Ability Of Amputees Research Articles

Closed-Loop Force Control by Biorealistic Hand Prosthesis with Visual and Tactile Sensory Feedback.

The ability of a novel biorealistic hand prosthesis for grasp force control reveals improved neural compatibility between the human-prosthetic interaction. The primary purpose here was to validate a virtual training platform for amputee subjects and evaluate the respective roles of visual and tactile information in fundamental force control tasks. We developed a digital twin of tendon-driven prosthetic hand in the MuJoCo environment. Biorealistic controllers emulated a pair of antagonistic muscles controlling the index finger of the virtual hand by surface electromyographic (sEMG) signals from amputees' residual forearm muscles. Grasp force information was transmitted to amputees through evoked tactile sensation (ETS) feedback. Six forearm amputees participated in force tracking and holding tasks under different feedback conditions or using their intact hands. Test results showed that visual feedback played a predominant role than ETS feedback in force tracking and holding tasks. However, in the absence of visual feedback during the force holding task, ETS feedback significantly enhanced motor performance compared to feedforward control alone. Thus, ETS feedback still supplied reliable sensory information to facilitate amputee's ability of stable grasp force control. The effects of tactile and visual feedback on force control were subject-specific when both types of feedback were provided simultaneously. Amputees were able to integrate visual and tactile information to the biorealistic controllers and achieve a good sensorimotor performance in grasp force regulation. The virtual platform may provide a training paradigm for amputees to adapt the biorealistic hand controller and ETS feedback optimally.

A Review of some Characteristics of a Composite Hybrid Socket for Prosthetics Derived from Plant Fibers

According to the ICF (International Classification of Functioning, Disability, and Health), a prosthetic is a device used to restore or replace the function of a missing limb as a result of a rare genetic defect, dangerous incident, surgical trauma, or disease that limits the amputee's ability to participate in daily life. Prosthetic limb sockets were formerly made out of a wide variety of materials before the development of thermoplastics and composites. Plant fibers are favored due to their low density. Both their strength and rigidity are remarkably high considering their low weight and inexpensiveness. Plant fiber is one of the most popular ways to give polymer composites more strength because of its low production costs and stretchability. Following a brief introduction to the many types of natural fibers (both plant and animal), this article provides a comprehensive assessment of the literature from the past decade that focuses on the mechanical characteristics of plant materials. Reinforced polymers are made with fibers. This literature study will focus on the mechanical properties and behavior of plant fibers used to create sockets for prosthetic limbs. If an article is written about the overall features of composites made with fibers made from the plant, it is expected to be of great use to the research community in the field of composites.

Application of Spare Parts in Combination with Targeted Muscle Reinnervation Surgery.

Targeted muscle reinnervation is a contemporary technique designed to enhance an amputee's ability to operate a myoelectric prosthesis. This technique has been shown to decrease neuropathic pain, including neuroma and phantom limb pain. In certain amputations, especially forequarter and hindlimb levels, there may be no nearby recipient muscle sites, or the residual nerve may be too short to perform targeted muscle reinnervation. Applying the spare parts concept can help solve this problem by providing nerve autograft or additional muscle recipient sites within the spare parts flap for successful targeted muscle reinnervation surgery procedures. A retrospective review of all patients that underwent spare parts targeted muscle reinnervation reconstructions between 2016 and 2019 at two institutions was performed. Patients were assessed for healing, neuroma and phantom limb pain, and function. Twelve patients underwent targeted muscle reinnervation during spare parts reconstruction; eight were male and four were female. The mean patient age was 55.3 years (range, 16 to 72 years). For those with known soft-tissue deficit size, the surface area of the donor site spared by using spare parts reconstruction ranged from 216 to 856 cm2. None of the 12 patients subsequently experienced neuroma, and 75 percent had no phantom limb pain after 3 months. Three patients have obtained insurance-approved myoelectric prosthetics, and all three demonstrated intuitive control of targeted muscles. Using a spare parts reconstruction in conjunction with targeted muscle reinnervation may optimize reconstructive efforts in the setting of major limb amputations and aid in decreasing phantom limb and neuroma pain, and facilitate the possibility of functional prosthetic and/or myoelectric prosthesis use. Therapeutic, IV.

