Syme Amputation: Function, Satisfaction, and Prostheses.

BACKGROUND: Syme amputation (SA) is a term used to describe an amputation at the level of the ankle joint in which the heel pad is preserved. It is performed for a number of indications in a pediatric population. SA is purported to hold the advantage of allowing weight bearing without a prosthesis. A limb length discrepancy (LLD) is useful for ambulation without a prosthesis but can be restrictive with regards to the fitting of modern prostheses. METHODS: A voluntary survey was distributed to persons living with SA. Recruitment occurred through hospital electronic database and electronic advertising. Data collected included baseline demographic information, data pertaining to weight bearing in different environments, as well as 2 validated outcome measures: the Trinity Amputation and Prosthesis Experience Scales-Revised (TAPES-R activity restriction scale) and the Locomotor Capabilities Index-5 (LCI-5). An illustration was designed to allow participants to classify their LLD by zone in relation to their nonamputated limb. RESULTS: At total of 47 persons living with SA participated. The average age at amputation was 3.7 years (range, 0.5 to 14.1 y), and at survey completion 15.8 years (1.7 to 60.3). Five of the described "zones" of LLD were represented. Average LCI-5 score was 52.6. Mean TAPES-R activity restriction scale was 0.59, the lowest mean being achieved by zone E participants, indicating the least restriction. Ability to walk without a prosthesis was lower in those participants over 11 years, when compared with those under, as well as being dependent on the walking environment. CONCLUSIONS: Our study found no trend indicating that a very low LLD was functionally optimal, and indeed found participants with a moderate LLD (zone E) to have the least mean restriction with regard to their prosthesis. Our study demonstrates that ambulation without a prosthesis depends on the environment (ie, flooring), and rates decrease significantly into adulthood. Optimal care should not focus simply "preserving length," but rather functional optimization and length modulation in parallel with a nuanced understanding of actual daily activities and prosthetic options. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Transplants for non-lethal conditions: a case against hand transplantation in minors.

Human allografts for life-threatening organ failure have been demonstrated to be lifesaving and are now considered to be standard of care for many conditions. Transplantation of non-vital anatomic body parts has also been accomplished. Hand transplantation after limb loss in adults has been shown to offer some promising benefits in both functional and psychological measures in preliminary studies. It has been suggested to expand eligibility criteria to include minors, with one such operation having already been performed. With this in mind, we examine the current state of hand transplantation research in the context of available alternatives. We examine the ethics of carrying out these operations in minors, including under the protections of clinical research. We argue that children should not be considered for this surgery due to the substantial risks of immunosuppressive medication, the likelihood that the graft will need to be replaced during the patient's lifetime and the lack of significant compensatory advantages over modern prosthetics.

State of the Art: Amputation and Prosthetics.

Amputation is not a defeat or failure of treatment, but an effective management strategy for certain conditions in the pediatric population. The principles of management, especially in the pediatric population, have not changed. Current surgical strategies focus on providing an optimal residual limb for prosthetic fitting. New technology provides improvement in the design and fabrication of prosthetic devices.

Hands-off and hands-on casting consistency of amputee below knee sockets using magnetic resonance imaging.

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit.

The role of feed-forward and feedback processes for closed-loop prosthesis control.

BACKGROUND: It is widely believed that both feed-forward and feed-back mechanisms are required for successful object manipulation. Open-loop upper-limb prosthesis wearers receive no tactile feedback, which may be the cause of their limited dexterity and compromised grip force control. In this paper we ask whether observed prosthesis control impairments are due to lack of feedback or due to inadequate feed-forward control. METHODS: Healthy subjects were fitted with a closed-loop robotic hand and instructed to grasp and lift objects of different weights as we recorded trajectories and force profiles. We conducted three experiments under different feed-forward and feed-back configurations to elucidate the role of tactile feedback (i) in ideal conditions, (ii) under sensory deprivation, and (iii) under feed-forward uncertainty. RESULTS: (i) We found that subjects formed economical grasps in ideal conditions. (ii) To our surprise, this ability was preserved even when visual and tactile feedback were removed. (iii) When we introduced uncertainty into the hand controller performance degraded significantly in the absence of either visual or tactile feedback. Greatest performance was achieved when both sources of feedback were present. CONCLUSIONS: We have introduced a novel method to understand the cognitive processes underlying grasping and lifting. We have shown quantitatively that tactile feedback can significantly improve performance in the presence of feed-forward uncertainty. However, our results indicate that feed-forward and feed-back mechanisms serve complementary roles, suggesting that to improve on the state-of-the-art in prosthetic hands we must develop prostheses that empower users to correct for the inevitable uncertainty in their feed-forward control.

