Flexible Dry Electrodes for EMG Acquisition within Lower Extremity Prosthetic Sockets.
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ABSTRACT:
SUBMITTER: Yeon SH
PROVIDER: S-EPMC8365363 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Neuromusculoskeletal disorders affecting walking ability are often difficult to manage, in part due to limited understanding of how a patient's lower extremity muscle excitations contribute to the patient's lower extremity joint moments. To assist in the study of these disorders, researchers have developed electromyography (EMG) driven neuromusculoskeletal models utilizing scaled generic musculoskeletal geometry. While these models can predict individual muscle contributions to lower extremity joint moments during walking, the accuracy of the predictions can be hindered by errors in the scaled geometry. This study presents a novel EMG-driven modeling method that automatically adjusts surrogate representations of the patient's musculoskeletal geometry to improve prediction of lower extremity joint moments during walking. In addition to commonly adjusted neuromusculoskeletal model parameters, the proposed method adjusts model parameters defining muscle-tendon lengths, velocities, and moment arms. We evaluated our EMG-driven modeling method using data collected from a high-functioning hemiparetic subject walking on an instrumented treadmill at speeds ranging from 0.4 to 0.8 m/s. EMG-driven model parameter values were calibrated to match inverse dynamic moments for five degrees of freedom in each leg while keeping musculoskeletal geometry close to that of an initial scaled musculoskeletal model. We found that our EMG-driven modeling method incorporating automated adjustment of musculoskeletal geometry predicted net joint moments during walking more accurately than did the same method without geometric adjustments. Geometric adjustments improved moment prediction errors by 25% on average and up to 52%, with the largest improvements occurring at the hip. Predicted adjustments to musculoskeletal geometry were comparable to errors reported in the literature between scaled generic geometric models and measurements made from imaging data. Our results demonstrate that with appropriate experimental data, joint moment predictions for walking generated by an EMG-driven model can be improved significantly when automated adjustment of musculoskeletal geometry is included in the model calibration process.
| S-EPMC5507406 | biostudies-other
Project description:BackgroundIn order to maintain nonweightbearing restrictions of the lower extremity, an assistive device must be utilized. Currently most devices require the restricted limb to be held in a static position while the contralateral extremity provides forward propulsion. Atrophy and disuse conditions ensue rapidly, slowing healing and prolonging recovery. A hands-free single crutch (HFSC) utilizes both lower extremities, potentially reducing atrophy. The purpose of this study was to examine the electromyographic (EMG) differences between an HFSC and standard axillary crutches (SAC).MethodsA prospective, crossover study was performed using 21 healthy volunteers from an active duty foot and ankle clinic. Demographic data were obtained and then subjects were fitted with an HFSC and SAC. Wireless surface EMG sensors were applied to the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and the gluteus maximus (GM) by a board-certified orthopedic surgeon. Subjects then ambulated at a self-selected velocity for 30 m while 15 seconds of the gait cycle were recorded for each device. Mean muscle activity and the maximum voluntary isometric contraction (MVIC) were recorded.ResultsThe RF, GM, and LG showed significantly increased levels of muscle activity while using the HFSC compared to SAC (respectively P = .05, P = .03, P = .03). The VL did not show significantly higher muscle activity while using the HFSC (P = .051). The RF, GM, and VL showed statistically significant higher MVIC percentages while using the HFSC compared with SAC (respectively P = .005, P = .005, P = .013). The LG did not show significantly higher MVIC percentage while using the HFSC (P = .076).ConclusionThe HFSC subjects demonstrated increased muscle recruitment and intensity while maintaining cyclic contractions consistent with bipedal gait pattern. SAC demonstrated less recruitment and intensity with an isometric pattern regardless of the phase of gait.Clinical relevanceMuscle atrophy following lower extremity immobilization.
| S-EPMC8697267 | biostudies-literature
Project description:Elevated vacuum (EV) is suggested to improve suspension and limb volume management for lower limb prosthesis users. However, few guidelines have been established to facilitate configuration of EV sockets to ensure their safe and proper function. A benchtop model of an EV socket was created to study how prosthetic liner tensile elasticity, socket fit, and socket vacuum pressure affect liner displacement and subsequent pressure on the residual limb. A domed carbon fiber layup was used to represent an EV socket. Inserts were used to simulate various air gaps between the socket and liner. Various prosthetic liner samples were placed under the carbon fiber layup. Liner displacement and the corresponding pressure change underneath the liner were measured as vacuum was applied between the liner sample and socket wall. Tissue vacuum pressure increased linearly with socket vacuum pressure until the liner contacted the socket wall. Predicted tissue vacuum pressure matched well with experimental results. Findings suggest that the effect of vacuum pressure on the residual limb is primarily determined by air gap distance. The developed model may be used to assess effects of EV on residual limb tissues based on an individual's socket fit, liner characteristics, and applied vacuum. Understanding the physiological effects of EV on the residual limb could help practitioners avoid blister formation and improve EV implementation.
