Walking ability of individuals fitted with transfemoral bone-anchored prostheses: A comparative study of gait parameters.

OBJECTIVE: This study presents the walking abilities of participants fitted with transfemoral bone-anchored prostheses using a total of 14 gait parameters. DESIGN: Two-centre retrospective cross-sectional comparative study. SETTING: Research facilities equipped with tridimensional motion capture systems. PARTICIPANTS: Two control arms included eight able-bodied participants arm (54 ± 9 years, 1.75 ± 0.07 m, 76 ± 7 kg) and nine participants fitted with transfemoral socket-suspended prostheses arm (59 ± 9 years, 1.73 ± 0.07 m, 80 ± 16 kg). The intervention arm included nine participants fitted with transfemoral bone-anchored prostheses arm (51 ± 13 years, 1.78 ± 0.09 m, 87.3 ± 16.1 kg). INTERVENTION: Fitting of transfemoral bone-anchored prostheses. MAIN MEASURES: Comparisons were performed for two spatio-temporal, three spatial and nine temporal gait parameters. RESULTS: The cadence and speed of walking were 107 ± 6 steps/min and 1.23 ± 0.19 m/s for the able-bodied participants arm, 88 ± 7 steps/min and 0.87 ± 0.17 m/s for the socket-suspended prosthesis arm, and 96 ± 6 steps/min and 1.03 ± 0.17 m/s for bone-anchored prosthesis arm, respectively. Able-bodied participants and bone-anchored prosthesis arms were comparable in age, height, and body mass index as well as cadence and speed of walking, but the able-bodied participant arm showed a swing phase 31% shorter. Bone-anchored and socket-suspended prostheses arms were comparable for age, height, mass, and body mass index as well as cadence and speed of walking, but the bone-anchored prosthesis arm showed a step width and duration of double support in seconds 65% and 41% shorter, respectively. CONCLUSIONS: Bone-anchored and socket-suspended prostheses restored equally well the gait parameters at a self-selected speed. This benchmark data provides new insights into the walking ability of individuals using transfemoral bionics bone-anchored prostheses.

Osseointegrated total knee replacement connected to a lower limb prosthesis: 4 cases.

BACKGROUND AND PURPOSE: Osseointegrated implants are an alternative for prosthetic attachment in individuals with amputation who are unable to wear a socket. However, the load transmitted through the osseointegrated fixation to the residual tibia and knee joint can be unbearable for those with transtibial amputation and knee arthritis. We report on the feasibility of combining total knee replacement (TKR) with an osseointegrated implant for prosthetic attachment. PATIENTS AND METHODS: We retrospectively reviewed all 4 cases (aged 38-77 years) of transtibial amputations managed with osseointegration and TKR in 2012-2014. The below-the-knee prosthesis was connected to the tibial base plate of a TKR, enabling the tibial residuum and knee joint to act as weight-sharing structures. A 2-stage procedure involved connecting a standard hinged TKR to custom-made implants and creation of a skin-implant interface. Clinical outcomes were assessed at baseline and after 1-3 years of follow-up using standard measures of health-related quality of life, ambulation, and activity level including the questionnaire for transfemoral amputees (Q-TFA) and the 6-minute walk test. RESULTS: There were no major complications, and there was 1 case of superficial infection. All patients showed improved clinical outcomes, with a Q-TFA improvement range of 29-52 and a 6-minute walk test improvement range of 37-84 meters. INTERPRETATION: It is possible to combine TKR with osseointegrated implants.

Next-generation devices to diagnose residuum health of individuals suffering from limb loss: A narrative review of trends, opportunities, and challenges.

OBJECTIVES: There is a need for diagnostic devices that can assist prosthetic care providers to better assess and maintain residuum health of individuals suffering from neuromusculoskeletal dysfunctions associated with limb loss. This paper outlines the trends, opportunities, and challenges that will facilitate the development of next-generation diagnostic devices. DESIGN: Narrative literature review. METHODS: Information about technologies suitable for integration into next-generation diagnostic devices was extracted from 41 references. We considered the invasiveness, comprehensiveness, and practicality of each technology subjectively. RESULTS: This review highlighted a trend toward future diagnostic devices of neuromusculoskeletal dysfunctions of the residuum capable to support evidence-based patient-specific prosthetic care, patient empowerment, and the development of bionic solutions. This device should positively disrupt the organization healthcare by enabling cost-utility analyses (e.g., fee-for-device business models) and addressing healthcare gaps due to labor shortages. There are opportunities to develop wireless, wearable and noninvasive diagnostic devices integrating wireless biosensors to measure change in mechanical constraints and topography of residuum tissues during real-life conditions as well as computational modeling using medical imaging and finite element analysis (e.g., digital twin). Developing the next-generation diagnostic devices will require to overcome critical barriers associated with the design (e.g., gaps between technology readiness levels of essential parts), clinical roll-out (e.g., identification of primary users), and commercialization (e.g., limited interest from investors). CONCLUSIONS: We anticipate that next-generation diagnostic devices will contribute to prosthetic care innovations that will safely increase mobility, thereby improving the quality of life of the growing global population of individuals suffering from limb loss.

