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BACKGROUND: The risk of tripping in people with amputation is greater than that of able-bodied individuals due to reduced toe clearance during the swing phase. Appropriate prosthetic suspension may increase toe clearance by providing more secured attachment between the residual limb and prosthetic socket. Research is lacking on the Unity suspension system's effect on swing toe clearance. METHODS: Twelve people with transtibial amputation were fitted with the Unity suspension system. After one month accommodation period, the person walked with active (ON) or inactive vacuum (OFF) in a CAREN-Extended virtual reality system, across multiple simulated real-world scenarios. Prosthetics minimum swing toe clearance, and kinematic data, while the vacuum was ON or OFF, were compared with the intact side and a group of 12 able-bodied individuals. RESULTS: Minimum swing toe clearance (MSTC) and knee flexion angle were larger on the prosthetic side (active and inactive vacuum) compared to both the intact side and the control group. However, hip flexion angle on the prosthetic side was approximately 17% smaller than the control group. Unlike the control group, MSTC with active and inactive vacuum suspension was not significantly different between level walking and other walking conditions. Finally, among all walking conditions, the lowest swing toe clearance for both control and the amputee groups was recorded when the limb was at the top of a side-slope. CONCLUSION: An effective suspension system could improve toe clearance; however, significant differences were not found between active and inactive vacuum conditions. The likelihood of inappropriate foot contact on side-slope ground might be greater than other walking conditions for both able-bodied and amputee groups, possibly leading to stumbling or falling.

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BACKGROUND: A posterior dynamic element ankle-foot orthosis (PDEAFO) uses a stiff carbon fibre strut to store and release energy during various mobility tasks, with the strut securely attached to the foot and shank-cuff sections. A design that allows the user to swap struts for specific activities could improve mobility by varying PDEAFO stiffness, but current approaches where bolts securely connect the strut to the orthosis make quick strut swapping time-consuming and impractical. OBJECTIVES: Design a novel quick release AFO (QRAFO) that can enable daily living strut-swapping and thereby enable better ankle biomechanics for the person's chosen activity. METHODOLOGY: The novel QRAFO enables device stiffness changes through a quick release mechanism that includes a quick-release key, weight-bearing pin, receptacle anchor, and immobilization pin. A prototype was modelled and simulated with SolidWorks. Mechanical tests were performed with an Instron 4482 machine to evaluate quick release mechanism strength with running and 20° slope downhill walking loads. Quick release efficiency was then evaluated via two quick release functional tests, with four participants wearing a 3D printed QRAFO. FINDINGS: Simulated stress on the weight bearing pin, anchor, and surrounding carbon fibre structure under running and downhill walking loads did not exceed the yielding stress. Mechanical tests verified the simulation results. Four participants successfully swapped the strut within 25.01 ± 3.66 seconds, outperforming the 60.48 ± 10.88 seconds result for the hand-tightened bolted strut. A learning evaluation with one participant showed that, after approximately 30 swapping iterations, swap time was consistently below 10 seconds. CONCLUSION: The quick release mechanism accommodated running and slope walking loads, and allowed easy and fast strut removal and attachment, greatly reducing strut swap time compared to screw-anchor connections. Overall, the novel quick release AFO improved strut-swapping time without sacrificing device strength, thereby enabling people to use the most appropriate AFO stiffness for their current activity and hence improve mobility and quality of life.

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Ankle-foot orthoses (AFO) are devices that assist lower limb motion. Mechanical testing an AFO would ideally load the device while worn on the leg, since AFO function is dependent on intimate leg contact. However, this is not appropriate for cyclic or load-to-failure applications. A surrogate lower limb (SLL) was designed for this AFO testing application, to provide anthropometric 3D movement when subjected to standard test loads. This novel four-joint SLL was inspired by the Rizzoli foot model, which segments the lower limb into five sections. SLL joint prototypes were validated by measuring rotation angles and comparing with typical anatomical ranges of motion. The 3D printed models were within acceptable variability of human joint movement and, therefore, were appropriate for use in the final SSL.

