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Foot/Ankle Prostheses Design Approach Based on Scientometric and Patentometric Analyses

1
Faculty of Engineering, Universidad Autónoma del Estado de México, 50130 Toluca, Mexico
2
Faculty of Medicine, Universidad Autónoma del Estado de México, 50180 Toluca, Mexico
3
Cátedras CONACYT, Universidad Autónoma del Estado de México, 50130 Toluca, Mexico
*
Author to whom correspondence should be addressed.
Academic Editor: Luca Testarelli
Appl. Sci. 2021, 11(12), 5591; https://doi.org/10.3390/app11125591
Received: 27 April 2021 / Revised: 27 May 2021 / Accepted: 8 June 2021 / Published: 17 June 2021

Abstract

There are different alternatives when selecting removable prostheses for below the knee amputated patients. The designs of these prostheses vary according to their different functions. These prostheses designs can be classified into Energy Storing and Return (ESAR), Controlled Energy Storing and Return (CESR), active, and hybrid. This paper aims to identify the state of the art related to the design of these prostheses of which ESAR prostheses are grouped into five types, and active and CESR are categorized into four groups. Regarding patent analysis, 324 were analyzed over the last six years. For scientific communications, a bibliometric analysis was performed using 104 scientific reports from the Web of Science in the same period. The results show a tendency of ESAR prostheses designs for patents (68%) and active prostheses designs for scientific documentation (40%).
Keywords: ankle prosthesis; prosthetic foot; lower limb rehabilitation; below-knee amputee ankle prosthesis; prosthetic foot; lower limb rehabilitation; below-knee amputee

1. Introduction

Below-knee amputation (BKA) is a surgical procedure that mainly originates from trauma, diabetes, and peripheral vascular diseases [1]. While it is estimated that an average person walks about 6500 steps per day, current trends suggest that 10,000 steps per day represent a healthy lifestyle [2] for which a suitable prosthesis is necessary for a BKA patient in order to achieve a complete user reintegration to his/her pre-amputation activities. These designs should adapt to different patient’s activities.
In scientific documents, there is wide confusion with the terms prosthesis, prosthetic, and prostheses; prosthetic is the process to manufacture an artificial member (AM), prosthesis a component of the AM, and prostheses are all the components that make up an AM. From patents and scientific document searches, the term prosthesis is more commonly used; in this paper, prostheses and prosthesis will be used interchangeably.
Understanding the functioning of these prostheses is necessary to identify the foot movements: internal–external axial rotation, eversion–inversion, dorsiflexion (DF), and plantarflexion (PF), as shown in Figure 1. The forces acting on the human foot are distributed with 60% towards the heel and 40% towards the phalanges. The loads are distributed between the heel and the metatarsals to the fourth and fifth phalanges and towards the big toe to the second and third phalanges [3].
In order to improve and develop ankle/foot prostheses, it is necessary to know and understand present-day solutions to walking and running for BKA patients (and the people behind those solutions), so our designs meet both user and technical requirements. A state-of-the-art analysis of BKA prostheses is performed in this research.
Foot prostheses can be classified as follows:
  • Ankle-cushion heel (SACH-foot): This was developed in the 1950s and incorporated a compressible heel that dampens the impact on the ground while emulating a plantarflexion movement. This type of prosthesis is used for its relatively low cost and weight [4].
  • ESAR, also known as ESR, was developed in the 1980s. This type of prosthesis uses a foot-modeled plate (usually carbon fiber made) that stores elastic potential energy and progressively releases it as kinetic energy [5].
  • CESR prostheses aim to capture the energy that is dissipated during a gait impact. On the loading phase of stance, energy is stored by a spring and locked. Then, this energy is timely released during the terminal stance of walking using microelectronic components [5].
  • Active prostheses are considered state-of-the-art prostheses due to the use of actuators, microcontrollers, or other electronic devices; usually, these work using ESAR foot systems combined with some external elements such as actuators or other electronic components. These prostheses have better control and stability during a walk cycle [6].
In the next section, it is explained how the investigation was performed for both patents and scientific communications. The Result Section presents a discussion about a new prosthesis classification according to this investigation, main authors, countries, and keywords analyzed. In the discussion Section, findings and other designs of prosthesis designs are disclosed.

2. Search Method

BKA prostheses designs vary in form and functions, so in order to understand the way these designs work, extensive patents and scientific documentation searches were performed.

2.1. Used Keywords

For the patents and scientific communications searches, the following boolean operations were used under the International Patent Classification (IPC) A61F2 belonging to artificial substitutes or replacements for parts of the body: ((Ankle OR foot) AND (prosthetic OR prosthesis OR artificial)). Dates ranges were set from 2014 to 2020. For the patent analysis, 9526 documents were found. A scientific communications search provided 406 results. Figure 2 shows the results filtered on different search engines and the total number of documents obtained in every stage, among which The Lens was the most effective.

2.2. Patent Search

For the patent search, five different search engines were used, of which four were free-source, and one was paid. The databases were Derwent analytics (842 results), Espacenet (86 results), Google patents (5539 results), Patentscope (2281 results), and The Lens (778 results), with a total of 9526 results (see Figure 2).
An initial filter was applied directly to the search engines where undesired categories and keywords were removed, in addition to a manual selection of patents directly on the website.
Subsequently, data cleaning was performed using Open refine®. The second filter was applied to eliminate duplicates, IPC categories that did not correspond, and keywords such as heart, valve, elbow, Arthroplasty, and Orthosis. An individual selection of the patents was made, and the unwanted results were eliminated. The remaining patents were as follows: Patentscope (369), Google patents (390), Espacenet (55), Derwent analytics (546), and The Lens (309), resulting in 1669 patents.
Based on a third filter, the results of all databases were merged, and keywords such as knee, orthosis, and tibia were eliminated. Duplicated results were filtered, and the remaining patents were individually analyzed for a total result of Derwent analytics (70), Espacenet (12), Google patents (19), Patentscope (72), and The Lens (151), resulting in 324 patents directly related to ankle and foot prostheses. From Figure 2, it can be observed that although Google patents and Patentscope were the ones with more results, these contained a higher number of duplicates or undesired data.

2.3. Scientific Communications Search

For the literature analysis, the same keywords as for the patents’ search were applied in the Web of Science (WOS), obtaining 406 documents related to foot/ankle prostheses. The first filter was performed directly on the website, removing undesired keywords for a total of 136 documents. Subsequently, a second filter was applied, deleting repeated and undesired results. An individual document selection was made, resulting in 97 results. Finally, a bibliometric analysis was performed using data recovery software (R studio®) and a complement for bibliometric analysis (Bibliometrix®).