Loading characteristics data applied on osseointegrated implant by transfemoral bone-anchored prostheses fitted with state-of-the-art components during daily activities.

The data in this paper are related to the research article entitled "Load applied on osseointegrated implant by transfemoral bone-anchored prostheses fitted with state-of-the-art prosthetic components" (Frossard et al. Clinical Biomechanics, 89 (2021) 105457. DOI: 10.1016/j.clinbiomech.2021.105457). This article contains the overall and individual loading characteristics applied on transfemoral press-fit osseointegrated implant generated by bone-anchored prostheses fitted with state-of-the-art components during daily activities (i.e., microprocessor-controlled Rheo Knee XC knee, energy-storing-and-returning Pro-Flex XC or LP feet (ÖSSUR, Iceland)). Confounders of the loads are presented. The load profiles are characterized by the loading patterns, loading boundaries and loading local extrema of the forces and moments applied during straight-level walking, ascending and descending ramp and stairs at self-selected comfortable pace. The confounders of the loading information as well as new insights into inter-participants variability of loading patterns, loading boundaries and loading local extrema can inform the design of subsequent cross-sectional and longitudinal studies as well as literature reviews and meta-analyzes. The loading datasets are critical to clinicians and engineers designing finite element models of osseointegrated implants (e.g., medullar and percutaneous parts) and prosthetic components, algorithms capable to recognize the loading patterns applied on a residuum during daily activities, as well as clinical trials assessing the effects of particular prosthetic care interventions. Altogether, these datasets provide promoters of prosthetic care innovations with valuable insights informing the prescription of advanced prosthetic components to the growing population of individuals suffering from lower limb loss choosing bionics solutions. Online repository contains the files: https://data.mendeley.com/datasets/gmsyv97cpc/1.

Loading Effect of Prosthetic Feet's Anthropomorphicity on Transtibial Osseointegrated Implant.

INTRODUCTION: Osseointegrated implants for direct skeletal attachment of transtibial prosthesis carry risks that are yet to be fully resolved, such as early loosening, mechanical failure of percutaneous and medullar parts of implant, periprosthetic issues, and infections. Underloading could lead to early loosening and infection. Overloading might compromise the bone-implant interface. Therefore, Goldilocks loading regimen applied by transtibial bone-anchored prostheses is critical for safe and efficient development of osseointegration around the implant during rehabilitation and beyond. We hypothesized that Goldilocks loading could be achieved when ambulating with a so-called anthropomorphic prosthetic ankle showing moment-angle relationship similar to a sound ankle. MATERIALS AND METHODS: Quantitative characteristics of the moment-angle curve of the sound ankle during dorsiflexion phase of a free-pace walking were extracted for 4 able-bodied participants (experiment 1). A slope of the moment-angle curve (stiffness) was calculated twice: for the first half and for the second half of the moment-angle curve. The difference of stiffnesses (those at the second half minus at the first half) was called the index of anthropomorphicity (IA). By definition, positive IA is associated with concave shape of the moment-angle curve, and the negative IA is associated with convex shape. In experiment 2, the same recordings and calculations were performed for 3 participants fitted with transtibial osseointegrated fixation during walking with their usual feet and the Free-Flow Foot (Ohio Willow Wood). The Free-Flow Foot was selected for its anthropomorphicity demonstrated in the previous studies with amputees using traditional socket attachment. RESULTS: The IA was 5.88 ± 0.93 for the able-bodied participants, indicating that the stiffness during the first part of the dorsiflexion phase was substantially fewer than during the second parts, as the calf muscles resisted to angulation in ankle substantially less than during the second part of dorsiflexion phase. For amputees fitted with Free-Flow Foot, IA was 2.68 ± 1.09 and -2.97 ± 2.37 for the same amputees fitted with their usual feet. CONCLUSIONS: Indexes of anthropomorphicity, while of different magnitude, were positive in control able-bodied group and in the amputee group wearing Free-Flow Foot, which was qualitatively associated with concave shape of their moment-angle curves. The 3 usual feet worn by the participants were classified as nonanthropomorphic as their individual moment-angle curves were convex and the corresponding IAs were negative. Furthermore, this study showed that a foot with anthropomorphic characteristics tends to decrease maximal loads at the bone-implant interface as compared to the nonanthropomorphic feet and possibly may minimize the risks to compromise the integrity of this interface.