Walking kinematics in young children with limb loss using early versus traditional prosthetic knee prescription protocols.

The traditional treatment protocol for young children with congenital or acquired amputations at or proximal to the knee prescribes a prosthesis without a working knee joint, based in part on the assumption that a child learning to walk cannot properly utilize a passively flexing prosthetic knee component. An alternative to this Traditional Knee (TK) protocol is an "Early Knee" (EK) protocol, which prescribes an articulating prosthetic knee in the child's first prosthesis, during development of crawling and transitioning into and out of upright positions. To date, no study has compared samples of children with limb loss at or proximal to the knee using TK and EK protocols. The purpose of this multi-site study was to examine kinematic outcomes during walking in separate groups of young children in an EK and a TK prosthesis protocol, along with a population of children without lower limb amputations. Eighteen children aged 12 months to five years were recruited for this study at two clinical sites, six in each of the three groups. Children in the two prosthesis groups had unilateral limb loss and had been treated either at one site with the TK protocol or at another with the EK protocol. Children in the EK group achieved swing phase prosthetic knee flexion averaging 59.8±8.4 degrees. Children wearing prosthetic limbs walked slower than age-matched peers. In most instances, walking speed and step length increased with age in the EK group, similar to the control group. However, this trend was not observed in the TK group. Clearance adaptations were present in both limb loss groups. Observed adaptations were twice as prevalent in the TK group versus the EK group; however, the groups differed in age and etiology. Children with limb loss provided with an articulating knee component in their first prosthesis incorporated knee flexion during swing phase and showed fewer gait adaptations than children in the TK protocol.

Minimum toe clearance and tripping probability in people with unilateral transtibial amputation walking on ramps with different prosthetic designs.

BACKGROUND: Minimum Toe Clearance (MTC) is defined as the minimum vertical distance between the lowest point under the front part of the foot and the ground, during mid-swing. Low values of MTC and walking on inclines are both related to higher probability of tripping and falling in lower limb amputees. New prosthetic designs aim at improving MTC, especially on ramps, however the real effect on MTC still needs investigation. The objective of this study was then to evaluate the effect of different prosthetic designs on MTC in inclined walking. METHODS: Thirteen transtibial amputees walked on a ramp using three different prostheses: non articulating ankle (NAA), articulating hydraulic ankle (AHA), and articulating hydraulic ankle with microprocessor (AHA-MP). Median MTC, coefficient of variation (CV), and tripping probability (TP) for obstacles of 10 and 15 mm were compared across ankle type in ascent and descent. FINDINGS: When using AHA-MP, larger MTC median values for ascending (P ≤ 0.001, W = 0.58) and descending the ramp (P = 0.003, W = 0.47) were found in the prosthetic limb. Also significantly lower CV was found on the prosthetic limb for both types of AHA feet when compared to NAA for descending the ramp (P = 0.014, W = 0.45). AHA-MP showed the lowest TP for the prosthetic leg in three conditions evaluated. On the sound limb results showed the median MTC was significantly larger (P = 0.009, W = 0.43) and CV significantly lower (P = 0.005, W = 0.41) when using an AHA in ascent. INTERPRETATION: Both AHA prosthetic designs help reduce the risk of tripping of the prosthetic limb by increasing the median MTC, lowering its variability and reducing TP for both legs when ascending and descending the ramp. For most of the conditions, AHA-MP showed the lowest TP values. Findings suggest that AHA prostheses, especially AHA-MP could reduce the risk of tripping on ramps in amputees.

Running-specific prostheses reduce lower-limb muscle activity compared to daily-use prostheses in people with unilateral transtibial amputations.

