BACKGROUND: Previous studies show that during level walking, the load on the contralateral side increases with more proximal amputation levels. Furthermore, a typical compensation mechanism, vaulting on the contralateral side, may also influence the load. However, no study has compared the load applied to the contralateral side across more than two different amputation levels. OBJECTIVE: The objectives of this study were to analyze the biomechanical impact of different lower limb amputation levels and vaulting on the load applied to the locomotor system. METHODOLOGY: Gait data from 82 individuals with different amputation levels (44 transtibial (TT), 30 transfemoral (TF), and 8 hip disarticulation (HD)) were retrospectively analyzed in this study. Peak knee adduction, flexion and extension moments, vertical ground reaction force peaks, and force rates were statistically analyzed between different amputation levels and between two groups “TF with vaulting” and “TF without vaulting”. FINDINGS: As the level of amputation increases, walking speed decreases and asymmetry of stance duration increases. TF individuals with vaulting tend to walk faster than those without vaulting. The first peak of vertical ground reaction forces, the peak knee adduction and extension moments increase, and the peak knee flexion moments decrease with higher amputation level. The higher the amputation level, the curve of the vertical ground reaction force becomes significantly steeper during the first 5% of the gait cycle (GC). The first peak of ground reaction forces, the knee flexion, extension and adduction moments tend to be higher in TF individuals with vaulting. CONCLUSION: In summary, a higher lower limb amputation level can increase loading on the contralateral limb and contribute to a higher incidence of vaulting during gait. The effect of vaulting as a compensation pattern leads to an additional increase in contralateral limb loading. Layman's Abstract Gait characteristics in people using lower limb prostheses deviate from normal gait patterns in individuals without amputation. Furthermore, some people with amputation rise onto the toes of their intact side (a movement known as vaulting) as a compensatory mechanism during walking, which helps them clear the ground on the prosthetic side. In people with lower limb amputation, the load applied to the intact side during level walking is higher compared to able-bodied individuals, and it increases as the level of amputation progresses from below the knee to hip disarticulation. No previous study has compared the load applied to the intact side across more than two different amputation levels. The aims of the present study were to analyze the influence of the amputation level and of vaulting on the load applied to the lower limb. Therefore, we analyzed previously collected gait data from 82 individuals with amputation (44 transtibial, 30 transfemoral, and 8 with hip disarticulation). As the level of amputation increases, walking speed decreases and individuals tend to spend more time on the intact side than the prosthetic side during each gait cycle. Individuals with transfemoral amputation who use vaulting as a compensatory movement tend to walk faster than those who do not use this strategy and experience higher forces on the intact limb. As the level of amputation increases, most of the forces applied to the body during level walking also increase. Furthermore, vaulting is more common in individuals with higher amputation levels. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/44416/33698 How To Cite: Pröbsting E, Schmalz T, Bellmann M. Impact of amputation level and vaulting on loading parameters during level ground walking. Canadian Prosthetics & Orthotics Journal. 2025; Volume 8, Issue 1, No. 2. Https://doi.org/10.33137/cpoj.v8i1.44416 Corresponding Author: Eva Pröbsting, Dipl.-Ing (FH) Affiliation: Clinical Research and Services, Research Biomechanics, Ottobock SE & Co. KGaA, Göttingen, Germany. E-Mail: Eva.Proebsting@ottobock.de ORCID ID: https://orcid.org/0000-0002-6349-2992

BACKGROUND:Increased ankle power on the prosthetic side seems to decrease biomechanical loading parameters on the sound side. This assumption is based on biomechanical comparisons of different foot constructions. However, such study designs could not show whether the amount of ankle power solely influences the sound side. OBJECTIVE:To analyze the influence of divergent ankle power, resulting from different foot constructions and from different ankle power settings, on the sound side loading parameters. STUDY DESIGN:Interventional cross sectional study. METHODS:Level walking of transfemoral amputees with a microprocessor knee joint and Solid Ankle Cushioned Heel (SACH), energy storing and returning (ESR) and powered foot (PF) was analyzed. The PF was adapted in three configurations: without power (np), low power (lp), and optimal power (op). An optoelectronic camera system with 12 cameras and two force plates were used. RESULTS:The ankle power on the prosthetic side shows significant differences about foot types and different settings of the PF. The knee adduction moment, the knee flexion moment, and the vertical ground reaction forces on the sound side were significantly reduced with PF_op and ESR in comparison to SACH. When analyzing these parameters for the different PF configurations, only some show significant results at normal velocity. CONCLUSIONS:The additional positive mechanical work for an active push off in the PF tends to have a relieving effect. The biomechanical sound side loading parameters are reduced with PF_op in comparison to SACH and ESR, resulting in a relief of the sound side of lower limb amputees.