Load applied on osseointegrated implant by transfemoral bone-anchored prostheses fitted with state-of-the-art prosthetic components.

BACKGROUND: This study presented the load profile applied on transfemoral osseointegrated implants by bone-anchored prostheses fitted with state-of-the-art ÖSSUR microprocessor-controlled Rheo Knee XC and energy-storing-and-returning Pro-Flex XC or LP feet during five standardized daily activities. METHODS: This cross-sectional cohort study included 13 participants fitted with a press-fit transfemoral osseointegrated implant. Loading data were directly measured with the tri-axial transducer of an iPecsLab (RTC Electronics, USA) fitted between the implant and knee unit. The loading profile was characterized by spatio-temporal gaits variables, magnitude of loading boundaries as well as onset and magnitude of loading extrema during walking, ascending and descending ramp and stairs. FINDINGS: A total of 2127 steps was analysed. The cadence ranged between 36 ± 7 and 47 ± 6 strides/min. The absolute maximum force and moments applied across all activities was 1322 N, 388 N and 133 N as well as 22 Nm, 52 Nm and 88 Nm on and around the long, anteroposterior and mediolateral axes of the implant, respectively. INTERPRETATION: This study provided new benchmark loading data applied by transfemoral bone-anchored prostheses fitted with selected ÖSSUR state-of-the-art components. Outcomes suggested that such prostheses can generate relevant loads at the interface with the osseointegrated implant to restore ambulation effectively. This study is a worthwhile contribution toward a systematic recording, analysis, and reporting of ecological prosthetic loading profiles as well as closing the evidence gaps between prescription and biomechanical benefits of state-of-the-art components. Hopefully, this will contribute to improve outcomes for growing number of individuals with limb loss opting for bionic solutions.

Effect of the material's stiffness on stress-shielding in osseointegrated implants for bone-anchored prostheses: a numerical analysis and initial benchmark data.

PURPOSE: This study attempted to establish the link between design of implants for bone-anchored prostheses and stress-shielding, affecting the stability of the bone-implant coupling using numerical approach. The objectives were to share a numerical model capable to evaluate the long-term stability of implants and to use this model to extract data sets showing how shape and material stiffness of threaded, press-fit and modular press-fit implants affect stress-shielding intensity. METHODS: Three designs were considered: threaded, press-fit and modular press-fit. The effect of shape and material stiffness of each design on stress-shielding intensity was assessed using Young's modulus (10 to 210 GPa). Furthermore, the impact of the diameter of percutaneous part (10 to 18 mm) and thickness of medullar part (5 to 1 mm) was investigated for the modular press-fit implant. RESULTS: The threaded design generated 4% more bone mass loss at the distal femur but an overall loss of bone mass was by 5% lower to press-fit design. The influence of Young's modulus on bone mass changes was noticeable for modular press-fit implant, depending on diameter of percutaneous or medullary part. A 20 GPa change of stiffness caused a bone mass change from 0.65% up to 2.45% and from 0.07% up to 0.32% for percutaneous parts with 18 mm and 10 mm diameter, respectively. CONCLUSIONS: Results suggested that threaded implant provides greater stability despite an increased bone loss at the distal femur. Altogether, this work provided an initial model that could be applied in subsequent studies on the long-term stability of current and upcoming implants.

Loading characteristics data applied on osseointegrated implant by transfemoral bone-anchored prostheses fitted with basic components during daily activities.