People with unilateral transtibial amputation (TTA) have biomechanical differences between the amputated and intact legs and compared to people without TTA during running. Additional biomechanical differences emerge between running with running-specific (RSPs) and daily-use prostheses (DUPs), but the associated underlying muscle activity is unclear. We collected surface electromyography from the biceps femoris long head, rectus femoris, vastus lateralis, and gastrocnemius as well as body kinematics and ground reaction forces in six people with and six people without TTA. We compared stance phase muscle activity and peak activation timing in people with and without TTA and between people using RSPs compared to DUPs during running at 3.5 m/s. Peak amputated leg hamstring activity occurred 34% (RSP) and 31% (DUP) earlier in stance phase compared to the intact leg. Peak amputated leg rectus femoris activity of people wearing DUPs occurred 8% and 9% later in stance phase than the intact leg of people wearing DUPs and amputated leg of people wearing RSPs, respectively. People with TTA had 45% (DUP) and 61% (RSP) smaller peak amputated leg knee extension moments compared to people without TTA, consistent with observations of quadriceps muscle activity. Using RSPs decreased overall muscle activity compared to DUPs.

Upper extremity prosthetic selection influences loading of transhumeral osseointegrated systems.

Percutaneous osseointegrated (OI) implants are increasingly viable as an alternative to socket suspension of prosthetic limbs. Upper extremity prostheses have also become more complex to better replicate hand and arm function and attempt to recreate pre-amputation functional levels. With more functionality comes heavier devices that put more stress on the bone-implant interface, which could be an issue for implant stability. This study quantified transhumeral loading at defined amputation levels using four simulated prosthetic limb-types: (1) body powered hook, (2) myoelectric hook, (3) myoelectric hand, and (4) advanced prosthetic limb. Computational models were constructed to replicate the weight distribution of each prosthesis type, then applied to motion capture data collected during Advanced Activities of Daily Living (AADLs). For activities that did not include a handheld weight, the body powered prosthesis bending moments were 13-33% (range of means for each activity across amputation levels) of the intact arm moments (reference 100%), torsional moments were 12-15%, and axial pullout forces were 30-40% of the intact case (p≤0.001). The myoelectric hook and hand bending moments were 60-99%, torsional moments were 44-97%, and axial pullout forces were 62-101% of the intact case. The advanced prosthesis bending moments were 177-201%, torsional moments were 164-326%, and axial pullout forces were 133-185% of the intact case (p≤0.001). The addition of a handheld weight for briefcase carry and jug lift activities reduced the overall impact of the prosthetic model itself, where the body powered forces and moments were much closer to those of the intact model, and more complex prostheses further increased forces and moments beyond the intact arm levels. These results reveal a ranked order in loading magnitude according to complexity of the prosthetic device, and highlight the importance of considering the patient's desired terminal device when planning post-operative percutaneous OI rehabilitation and training.

Ambulatory searching task reveals importance of somatosensation for lower-limb amputees.

The contribution of somatosensation to locomotor deficits in below-knee amputees (BKAs) has not been fully explored. Unilateral disruption of plantar sensation causes able-bodied individuals to adopt locomotor characteristics that resemble those of unilateral BKAs, suggesting that restoring somatosensation may improve locomotion for amputees. In prior studies, we demonstrated that electrically stimulating the residual nerves of amputees elicited somatosensory percepts that were felt as occurring in the missing foot. Subsequently, we developed a sensory neuroprosthesis that modulated stimulation-evoked sensation in response to interactions between the prosthesis and the environment. To characterize the impact of the sensory neuroprosthesis on locomotion, we created a novel ambulatory searching task. The task involved walking on a horizontal ladder while blindfolded, which engaged plantar sensation while minimizing visual compensation. We first compared the performance of six BKAs to 14 able-bodied controls. Able-bodied individuals demonstrated higher foot placement accuracy than BKAs, indicating that the ladder test was sensitive enough to detect locomotor deficits. When three of the original six BKAs used the sensory neuroprosthesis, the tradeoff between speed and accuracy significantly improved for two of them. This study advanced our understanding of how cutaneous plantar sensation can be used to acquire action-related information during challenging locomotor tasks.

Stakeholder perspectives for possible residual limb monitoring system for persons with lower-limb amputation.