3. Results

3.1. Patentometric Analysis

Among the 324 results obtained, 208 results match prostheses designs, 51 match prosthetic mechanisms (motion blocking systems, aids to align prostheses, etc.), 22 match sockets, 11 match aesthetic covers, and 10 match joints. In total, 22 results are associated with methodologies (manufacturing methods, design methods, tests). Figure 3 shows these results; the number of prosthesis designs suggests a high interest in the development of new solutions for BKA amputees.
The main offices in which patents are registered are the United States (178 patents), European Office (45 patents), International Office (37 patents), and China (34 patents).
Among the results, 95 refer to foot prostheses, 65 to ankle prostheses, and 48 to a combination of both, of which 182 are removable, and 26 are osseointegrated. In this investigation, only removable prostheses are considered. Table 1 shows the selected patents, the technology used, and the type of prostheses. Among removable prostheses, 135 are mechanical or propelled with the body, hydraulic (18 results), and electronic or active (29 results). These results are distributed among ESAR, CESR, active, and hybrid (which did not match any of the aforementioned technologies or they are a combination of two or more categories). From Figure 4, it can be observed that for electronic prostheses, 17 are active, three are CERS (use a controlled energy return without the use of complex devices), one is ESAR, and eight are hybrid. For hydraulic prostheses, four use electronic components, three are based on CERS, three on ESAR, and eight are a combination of three or more categories. For mechanical prostheses, 94 use ESAR systems exclusively, 26 combine different technologies (but mostly are mechanical), 13 are CERS (energy return is controlled using only mechanical devices), and two use actuators to release the energy.
Applicants and inventors in the databases were considered. Otto Bock Health Co. and Clausen Arinbjorn V. are the main applicants with ten and eight patents, respectively, from 2014 to 2020. Figure 5 shows the main applicants for BKA prostheses.

3.2. Scientometric Analysis

After the final filter was applied, 98 scientific documents directly related to ankle/foot prostheses were selected; results are shown in Table 2. Keywords were analyzed resulting in the top 10: gait (frequency = 15 articles), prosthesis (frequency =14 articles), prosthetics (frequency =13 articles), amputation (frequency =11 articles), biomechanics (frequency =11 articles), ankle (frequency = eight articles), transtibial (frequency = eight articles) prosthetic foot (frequency = seven articles), powered prosthesis (frequency = six articles), and gait analysis (frequency = five articles). This means there is a major trend in developing prostheses devices compared with gait studies or the creation of new methodologies.
From the information obtained by the scientific documents, several aspects must be considered when designing a new prosthesis, such as aesthetics, which allows empathy between the users and their prosthesis [1], a size that permits the use of footwear, a mass corresponding to 2.5% of bodyweight [160] (literature shows an average of 2.5 kg for a 75 kg person), an ankle torque corresponding to 100–140 Nm, an ankle power between 250-300 W, and a device capable of storing and releasing energy (5–9 J)
On the authors’ part, Lefeber D. and Vanderborght B. are the top authors (11 articles each). Nevertheless, Hugh M. Herr is the most cited author in this field, with five of the most cited articles.
Table 3 shows, in order, the most cited articles, and Figure 6 shows the most relevant authors in scientific documentation.
The United States (US) is the most productive country (46 documents), followed by Belgium (seven documents) and China (five documents). Some documents showed multiple country collaborations (Figure 7). There is a clear relation between authors, journals, and countries. For example, most of the documents submitted in the US are from IEEE magazines and Plos One; meanwhile, Europe tends to apply to Prosthetic and Orthotic international and the American society of mechanical engineers (ASME).

4. Discussion

4.1. Device Classification

From the selected patents and scientific documentation, a new ankle/foot prosthesis classification has been created besides ESAR, CERS, and active, based on its components and prosthesis functions.
ESAR prostheses are categorized into five different designs (see Figure 8). CERS and active categories are merged and divided into five different categories. There are some unique designs whose components cannot be grouped; these will be discussed individually.
From the previous analyses, it can be determined that the general form for ESAR prosthesis is similar to the one illustrated in Figure 8A and mostly differs in form; sometimes, a single talon plate is aggregated, or the disposition of the plates may vary. In other cases, as in Figure 8B, the center of mass is moved, and the plates are rearranged. In the variation represented by Figure 8C, the foot plates are divided, so the prosthesis emulates eversion and inversion movements. In Figure 8D, some polymeric cushions are aggregated, replacing the use of extra plates. Figure 8E shows the usage of different types of damping systems (springs, actuators, etc.) that replace some plates. All of these designs use pyramid adapters as a connection between the prosthesis and transtibial components.
There are some variations for ESAR prostheses that use a simple plate arrangement to adjust the return of energy (see Figure 9A). Other designs use a single spring bar that regulates the energy storage/release (see Figure 9B).
For CERS prosthesis, the model by Endo Ken [129] (see Figure 10) considers a locking mechanism that preserves the energy storage in the spring. This energy is released upon the foot movement during the terminal stance. This impulse, in combination with the ESAR foot, provides necessary torque during the walk cycle.
Active prostheses can be categorized by the components they use into three types: Multi-Array Prostheses (MAP), Low Powered Prostheses (LPP), and Controlled Adaptative Stiffness (CAS). For MAP, the form is similar to the one shown in Figure 11. It uses an ESAR composite foot (E), and a DC motor (A), usually a 200 W Maxon® connected to a ball-screw transmission (C) that moves the linkage system (D) upward/downward and converts motor rotary motion into linear motion. In some cases, the motor is located instead of the spring (G) and connected to (C) using a timing belt. The linkage system (D) is in charge of connecting different mechanisms and allows plantarflexion and dorsiflexion movements; it may be composed of cables and/or pulleys, a bar mechanism, or crank sliders. F and G, depending on the prostheses, represent springs or actuators (pneumatic, electric, or hydraulic), for which torque varies from 100 to 140 Nm. Sometimes a parallel spring is aggregated due to the demanding torque requirements, and it aims to reduce the loads supported by the linkage system. Spring (G) saves energy during plantarflexion and dorsiflexion and supplements it during the swing phase. Housing (B) allocates all the electronic systems and provides stability to the system. The pyramid adapter (H) provides a connection between the transtibial components and the prosthesis. Some models have a lock mechanism, so the prosthesis could be used in a passive mode. See Figure 11, Figure 12, Figure 13, Figure 14 and Figure 15.
Another powered prosthesis design is the LPP shown in Figure 12. It aims to reduce the necessary power required by the actuators. It contains different Footplates (G and C), which in some designs (similar to the AMP Foot 2.1 [199]) are merged into a single plate. In another case such as the VSPA Foot [245], footplates (G) are individually controlled, allowing eversion–inversion movements; the DC motor (A) is located in a Housing (J) and rotates the Ball screw transmission (B), which moves the Footplate (C) up or down, allowing plantarflexion and dorsiflexion movement. Heel (D) may be composed of a flexible plate; ankle stiffness is provided by Springs (H) and (E). Depending on the model, two Springs (H) are used when there are individually controlled Footplates, and Spring (E) is used when (G) and (C) are merged. In this case, Spring (E) is attached directly to Footplate (C). Spring (E) is elongated using a Pulley system (F) connected to the Footplate (C). The pyramid adapter (I) provides a connection between the transtibial components and the prosthesis. Designs for this model use an external power supply that is not integrated into the main prosthesis body.
CAS prostheses (see Figure 13) are mainly based on an ESAR foot (D), and in some cases complemented with a Cushion (E). The main goal of this prosthesis is the modulation of the stiffness during different stages of a gait cycle. This is granted by moving a Slider (G) along the length of the foot. Depending on the gait cycle, this slider moves forward and backward, providing the necessary stiffness to adapt to different situations such as walking, running, or climbing stairs, and it is controlled by a DC motor (C). A linkage system could be provided by a Ball screw transmission (F) or pulleys and belts. Motor (C) could be programmed to adapt to different activities. Housing (B) provides support for all the components and allows one degree of freedom (DOF) for the foot. The pyramid adapter (A) provides a connection between the transtibial components and the prosthesis.