The performance of conventional prosthetic feet depends on material and construction principles. Certain powered feet can even generate net positive mechanical work in order to provide an active push-off. The aim of this study was to evaluate the influence of ankle power on the gait of transfemoral amputees. For this purpose level walking of six transfemoral amputees was analysed with a basic and an active foot and three different power settings of the latter. The results show clear advantages of the active foot in comparison with a basic foot. However, a strong relation of the sound side knee loading parameters with the varied ankle power outputs of the active foot couldn’t be shown.

STUDY DESIGN:Retrospective analysis.BACKGROUND:The gait characteristics of transtibial amputees (TTs) have been described many times. In general, the literature reported nearly consistent results for the kinematic and kinetic parameters of the prosthetic side. However, the literature revealed inconsistent findings on kinetic parameters for determining the risk of developing knee osteoarthritis, such as the peak knee adduction moment, knee flexion moment and vertical ground reaction forces.OBJECTIVES:The objective of our study was to describe the sagittal kinetic and kinematic gait characteristics of the ankle and residual knee joint of the prosthetic limb and the knee loading parameters of the sound side of unilateral TTs. This specific consideration may contribute to resolving the controversy of these parameters in the literature.METHODS:We analysed our database containing gait analyses from 53 unilateral TTs and compared data to a control group (CG), also taken from our database. The sagittal kinetic and kinematic gait characteristics of the ankle and residual knee joint of the prosthetic limb, and selected knee loading parameters of the sound side (the peak knee adduction moment, knee flexion moment and vertical ground reaction forces) were evaluated. Beside these parameters we reported typical spatiotemporal gait parameters as gait velocity, step length, step length asymmetry, stance phase duration and asymmetry of stance phase duration.RESULTS:The TTs walked slower and more asymmetrically than the CG. The kinematic pattern of the prosthetic ankle differed from that found in the CG. The largest difference was observed for the range of motion of the plantarflexion at push-off, which was significantly reduced for the prosthetic foot. The residual knee joint was generally affected with respect to decreased moments and reduced knee flexion during stance phase. The peaks of the vertical ground reaction forces and knee adduction moments showed no differences between the sound side of amputees and the CG. The peak knee flexion moment at midstance was significantly reduced for the sound side of amputees in comparison with the CG.CONCLUSION:The biomechanical data measured for the prosthetic side in a cohort of 53 unilateral TT amputees conformed with the literature. The parameters determining the risk of developing knee osteoarthritis investigated in our retrospective analysis were not increased on the sound side in comparison with non-amputees. We deem it reasonable to assume that an appropriate prosthesis will reduce the likelihood of overloading the knee on the sound side during normal walking.

INTRODUCTION Long-term damages after lower extremity amputation have previously been analysed in three systematic reviews 5–7 showing that amputees have a higher risk for developing knee and hip osteoarthritis on the sound side. The altered gait pattern appears to increase the load on the sound side.1–3 This paper analysed the extent to which the above described assumption is supported by the scientific literature with specific focus on the risk of developing back pain and osteoarthritis in amputees. Abstract PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32034/24450 How to cite: Pröbsting E, Kannenberg A, Blumentritt S. BACK PAIN AND OSTEOARTHRITIS AS SECONDARY DISABILITIES OF LOWER LIMB AMPUTATION. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, ORAL PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. DOI: https://doi.org/10.33137/cpoj.v1i2.32034 Abstracts were Peer-reviewed by the American Orthotic Prosthetic Association (AOPA) 101st National Assembly Scientific Committee. http://www.aopanet.org/