The data in this paper are related to the research articles entitled "Kinetics of transfemoral amputees with osseointegrated fixation performing common activities of daily living" (Lee et al., Clinical Biomechanics, 2007.22(6). p. 665-673) and "Magnitude and variability of loading on the osseointegrated implant of transfemoral amputees during walking" (Lee et al., Med Eng Phys, 2008.30(7). p. 825-833). This article contains the overall and individual loading characteristics applied on screw-type osseointegrated implant generated by transfemoral bone-anchored prostheses fitted with basic components during daily activities at self-selected comfortable pace. Overall and individual data was presented for the (A) spatio-temporal characteristics, (B) loading patterns, (C) loading boundaries and (D) the loading local extremum during level walking, ascending and descending ramp and stairs. Inter-participant variability of these new datasets with basic components is critical to improve the efficacy and safety of prosthetic components as well as the design of future automated algorithms and clinical trials. Online repository contains the files: https://data.mendeley.com/datasets/hh8rjjh73w/1.

Inter-participant variability data in loading applied on osseointegrated implant by transtibial bone-anchored prostheses during daily activities.

The data in this paper are related to the research article entitled "Loading applied on osseointegrated implant by transtibial bone-anchored prostheses during daily activities: Preliminary characterization of prosthetic feet" (Frossard et al., 2019: Accepted). This article contains the individual and grouped loading characteristics applied on transtibial osseointegrated implant generated while walking with bone-anchored prostheses including prosthetic feet with different index of anthropomorphicity. Inter-participant variability was presented for (A) the spatio-temporal characteristics, (B) the loading boundaries and (C) the loading local extremum during walking, ascending and descending ramp and stairs. These initial inter-participant variability benchmark datasets are critical to improve the efficacy and safety of prosthetic components for transtibial prostheses as well as the design of future automated algorithms and clinical trials. Online repository contains the files: https://doi.org/10.17632/vhc6sf7ngy.1.

Survey data on the quality of life of consumers fitted with osseointegrated fixation and bone-anchored limb prostheses provided by government organization.

The data in this paper are related to the research article entitled "Development of a government continuous quality improvement procedure for assessing the provision of bone anchored limb prosthesis: A process re-design descriptive study" (Frossard et al., Canadian Prosthetics & Orthotics Journal, 2018. 1(2). p. 1-14). This article contains quality of life data experienced by individuals before and after implantation of a press-fit or screw-type osseointegrated fixation when fitted with conventional socket-suspended and bone-anchored limb prosthesis, respectively. This specifically-designed survey was developed and administered by Queensland Artificial Limb Services (QALS), an Australian State government organization. It was an integrated part of QALS' continuous quality improvement procedure for assessing the provision of bone-anchored prosthesis. A total of 12 out of the 65 consumers completed to the survey, giving a return rate of 18%. This benchmark information can contribute to inform the design of (A) other patients' experience surveys including those built-in governmental continuous quality improvement procedure as well as (B) clinical trials looking at the overall effects of surgical implantation of ossoeintegrated fixation on patients' quality of life. Online repository contains the files: https://data.mendeley.com/datasets/bkbxxmrhfh/1.

Inter-participant variability data in characterization of anthropomorphicity of prosthetic feet fitted to bone-anchored transtibial prosthesis.

The data in this paper are related to the research article entitled "Automated characterization of anthropomorphicity of prosthetic feet fitted to bone-anchored transtibial prosthesis" (Frossard et al., 2019: DOI: 10.1109/TBME.2019.2904713). This article contains the individual angles of dorsiflexion and bending moments generated while walking with transtibial bone-anchored prostheses including prosthetic feet with different index of anthropomorphicity. Inter-participant variability were presented for the (A) position of the load cell measuring directly to the bending moments, (B) patterns of angles of dorsiflexion and bending moment as well as moment-angle curves and (C) variations of magnitude of angles of dorsiflexion as well as the raw and bodyweight-normalized bending moments between toe contact and heel off. These initial inter-participant variability benchmark datasets are critical to design future automated algorithms and clinical trials. Online repository contains the files: https://eprints.qut.edu.au/127745/1/127745.pdf.

Automated characterization of anthropomorphicity of prosthetic feet fitted to bone-anchored transtibial prosthesis.