4.2. Other Designs

Some designs do not correspond to the categories previously described. These designs are the pneumatic foot prosthesis by Huang et al. [189] (see Figure 14A), where DF and PF are managed by two artificial muscles each, so stiffness and PF torque are easier to control. It is capable of emulating 3 DOF and is controlled via a desktop computer. Another design is the two DOF cable-driven ankle–foot prosthesis by Ficanha et al. [213], where instead of using pneumatic systems, it uses pulleys and Bowden cables that are externally controlled by two motors (Maxon EC-4), see Figure 14B. Both systems have an external power source and are capable of emulating foot eversion and inversion movements.
Another case is the robotic foot prosthesis made by Lapre [229]. This device aims to actively align the foot during different stances of the gait cycle using a four-bar linkage system to rotate and translate the foot with the use of a single actuator. It works using an ESAR foot and a DC motor (Maxon® EC-30 200 W) that moves a Ball screw transmission via a belt drive. As this actuator system (motor and ball screw) contracts, it extends and shifts the foot center (see Figure 15).

4.3. ESAR Analysis

Most of the active prostheses use ESAR foot to generate enough power to initiate the gait cycle. From the patentometric and scientometric analysis, it is evident that types A, B, and C are the most used (see Figure 8). A structural analysis was performed to make a comparison between these types. Carbon-fiber footplates and a concrete floor were used. A load of 785 N was applied on the prosthesis upper faces obtaining a maximum deformation on the Y-axis of 0.63, 0.33, and 0.67 mm for types A, B, and C, respectively (see Figure 16). Meanwhile, deformations on A and C mostly occur on the ankle; B shows major flexibility along the foot. The red color shows maximum displacements on the foot connection with the body, but blue shows no deformation.
According to the structural analysis, B tends to offer major elastic energy compared to A and C, as shown in the instep colored in green/blue.
To compare the effectiveness during a walk cycle on uneven terrain, prostheses A, B, and C were analyzed using the same velocity and loads. Figure 17 shows a clear advantage of (C) over the other two models, thanks to the uneven deformation on its divided footplates, as shown for the displacement colored in red.

5. Conclusions

The number of results per database does not reflect the effectiveness of each search engine. For this research, priority was given to search engines that provided useful data such as direct links to patents, the inventor’s name, and IPC codes. Nevertheless, there are some difficulties with some of them, such as the lack of options for filtering results or IPC categories, among others. Besides, some applicants may be included in the name of their companies (for example, Herr Hugh in Massachusetts Institute of Technology); this is because some search engines only show the applicant/owner’s name instead of the inventor. In some cases, there is a lack of consistency between the author’s names in different patents (for example, Smith Keith and Smith, Keith, B.); these kinds of inconsistencies were clustered, but still, results could not be entirely precise.
The United States has 56% of patent applications and 34% of scientific documents registered. These results do not necessarily display that they produce most of the knowledge on this topic, but because of the language, most of the search engines are capable of accessing the data, unlike languages such as Spanish, Chinese, or languages spoken in India. Therefore, some designs could remain undiscovered for this investigation.
Based on the obtained results, it can be established that for this study, the effectiveness per search engine is as follows: Derwent 8.4%, Google patents 0.34%, Patentscope 3.2%, The Lens 19.9%, and Espacenet 13.95%.
The classification of the 208 prosthesis patents related to prostheses designs was obtained according to the main technology used; results show that the ESAR mechanical prosthesis is the main patent object by 44%, although claims are different for each one. All of them can be classified based on the five ESAR categories presented in this document. Outcomes also show a tendency for the use of ESAR regardless of the technology used. For 151 removable foot/ankle patent prostheses analyzed, 53% use only ESAR-type prosthesis, and 90% use ESAR in its components. From these, the more commonly used were selected and compared using Ansys, with no major differences between A and C, but for B, results show a more elastic foot thanks to its mass-centered design.
The significant trend in the use of ESAR prostheses may be because of their lower cost and greater energy efficiency. Different designs are used according to the user’s lifestyle.
The minimum amount of components found for designing an active prosthesis is a DC motor, housing, a power transmission unit, a composite foot or equivalent, an energy storage device (springs, locking systems), a linkage system, an energy power supply, and a prosthesis/socket connector. From these components, most prostheses use a Maxon® Brushless motor between 12 and 200 W. Power variations are mostly due to the gear ratio used (the more power, the lower the gear ratio), springs with stiffness between 60–445 kNm, and a Li-ion battery between 12–24 V. From these components it is especially important to consider when designing a BKA prosthesis the linkage system that needs to support most of the necessary loads, and it must be capable of tolerating at least 2 kN (for an 80 kg patient) without any failure.
Materials also play a vital role in supporting loads with 4000/5000 duty cycles per day; that is why aluminum, carbon fiber, and other composites are used in fabrication, and sometimes load reduction along the system is necessary and archived using a parallel spring arrangement.
The current development of batteries allows active prostheses to obtain enough power and charge duration without adding extra mass and weight, but for hydraulic and pneumatic prostheses, power supply currently is a problem because most of these systems are connected externally and the mass could reach up to 15 kg. Nevertheless, these systems are more efficient in mimicking human ankle movements.
For BKA prostheses, continuous growth in the development of active ones is estimated. Even though actual prostheses are capable of emulating three degrees of freedom, there is space for a complete body-integrated ankle/foot prosthesis.