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Study Design: Experimental study.Objectives: Research is lacking on the Unity suspension system's effect on gait performance. The purpose of this study was to evaluate the effects of the Unity elevated vacuum system on level walking performance while the vacuum was active (ON) and inactive (OFF).Methods: Twelve unilateral transtibial amputees were fit with the Ossur elevated vacuum suspension system (Unity) and Pro-flex XC foot. After one month accommodation period, 3D motion analysis was performed using the CAREN-Extended system. Temporal-spatial, kinematics, and kinetics were examined during level walking to understand the effect of the elevated vacuum, separate trials were completed with the vacuum active (ON) or inactive (OFF).Results: Significant differences were found between vacuum conditions (ON and OFF) for some temporal-spatial gait parameters, but differences were very small and may not be clinically significant. Differences between vacuum conditions on most kinetic and kinematic gait parameters were also low. However, step length symmetry between intact and prosthetic limbs improved with active elevated vacuum (ON).Conclusions: Elevated vacuum suspension's effect on level walking gait is small if a well-fitting liner-based socket is provided.Implications for rehabilitationStep length symmetry between intact and prosthetic limbs improved with an active vacuum system.Differences between vacuum conditions on most gait parameters were small during level walking.Subjective feedback showed improved proprioception and comfort with an active vacuum system.

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BACKGROUND: Small residual limb-socket displacement is a good indicator of prosthetic suspension system quality. Active vacuum suspension systems can decrease vertical movement inside the socket, compared to non-active suction systems. This study mechanically evaluated limb-socket displacement with the Össur Unity active vacuum system. METHOD: Forty-eight conditions were evaluated: four cylindrical and four conical sockets (polypropylene, polyethylene terephthalate glycol-modified (PETG), thermoset resin (acrylic), Thermolyn soft materials); two Iceross Seal-In V liners (standard, high profile); three vacuum conditions (active vacuum, inactive vacuum, no suction with valve open). An Instron 4428 test machine applied 0-100N linear ramped tensile loads to each positive mold, with the socket secured in place, while displacement between the mold and socket was recorded. Following the displacement tests, the load before failure (i.e., 10 mm displacement) was measured. RESULTS: Average and standard deviations for movement between the mold and sockets were small. The displacement average for all conditions was 0.30±0.16mm for active vacuum, 0.32±0.16mm for inactive vacuum, and 0.39±0.22mm for no suction. Across all trials, active vacuum systems tolerated significantly (p<0.001) more load before failure (812±221N) compared to inactive vacuum (727±213N), and no suction (401±184N). The maximum load before failure (1142±53N) was for the cylindrical polypropylene socket and high-profile liner. CONCLUSION: The Unity system successfully controlled pistoning inside the socket for regular activity loads and also controlled the greatest traction loads. While relative movement was smallest for Unity, all conditions (inactive vacuum, no suction) were viable for loads less than 100N. Furthermore, similar results can be achieved when using different socket fabrication materials.

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BACKGROUND: An optimal suspension system can improve comfort and quality of life in people with limb loss. To guide practice on prosthetic vacuum suspension systems, assessment of the current evidence and professional opinion are required. METHODS: PubMed, Web of Science, and Google Scholar databases were explored to find related articles. Search terms were amputees, artificial limb, prosthetic suspension, prosthetic liner, vacuum, and prosthesis. The results were refined by vacuum socket or vacuum assisted suspension or sub-atmospheric suspension. Study design, research instrument, sample size, and outcome measures were reviewed. An online questionnaire was also designed and distributed worldwide among professionals and prosthetists (www.ispoint.org, OANDP-L, LinkedIn, personal email). FINDINGS: 26 articles were published from 2001 to March 2016. The number of participants averaged 7 (SD=4) for transtibial and 6 (SD=6) for transfemoral amputees. Most studies evaluated the short-term effects of vacuum systems by measuring stump volume changes, gait parameters, pistoning, interface pressures, satisfaction, balance, and wound healing. 155 professionals replied to the questionnaire and supported results from the literature. Elevated vacuum systems may have some advantages over the other suspension systems, but may not be appropriate for all people with limb loss. INTERPRETATION: Elevated vacuum suspension could improve comfort and quality of life for people with limb loss. However, future investigations with larger sample sizes are needed to provide strong statistical conclusions and to evaluate long-term effects of these systems.