OBJECTIVE: This study describes differentiating prosthetic feet designs fitted to bone-anchored transtibial prostheses based on an automated characterization of ankle stiffness profile relying on direct loading measurements. The objectives were (A) to present a process characterizing stiffness using innovative macro, meso and micro analyses, (B) to present stiffness profiles for feet with and without anthropomorphic designs, where anthropomorphicity is defined as a similarity of the moment-angle dependency in prosthetic and in the anatomical ankle, (C) to determine sensitivity of characterization. METHODS: Three participants walked consecutively with two instrumented bone-anchored prostheses including their own prosthetic feet and Free-Flow foot meeting the anthropomorphicity criterion by design. Angle of dorsiflexion was extracted from video footage. Bending moment was recorded using multi-axis transducer attached to osseointegrated fixation. The automated characterization of stiffness involved a 12-step process relying on data-based criterion. RESULTS: The meso analyses confirmed bilinear behavior of moment-angle curves with Index of Anthropomorphicity of -2.966±2.369 Nm/Deg and 2.681±1.089 Nm/Deg indicating a convex and concave shape of usual and Free-Flow feet without and with anthropomorphic designs, respectively. CONCLUSIONS: The proposed straightforward meso analysis of the stiffness was capable to report clinical meaningful differences sensitive to feet's anthropomorphicity. Results confirmed the benefits for clinicians to rely on direct loading measurement providing individualized complementary insight into impact of components. SIGNIFICANCE: This work could assist the developments of standards and guidelines for manufacturing and safe fitting of components to growing population requiring transtibial prostheses with socket or direct skeletal attachment worldwide.

Magnitude and variability of loading on the osseointegrated implant of transfemoral amputees during walking.

This study directly measured the load acting on the abutment of the osseointegrated implant system of transfemoral amputees during level walking, and studied the variability of the load within and among amputees. Twelve active transfemoral amputees (age: 54 +/- 12 years, mass: 84.3 +/- 16.3 kg, height: 17.8 +/- 0.10 m) fitted with an osseointegrated implant for over 1 year participated in the study. The load applied on the abutment was measured during unimpeded, level walking in a straight line using a commercial six-channel transducer mounted between the abutment and the prosthetic knee. The pattern and the magnitude of the three-dimensional forces and moments were revealed. Results showed a low step-to-step variability of each subject, but a high subject-to-subject variability in local extrema of body-weight normalized forces and moments and impulse data. The high subject-to-subject variability suggests that the mechanical design of the implant system should be customized for each individual, or that a fit-all design should take into consideration the highest values of load within a broad range of amputees. It also suggests specific loading regime in rehabilitation training are necessary for a given subject. Thus the loading magnitude and variability demonstrated should be useful in designing an osseointegrated implant system better able to resist mechanical failure and in refining the rehabilitation protocol.

Effects of transcranial direct current stimulation on gait in people with Parkinson's disease: study protocol for a randomized, controlled clinical trial.

BACKGROUND: Gait difficulties are common and frequently devastating to people with Parkinson's disease (PD). These difficulties are often followed by an increased risk of falls, leading to injury, hospitalization and mortality. The dysfunction in the basal ganglia-thalamocortical motor circuits and reduced activity in the premotor and primary motor cortices has raised interest in transcranial direct current stimulation (tDCS) as an adjunct intervention in PD. tDCS might provide a potentially safe and non-invasive treatment by modulating cortical excitability and behavioural outcomes. The aim of this study is to compare the effects of different monopolar and bipolar montages of tDCS administered to the motor cortex and cerebellum on gait speed in PD. METHODS: This study will be conducted in a randomized, double-blind cross-over design. Eighteen participants diagnosed with Parkinson's disease will receive anodal and sham tDCS (1 mA, 20 min, 10 × 4 cm2) over the premotor and primary motor cortices with the cathode over the cerebellum during treadmill walking. Three montages will be applied over three sessions and compared: anodal tDCS with a small active cathode (4 × 4 cm2); anodal tDCS with a large, functionally inert cathode (10 × 10 cm2); and sham tDCS. The primary outcome measure is gait speed, and secondary outcome measures include gait parameters (temporospatial, segmental, kinematic), the Timed Up and Go test and lower limb muscle activity patterns as measured by electromyography. DISCUSSION: This study will investigate the short-term effects of anodal tDCS over the premotor and primary motor cortices on gait abilities using monopolar and bipolar montages in people with PD. The outcomes will inform future studies aimed at inducing longer-lasting changes in neural excitability and performance using multisession tDCS designs in PD. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12618000063213 . Registered on 17 January 2018. Retrospectively registered.

Cost-effectiveness of bone-anchored prostheses using osseointegrated fixation: Myth or reality?

