The Physiatrist's Approach to Limb Loss: Pre-amputation Through Lifelong Care.

Limb-loss is a significant medical event with lifelong consequences, impacting various aspects of a patient's well-being. Care for these often-complex patients involves providers from many different specialties working toward a set of patient-centered goals. This article aims to highlight the important role of physiatrists in directing the interdisciplinary care for these patients. Through evidence-based concepts, the authors aim to lay a roadmap for comprehensive, longitudinal management of these patients from pre-amputation assessment through lifelong care.

Adaptive Sports and Recreation in Persons with Limb Loss/Limb Deficiency.

Adaptive sports are a vital component in the continuum of rehabilitation for people with limb loss/limb deficiency (LL/LD), across the lifespan. Identifying the barriers and understanding health care disparities inform ways to help people with LL/LD stay active and reach their health and wellness goals. Building knowledge in adaptive sports helps facilitate having a person go beyond activities of daily living and basic locomotion. Considering the participant, requirements of the sport, and the activity-specific prosthesis/equipment required leads to successful participation in adaptive sports.

Prosthetic Componentry in Upper Limb Prosthetic Restoration.

This article provides an overview of fundamental upper limb prosthesis concepts and componentry, including control systems (body-powered, externally powered, passive, and hybrid), sockets and suspension, and terminal devices.

Reintegration Following Amputation: A Biopsychosocial Approach.

Reintegration back into one's life following limb loss is heavily influenced by the interaction among the individual's mental health, environment, and physical factors (eg, pain and prostheses). While many patients experience posttraumatic growth and successfully reintegrate back into their lives, others have a more difficult adjustment. Interdisciplinary teams can best facilitate reintegration through early screening for barriers to reintegration such as depression, pain, body image, and inaccessible environments, to intervene early after amputation. With these barriers addressed, amputees may be able to return to driving and other valued activities more quickly, resulting in improved reintegration across life domains.

Prosthesis applications and challenges in children with earthquake-related amputations.

BACKGROUND: Amputations are among the most important traumatic injuries caused by earthquakes. However, data on amputee children and prosthesis application is quite limited in the literature. The aim of the study is to evaluate the injury-related data, stump problems, prosthesis application, difficulties and complications experienced with prosthesis during follow-up of children with 2023 Kahramanmaras earthquake-related limb loss. PATIENTS AND METHODS: Sociodemographic and injury-related data, pre-amputation and post-amputation interventions, prosthesis application, current prosthetic problems, and revision surgeries of the amputee children were recorded. RESULTS: Median age of patients (n = 102) admitted to our center was 13.0 years. 67.6 % of patients had one or more concomitant injuries. Median time and number of amputations were 4 (0-57) days and 1 (1-4), respectively. Of the total 120 amputations, 67.5 % (n = 81) were lower extremity amputations. Most common amputation levels were transtibial (29.1 %, n = 35), transfemoral (22.5 %, n = 27), and transhumeral (15.8 %, n = 19). Most amputees (56.8 %) underwent revision surgery after initial amputation. Median duration of time from amputation to prosthesis application was 184 (28-314) days. For 25 prostheses, a socket revision was required. Six patients had surgical revision of the stumps to allow prosthetic fit and mobility (due to bone overgrowth, soft tissue failure, heterotopic ossification). CONCLUSION: Limited healthcare facilities, surgeries performed under emergency conditions, accompanying multiple traumas, inadequate follow-up conditions, and additional difficulties arising from the pediatric patient group lead to difficulties in the care of pediatric amputee patients. Our results will guide the care of this vulnerable patient population in the event of a similar unfortunate disaster.

A clinical comparison of a digital versus conventional design methodology for transtibial prosthetic interfaces.