| S-EPMC7954222 | biostudies-literature
Project description:Electroencephalogram (EEG) neurofeedback improves cognitive capacity and behaviors by regulating brain activity, which can lead to cognitive enhancement in healthy people and better rehabilitation in patients. The increased use of EEG neurofeedback highlights the urgent need to reduce the discomfort and preparation time and increase the stability and simplicity of the system's operation. Based on brain-computer interface technology and a multithreading design, we describe a neurofeedback system with an integrated design that incorporates wearable, multichannel, dry electrode EEG acquisition equipment and cognitive function assessment. Then, we evaluated the effectiveness of the system in a single-blind control experiment in healthy people, who increased the alpha frequency band power in a neurofeedback protocol. We found that upregulation of the alpha power density improved working memory following short-term training (only five training sessions in a week), while the attention network regulation may be related to other frequency band activities, such as theta and beta. Our integrated system will be an effective neurofeedback training and cognitive function assessment system for personal and clinical use.
| S-EPMC6211015 | biostudies-literature
Project description:(1) Background: A sustainable casting system that combines the use of a polystyrene bag, a prosthetic liner and a vacuum system was developed to reduce fabrication time while maintaining comfort for the trans-tibial prosthesis user. (2) Methods: Eight prosthetists (28.7 ± 8.25 years old) fit ten trans-tibial prosthesis wearers (46 ± 12.4 years old) with two types of total surface bearing (TSB) prostheses; a polystyrene bead (PS) prosthesis and a plaster of paris (POP) prosthesis. Duration of casting and combined mean peak pressure was measured at six locations on the residual limb using Force Sensing Resistors (FSR). A pressure uniformity score (%) was determined. Socket Comfort Scale (SCS) was also measured. (3) Results: Duration of casting for the POP method was 64.8 ± 9.53 min and 7.8 ± 2 min for the PS method, (p = 0.006). Pressure uniformity in the POP prosthesis was 79.3 ± 6.54 and 81.7 ± 5.83 in the PS prosthesis (p = 0.027). SCS in both prosthesis types were equivalent. (4) Conclusion: A rapid fit PS prosthesis was developed, with significantly shorter duration than the traditional POP method. Socket pressure uniformity was confirmed and improved in the PS method. Socket comfort was equal between the two prothesis types.
| S-EPMC9319515 | biostudies-literature
Project description:People with transtibial amputation often experience skin breakdown due to the pressures and shear stresses that occur at the limb-socket interface. The purpose of this research was to create a transtibial finite element model (FEM) of a contemporary prosthesis that included complete socket geometry, two frictional interactions (limb-liner and liner-socket), and an elastomeric liner. Magnetic resonance imaging scans from three people with characteristic transtibial limb shapes (i.e., short-conical, long-conical, and cylindrical) were acquired and used to develop the models. Each model was evaluated with two loading profiles to identify locations of focused stresses during stance phase. The models identified five locations on the participants' residual limbs where peak stresses matched locations of mechanically induced skin issues they experienced in the 9 months prior to being scanned. The peak contact pressure across all simulations was 98 kPa and the maximum resultant shear stress was 50 kPa, showing reasonable agreement with interface stress measurements reported in the literature. Future research could take advantage of the developed FEM to assess the influence of changes in limb volume or liner material properties on interface stress distributions. Graphical abstract Residual limb finite element model. Left: model components. Right: interface pressures during stance phase.