Background: The microprocessor-controlled leg orthosis C-Brace enables patients with paretic or paralysed lower limb muscles to use dampened knee flexion under weight-bearing and speed-adapted control of the swing phase. Objectives: The objective of the present study was to investigate the new technical functions of the C-Brace orthosis, based on biomechanical parameters. Study design: The study enrolled six patients. The C-Brace orthosis is compared with conventional leg orthoses (four stance control orthoses, two locked knee–ankle–foot orthoses) using biomechanical parameters of level walking, descending ramps and descending stairs. Methods: Ground reaction forces, joint moments and kinematic parameters were measured for level walking as well as ascending and descending ramps and stairs. Results: With the C-Brace, a nearly natural stance phase knee flexion was measured during level walking (mean value 11° ± 5.6°). The maximum swing phase knee flexion angle of the C-Brace approached the normal value of 65° more closely than the stance control orthoses (66° ± 8.5° vs 74° ± 6.4°). No significant differences in the joint moments were found between the C-Brace and stance control orthosis conditions. In contrast to the conventional orthoses, all patients were able to ambulate ramps and stairs using a step-over-step technique with C-Brace (flexion angle 64.6° ± 8.2° and 70.5° ± 12.4°). Conclusion: The results show that the functions of the C-Brace for situation-dependent knee flexion under weight bearing have been used by patients with a high level of confidence. Clinical relevance The functional benefits of the C-Brace in comparison with the conventional orthotic mechanisms could be demonstrated most clearly for descending ramps and stairs. The C-Brace orthosis is able to combine improved orthotic function with sustained orthotic safety.

Background: There are clear indications for benefits of stance control orthoses compared to locked knee ankle foot orthoses. However, stance control orthoses still have limited function compared with a sound human leg. Objectives: The aim of this study was to evaluate the potential benefits of a microprocessor stance and swing control orthosis compared to stance control orthoses and locked knee ankle foot orthoses in activities of daily living. Study design: Survey of lower limb orthosis users before and after fitting of a microprocessor stance and swing control orthosis. Methods: Thirteen patients with various lower limb pareses completed a baseline survey for their current orthotic device (locked knee ankle foot orthosis or stance control orthosis) and a follow-up for the microprocessor stance and swing control orthosis with the Orthosis Evaluation Questionnaire, a new self-reported outcome measure devised by modifying the Prosthesis Evaluation Questionnaire for use in lower limb orthotics and the Activities of Daily Living Questionnaire. Results: The Orthosis Evaluation Questionnaire results demonstrated significant improvements by microprocessor stance and swing control orthosis use in the total score and the domains of ambulation (p = .001), paretic limb health (p = .04), sounds (p = .02), and well-being (p = .01). Activities of Daily Living Questionnaire results showed significant improvements with the microprocessor stance and swing control orthosis with regard to perceived safety and difficulty of activities of daily living. Conclusion: The microprocessor stance and swing control orthosis may facilitate an easier, more physiological, and safer execution of many activities of daily living compared to traditional leg orthosis technologies. Clinical relevance This study compared patient-reported outcomes of a microprocessor stance and swing control orthosis (C-Brace) to those with traditional knee ankle foot orthosis and stance control orthosis devices. The C-Brace offers new functions including controlled knee flexion during weight bearing and dynamic swing control, resulting in significant improvements in perceived orthotic mobility and safety.

Ankle–foot orthoses can be prescribed to improve gait in children with cerebral palsy. Before evaluating the effects of ankle–foot orthoses on gait, a period to adapt or acclimatize is usually applied. It is however unknown whether an acclimatization period is actually needed to reliably evaluate the effect of a new orthosis on gait. This study aimed to investigate whether specific gait parameters in children with cerebral palsy would change within an acclimatization period after being provided with new ankle–foot orthoses.Ten children with cerebral palsy, walking with excessive knee flexion in midstance (8 boys; mean (SD) 10.2 (1.9) years; Gross Motor Function Classification System levels I–II) were provided with ventral shell ankle–foot orthoses. The orthoses were worn in combination with the child's own shoes and tuned, based on ground reaction force alignment with respect to the lower limb joints. Directly after tuning (T0) and four weeks later (T1), 3D-gait analysis was performed using an optoelectronic motion capture system and a force plate. From this assessment, ten spatiotemporal, kinematic and kinetic gait parameters were derived for the most affected leg. Differences in parameters between T0 and T1 were analyzed using paired t-tests or Wilcoxon signed rank tests (P < 0.05).Over the course of four weeks, no significant differences (P ≥ 0.080) were observed for any investigated parameter.These results imply that the biomechanical effect of ventral shell ankle–foot orthoses on gait in independent walking children with cerebral palsy is immediately apparent, i.e., there is no further change after acclimatization.