A transtibial prosthetic interface typically comprises a compliant liner and an outer rigid socket. The preponderance of today's conventional liners are mass produced in standard sizes, and conventional socket design is labor-intensive and artisanal, lacking clear scientific rationale. This work tests the clinical efficacy of a novel, physics-based digital design framework to create custom prosthetic liner-socket interfaces. In this investigation, we hypothesize that the novel digital approach will improve comfort outcomes compared to a conventional method of liner-socket design. The digital design framework generates custom transtibial prosthetic interfaces starting from MRI or CT image scans of the residual limb. The interface design employs FEA to simulate limb deformation under load. Interfaces are fabricated for 9 limbs from 8 amputees (1 bilateral). Testing compares novel and conventional interfaces across four assessments: 5-min walking trial, thermal imaging, 90-s standing pressure trial, and an evaluation questionnaire. Outcome measures include antalgic gait criterion, skin surface pressures, skin temperature changes, and direct questionnaire feedback. Antalgic gait is compared via a repeated measures linear mixed model while the other assessments are compared via a non-parametric Wilcoxon sign-rank test. A statistically significant ([Formula: see text]) decrease in pain is demonstrated when walking on the novel interfaces compared to the conventional. Standing pressure data show a significant decrease in pressure on novel interfaces at the anterior distal tibia ([Formula: see text]), with no significant difference at other measured locations. Thermal results show no statistically significant difference related to skin temperature. Questionnaire feedback shows improved comfort on novel interfaces on posterior and medial sides while standing and the medial side while walking. Study results support the hypothesis that the novel digital approach improves comfort outcomes compared to the evaluated conventional method. The digital interface design methodology also has the potential to provide benefits in design time, repeatability, and cost.

Listening to children with lower limb loss: Rationale, design, and protocol for delivery of a novel globally applicable research toolkit-Prosthetic user needs, quality of life, pain, and physical function.

INTRODUCTION: Rehabilitation after childhood lower limb loss is complex and dependent on multiple stakeholders and environmental factors. While research with adults underscores the importance of involving prosthetic limb users and caregivers in discussions to drive innovation, children are often excluded or not effectively engaged. This protocol lays out the development and implementation protocol for an internationally applicable research toolkit which has been designed and evaluated around the essential presence of the child. Research domains span their unique prosthetic needs, quality of life, pain, and mobility. METHODS AND ANALYSIS: Cohorts of children in contrasting environments were identified (Cambodia, Gaza Strip, and the UK) to provide a comprehensive global understanding of the child with lower limb loss. A literature review revealed a lack of appropriate tools for identifying paediatric prosthetic user requirements leading to the development of novel interview guides for each key stakeholder: child, caregiver, and prosthetist. The child's guide centred around enjoyment and engagement using card games and activities. A panel of experts in paediatric limb loss and mental health rigorously reviewed the guides. Guides were integrated with existing validated measures for quality of life, pain, and mobility to form a comprehensive toolkit. The toolkit was successfully piloted with 5 children, their families, and 2 prosthetists. This protocol lays out the toolkit rationale and implementation plan (Jan 2023 to Dec 2025). This work offers the opportunity for this cohort to enjoyably engage with research that seeks to radically improve prospects for all children living with limb loss. The outlined best practices ensure ethical considerations when working with vulnerable cohorts. ETHICS AND DISSEMINATION: This study is approved to cover implementation at all geographical locations as well as the researcher institutions. Results will be disseminated through national and international conferences, as well as through manuscripts in leading peer-reviewed journals.

Restoration of grasping in an upper limb amputee using the myokinetic prosthesis with implanted magnets.

The loss of a hand disrupts the sophisticated neural pathways between the brain and the hand, severely affecting the level of independence of the patient and the ability to carry out daily work and social activities. Recent years have witnessed a rapid evolution of surgical techniques and technologies aimed at restoring dexterous motor functions akin to those of the human hand through bionic solutions, mainly relying on probing of electrical signals from the residual nerves and muscles. Here, we report the clinical implementation of an interface aimed at achieving this goal by exploiting muscle deformation, sensed through passive magnetic implants: the myokinetic interface. One participant with a transradial amputation received an implantation of six permanent magnets in three muscles of the residual limb. A truly self-contained myokinetic prosthetic arm embedding all hardware components and the battery within the prosthetic socket was developed. By retrieving muscle deformation caused by voluntary contraction through magnet localization, we were able to control in real time a dexterous robotic hand following both a direct control strategy and a pattern recognition approach. In just 6 weeks, the participant successfully completed a series of functional tests, achieving scores similar to those achieved when using myoelectric controllers, a standard-of-care solution, with comparable physical and mental workloads. This experience raised conceptual and technical limits of the interface, which nevertheless pave the way for further investigations in a partially unexplored field. This study also demonstrates a viable possibility for intuitively interfacing humans with robotic technologies.