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BACKGROUND: Mobile health monitoring using wearable sensors is a growing area of interest. As the world's population ages and locomotor capabilities decrease, the ability to report on a person's mobility activities outside a hospital setting becomes a valuable tool for clinical decision-making and evaluating healthcare interventions. Smartphones are omnipresent in society and offer convenient and suitable sensors for mobility monitoring applications. To enhance our understanding of human activity recognition (HAR) system performance for able-bodied and populations with gait deviations, this research evaluated a custom smartphone-based HAR classifier on fifteen able-bodied participants and fifteen participants who suffered a stroke. METHODS: Participants performed a consecutive series of mobility tasks and daily living activities while wearing a BlackBerry Z10 smartphone on their waist to collect accelerometer and gyroscope data. Five features were derived from the sensor data and used to classify participant activities (decision tree). Sensitivity, specificity and F-scores were calculated to evaluate HAR classifier performance. RESULTS: The classifier performed well for both populations when differentiating mobile from immobile states (F-score > 94 %). As activity recognition complexity increased, HAR system sensitivity and specificity decreased for the stroke population, particularly when using information derived from participant posture to make classification decisions. CONCLUSIONS: Human activity recognition using a smartphone based system can be accomplished for both able-bodied and stroke populations; however, an increase in activity classification complexity leads to a decrease in HAR performance with a stroke population. The study results can be used to guide smartphone HAR system development for populations with differing movement characteristics.

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An improved understanding of factors related to dynamic stability in lower-limb prosthesis users is important, given the high occurrence of falls in this population. Current methods of assessing stability are unable to adequately characterize dynamic stability over a variety of walking conditions. F-Scan Mobile has been used to collect plantar pressure data and six extracted parameters were useful measures of dynamic stability. The aim of this study was to investigate dynamic stability in individuals with unilateral transtibial amputation based on these six parameters. Twenty community ambulators with a unilateral transtibial amputation walked over level ground, uneven ground, stairs, and a ramp while plantar pressure data were collected. For each limb (intact and prosthetic) and condition, six stability parameters related to plantar center-of-pressure perturbations and gait temporal parameters, were computed from the plantar pressure data. Parameter values were compared between limbs, walking condition, and groups (unilateral transtibial prosthesis users and able-bodied subjects). Differences in parameters were found between limbs and conditions, and between prosthesis users and able-bodied individuals. Further research could investigate optimizing parameter calculations for unilateral transtibial prosthesis users and define relationships between potential for falls and the dynamic stability measures.

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A web-based transitional health record was created to provide regional healthcare professionals with ubiquitous access to information on people with brain injuries as they move through the healthcare system. Participants included public, private, and community healthcare organizations/providers in Eastern Ontario (Canada). One hundred and nineteen service providers and 39 brain injury survivors registered over 6 months. Fifty-eight percent received English and 42% received bilingual services (English-French). Public health providers contacted the regional service coordinator more than private providers (52% urban centres, 26% rural service providers, and 22% both areas). Thirty-five percent of contacts were for technical difficulties, 32% registration inquiries, 21% forms and processes, 6% resources, and 6% education. Seventeen technical enquiries required action by technical support personnel: 41% digital certificates, 29% web forms, and 12% log-in. This web-based approach to clinical information sharing provided access to relevant data as clients moved through or re-entered the health system. Improvements include automated digital certificate management, institutional health records system integration, and more referral tracking tools. More sensitive test data could be accessed on-line with increasing consumer/clinician confidence. In addition to a strong technical infrastructure, human resource issues are a major information security component and require continuing attention to ensure a viable on-line information environment.

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A Write-Once Publish-Everywhere model was used to create and deliver on-line clinical training and education for undergraduate prosthetics and orthotics students. This project consisted of three phases: developing multimedia learning and teaching tools, integrating these tools into the curriculum (combination of e-Learning and live practical sessions), and evaluating the outcomes. Video-based multimedia contents were captured and integrated with graphic, audio and text into a PowerPoint presentation software format. The web-based content was integrated into the WebCT platform for course management. Questionnaires were used to obtain student feedback on this e-Learning approach. Results were compared within the prosthetics and orthotics (P&O) programme, with other Health Sciences programmes, and overall with the University. P&O student responses were significantly higher than other groups for career relevance and problem solving. Qualitative feedback indicated that students appreciated the easy access, integrated and interactive approach of the text materials, concise PowerPoint presentation, demonstration video and the on-line case discussion via the WebCT platform. Educators appreciated the ability easily to maintain contents and publish the modules across multiple media without recreating the contents.

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Telehealth has the potential to be a valuable tool for technical and clinical support of computer controlled prosthetic devices. This pilot study examined the use of Internet-based, desktop video conferencing for remote configuration of the Otto Bock C-Leg. Laboratory tests involved connecting two computers running Microsoft NetMeeting over a local area network (IP protocol). Over 56 Kbs(-1), DSL/Cable, and 10 Mbs(-1) LAN speeds, a prosthetist remotely configured a user's C-Leg by using Application Sharing, Live Video, and Live Audio. A similar test between sites in Ottawa and Toronto, Canada was limited by the notebook computer's 28 Kbs(-1) modem. At the 28 Kbs(-1) Internet-connection speed, NetMeeting's application sharing feature was not able to update the remote Sliders window fast enough to display peak toe loads and peak knee angles. These results support the use of NetMeeting as an accessible and cost-effective tool for remote C-Leg configuration, provided that sufficient Internet data transfer speed is available.