| S-EPMC5999538 | biostudies-literature
Project description:IntroductionDiabetes mellitus (DM) is associated with systemic musculoskeletal system impairments suggesting concurrent development of lower and upper extremity musculoskeletal problems. This study aims to examine relationships between lower and upper extremity function in people with DM.MethodsSixty people with type 2 DM and peripheral neuropathy [mean (standard deviation); 67(6) years old, DM duration 14(10) yrs] completed the following measures: 1) Self-reports of function: Foot and Ankle Ability Measure (FAAM; higher = better function) and Shoulder Pain and Disability Index (SPADI; lower = better function), 2) Range of motion (goniometry): ankle dorsiflexion and shoulder flexion, and 3) Strength: unilateral heel rise power (UHR, 3D kinetics) and hand grip dynamometry. Pearson correlations examined associations between lower and upper extremity measures, p < .05.ResultsForty of 60 (67%) reported pain/disability in both the foot/ankle and shoulder and 95% of study participants had some limitation in foot or shoulder function. Significant between extremity correlations: FAAM and SPADI (r = -0.39), ankle dorsiflexion and shoulder flexion range of motion (r = 0.35), and UHR and hand grip strength (r = 0.40). Significant within extremity correlations: FAAM and UHR (r = .47) and SPADI with shoulder flexion (r = -0.44).ConclusionUpper and lower extremity inter- and intra-relationships indicate systemic musculoskeletal impairments in people with DM. Healthcare practitioners should consider the potential for concurrent and disabling musculoskeletal problems in people with DM.
| S-EPMC7483835 | biostudies-literature
Project description: Not available
| S-EPMC9732677 | biostudies-literature
Project description:BackgroundThe prosthetic socket is a key component that influences prosthesis satisfaction, with a poorly fitting prosthetic socket linked to prosthesis abandonment and reduced community participation. This paper reviews adjustable socket designs, as they have the potential to improve prosthetic fit and comfort through accommodating residual limb volume fluctuations and alleviating undue socket pressure.MethodsSystematic literature and patent searches were conducted across multiple databases to identify articles and patents that discussed adjustable prosthetic sockets. The patents were used to find companies, organisations, and institutions who currently sell adjustable sockets or who are developing devices.Results50 literature articles and 63 patents were identified for inclusion, representing 35 different designs used in literature and 16 commercially available products. Adjustable sockets are becoming more prevalent with 73% of publications (literature, patents, and news) occurring within the last ten years. Two key design characteristics were identified: principle of adjustability (inflatable bladders, moveable panels, circumferential adjustment, variable length), and surface form (conformable, rigid multi-DOF, and rigid single DOF). Inflatable bladders contributed to 40% of literature used designs with only one identified commercially available design (n = 16) using this approach. Whereas circumferential adjustment designs covered 75% of identified industry designs compared to only 36% of literature devices. Clinical studies were generally small in size and only 17.6% of them assessed a commercially available socket.DiscussionThere are clear differences in the design focus taken by industry and researchers, with justification for choice of design and range of adjustment often being unclear. Whilst comfort is often reported as improved with an adjustable socket, the rationale behind this is not often discussed, and small study sizes reduce the outcome viability. Many adjustable sockets lack appropriate safety features to limit over or under tightening, which may present a risk of tissue damage or provide inadequate coupling, affecting function and satisfaction. Furthermore, the relationship between design and comfort or function are rarely investigated and remain a significant gap in the literature. Finally, this review highlights the need for improved collaboration between academia and industry, with a strong disconnect observed between commercial devices and published research studies.
| S-EPMC10626671 | biostudies-literature
Project description:BackgroundAcute care events including emergency department (ED) visits and unscheduled inpatient re-admissions following lower-extremity arthroplasty are not fully understood.Question/purposesThe purpose of this study was to characterize acute care events occurring after discharge in patients who received a lower-extremity arthroplasty: the incidence, timing, and risk factors of inpatient admission and ED visits within 90 days of discharge.MethodsThe New York State Inpatient and Emergency Department Databases were used to identify patients who underwent elective total knee arthroplasty (TKA) or total hip arthroplasty (THA) from 2009 to 2013 (124,234 and 76,411 patients, respectively). Multivariate logistic regression analysis was used to determine the predictors of and the most frequent reasons for unscheduled acute care within 90 days of discharge.ResultsUnscheduled acute care was needed in 13.79% of patients (8.81% of inpatient re-admissions and 4.98% of ED visits), most often in the first week after discharge (61.05% of all inpatient re-admissions and 20.46% of all ED visits). Most of these visits were for musculoskeletal pain, peri-prosthetic joint or wound infection, cardiac complications, blood transfusion, psychiatric events, mechanical complications, and deep vein thrombosis. Predictors for the need for acute care after TKA included African American and Hispanic race or ethnicity, Medicaid coverage, and neuraxial anesthesia. Predictors for the need for acute care after THA included older age (over 85 years), African American race, and Medicaid coverage.ConclusionWe identified demographic and procedure-related variables associated with an increased risk of ED visits and inpatient re-admissions after TKA or THA. Understanding these variables will contribute to improved care quality.
| S-EPMC6148588 | biostudies-literature