A leg up for neuroprosthetics

Neuroprosthetics Amputation severs bone, nerves, and muscles needed for limb movement, limiting an amputee's ability to sense and control a prosthesis. Clites et al. tested autologous muscle-nerve interfaces made at the time of below-knee amputation in a human subject. In comparison with traditional

Staying in dynamic balance on a prosthetic limb: A leg to stand on?

With the loss of a lower limb, amputees lack the active muscle empowered control of the ankle that is important for balance control. We examined single-leg stance on prosthesis vs. sound limb balancing on narrow ridges in transtibial amputees. When balancing on the prosthetic limb, the lateral displacement of the center of pressure was reduced and was compensated by an increase in counter-rotation. We show that single-leg stance on a prosthetic limb can be compared to balancing on a narrow ridge. Standing on a prosthetic limb involves the same balance mechanisms as balancing on narrow ridges of 40-mm to 20-mm width. Yet, the ability to balance on a narrow ridge with the sound limb was only a weak predictor for an amputee's ability to stand on the prosthetic limb. Balancing in single-leg stance on a prosthetic limb is not a common activity. The ability to compensate with the sound limb may therefore be functionally more important than the ability to stay in dynamic balance on the prosthetic limb.

Influence of Prosthetic Sagittal Alignment on Trans-Tibial Amputee Gait and Compensating Pattern: A Case Study

This study relates the gait asymmetry, residual limb comfort, and energy cost during walking and identifies a compensating pattern for the trans-tibial amputees when the prostheses are misaligned. One male subject with a trans-tibial amputation volunteered for the study. The knee joint moments at the prosthetic side, the phase symmetry index, and the interface pressures were discussed under three sagittal alignment settings. The results show that the subject changes the knee joint moment, gait symmetry, and interface pressure with a misaligned prosthesis to improve his comfort and movement during walking. A high-quality liner reduces the gait sensitivity to misalignment and enhances the amputee's ability to compensate for misalignment. Since different people have different compensation patterns, more cases will be studied in future work.

Summary and Conclusions From the Academy??s Sixth State-of-the-Science Conference on Lower Limb Prosthetic Outcome Measures

Summary and Conclusions From the Academy??s Sixth State-of-the-Science Conference on Lower Limb Prosthetic Outcome Measures

Walking and running inter-limb asymmetry for Paralympic trans-femoral amputees, a biomechanical analysis.

The aim of this project was to further the research and understanding of the trans-femoral amputee's ability to walk and run by comparing the changes in walking and running inter-limb asymmetry. An objective biomechanical analysis was conducted on four male transfemoral amputees, all members of the Australian Paralympic training squad for the 1996 Atlanta Paralympic Games. The data was collected in the biomechanics laboratories at Queensland University of Technology and the Australian Institute of Sport. The main outcomes measure a synchronised 3D kinematic (200 Hz), kinetic (600 Hz) and temporal analysis of walking at self-selected (1.1-1.3 m/s), and at maximal running speed (2.5-4.3 m/s). The walking and running biomechanical data was summarised into 27 indices of symmetry. The results showed that for all subjects the inter-limb asymmetry was significantly different at running speed, when compared to the walking speed. Using indices of symmetry 79% of the kinematic, 67% of the kinetic, and 67% of the temporal measurements identified better inter-limb asymmetry when the subjects walked, compared to running. This study objectively identified that when Paralympic level amputees ran on their standard running prosthesis, the inter-limb asymmetry was exacerbated.

The Amputee Mobility Predictor: An instrument to assess determinants of the lower-limb amputee's ability to ambulate