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A rehabilitation outreach team created evidence-based and peer-reviewed educational modules using standard desktop presentation software. Eighteen modules on various topics in physical rehabilitation were published in several formats, including Web pages, directly from the presentation file, for the benefit of health-care providers in eastern and north-eastern Ontario. An online evaluation form could be completed by anyone visiting the Website; the people responsible for community rehabilitation services were asked to encourage their staff to complete the forms. A total of 174 forms were received. The module 'Principles of transfers for health-care workers' accounted for 18% of the evaluations and the module 'Assisted range-of-motion exercises for arms and legs to maintain joint flexibility' accounted for 14%. Thirty-nine per cent of respondents were registered nurses, 13% were physiotherapists and 26% were people with disabilities. Thirty per cent of the participants had limited or no experience with online learning. In the evaluation, high ratings were given for satisfaction and usefulness. From an educator's perspective, multimedia content could be created and distributed without a substantial investment in equipment, software, training and publication time; this represents a 'write once, publish everywhere' approach.

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Low-bandwidth, Internet-based videoconferencing was used to provide physical rehabilitation consultation services for eight community hospitals. Videoconferencing and file transmission used a PC and modem. A separate telephone line was used for voice. Over 21 months, 47 physical rehabilitation consultations were completed for communication disorders, foot care, gait problems, orthotics, prosthetics, arm weakness and wheelchair prescription. Consultations were approximately 40 min long. Clinician questionnaires were completed by 47 individuals. While more than 80% of the questionnaire responses supported the telemedicine approach, remote clinicians rated their satisfaction higher than did the specialists. Client questionnaires were completed by 24 individuals (a response rate of 51%). All clients were comfortable with and had confidence in the teleconsultations.

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Vertical plantar forces are known to be a major precipitating factor in the development of foot pathology. It is also postulated that shear forces are important in the pathogenesis of foot ulcers in patients with diabetes mellitus. Various materials are used in insoles designed to reduce forces on the foot. While many foam materials have been tested for their ability to dissipate vertical forces, few studies have tested the effect of these materials on shear forces. This study assessed the effectiveness of five different materials in reducing plantar shear forces and compared two new gel materials with three of the more conventional foam materials. Four subjects were tested while walking over a force platform with one of the five materials taped to the surface. Peak force, impulse, and resultant shear force data were analyzed. The gel materials were significantly better than the foam materials at reducing shear forces. Thus the use of gel materials in insoles may be indicated for the reduction of plantar shear forces on the diabetic foot.

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A low-bandwidth telemedicine system was evaluated in eight community hospitals connected to a central hospital via the Internet. PCs were used with videoconferencing software and modem connections to the telephone network. The average data connection rates, still-image transfer times and live-video transmission rates were determined. The time to send 640 x 480, 320 x 240 and 160 x 120 pixel, 24-bit still images ranged from 29 s to 411 s. The average file transfer times for a 10 s MPEG video-clip was 8.6 min. The average live video frame rate was 1 frame/s (at the best image quality), with an average latency of 3 s. The results suggest that Internet-based videoconferencing is acceptable for certain telemedicine applications.

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OBJECTIVE: To test a prosthetic simulator developed to allow persons without amputation to walk like a person with a transfemoral (TF) amputation. PATIENTS: Five able-bodied subjects; comparison with data from the literature on persons with TF amputations. SETTING: Motion analysis laboratory. DESIGN: Two 45- to 60-minute gait training sessions before subjects walked along a 10-meter walkway. There were 6 trials: 3 walking with a cane, 3 without a cane. MAIN OBJECTIVE MEASURES: Sagittal plane kinematic and kinetic analysis of ankle, knee, and hip: angular velocity, joint moment, and power. RESULTS: Kinematic and kinetic analyses showed that joint mechanics during walking were similar between the test subjects and comparative results from persons with TF amputations (reported in the literature). Test subjects walked slower and moved their hip and knee joints faster (higher angular velocity values during the terminal swing) than the TF amputee subjects, although these results were not statistically significant (p < .05). These findings were consistent with new prosthetic users who are more tentative during gait training. However, a perfect simulation would show no difference in kinematic results. CONCLUSION: These results support the use of a TF prosthetic simulator to help health care professionals experience the process of fitting the prosthesis from the client's perspective.