Author Contributions

J.Z.-L. developed the practical aspects of this research, L.A.Z.-A. provided original schematic, exhaustive work on reviewing and editing, and supervised this research, A.H.V.-G. and J.C.Á.-V. reviewed, edited, and corrected this document. All authors participated in reviewing and writing this manuscript. All authors have read and agreed to the published version of the manuscript.

Funding

The present article used free software except for Derwent analytics for the patent analysis; this software was provided by the Autonomous University of Mexico State. This research was funded by CONACYT (Consejo Nacional de Ciencia y Tecnología), Grant 1009402.

Institutional Review Board Statement

Not applicable, because of this review did not involving humans or animals.

Informed Consent Statement

Not applicable, because of this review did not involving humans or animals.

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. Different movements of the foot.
Figure 1. Different movements of the foot.
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Figure 2. Search method for patents/scientific documents and total results.
Figure 2. Search method for patents/scientific documents and total results.
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Figure 3. Categories of the patents’ analysis and results by category.
Figure 3. Categories of the patents’ analysis and results by category.
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Figure 4. A display of prosthesis types in terms of electronic, hydraulic, and mechanical technology.
Figure 4. A display of prosthesis types in terms of electronic, hydraulic, and mechanical technology.
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Figure 5. Top patent applicants for lower limb prosthesis.
Figure 5. Top patent applicants for lower limb prosthesis.
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Figure 6. Top 10 most relevant authors on lower limb prosthesis design.
Figure 6. Top 10 most relevant authors on lower limb prosthesis design.
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Figure 7. Most productive countries for ankle/foot prosthesis literature.
Figure 7. Most productive countries for ankle/foot prosthesis literature.
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Figure 8. (A) General form of ESAR prosthesis, (B) Modified ESAR prosthesis, (C) ESAR with split plates, (D) ESAR prosthesis with cushions, (E) ESAR with damping system.
Figure 8. (A) General form of ESAR prosthesis, (B) Modified ESAR prosthesis, (C) ESAR with split plates, (D) ESAR prosthesis with cushions, (E) ESAR with damping system.
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Figure 9. (A) Multiple plates prosthesis, (B) Single spring prosthesis by Kim Sa Yeop [74].
Figure 9. (A) Multiple plates prosthesis, (B) Single spring prosthesis by Kim Sa Yeop [74].
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Figure 10. CERS prosthesis by Endo Ken [129].
Figure 10. CERS prosthesis by Endo Ken [129].
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Figure 11. MAP active ankle–foot prosthesis.
Figure 11. MAP active ankle–foot prosthesis.
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Figure 12. LPP active prosthesis.
Figure 12. LPP active prosthesis.
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Figure 13. CAS Prosthesis.
Figure 13. CAS Prosthesis.
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Figure 14. (A) Experimental powered lower limb prosthesis by Huang et al. [189] and (B) two DOF cable-driven ankle–foot prosthesis by Ficanha et al. [213].
Figure 14. (A) Experimental powered lower limb prosthesis by Huang et al. [189] and (B) two DOF cable-driven ankle–foot prosthesis by Ficanha et al. [213].
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Figure 15. A robotic ankle–foot prosthesis by LaPre [229].
Figure 15. A robotic ankle–foot prosthesis by LaPre [229].
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Figure 16. Comparative static analysis of ESAR prosthesis.
Figure 16. Comparative static analysis of ESAR prosthesis.
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Figure 17. Results of deformations on uneven terrain.
Figure 17. Results of deformations on uneven terrain.
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Table 1. Removable ankle/foot prostheses patents.
Table 1. Removable ankle/foot prostheses patents.
CiteTitleMain ApplicantBody PartTechnologyType
[7]-Adjustment Device for A Lower Limb ProsthesisBlatchford Products Limited.AnkleHydraulicHybrid
[8]-Below-knee Prosthesis Provided with Power Ankle Beijing Gongdao Fengxing IntelligentAnkle/FootElectronicESAR
[9]-Bifurcated, Multi-purpose Prosthetic FootChristensen Roland J.FootMechanicalESAR
[10]-Bi-modal Ankle-foot DeviceHansen Andrew H.Ankle/FootMechanicalCESR
[11]-Controlling Power in A Prosthesis or orthosis Based on Predicted Walking Speed or Surrogate for SameHerr Hugh M.Ankle/FootElectronicCESR
[12]-Damping Device for A ProsthesisOssur Hf.AnkleMechanicalHybrid
[13]-Energy Storing Foot PlateIversen Edwin KayAnkle/FootMechanicalESAR
[14]-Further Improvements to Ankle–foot Prosthesis and orthosis Capable of Automatic Adaptation to Sloped Walking SurfacesHansen Andrew H.Ankle/FootMechanicalCESR