Transforming the Anthropomorphic Passive Free-Flow Foot Prosthesis Into a Powered Foot Prosthesis With Intuitive Control and Sensation (Bionic FFF).

INTRODUCTION: Approximately 89% of all service members with amputations do not return to duty. Restoring intuitive neural control with somatosensory sensation is a key to improving the safety and efficacy of prosthetic locomotion. However, natural somatosensory feedback from lower-limb prostheses has not yet been incorporated into any commercial prostheses. MATERIALS AND METHODS: We developed a neuroprosthesis with intuitive bidirectional control and somatosensation and evoking phase-dependent locomotor reflexes, we aspire to significantly improve the prosthetic rehabilitation and long-term functional outcomes of U.S. amputees. We implanted the skin and bone integrated pylon with peripheral neural interface pylon into the cat distal tibia, electromyographic electrodes into the residual gastrocnemius muscle, and nerve cuff electrodes on the distal tibial and sciatic nerves. Results. The bidirectional neural interface that was developed was integrated into the existing passive Free-Flow Foot and Ankle prosthesis, WillowWood, Mount Sterling, OH. The Free-Flow Foot was chosen because it had the highest Index of Anthropomorphicity among lower-limb prostheses and was the first anthropomorphic prosthesis brought to market. Conclusion. The cats walked on a treadmill with no cutaneous feedback from the foot in the control condition and with their residual distal tibial nerve stimulated during the stance phase of walking.

Analysis of amputations occurring in the earthquakes centered in Kahramanmaras: Adiyaman experience.

PURPOSE: Amputations are a common surgical procedure resulting from trauma during earthquakes, leading to severe disability. This study aims to investigate surgical outcomes specific to amputations that occurred in Adiyaman after the Kahramanmaras earthquakes. METHODS: This descriptive study included amputees who presented to Adiyaman University Training and Research Hospital. Between March 6, 2024 and March 29, 2024, amputees were contacted by phone and asked the questions in the form. Data analyzed included demographic information, number and level of amputated extremities, phantom limb pain, stump infection, extrication time, time to initiation of rehabilitation, number of revision, and whether a prosthesis was fitted. RESULTS: The study reached 75 amputees. The mean age was 37.9 ± 19.2, and the most frequently amputated age group was adults. Stump infection was observed in 40 amputees (53.3%), phantom limb pain in 47 (62.6%), and revision in 29 (38.7%). The median extrication time was 36 h and initiation of rehabilitation time was 45 days. It was noted that 35 amputees (62.5%) used prostheses. A statistically significant relationship was found between fasciotomy and stump infection (p = .000). Infection was detected in 65% of those who underwent fasciotomy. CONCLUSION: Earthquake-related amputations most frequently affected the adult age group and primarily involved lower extremity amputations, such as transfemoral and transtibial amputations. Phantom limb pain, need for revision, and infection are common in earthquake-induced amputations. Delayed fasciotomy increases the risk of stump infection. The data obtained in this study will help plan local health services to coordinate amputation care in disasters.

Eliciting Force and Slippage in Upper Limb Amputees Through Transcutaneous Electrical Nerve Stimulation (TENS).