Purpose: To gather ideas from lower-limb prosthesis users and certified prosthetists regarding possible residual limb monitoring system features and data presentation. We also gathered information on the type of residual limb problems typically encountered, how they currently manage those problems, and their ideas for methods to better manage them.Materials and methods: Two focus groups were held; one with certified prosthetists and another with lower-limb prosthesis users. Open-ended questions were used in a moderated discussion that was audio recorded, transcribed, and assessed using applied thematic analysis.Results and conclusions: Seven individuals participated in each focus group. Prosthetists came from a mix of practice settings, while prosthesis users were diverse in level of amputation, aetiology, and years of experience using lower-limb prostheses. Residual limb problems reported by participants were consistent with those in the literature. Participants suggested better managing residual limb problems through improved education, better detection of residual limb problems, and using sensor-based information to improve prosthetic technology. Participants favoured short-term use of a possible residual limb monitoring systems to troubleshoot residual limb problems, with temperature and pressure the most frequently mentioned measurements. Participants described that an ideal residual limb monitoring system would be lightweight, not interfere with prosthesis function, and result in benefits with regard to prosthetic care and socket function that outweighed inconveniences or concerns regarding system use. A potential positive of system use included having objective data for reimbursement justification, although it was pointed out that the residual limb monitoring system itself also needed to be reimbursable.Implications for RehabilitationStakeholders suggested better managing residual limb problems through improved education, better detection of residual limb problems, and using sensor-based information to improve prosthetic technology.Stakeholders favored short-term use of a possible system to troubleshoot residual limb problems, with temperature and pressure the most frequently mentioned measurements.Stakeholders described that an ideal residual limb monitoring system would be lightweight, not interfere with prosthesis function, and result in benefits with regard to prosthetic care and socket function that outweighs any inconveniences or concerns regarding system use.Stakeholders indicated that a potential positive of system use included having objective data for reimbursement justification, although it was pointed out that the residual limb monitoring system itself also needed to be reimbursable.

Characterization of the Sense of Agency over the Actions of Neural-machine Interface-operated Prostheses.

This work describes a methodological framework that can be used to explicitly and implicitly characterize the sense of agency developed over the neural-machine interface (NMI) control of sensate virtual or robotic prosthetic hands. The formation of agency is fundamental in distinguishing the actions that we perform with our limbs as being our own. By striving to incorporate advanced upper-limb prostheses into these same perceptual mechanisms, we can begin to integrate an artificial limb more closely into the user's existing cognitive framework for limb control. This has important implications in promoting user acceptance, use, and effective control of advanced upper-limb prostheses. In this protocol, participants control a virtual prosthetic hand and receive kinesthetic sensory feedback through their preexisting NMIs. A series of virtual grasping tasks are performed and perturbations are systematically introduced to the kinesthetic feedback and virtual hand movements. Two separate measures of agency are employed: established psychophysical questionnaires (to capture the explicit experience of agency) and a time interval estimate task to capture the implicit sense of agency (intentional binding). Results of this protocol (questionnaire scores and time interval estimates) can be analyzed to quantify the extent of agency formation.

Dynamic time warping for reducing the effect of force variation on myoelectric control of hand prostheses.

Research in pattern recognition (PR) for myoelectric control of the upper limb prostheses has been extensive. However, there has been limited attention to the factors that influence the clinical translation of this technology. A relevant factor of influence in clinical performance of EMG PR-based control of prostheses is the variation in muscle activation level, which modifies the EMG patterns even when the amputee attempts the same movement. To decrease the effect of muscle activation level variations on EMG PR, this work proposes to use dynamic time warping (DTW) and is validated on two databases. The first database, which has data from ten intact-limbed subjects, was used to test the baseline performance of DTW, resulting in an average classification accuracy of more than 90%. The second database comprised data from nine upper limb amputees recorded at three levels of force for six hand grips. The results showed that DTW trained at a single force level achieved an average classification accuracy of 60 ±â€¯9%, 70 ±â€¯8%, and 60 ±â€¯7% at the low, medium and high force levels respectively across all amputee subjects. The proposed scheme with DTW achieved a significant 10% improvement in classification accuracy when trained at a low force level when compared to the traditional time-dependent power spectrum descriptors (TD-PSD) method.