[15]-Joints for Prosthetic, orthotic and/or Robotic DevicesRifkin Jerome R.FootMechanicalHybrid
[16]-Low Profile Prosthetic FootJonsson Orn IngviFootMechanicalESAR
[17]-Lower Limb Prosthetic Device with A Wave SpringRubie Eric W.FootMechanicalESAR
[18]-Modular Prosthetic FootMiller Joseph A.FootMechanicalESAR
[19]-Orthopedic Foot PartOtto Bock HoldingAnkle/FootElectronicActive
[20]-Passive Ankle Prosthesis with Energy Return Simulating that of A Natural AnkleJoseph M. SchimmelsAnkle/FootMechanicalCESR
[21]-Passive orthopedic Aid in the form of a Foot Prosthesis or Foot orthosisOtto Bock HealthcareAnkle/FootHydraulicActive
[22]-Power Below-knee Prosthesis with Discrete Soft Toe Joints Beijing Gongdao Fengxing IntelligentAnkle/FootMechanicalESAR
[23]-Prosthetic Ankle–foot System Universiteit GentAnkle/FootMechanicalHybrid
[24]-Prosthetic Energy Storing and Releasing Apparatus and MethodsPhillips Van L.FootMechanicalESAR
[25]-Prosthetic FootKeith B. SmithFootMechanicalESAR
[26]-Prosthetics Using Curved Dampening CylindersAaron TaszreakAnkle/footMechanicalESAR
[27]-A Foot with A Vacuum Unit Activated by an Ankle MotionDuger MustafaAnkleMechanicalHybrid
[28]-Artificial Ankle, Artificial Foot and Artificial LegFalz & Kannenberg GmbhAnkleElectronicActive
[29]-Artificial Limb Prosthesis Leg Below Knee & Above KneeUniv BharathAnkle/FootMechanicalESAR
[30]-Flexible Prosthetic ApplianceBrown Christopher A.FootMechanicalHybrid
[31]-Foot for Mobility DeviceSanders Michael R.FootMechanicalESAR
[32]-High-performance Multi-component Prosthetic FootRubie Eric W.FootMechanicalESAR
[33]-Hydraulic Actuating Unit and Artificial Foot Prosthesis System Having the Same GyeonggyeongcheolAnkleElectronicHybrid
[34]-Hydraulic System for A Knee-ankle Assembly Controlled by a MicroprocessorXavier BonnetAnkleElectronicCESR
[35]-Prosthesis Structure for Lower-limb Amputees Officine Ortopediche Rizzoli Sr.Ankle/FootElectronicHybrid
[36]-Prosthetic FootAbility Dynamics Llc.FootMechanicalESAR
[37]-Prosthetic FootFrizen FootMechanicalESAR
[38]-Prosthetic FootFrizen DzheffFootMechanicalESAR
[39]-Prosthetic FootLuder MoslerFootMechanicalESAR
[40]-Prosthetic FootThe Ohio Willow Wood CompanyFootMechanicalESAR
[41]-Prosthetic Foot with a Curved SplitJonsson Vilhjalmur FreyrFootMechanicalESAR
[42]-Prosthetic Foot with Dual Foot Blades and Vertically offset ToeLecomte Christophe GuyFootMechanicalESAR
[43]-Prosthetic Foot with Floating forefoot KeelChristensen Roland J.FootMechanicalESAR
[44]-Prosthetic Limb3d SystemsAnkle/FootMechanicalESAR
[45]-Prosthetic SystemHawkins RyanAnkleMechanicalHybrid
[46]-Smooth Rollover insole for Prosthetic FootClausen Arinbjorn ViggoFootMechanicalESAR
[47]-System for Powered Ankle–foot Prosthesis with Active Control of Dorsiflexion-plantarflexion and inversion-eversionMo RastgaarAnkleElectronicHybrid
[48]-Walking Controller for Powered Ankle ProsthesesMichael GoldfarbAnkleElectronicActive
[49]-Actuated Prosthesis for AmputeesBedard StephaneAnkle/FootElectronicActive
[50]-Additive Manufacturing Produced Prosthetic FootJames M. ColvinFootMechanicalESAR
[51]-Ankle Prosthesis AssemblyErmalyuk Vladimir NikolaevichFootHydraulicHybrid
[52]-Ankle Prosthesis Assembly of FootSuslov Andrej VladimirovichFootMechanicalESAR
[53]-Artificial FootInha Industry Partnership InstituteFootElectronicActive
[54]-Artificial Foot for Sports Seo Jung WoongAnkle/FootMechanicalESAR
[55]-Artificial Foot Prosthesis System Sogang UniversityAnkleElectronicActive
[56]-Artificial Human Limbs and Joints Employing Actuators, Springs, and Variable-damper ElementsMassachusetts Institute of TechnologyAnkleMechanicalActive
[57]-Controlled Coronal Stiffness Prosthetic AnkleKlute GlennAnkleMechanicalHybrid
[58]-False Foot of Carbon -fibre Composite Beijing Baimtec.FootMechanicalESAR
[59]-Foot ProsthesisMedi Gmbh & Co.FootMechanicalESAR
[60]-Foot Prosthesis with Adjustable RolloverMccarvill SarahFootMechanicalESAR
[61]-Hybrid Ankle Joints Jo HyunAnkleElectronicActive
[62]-instrumented Prosthetic FootVicthom Human Bionics Inc.FootMechanicalESAR
[63]-Layering Technique for An Adjustable, Repairable Variable Stiffness Prosthetic FootGonzalez Roger V.FootMechanicalESAR
[64]-Passive orthopaedic Aid in the form of a Foot Prosthetic or orthotic MoslerFootMechanicalHybrid
[65]-Prosthetic Ankle ModuleÁsgeirsson SigurõurFootMechanicalESAR
[66]-Prosthetic Ankle ModuleNijman JeroenFootMechanicalESAR
[67]-Prosthetic Ankle: A Method of Controlling Based on Adaptation to SpeedArinbjorn ClausenAnkleMechanicalActive
[68]-Prosthetic Device and Method with Compliant Linking Member and Actuating Linking MemberMatthew A. HolgateAnkle/FootElectronicCESR
[69]-Prosthetic FootAbility Dynamics Llc.FootMechanicalESAR
[70]-Prosthetic FootAbility Dynamics Llc.FootMechanicalESAR
[71]-Prosthetic FootDoddroe Jeffrey L.FootMechanicalESAR
[72]-Prosthetic FootStarker FelixFootMechanicalESAR
[73]-Prosthetic FootSulprizio Michael ScottFootMechanicalESAR
[74]-Prosthetic Foot and Manufacturing Method ThereofKim Sa YeopFootMechanicalESAR
[75]-Prosthetic Vacuum SystemOssur Hf.FootElectronicHybrid
[76]-Responsive ProsthesisHowellFootMechanicalESAR