BACKGROUND: In principle, lower limb bone-anchored prostheses could alleviate expenditure associated with typical socket manufacturing and residuum treatments due to socket-suspended prostheses. OBJECTIVE: This study reports (a) the incremental costs and (b) heath gain as well as (c) cost-effectiveness of bone-anchored prostheses compared to socket-suspended prostheses. STUDY DESIGN: Retrospective individual case-controlled observations and systematic review. METHODS: Actual costs were extracted from financial records and completed by typical costs when needed over 6-year time horizon for a cohort of 16 individuals. Health gains corresponding to quality-adjusted life-year were calculated using health-related quality-of-life data presented in the literature. RESULTS: The provision of bone-anchored prostheses costed 21% ± 41% more but increased quality-adjusted life-years by 17% ± 5% compared to socket-suspended prostheses. The incremental cost-effectiveness ratio ranged between -$25,700 per quality-adjusted life-year and $53,500 per quality-adjusted life-year with indicative incremental cost-effectiveness ratio of approximately $17,000 per quality-adjusted life-year. Bone-anchored prosthesis was cost-saving and cost-effective for 19% and 88% of the participants, respectively. CONCLUSION: This study indicated that bone-anchored prostheses might be an acceptable alternative to socket-suspended prostheses at least from a prosthetic care perspective in Australian context. Altogether, this initial evidence-based economic evaluation provided a working approach for decision makers responsible for policies around care of individuals with lower limb amputation worldwide. Clinical relevance For the first time, this study provided evidence-based health economic benefits of lower limb bone-anchored prostheses compared to typical socket-suspended prostheses from a prosthetic care perspective that is essential to clinicians and decision makers responsible for policies.

Load characteristics following transfemoral amputation in individuals fitted with bone-anchored prostheses: a scoping review protocol.

REVIEW QUESTION: The main purpose of this scoping review is to characterize loading information applied on the residuum of individuals with transfemoral amputation fitted with an osseointegrated fixation for bone-anchored prostheses.The objectives of this scoping review are: i) to map the scope of loading variables, and ii) to report the range of magnitude of loads that has been directly measured using a portable kinetic recording apparatus fitted at the distal end of the residuum during rehabilitation exercises, standardized and unscripted activities of daily living, and adverse events.The specific review questions are.

Kinetics of transfemoral amputees with osseointegrated fixation performing common activities of daily living.

BACKGROUND: Direct anchorage of a lower-limb prosthesis to the bone through an implanted fixation (osseointegration) has been suggested as an excellent alternative for amputees experiencing complications from use of a conventional socket-type prosthesis. However, an attempt needs to be made to optimize the mechanical design of the fixation and refine the rehabilitation program. Understanding the load applied on the fixation is a crucial step towards this goal. METHODS: The load applied on the osseointegrated fixation of nine transfemoral amputees was measured using a load transducer, when the amputees performed activities which included straight-line level walking, ascending and descending stairs and a ramp as well as walking around a circle. Force and moment patterns along each gait cycle, magnitudes and time of occurrence of the local extrema of the load, as well as impulses were analysed. FINDINGS: Managing a ramp and stairs, and walking around a circle did not produce a significant increase (P>0.05) in load compared to straight-line level walking. The patterns of the moment about the medio-lateral axis were different among the six activities which may reflect the different strategies used in controlling the prosthetic knee joint. INTERPRETATIONS: This study increases the understanding of biomechanics of bone-anchored osseointegrated prostheses. The loading data provided will be useful in designing the osseointegrated fixation to increase the fatigue life and to refine the rehabilitation protocol.

Gait Analysis of Transfemoral Amputees: Errors in Inverse Dynamics Are Substantial and Depend on Prosthetic Design.

Quantitative assessments of prostheses performances rely more and more frequently on gait analysis focusing on prosthetic knee joint forces and moments computed by inverse dynamics. However, this method is prone to errors, as demonstrated in comparison with direct measurements of these forces and moments. The magnitude of errors reported in the literature seems to vary depending on prosthetic components. Therefore, the purposes of this study were (A) to quantify and compare the magnitude of errors in knee joint forces and moments obtained with inverse dynamics and direct measurements on ten participants with transfemoral amputation during walking and (B) to investigate if these errors can be characterised for different prosthetic knees. Knee joint forces and moments computed by inverse dynamics presented substantial errors, especially during the swing phase of gait. Indeed, the median errors in percentage of the moment magnitude were 4% and 26% in extension/flexion, 6% and 19% in adduction/abduction as well as 14% and 27% in internal/external rotation during stance and swing phase, respectively. Moreover, errors varied depending on the prosthetic limb fitted with mechanical or microprocessor-controlled knees. This study confirmed that inverse dynamics should be used cautiously while performing gait analysis of amputees. Alternatively, direct measurements of joint forces and moments could be relevant for mechanical characterising of components and alignments of prosthetic limbs.