Touch on predefined areas on the forearm can be associated with specific fingers: Towards a new principle for sensory feedback in hand prostheses.

OBJECTIVE: Currently available hand prostheses lack sensory feedback. A "phantom hand map", a referred sensation, on the skin of the residual arm is a possible target to provide amputees with non-invasive somatotopically matched sensory feedback. How-ever, not all amputees experience a phantom hand map. The aim of this study was to explore whether touch on predefined areas on the forearm can be associated with specific fingers. DESIGN: A longitudinal cohort study. SUBJECTS: A total of 31 able-bodied individuals. METHODS: A "tactile display" was developed consisting of 5 servo motors, which provided the user with mechanotactile stimulus. Predefined pressure points on the volar aspect of the forearm were stimulated during a 2-week structured training period. RESULTS: Agreement between the stimulated areas and the subjects' ability to discriminate the stimulation was high, with a distinct improvement up to the third training occasion, after which the kappa score stabilized for the rest of the period. CONCLUSION: It is possible to associate touch on intact skin on the forearm with specific fingers after a structured training period, and the effect persisted after 2 weeks. These results may be of importance for the development of non-invasive sensory feedback systems in hand prostheses.

Evaluation of early wound leakage as a risk factor for prosthetic joint infection.

BACKGROUND AND PURPOSE: Prosthetic joint infection (PJI) is a serious complication resulting from total knee arthroplasty (TKA) or total hip arthroplasty (THA). In this study, patients with a PJI are compared with patients with an uncomplicated postoperative course to identify relevant risk factors for PJI. METHODS: A matched case-control study was performed with patients undergoing fast-track, elective unilateral TKA or THA. The following data were collected: demographics, surgery-related characteristics (perioperative blood loss, use of cement, body temperature), and postoperative characteristics (hematoma formation, wound leakage, blood transfusion, length of stay [LOS]). CONCLUSIONS: When the PJI group was compared with the control group, there was significantly more wound leakage during hospital stay (88% vs. 36%, p = .001) and early wound dressing changes in the first 3 days after surgery (88% vs. 40%, p = .002). Hematoma formation was observed more in the PJI patients group (44% vs. 10%, p = .005). A trend test revealed a significant association between the total number of wound dressing changes and development of PJI (p < .001); 72% of PJI patients had a length of stay of ≥4 days compared with 34% of controls (odds ratio 10.5; 95% CI [2.1-52.3]; p = .004). IMPLICATIONS FOR PRACTICE: Early postoperative wound drainage and hematoma formation directly correlate with PJI. This resulted in a significantly higher number of dressing changes and longer LOS. The nurse practitioner has a central role in postoperative care and is the first to recognize signs of an adverse postoperative clinical course.

Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits.

The human ankle varies impedance and delivers net positive work during the stance period of walking. In contrast, commercially available ankle-foot prostheses are passive during stance, causing many clinical problems for transtibial amputees, including non-symmetric gait patterns, higher gait metabolism, and poorer shock absorption. In this investigation, we develop and evaluate a myoelectric-driven, finite state controller for a powered ankle-foot prosthesis that modulates both impedance and power output during stance. The system employs both sensory inputs measured local to the external prosthesis, and myoelectric inputs measured from residual limb muscles. Using local prosthetic sensing, we first develop two finite state controllers to produce biomimetic movement patterns for level-ground and stair-descent gaits. We then employ myoelectric signals as control commands to manage the transition between these finite state controllers. To transition from level-ground to stairs, the amputee flexes the gastrocnemius muscle, triggering the prosthetic ankle to plantar flex at terminal swing, and initiating the stair-descent state machine algorithm. To transition back to level-ground walking, the amputee flexes the tibialis anterior muscle, triggering the ankle to remain dorsiflexed at terminal swing, and initiating the level-ground state machine algorithm. As a preliminary evaluation of clinical efficacy, we test the device on a transtibial amputee with both the proposed controller and a conventional passive-elastic control. We find that the amputee can robustly transition between the finite state controllers through direct muscle activation, allowing rapid transitioning from level-ground to stair walking patterns. Additionally, we find that the proposed finite state controllers result in a more biomimetic ankle response, producing net propulsive work during level-ground walking and greater shock absorption during stair descent. The results of this study highlight the potential of prosthetic leg controllers that exploit neural signals to trigger terrain-appropriate, local prosthetic leg behaviors.