[77]-A Prosthesis or orthosis Comprising a Hinge Joint System for Functionally Assisting, Enhancing and/or Replacing A Hinge Joint of a Human or Animal SubjectVrije Universiteit BrusselAnkle/FootMechanicalCESR
[78]-Active Lower Leg Prosthesis Device Sogang UniversityAnkleHydraulicCESR
[79]-Apparatus and Method for A Split Toe BladeRubie Eric W.FootMechanicalESAR
[80]-Artificial Ankle Joint Limb Based on Flexible Driver Nanjing Institute of TechnologyAnkleMechanicalHybrid
[81]-Artificial FootHornos PedroFootMechanicalESAR
[82]-Artificial Foot and Method for Controlling the Movement ThereofOtto Bock Holding.FootMechanicalESAR
[83]-Bow -shaped Ankle Structure Combined Material Artificial Limb Foot CoreLin Yusen.FootMechanicalESAR
[84]-Catapult Ankle and Related MethodsRouse Elliott J.AnkleElectronicHybrid
[85]-Dispositif De Prothese De Cheville Controle Par Une Prothese De Genou Motorisee Sensible A La PesanteurMillinavAnkleMechanicalHybrid
[86]-Electronically Controlled Prosthetic SystemMartin James JayFootElectronicActive
[87]-Fine Energy Storage Foot of CarbonSun YongshangFootMechanicalESAR
[88]-Foot ProsthesisKranner WernerFootMechanicalESAR
[89]-Foot Prosthesis with Resilient Multi-axial AnkleLecomte Christophe GuyFootMechanicalESAR
[90]-Microprocessor Controlled Prosthetic Ankle System for Footwear and Terrain AdaptationPalmer MichaelAnkleHydraulicActive
[91]-Novel Fine Prosthetic Foot of Comfortable Energy Storage CarbonGuangzhou Kangmeite Prostheses Co Ltd.FootMechanicalESAR
[92]-Oil Pressure Ankle Joint Ken Dall Enterprise.AnkleHydraulicHybrid
[93]-Overmould Attachments for Prosthetic FootLecomte Christophe GuyFootMechanicalESAR
[94]-Prosthetic Ankle and Method of Controlling Same Based on Adaptation to SpeedOssur Hf.AnkleElectronicActive
[95]-Prosthetic FootKeith B. SmithFootMechanicalESAR
[96]-Prosthetic FootOtto Bock Holding.FootMechanicalESAR
[97]-Prosthetic FootSun YongshangFootMechanicalESAR
[98]-Prosthetic Foot StructureCheng Yao TengFootMechanicalESAR
[99]-Prosthetic Foot with Energy Transfer Medium including Variable Viscosity FluidChristensen Roland J.FootMechanicalESAR
[100]-Prosthetic Foot, System of A Prosthetic Foot and A Shoe, and Method for Adapting the Heel Height of a Prosthetic FootHermann MeyerAnkle/FootMechanicalESAR
[101]-Prosthetic Joint with Mechanical Response System to Position and Rate of ChangeLincoln Lucas SamuelAnkleMechanicalCESR
[102]-Prosthetic Sport FeetClausen Arinbjorn V.FootMechanicalESAR
[103]-Shock Attenuation Energy -absorbing Prosthetic Foot Foot CoreLi JingtongFootMechanicalESAR
[104]-Single-freedom-degree Active Type Ankle Joint Artificial Limb Based on Closed Type Hydraulic Driving System Wang XingjianAnkle/FootHydraulicActive
[105]-Systems and Control Methodologies for Improving Stability in Powered Lower Limb DevicesVanderbilt UniversityAnkle/FootElectronicActive
[106]-Actuator Control System and Related MethodsNorthern Arizona University.Ankle/FootElectronicActive
[107]-Ankle–foot Prosthesis DeviceLiu Yan NanAnkleElectronicActive
[108]-Articulated orthopaedic Foot with Shock Absorption, Which Prevents the Impact Produced in Each Foot-loading Cycle When Walking or Running, Providing Natural Movement and Stability for The UserMora Morales MiguelFootMechanicalESAR
[109]-Artificial FootLindhe Christoffer.FootMechanicalESAR
[110]-Biomimetic and Variable Stiffness Ankle System and Related MethodsRouse Elliott J.AnkleMechanicalHybrid
[111]-Bionic Prosthetic Mechanical Foot with Parallel JointsXing ZhipingAnkle/FootElectronicHybrid
[112]-Clearance Enhancer for Lower Limb ProsthesisPalmer Jeffrey RayFootMechanicalESAR
[113]-Energy Storage FootBonawei Rehabilitation.Ankle/FootMechanicalESAR
[114]-Foot ProsthesisOtto Bock Holding.Ankle/FootElectronicHybrid
[115]-Foot ProsthesisSven KaltenbornAnkle/FootHydraulicHybrid
[116]-Foot Prosthesis Has Blade Benjamin PenotAnkle/FootMechanicalHybrid
[117]-Foot Prosthesis with Dymic Variable Keel Resistance Matthew J. HabeckerAnkle/FootMechanicalCESR
[118]-Foot Prosthesis with Dynamic Variable Keel ResistanceMatthew J. HabeckerAnkle/FootMechanicalHybrid
[119]-Hydraulic Ankle Chia-pao ChengAnkleHydraulicHybrid
[120]-Hydraulic Ankle JointKen Dall Enterprise.AnkleHydraulicHybrid
[121]-Jointless Prosthetic FootBoiten Herman.FootMechanicalESAR
[122]-Light intelligent Energy-storage Energy-releasing Ankle ProsthesisYe Yanhong.FootMechanicalCESR
[123]-Limb Prosthesis System and MethodBartlett Brian.Ankle/FootMechanicalHybrid
[124]-Linear Actuator for Asymmetric Power Generation and DissipationMichael Goldfarb.AnkleElectronicHybrid
[125]-Lower Limb Prosthesis Comprising A Hydraulic Damping and A Vacuum Generating MechanismGraham Harris.Ankle/FootHydraulicActive
[126]-Medial-lateral Stabilizing Prosthetic Ankle/foot for Angled and Rough Ground GaitMaitland Murray E.Ankle/FootMechanicalHybrid
[127]-Method for Operating A Prosthetic Ankle Clausen Arinbjorn V.FootElectronicActive
[128]-Modular Lower Limb Prosthesis SystemFairley Joseph.FootMechanicalESAR
[129]-Movement Support ApparatusEndo Ken.Ankle/FootMechanicalCESR
[130]-Polycentric Powered Ankle ProsthesisLenzi Tommaso.AnkleElectronicActive
[131]-Powered Artificial Ankle Based on Electro-hydraulic Direct Drive Technology Huang Qi-tao.AnkleHydraulicHybrid
