Life Questionnaire-Brief Version. RESULTS: There were no significant differences in any of the QOL domain scores (physical health, psychological, social relationships, environmental) arising from age, gender, level of amputation, or cause of amputation. However, there were significant differences depending on the length of time living with the prosthesis and the degree of prosthetic use. Stepwise regression identified different significant predictors for each domain of QOL. CONCLUSIONS: These findings support the claim that the TAPES can be used to evaluate QOL for this patient group. Further research is warranted to learn how sensitive the scale and its items are to change in clinical status.     

Comparison of transhumeral socket designs utilizing patient assessment and in vivo skeletal and socket motion tracking: a case study

Purpose: This case study compares the impact of two prosthetic socket designs, a “traditional” transhumeral (TH) socket design and a Compression Released Stabilized (CRS) socket. Methods: A CRS socket was compared to the existing socket of two persons with transhumeral amputation. Comparisons included assessments of patient comfort and satisfaction with fit, as well as dynamic kinematic assessment using a novel high-speed, high-resolution, bi-plane video radiography system (XROMM, for X-ray Reconstruction of Moving Morphology). Results: Subjects were more satisfied with the comfort of the traditional sockets, although they had positive impressions about aspects of the fit and style of the CRS socket, and thought that it provided better control. Dynamic kinematic assessment revealed that the CRS socket provided better control of the residual limb within the socket, and had less slippage as compared to a traditional TH socket design. Conclusions: The TH CRS socket provided better control of the residual limb within the socket, and had less slippage. However, participants were less satisfied with the comfort and overall utility of the CRS socket, and stated that additional fitting visits/modifications to the CRS socket were needed. It is possible that satisfaction with the CRS socket may have improved with prosthetic adjustment and more acclimation time.

• Implications for Rehabilitation

• A comfortable, good fitting prosthetic socket is the key factor in determining how long (or if) an upper limb amputee can tolerate wearing a prosthesis.

• This case series was a comparison of two socket designs, a 'traditional' socket design and a Compression Released Stabilized (CRS) socket design in persons with transhumeral amputation.

• The CRS socket provided better control of the residual limb within the socket, and had less slippage. However, its tightness made it more difficult to don.

• Both subjects were less satisfied with the comfort and overall utility of the CRS socket. However, satisfaction might have been improved with additional fitting visits and more acclimation time.

     

Investigation of lower-limb tissue perfusion during loading

An extant tissue indentor used for amputee residual limb tissue indentation studies was modified to include laser Doppler flowmetry (LDF) to enable measurement of tissue perfusion during indentation. This device allows quantitative assessment of the mechanical and physiological response of soft tissues to load, as demonstrated by indentation studies of the lower-limb tissues of young healthy subjects. Potential measures of interest include the relative change in tissue perfusion with load and the time delays associated with the perfusion response during tissue loading and unloading. Such measures may prove useful in future studies of residual limb tissues, improving our understanding of tissue viability risk factors for individuals with lower-limb amputation.     

Walking and balance in children and adolescents with lower-limb amputation: A review of literature

BackgroundChildren with lower limb loss face gait and balance limitations. Prosthetic rehabilitation is thus aimed at improving functional capacity and mobility throughout the developmental phases of the child amputee. This review of literature was conducted to determine the characteristics of prosthetic gait and balance among children and adolescents with lower-limb amputation or other limb loss.MethodsBoth qualitative and quantitative studies were included in this review and data were organized by amputation etiology, age range and level of amputation.FindingsThe findings indicated that the structural differences between children with lower-limb amputations and typically developing children lead to functional differences. Significant differences with respect to typically developing children were found in spatiotemporal, kinematic, and kinematic parameters and ground-reaction forces. Children with transtibial amputation place significantly larger load on their intact leg compared to the prosthetic leg during balance tasks. In more complex dynamic balance tests, they generally score lower than their typically developing peers.InterpretationThere is limited literature pertaining to improving physical therapy protocols, especially for different age groups, targeting gait and balance enhancements. Understanding gait and balance patterns of children with lower-limb amputation will benefit the design of prosthetic components and mobility rehabilitation protocols that improve long-term outcomes through adulthood.     

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.     

Pain site and impairment in individuals with amputation pain

OBJECTIVE: To determine the association between pain site and pain interference with activities of daily living (ADLs) among persons with acquired amputation. DESIGN: Survey. SETTING: Community-based survey from clinical databases, flyer postings, and an advertisement in the inMotion magazine. PARTICIPANTS: Persons with lower-limb amputations (N=478). INTERVENTIONS: Six or more months after lower-limb amputation, participants completed an amputation pain questionnaire that included several standardized pain measures. MAIN OUTCOME MEASURES: Numeric rating scale measures of average phantom limb, residual limb, and back pain and pain-related impairment as measured by a modified version of the Pain Interference Scale of the Brief Pain Inventory. RESULTS: Phantom limb, residual limb, and back pain intensity ratings, as a group, accounted for 20% of the variance in pain interference. The pain intensity ratings associated with each individual pain site made a statistically significant contribution to the prediction of pain interference with ADLs even after controlling for the pain intensity of the other 2 sites. CONCLUSIONS: Pain in each of 3 sites (phantom limb, residual limb, back) appears to be important to pain-related impairment and function. Measurement of the intensity of pain at each site appears to be required for a thorough assessment of amputation pain-related impairment.     

Volume changes occurring in postoperative below-knee residual limbs

Comparative maturation rates of 36 below-knee postoperative, healed amputation residual limbs were observed. Measured were the limb volumes and circumferences. Three methods of residual limb stabilization were employed: 1) elastic wrap; 2) plaster cast and pylon; and, 3) plastic laminate socket and pylon. The limbs receiving the plastic laminate showed the most rapid stabilization, while the elastic wrap did not stabilize. Considerable variance existed in relations between variables. Correlation between limb circumference and volume was poor. However, in general, the rates of change, i.e., the relations between volume and time, and circumference and time, were statistically significant (p less than .05).     

A quasi-dynamic nonlinear finite element model to investigate prosthetic interface stresses during walking for trans-tibial amputees

BACKGROUND: To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. METHODS: A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. RESULTS: Interface pressure distribution was found to have the same profile during walking. The high pressures fall over popliteal depression, middle patella tendon, lateral tibia and medial tibia regions. Interface pressure predicted by static or quasi-dynamic analysis had the similar double-peaked waveform shape in stance phase. INTERPRETATION: The consideration of inertial effects and motion of knee joint cause 210% average variation of the area between the pressure curve and the horizontal line of pressure threshold between two cases, even though there is only a small change in the peak pressure. The findings in this paper show that the coupling dynamic effects of inertial loads and knee flexion must be considered to study interface pressure between residual limb and prosthetic socket during walking.     

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.     

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.