[A new adaptive hand prosthesis]. / Eine neue adaptive Handprothese.

In the paper, a new adaptive hand prosthesis developed in the Institute of Applied Computer Sciences of the Forschungszentrum Karlsruhe is described. Starting from the state-of-the-art, the requirements of the hand prosthesis are derived and the realisation of the new prosthesis is shown. Finally the results obtained are discussed.

[Selective nerve transfers to improve the control of myoelectrical arm prostheses]. / Selektive Nerventransfers zur verbesserten Steuerung myoelektrischer Armprothesen.

To date, the movement of myoelectrical arm prostheses proceeds via two transcutaneous electrodes that are controlled by two separately innervated muscle groups. The various control levels are chosen by co-contractions of these muscles and the respective level is linearly controlled by the same muscles. A harmonious course of movement as in the corresponding natural pattern of motion is not possible in this way. An appreciable improvement would be given by the control of the individual movement levels by signals that correspond neuronally with the natural pattern of motion. Just recently, prostheses with six control levels have been realised technically. The objective is to separate the major arm nerves, such as the musculocutaneous nerve, radial nerve, median nerve and ulnar nerve, from the proximal arm nerve plexus and to transfer them to the residual nerve branches of muscles near the stem in order to create meaningful neuromuscular units that can serve as impulse sources for myoelectrical prosthesis. As target muscles, above all, one can consider the major/minor pectoral muscles or, respectively, the latissimus muscle. According to the activity of the donor nerves, these muscles would contract and control the prosthesis via transcutaneous electrode. In this way, a harmonious control corresponding intuitively to the natural pattern of movement would be possible without the necessity for the patient to continuously switch between the various control levels. Prerequisites for this are intact proximal muscle groups and a more or less intact arm nerve plexus with the possibility to isolate donor nerves according to the topographic-anatomic situation. For this reason, a preoperative MRI examination, a high resolution sonographic study and balancing NLG and EMG of the residual nerve plexus are necessary. For the preoperative planning phase as well as for the postoperative follow-up, a detailed procedure has been established, in cooperation with the innovation department of the Otto Bock company, to create the most meaningful switch levels, to optimise electrode placement as well as to clarify prosthesis incorporation. Finally, a complex rehabilitation programme is necessary for the patient to achieve an optimal result.

Epidemiological study of failures of the Jaipur Foot.

OBJECTIVE: The purpose of this study was to examine effects of usage and demographics on damage to the Jaipur Foot prosthesis as well as the epidemiology and etiology of amputations performed at Santokba Durlabjhi Memorial Hospital (SDMH) in Jaipur, India. DESIGN: Total time spent standing, total time spent wearing and total distance walked were compared against severity and location of damage to the prosthesis. Time between initial fitting and follow-up visit for damaged prosthetic was also considered in this analysis. A novel damage severity scale based on prosthesis functionality is presented along with a damage location legend. RESULTS: Patients from 10 different states and two territories throughout India were included in the study. No main effects were found to be statistically significant in predicting severity or location of damage. Only the interaction between a patient's total time spent standing and their total time spent wearing the prosthesis as well as the interaction between a patient's total time spent standing and total distance walked was significant in predicting location of damage to the Jaipur Foot (p = .0327, p = .0278, respectively). CONCLUSIONS: The lack of significant usage factor effect on damage severity or location could support previous findings that lack standardization in materials and manufacturing processes, which is the major drawback of the Jaipur Foot. Implications for Rehabilitation The Jaipur Foot is a safe, reliable and stable product as no abrupt breakage or sudden falls causing injury to the patient were noted. Hence, it is a safe rehabilitation device for lost limbs. The population can squat and sit cross-legged while wearing the prosthetic foot and it does not affect damage severity or location of damage, allowing for these activities to be performed while rehabilitating. The manufacturing of the foot needs to be standardized to improve life of foot. Total time spent standing, total time spent wearing and total distance walked were not predictive of severity or location of damage to the prosthesis, hence providing patient guidelines for activity during rehabilitation.