[132]-Prosthetic and Orthotic Devices Having Magnetorheological Elastomer Spring with Controllable StiffnessGudmundsson Ivar.FootMechanicalESAR
[133]-Prosthetic Ankle and Foot CombinationMoser David.Ankle/FootMechanicalESAR
[134]-Prosthetic DeviceFillauer Euro Ab.Ankle/FootMechanicalESAR
[135]-Prosthetic DeviceRamirez Christoffer.FootMechanicalESAR
[136]-Prosthetic FootBonacini Daniele.FootMechanicalESAR
[137]-Prosthetic FootSmith Keith.FootMechanicalESAR
[138]-Prosthetic FootWillowwood Global.FootMechanicalESAR
[139]-Prosthetic FootZamora David A.FootMechanicalESAR
[140]-Prosthetic Foot with Hybrid LayupGunnarssonn Ragnar.FootMechanicalESAR
[141]-Prosthetic Foot with Modular ConstructionKramer Leslie D.FootMechanicalESAR
[142]-Shank Prosthesis Provided with Double Foot Sole PlatesZhang Jun.FootHydraulicESAR
[143]-Spring Design for Prosthetic ApplicationsProst Victor.FootMechanicalHybrid
[144]-Stair Ascent and Descent Control for Powered Lower Limb Devices Vanderbilt University.Ankle/FootMechanicalESAR
[145]-Tapered Flex Plate for Prosthetic FootJonsson Orn Ingvi.FootMechanicalESAR
[146]-Variable Bar Length Gear Five-bar Mechanism Active and Passive Ankle Artificial Limb Univ Northwestern Polytechnical.AnkleMechanicalHybrid
[147]-Variable Stiffness Prosthetic FootSandahl David.FootMechanicalESAR
[148]-Adjustable Stiffness Prosthetic FootSmith Justin R.FootMechanicalESAR
[149]-Ankle–foot Prosthesis for Automatic Adaptation to Sloped Walking SurfacesHansen Andrew H.FootMechanicalCESR
[150]-Artificial Ankle–foot System with Spring, Variable-damping, and Series-elastic Actuator ComponentsMassachusetts Institute of Technology.Ankle/FootElectronicActive
[151]-Biomimetic Prosthetic DeviceSchlafly Millicent KayFootMechanicalCESR
[152]-Carbon Fiber Prosthetic FootNelson Ronald Harry.footMechanicalESAR
[153]-Compression Heel Prosthetic FootParker Gene.FootMechanicalESAR
[154]-Foot ProsthesisPusch Martin.FootMechanicalESAR
[155]-Hydraulic Pressure Energy Storage Prosthetic FootWang Zitong.Ankle/FootHydraulicESAR
[156]-Hydraulic Prosthetic AnklePoulson Arlo Iii.AnkleMechanicalCESR
[157]-Low-energy Artificial LimbWang Jianhua.FootMechanicalESAR
[158]-Lower Limb ProsthesisBlatchford Products.Ankle/FootElectronicActive
[159]-Passive and Slope Adaptable Prosthetic Foot AnkleAmiot DavidFootHydraulicCESR
[160]-Powered Ankle–foot ProsthesisHerr Hugh M.Ankle/FootElectronicActive
[161]-Prosthesis and Prosthetic Foot AdapterAllermann Ralf.Ankle/FootMechanicalESAR
[162]-Prosthetic Ankle Joint MechanismMoser David.AnkleHydraulicHybrid
[163]-Prosthetic Apparatus and Method ThereforPeter Gabriel A.FootMechanicalESAR
[164]-Prosthetic Feet Having Heel Height AdjustabilityAlbertson Aron Kristhjorn.AnkleMechanicalCESR
[165]-Prosthetic FootFriesen Jeff.FootMechanicalESAR
[166]-Prosthetic FootGrosskopf Stefan.FootMechanicalESAR
[167]-Prosthetic FootGuangdong Lanwan Intelligent Technology.Ankle/FootMechanicalHybrid
[168]-Prosthetic FootJo Sung Hun.FootMechanicalESAR
[169]-Prosthetic FootPusch Martin.FootMechanicalESAR
[170]-Prosthetic Foot Having A Function of AnkleKim Hyun Cheol.Ankle/FootMechanicalESAR
[171]-Prosthetic Foot insert and Prosthetic FootMosler Loder.FootMechanicalESAR
[172]-Prosthetic Foot that Toe Part Can RotateKim Hyun Cheol.FootMechanicalESAR
[173]-Prosthetic Foot with Enhanced Stability and Elastic Energy ReturnClausen Arinbjorn Viggo.FootHydraulicCESR
[174]-Prosthetic Foot with Removable Flexible MembersClausen Arinbjorn Viggo.Ankle/FootHydraulicESAR
[175]-Prosthetic Foot with Spaced Spring ElementsDay Jesse.FootMechanicalESAR
[176]-Prosthetic Foot and Prosthesis for A Lower ExtremityRadspieler Andreas.Ankle/FootMechanicalESAR
[177]-A Prosthetic Ankle and Foot CombinationBlatchford Products.Ankle/FootMechanicalHybrid
[178]-Foot Prosthesis Comprising A Damping ElementPm Ingenierie Et Design.FootMechanicalHybrid
[179]-Lower Limb ProsthesisBlatchford Products.Ankle/FootMechanicalHybrid
[180]-OberschenkelprothesenpassteilKlopf, Johannes.Ankle/FootMechanicalHybrid
[181]-Prosthesis or orthosisUniversité Catholique De Louvain.FootMechanicalHybrid
[182]-Prosthetic Ankle Assembly and Ankle–foot System Comprising SameHein, Emily.Ankle/FootMechanicalHybrid
[183]-Prosthetic External Fixation Assembly for Post-amputee AmbulationDennis G. Haun.Ankle/FootMechanicalHybrid
[184]-Prosthetic FootComité International De La Croix-rouge.FootMechanicalHybrid
[185]-Prosthetic Foot and Connector for Prosthetic FootXiborg Inc.FootMechanicalESAR
[186]-Prótesis Mecánica De PieInstituto Tecnológico José Mario Molina Pasquel Y. Henriquez.FootMechanicalCESR
[187]-Pyramidal Prosthetic FootGosakan, Haripriya.FootMechanicalESAR
[188]-Single Axis Ankle–foot Prosthesis with Mechanically Adjustable Range of MotionMcnicholas Sara Koehler.Ankle/FootMechanicalHybrid
Table 2. Articles analyzed for ankle/foot prosthesis.
Table 2. Articles analyzed for ankle/foot prosthesis.
CiteMain AuthorDocument TopicsYear
[189]Huang, StephaniePowered Ankle Prosthesis Design2014
[190]Sun, JinmingClinical Study2014
[191]Wezenberg, DaphneComparative Study2014
[192]Nickel, EricComponent Design2014
[193]Mulder, Inge A.Foot Prosthesis Design2014
[194,195]Safaeepour, ZahraPowered Ankle/foot Prosthesis design2014
[196]Zhu, JinyingPowered Ankle/foot Prosthesis design2014
[197,198]Ko, Chang-YongClinical Study2014–2016