Upper limb amputation severely affects the quality of life of individuals. Therefore, developing closed-loop upper-limb prostheses would enhance the sensory-motor capabilities of the prosthetic user. Considering design priorities based on user needs, the restoration of sensory feedback is one of the most desired features. This study focuses on employing Transcutaneous Electrical Nerve Stimulation (TENS) as a non-invasive somatotopic stimulation technique for restoring somatic sensations in upper-limb amputees. The aim of this study is to propose two encoding strategies to elicit force and slippage sensations in transradial amputees. The former aims at restoring three different levels of force through a Linear Pulse Amplitude Modulation (LPAM); the latter is devoted to elicit slippage sensations through Apparent Moving Sensation (AMS) by means of three different algorithms, i.e. the Pulse Amplitude Variation (PAV), the Pulse Width Variation (PWV) and Inter-Stimulus Delay Modulation (ISDM). Amputees had to characterize perceived sensations and to perform force and slippage recognition tasks. Results demonstrates that amputees were able to correctly identify low, medium and high levels of force, with an accuracy above the 80% and similarly, to also discriminate the slippage moving direction with a high accuracy above 90%, also highlighting that ISDM would be the most suitable method, among the three AMS strategies to deliver slippage sensations. It was demonstrated for the first time that the developed encoding strategies are effective methods to somatotopically reintroduce in the amputees, by means of TENS, force and slippage sensations.

Walking Ankle Biomechanics of Individuals With Transtibial Amputations Using a Prescribed Prosthesis and a Portable Bionic Prosthesis Under Myoelectric Control.

Individuals with transtibial amputation can activate residual limb muscles to volitionally control robotic ankle prostheses for walking and postural control. Most continuous myoelectric ankle prostheses have used a tethered, pneumatic device. The Open Source Leg allows for myoelectric control on an untethered electromechanically actuated ankle. To evaluate continuous proportional myoelectric control on the Open Source Ankle, we recruited five individuals with transtibial amputation. Participants walked over ground with an experimental powered prosthesis and their prescribed passive prosthesis before and after multiple powered device practice sessions. Participants averaged five hours of total walking time. After the final testing session, participants indicated their prosthesis preference via questionnaire. Participants tended to increase peak ankle power after practice (powered 0.80 ± 1.02 W/kg and passive 0.39 ± 0.31 W/kg). Additionally, participants tended to generate greater ankle work with the powered prosthesis compared to their passive device ( 0.13 ± .15 J/kg increase). Although work and peak power generation were not statistically different between the two prostheses, participants preferred walking with the prosthesis under myoelectric control compared to the passive prosthesis. These results indicate individuals with transtibial amputation learned to walk with an untethered powered prosthesis under continuous myoelectric control. Four out 5 participants generated larger magnitudes in peak power compared to their passive prosthesis after practice sessions. An additional important finding was participants chose to walk with peak ankle powers about half of what the powered prosthesis was capable of based on mechanical testing.

Using eye tracking to assess learning of a multifunction prosthetic hand: an exploratory study from a rehabilitation perspective.

BACKGROUND: Eye tracking technology not only reveals the acquisition of visual information at fixation but also has the potential to unveil underlying cognitive processes involved in learning to use a multifunction prosthetic hand. It also reveals gaze behaviours observed during standardized tasks and self-chosen tasks. The aim of the study was to explore the use of eye tracking to track learning progress of multifunction hands at two different time points in prosthetic rehabilitation. METHODS: Three amputees received control training of a multifunction hand with new control strategy. Detailed description of control training was collected first. They wore Tobii Pro2 eye-tracking glasses and performed a set of standardized tasks (required to switch to different grips for each task) after one day of training and at one-year-follow-up (missing data for Subject 3 at the follow up due to socket problem). They also performed a self-chosen task (free to use any grip for any object) and were instructed to perform the task in a way how they would normally do at home. The gaze-overlaid videos were analysed using the Tobii Pro Lab and the following metrics were extracted: fixation duration, saccade amplitude, eye-hand latency, fixation count and time to first fixation. RESULTS: During control training, the subjects learned 3 to 4 grips. Some grips were easier, and others were more difficult because they forgot or were confused with the switching strategies. At the one-year-follow-up, a decrease in performance time, fixation duration, eye-hand latency, and fixation count was observed in Subject 1 and 2, indicating an improvement in the ability to control the multifunction hand and a reduction of cognitive load. An increase in saccade amplitude was observed in both subjects, suggesting a decrease in difficulty to control the prosthetic hand. During the standardized tasks, the first fixation of all three subjects were on the multifunction hand in all objects. During the self-chosen tasks, the first fixations were mostly on the objects first. CONCLUSION: The qualitative data from control training and the quantitative eye tracking data from clinical standardized tasks provided a rich exploration of cognitive processing in learning to control a multifunction hand. Many prosthesis users prefer multifunction hands and with this study we have demonstrated that a targeted prosthetic training protocol with reliable assessment methods will help to lay the foundation for measuring functional benefits of multifunction hands.