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UNLABELLED: Ambulatory assistive device use can improve functional independence following spinal cord injury and, potentially, quality of life. However, the interaction between aids and user in this population is poorly understood. OBJECTIVES: To determine the influence of walkers, crutches and canes on assisted-gait following incomplete spinal cord injury. STUDY DESIGN/METHODS: Outcome parameters evaluated in ten individuals included orthogonal forces exerted on instrumented assistive devices, walking speed, cadence, step length, trunk and thigh angles, as well as knee and ankle joint angles. Kinetic data included axial compressive force, and medio/lateral and antero/posterior bending forces. SETTING: Canada. RESULTS: Results indicated that walkers (n= 5) provided the greatest vertical support (up to 100% body weight), but resulted in slow gait with a forward flexed posture. Elbow crutch users (n = 3) walked faster (greater step length and cadence) and had a more upright posture than the walker users. Crutches supported up to 50% of the subject's body weight, granted lateral stability, and provided restraint in the antero/posterior direction. Canes (n = 2) offered restraining and propulsive assistance, some lateral stability, and the least amount of vertical support. CONCLUSION: Ambulatory devices affected posture and walking speed while fulfilling various assistive functions during locomotion. The conclusion drawn is that rehabilitation specialists are advised to match device characteristics to user needs when prescribing walking aids. SPONSORSHIP: Natural Sciences and Engineering Research Council of Canada (NSERC).

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A quantitative method was developed for defining manual socket modifications, averaging these modifications over a series of amputees, and using the average modifications as a template in commercial CAD/CAM systems. The CADVIEW programme (i.e. software for viewing and analysing CAD sockets) was rewritten to provide comparison functions for aligning sockets to a common axis, visualising the differences between sockets, generating modification outlines, assigning apex point values, and averaging the modification outlines. A CAD template generated in this manner should be the best general representation of a prosthetist's modification style. To test this hypothesis, 13 people with trans-tibial amputations were fitted with both a manual and a CAD/CAM socket. Questionnaires were completed by the subjects and by the prosthetist to obtain information on prosthetic comfort, function, and overall satisfaction. Ground reaction force and stride parameter data were also collected for each prosthesis during gait laboratory testing. No significant differences were found between the manually designed socket and the CAD/CAM designed socket for all data except the vertical peak forces on the amputated side. These results support the clinical application of this quantitative technique for making the transition from manual to CAD/CAM prosthetic modification procedures.

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A model for performing remote orthotic assessments using low-bandwidth computer communication technology (video conferencing) was developed, tested, and evaluated. System evaluation involved comparing a series of remote assessments with on-site assessments. While most on-site and on-line results were similar, discrepancies which occurred were attributed to between-clinician differences, measurement technique differences, technical and learning obstacles at the start of the project, and within subject variations during the day. On-line assessment efficiency improved with each on-line session and corresponded with increased confidence in the system, easier system use, and better overall satisfaction. An on-line debriefing session was held with all project clinicians. These clinicians supported continued use of the communication system for rehabilitation consultation and education. Clinically. preliminary face-to-face meetings and a regular practice schedule were recommended. Technically, the system was considered good; however, suggested improvements included using a high quality speaker-phone system, streamlining the video capture process, and providing more reliable telecommunication connections.

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Manually designed prosthetic sockets are difficult to evaluate since the hand-sculpting modification process does not retain the initial shape for comparison. A quantitative method for defining and comparing manual socket modifications was developed and integrated into the CADVIEW software package. The numerical comparison procedure consisted of a) digitizing premodification and post-modification models of a prosthetic socket, b) aligning these two shapes to a common axis (calculate cross section centroids, determine line of best fit through the centroids, rotate and move the line of best fit to a common axis), and c) displaying the differences in shape both numerically and using a color-coded three dimensional image. Alignment technique testing showed a between-radial-point average error of 2.5 mm using automatic alignment and 1.4 mm after further manual alignment adjustment. The between socket difference values were used to outline individual modifications and save these outlines to disk. Modification outlines from a series of patients were averaged to determine a prosthetist's general modification style. Averaged results from two prosthetists qualitatively supported the effectiveness of this procedure. This alignment and comparison system should help transfer hand-sculpting skills to prosthetic CAD/CAM systems, clinical research, and education for new clinicians.

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