To describe the development of the Amputee Mobility Predictor (AMP) instrument designed to measure ambulatory potential of lower-limb amputees with (AMPPRO) and without (AMPnoPRO) the use of a prosthesis, and to test its reliability and validity. Measurement study using known groups method and concurrence with existing measures. Academic medical center. A convenience sample of 191 lower-limb amputee subjects who had completed prosthetic training, 24 in the reliability study (mean age +/- standard deviation, 68.3+/-17.9y, range, 28-99y) and 167 in the validity study (mean age, 54.8+/-18.6y; range, 18-100y). Not applicable. Intra- and interrater reliability; construct validity by known groups method; concurrent validity by comparisons with 6-minute walk test, Comorbidity Index, age, and time since amputation; predictive validity by comparison with 6-minute walk test after controlling for other factors. Interrater reliability was.99 for subjects tested with and without their prosthesis; intrarater reliability was.96 and.97. Both the AMPnoPRO (P<.0001) and the AMPPRO scores (P<.0001) distinguished among the 4 Medicare functional classification levels. The AMP correlated strongly with 6-minute walk scores (AMPnoPRO r=.69, P<.0001; AMPPRO r=.82, P<.0001) and the amputee activity survey (AMPnoPRO r=.67, P<.0001; AMPPRO r=.77, P<.0001), and negatively correlated with age (AMPnoPRO r=-.69, P<.0001; AMPPRO r=.56, P<.0001) and comorbidity (AMPnoPRO r=-.43, P<.0001; AMPPRO r=.38, P<.0001). The AMP with and without a prosthesis are reliable and valid measures for the assessment of functional ambulation in lower-limb amputee subjects.

The Amputee Mobility Predictor: An instrument to assess determinants of the lower-limb amputee's ability to ambulate

Gailey RS, Roach KE, Applegate EB, Cho B, Cunniffe B, Licht S, Maguire M, Nash MS. The Amputee Mobility Predictor: an instrument to assess determinants of the lower-limb amputee ability to ambulate. Arch Phys Med Rehabil 2002;83:613-27. Objectives: To describe the development of the Amputee Mobility Predictor© (AMP) instrument designed to measure ambulatory potential of lower-limb amputees with (AMPPRO) and without (AMPnoPRO) the use of a prosthesis, and to test its reliability and validity. Design: Measurement study using known groups method and concurrence with existing measures. Setting: Academic medical center. Participants: A convenience sample of 191 lower-limb amputee subjects who had completed prosthetic training, 24 in the reliability study (mean age ± standard deviation, 68.3±17.9y, range, 28-99y) and 167 in the validity study (mean age, 54.8±18.6y; range, 18-100y). Interventions: Not applicable. Main Outcome Measures: Intra- and interrater reliability; construct validy by known groups method; concurrent validity by comparisons with 6-minute walk test, Comorbidity Index, age, and time since amputation; predictive validity by comparison with 6-minute walk test after controlling for other factors. Results: Interrater reliability was.99 for subjects tested with and without their prosthesis; intrarater reliability was.96 and.97. Both the AMPnoPRO (P<.0001) and the AMPPRO scores (P<.0001) distinguished among the 4 Medicare functional classification levels. The AMP correlated strongly with 6-minute walk scores (AMPnoPRO r=.69, P<.0001; AMPPRO r=.82, P<.0001) and the amputee activity survey (AMPnoPRO r=.67, P<.0001; AMPPRO r=.77, P<.0001), and negatively correlated with age (AMPnoPRO r=−.69, P<.0001; AMPPRO r=.56, P<.0001) and comorbidity (AMPnoPRO r=−.43, P<.0001; AMPPRO r=.38, P<.0001). Conclusion: The AMP with and without a prosthesis are reliable and valid measures for the assessment of functional ambulation in lower-limb amputee subjects. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Kinesthetic Sensing for the EMG Controlled "Boston Arm"

The contribution of a novel cutaneous display of elbow angle to an amputee's ability to position an EMG-controlled externally powered elbow prosthesis was objectively evaluated. Comparisons were made between the amputee's positional control of his conventional mechanical cable-operated elbow and the EMG "Boston Arm"l elbow, with and without angle feedback, in REACHING tasks with vision occluded in all cases and with and without auditory occlusion. MATCHING tasks compared his ability to position the EMG limb to conform with the flexion of his normal (contralateral) elbow. Computer reduction of almost 9000 individual trials and analysis of variance indicated that for the EMG limb the tactile feedback with sound occluded reduced errors by 50 percent. Terminal device load did not significantly affect positioningperformance due to the force proprioception built into the Boston Arm. In comparison with the standard mechanical prosthesis, the EMG limb with feedback achieves virtually identical kinesthetic performance. The display is completely compatible with the EMG control, causes no discomfort to the wearer, and is not significantly degraded by the environmental conditions of the limb socket.