Assessment of TENS-Evoked Tactile Sensations for Transradial Amputees via EEG Investigation.

Most of current prostheses can offer motor function restoration for limb amputees but usually lack natural and intuitive sensory feedback. Many studies have demonstrated that Transcutaneous Electrical Nerve Stimulation (TENS) is promising in non-invasive sensation evoking for amputees. However, the objective evaluation and mechanism analysis on sensation feedback are still limited. This work utilized multi-channel TENS with diverse stimulus patterns to evoke sensations on four non-disabled subjects and two transradial amputees. Meanwhile, electroencephalogram (EEG) was collected to objectively assess the evoked sensations, where event-related potentials (ERPs), brain electrical activity maps (BEAMs), and functional connectivity (FC) were computed. The results show that various sensations could be successfully evoked for both amputees and non-disabled subjects by customizing stimulus parameters. The ERP confirmed the sensation and revealed the sensory-processing-related components like N100 and P200; the BEAMs confirmed the corresponding regions of somatosensory cortex were activated by stimulation; the FC indicated an increase of interactions between the regions of sensorimotor cortex. This study may shed light on how the brain responds to external stimulation as sensory feedback and serve as a pilot for further bidirectional closed-loop prosthetic control.

Unravelling Influence Factors in Pattern Recognition Myoelectric Control Systems: The Impact of Limb Positions and Electrode Shifts.

Pattern recognition (PR)-based myoelectric control systems can naturally provide multifunctional and intuitive control of upper limb prostheses and restore lost limb function, but understanding their robustness remains an open scientific question. This study investigates how limb positions and electrode shifts-two factors that have been suggested to cause classification deterioration-affect classifiers' performance by quantifying changes in the class distribution using each factor as a class and computing the repeatability and modified separability indices. Ten intact-limb participants took part in the study. Linear discriminant analysis (LDA) was used as the classifier. The results confirmed previous studies that limb positions and electrode shifts deteriorate classification performance (14-21% decrease) with no difference between factors (p > 0.05). When considering limb positions and electrode shifts as classes, we could classify them with an accuracy of 96.13 ± 1.44% and 65.40 ± 8.23% for single and all motions, respectively. Testing on five amputees corroborated the above findings. We have demonstrated that each factor introduces changes in the feature space that are statistically new class instances. Thus, the feature space contains two statistically classifiable clusters when the same motion is collected in two different limb positions or electrode shifts. Our results are a step forward in understanding PR schemes' challenges for myoelectric control of prostheses and further validation needs be conducted on more amputee-related datasets.

L Test Subtask Segmentation for Lower-Limb Amputees Using a Random Forest Algorithm.

Functional mobility tests, such as the L test of functional mobility, are recommended to provide clinicians with information regarding the mobility progress of lower-limb amputees. Smartphone inertial sensors have been used to perform subtask segmentation on functional mobility tests, providing further clinically useful measures such as fall risk. However, L test subtask segmentation rule-based algorithms developed for able-bodied individuals have not produced sufficiently acceptable results when tested with lower-limb amputee data. In this paper, a random forest machine learning model was trained to segment subtasks of the L test for application to lower-limb amputees. The model was trained with 105 trials completed by able-bodied participants and 25 trials completed by lower-limb amputee participants and tested using a leave-one-out method with lower-limb amputees. This algorithm successfully classified subtasks within a one-foot strike for most lower-limb amputee participants. The algorithm produced acceptable results to enhance clinician understanding of a person's mobility status (>85% accuracy, >75% sensitivity, >95% specificity).

Robotic-Enhanced Prosthetic Liners for Vibration Therapy: Reducing Phantom Limb Pain in Transfemoral Amputees.