[199,200]Cherelle, PierrePowered Ankle/foot Prosthesis design2014–2017
[201,202,203]Simon, Ann M.Component Design/Study2014–2018
[204]Caputo, Joshua M.Gait Study2014
[205]Asencio, J. G.Clinical Study2015
[206]Bonnet, XavierComparative Study2015
[207]Fairhurst, Stuart R.Component Design2015
[208]Realmuto, JonathanComponent Design2015
[209]Hessel, A. L.Powered Ankle/foot Prosthesis design2015
[210]Rouse, Elliott J.Powered Ankle/foot Prosthesis design2015
[211]Flynn, LouisPowered Ankle/knee Prosthesis design2015
[212]Ficanha, Evandro MaiconPowered Ankle/foot Prosthesis design2015
[213,214]Rice, Jacob J.Powered Ankle/foot Prosthesis design2015–2016
[215]Jimenez-Fabian, ReneComponent Design2017
[216,217,218]Shultz, Amanda H.Component Design/Study2015–2018
[219,220]Kim, MyungheePowered Ankle/foot Prosthesis design2015–2018
[221]Ingraham, Kimberly A.Powered Ankle Prosthesis Study2016
[222]Quesada, Roberto E.Clinical Study2016
[223]Delussu, Anna S.Comparative Study2016
[224]Khaghani, AlirezaComponent Design2016
[225]Narayanan, GovindarajanFoot Prosthesis Design2016
[226]Isaacs, M. R.Passive Ankle foot prosthesis study2016
[227]Grimmer, MartinPowered Ankle Prosthesis Design2016
[228]LaPre, Andrew KennedyPowered Ankle/foot Prosthesis design2016
[229]Rabago, Christopher A.Prosthesis Study2016
[230]Ettinger, SarahStudy2016
[231,232,233]Esposito, Elizabeth RussellGait Study2016–2018
[234]Lacraz, AlainComparative Study2017
[235]Gardiner, JamesComparative Study2017
[236]Ke, Ming-JenComponent Design2017
[237]Tao, ZhenFoot Prosthesis Design2017
[238]Lee, Jeffrey D.Pneumatic Ankle/foot Prosthesis design2017
[239]Mazumder, O.Powered Ankle/foot Prosthesis design2017
[240]AnonymousPowered Foot Prosthesis Design2017
[241]Weerakkody, Thilina H.Review2017
[242,243]Koehler-McNicholas, Sara R.Powered Ankle/foot Prosthesis design2017–2018
[244]Shepherd, Max K.Powered Ankle/foot Prosthesis design2017
[245,246]Dong, DianbiaoPowered Ankle/foot Prosthesis design2017–2018
[247]Lechler, KnutClinical Study2018
[248]Eslamy, MahdyBiomechanical Study2018
[249]Jayaraman, ChandrasekaranPowered Ankle/foot Prosthesis study2018
[250]Hahn, AndreasPowered Foot Prosthesis Evaluation2018
[251]Armannsdottir, AnnaAnathomical Study2018
[252]Zelik, Karl E.Anathomical Study2018
[253]Gardinier, Emily S.Clinical Study2018
[254]Heitzmann, Daniel W. W.Clinical Study2018
[255]Montgomery, Jana R.Clinical Study2018
[256]Preissler, SandraClinical Study2018
[257]Guerra-Farfan, ErnestoComparative Study2018
[258]Yang, Ja RyungComparative Study2018
[259]Culver, StevenComponent Design2018
[260]Geeroms, JoostComponent Design2018
[261,262]Quintero, DavidComponent Design2018
[263]Tahir, UzmaComponent Design2018
[264]Yin, KaiyangComponent Design2018
[265]Houdijk, HanFoot Prosthesis Design2018
[266]Glanzer, Evan M.Powered Foot Prosthesis Design2018
[267]Bai, XuefeiProsthesis Study2018
[268]Ray, Samuel F.Prosthesis Study2018
[269]Burger, HelenaReview2018
[270,271]De Pauw, KevinAnathomical Study2018–2019
[272,273]Gao, FeiPowered Ankle/foot Prosthesis design2018–2019
[274]Sahoo, SaikatPowered Ankle/foot Prosthesis design2018
[275]Schmalz, ThomasComparative Study2019
[276]Wurdeman, Shane R.Comparative Study2019
[277]Zarezadeh, FatemehComparative Study2019
[278]Bhargava, RakeshFoot Prosthesis Design2019
[279]Zhang, XueyiGait Study2019
[280]Bartlett, Harrison L.Powered Ankle Prosthesis Design2019
[281]Agboola-Dobson, AlexanderPowered Ankle/foot Prosthesis design2019
[282]Convens, BryanPowered Ankle/foot Prosthesis design2019
[283]Lenzi, TommasoPowered Ankle/foot Prosthesis design2019
[284]Yu, TianPowered Ankle/foot Prosthesis design2019
[285]Popescu, Stefan-CatalinProsthesis Study2019
Table 3. Top 10 most cited articles in ankle/foot prosthesis.
Table 3. Top 10 most cited articles in ankle/foot prosthesis.
No.CiteArticleAuthorsYear
1[286]Bionic ankle–foot prosthesis normalizes walking gait for persons with leg amputationHugh M. Herr, Alena M. Grabowski2012
2[287]Powered ankle–foot prosthesis to assist level-ground and stair-descent gaitsSamuel Aua, Max Berniker a, Hugh Herr2008
3[288]Powered Ankle-Foot Prosthesis Improves Walking Metabolic EconomySamuel K. Au, Jeff Weber, Hugh Herr2009
4[289]Control of a Powered Ankle-Foot Prosthesis Based on a Neuromuscular ModelMichael F. Eilenberg, Hartmut Geyer, Hugh Herr2010
5[290]Powered Ankle-Foot ProsthesisSamuel K. Aa, Hugh M. Herr2008
6[291]Design and Control of a Powered Transfemoral ProsthesisFrank Sup, Amit Bohara, Michael Goldfarb2008
7[292]The human ankle during walking: implications for design of biomimetic ankle prosthesesAndrew H. Hansena, Dudley S. Childressa, Steve C. Miff, Steven A. Garda, Kent P. Mesplayd2004
8[293]Recycling Energy to Restore Impaired Ankle Function during Human WalkingSteven H. Collins, Arthur D. Kuo2010
9[294]Energy expenditure during ambulation in dysvascular and traumatic below-knee amputees: A comparison of five prosthetic feetLeslie Torburn, Christopher M. Powers, Robert Guiterrez, Jacquelin Perry1995
10[295]Estimating the Prevalence of Limb Loss in the United States: 2005 to 2050Kathryn Ziegler-Graham, Ellen J. MacKenzie, Patti L. Ephraim, Thomas G. Travison, Ron Brookmeyer2008
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