Phantom limb pain, a common challenge for amputees, lacks effective treatment options. Vibration therapy is a promising non-pharmacologic intervention for reducing pain intensity, but its efficacy in alleviating phantom limb pain requires further investigation. This study focused on developing prosthesis liners with integrated vibration motors to administer vibration therapy for phantom limb pain. The prototypes developed for this study addressed previous issues with wiring the electronic components. Two transfemoral amputees participated in a four-week at-home trial, during which they used the vibration liner and rated their initial and final pain intensity on a numeric rating scale each time they had phantom pain. Semi-structured interviews were conducted to gather feedback following the at-home trial. Both participants described relaxing and soothing sensations in their residual limb and phantom limb while using vibration therapy. One participant reported a relaxation of his phantom limb sensations, while both participants noted a decrease in the intensity of their phantom limb pain. Participants said the vibration liners were comfortable but suggested that the vibration could be stronger and that aligning the contacts could be easier. The results of this study highlight the potential effectiveness of using vibration therapy to reduce the intensity of phantom limb pain and suggest a vibration liner may be a feasible mode of administering the therapy. Future research should address optimizing the performance of the vibration liners to maximize their therapeutic benefits.

A compact solution for vibrotactile proprioceptive feedback of wrist rotation and hand aperture.

BACKGROUND: Closing the control loop between users and their prostheses by providing artificial sensory feedback is a fundamental step toward the full restoration of lost sensory-motor functions. METHODS: We propose a novel approach to provide artificial proprioceptive feedback about two degrees of freedom using a single array of 8 vibration motors (compact solution). The performance afforded by the novel method during an online closed-loop control task was compared to that achieved using the conventional approach, in which the same information was conveyed using two arrays of 8 and 4 vibromotors (one array per degree of freedom), respectively. The new method employed Gaussian interpolation to modulate the intensity profile across a single array of vibration motors (compact feedback) to convey wrist rotation and hand aperture by adjusting the mean and standard deviation of the Gaussian, respectively. Ten able-bodied participants and four transradial amputees performed a target achievement control test by utilizing pattern recognition with compact and conventional vibrotactile feedback to control the Hannes prosthetic hand (test conditions). A second group of ten able-bodied participants performed the same experiment in control conditions with visual and auditory feedback as well as no-feedback. RESULTS: Conventional and compact approaches resulted in similar positioning accuracy, time and path efficiency, and total trial time. The comparison with control condition revealed that vibrational feedback was intuitive and useful, but also underlined the power of incidental feedback sources. Notably, amputee participants achieved similar performance to that of able-bodied participants. CONCLUSIONS: The study therefore shows that the novel feedback strategy conveys useful information about prosthesis movements while reducing the number of motors without compromising performance. This is an important step toward the full integration of such an interface into a prosthesis socket for clinical use.

Cognitive load in individuals with a transfemoral amputation during single- and dual-task walking: a pilot study of brain activity in people using a socket prosthesis or a bone-anchored prosthesis.

OBJECTIVE: To explore cognitive load in people with transfemoral amputations fitted with socket or bone-anchored prostheses by describing activity in the left and right dorsolateral prefrontal cortices during single- and dual-task walking. DESIGN: Cross-sectional pilot study. PATIENTS: 8 socket prosthesis users and 8 bone-anchored prosthesis users. All were fitted with microprocessor-controlled prosthetic knees. METHODS: Participants answered self-report questionnaires and performed gait tests during 1 single-task walking condition and 2 dual-task walking conditions. While walking, activity in the dorsolateral prefrontal cortex was measured using functional near-infrared spectroscopy. Cognitive load was investigated for each participant by exploring the relative concentration of oxygenated haemoglobin in the left and right dorsolateral prefrontal cortex. Symmetry of brain activity was investigated by calculating a laterality index. RESULTS: Self-report measures and basic gait variables did not show differences between the groups. No obvious between-group differences were observed in the relative concentration of oxygenated haemoglobin for any walking condition. There was a tendency towards more right-side brain activity for participants using a socket prosthesis during dual-task conditions. CONCLUSIONS: This pilot study did not identify substantial differences in cognitive load or lateralization between socket prosthesis users and bone-anchored prosthesis users.