Introduction: The human hand is greatly complex and makes it possible to manipulate and hold objects using many different grips, whereas the function of traditional myoelectric prosthetic hands is dramatically limited, offering only the tripod grip. Therefore, amputees use the prosthesis actively for only about 50% of activities of daily living (ADLs). The purpose of this study was to investigate whether the Michelangelo hand (Otto Bock HealthCare GmbH, Duderstadt, Germany) offering more grip modes as well as a flexible wrist improves function and reduces perceived difficulty of performing ADLs in comparison to conventional myoelectric hands. Materials and Methods: A questionnaire that combined the validated Orthotics and Prosthetics User Survey–Upper Extremity Functional Status (OPUS-UEFS) and the Prosthetic Upper Extremity Functional Index (PUFI) was used to assess perceived difficulty and usefulness of the prosthesis in performing 23 ADLs. Patients completed this questionnaire at baseline for their existing prosthetic hand and after a minimum of 4 weeks of use of the Michelangelo hand. Results: Sixteen male transradial amputees with an average age of 41 ± 14 years were enrolled. The mean period since amputation was 11.8 ± 16.1 years, and the mean duration of Michelangelo use was 12.4 ± 7.3 weeks. The Michelangelo hand significantly improved the ease of performing the 23 ADLs in the OPUS-UEFS from 27.0 ± 9.7 to 36.4 ± 12.7 (p = 0.03). The mean total score for bimanual activities improved highly significantly (p = 0.01) with 26.2 ± 8.1 for Michelangelo as compared with 20.0 ± 7.1 with the previous hand. Using the Michelangelo hand patients performed significantly more ADLs with “both hands together with the prosthetic hand used actively to grasp” as compared with the conventional myoelectric hands (means 9.3 ± 4.6 vs. 7.1 ± 4.1 ADLs; p = 0.04). In addition, the Michelangelo hand was rated as very useful for significantly more ADLs (9.1 ± 4.3 vs. 6.4 ± 4.1 ADLs; p = 0.01). Conclusions: These results suggest that the Michelangelo hand offering more grip types and functional hand positions as well as a flexible wrist may be used more actively and for more ADLs. These effects seem to be promoted by a reduced perceived difficulty to perform many ADLs as Michelangelo shortens the functional gap between prosthetic and sound human hands.

Ten established transfemoral amputees completed biomechanical tests after they had been fitted with a new prosthetic knee joint (test sessions: a few hours and 3 months after fitting). The required adaptation phase after fitting of a new prosthesis is frequently discussed. This phase is considered to be completed when the test result is no longer influenced by the patients’ learning processes. The study contributes to the understanding of the adaptation effects experienced prosthesis users require to master various motion patterns after being fitted with functionally new prosthetic knee joints. Biomechanical parameters (ground reaction forces, joint moments, and joint angles at the knee and the hip) were measured for level walking as well as ascending and descending ramps and stairs. For level walking, walking on ramps, and descending stairs, relevant differences in the parameters between the two tests could not be identified. For ascending stairs, the results of both tests showed obvious differences. The functions of a newly fitted prosthetic component can be intuitively used after a few hours of adaptation time if the motion patterns required are similar to that of the previous fitting. If specific functions require the learning of a motion, the learning processes will require a longer adaptation period.

The benefits of microprocessor-controlled prosthetic knees (MPKs) have been well established in community ambulators (Medicare Functional Classification Level [MFCL]-3) with a transfemoral amputation (TFA). A systematic review of the literature was performed to analyze whether limited community ambulators (MFCL-2) may also benefit from using an MPK in safety, performance-based function and mobility, and perceived function and satisfaction. We searched 10 scientific databases for clinical trials with MPKs and identified six publications with 57 subjects with TFA and MFCL-2 mobility grade. Using the criteria of a Cochrane Review on prosthetic components, we rated methodological quality moderate in four publications and low in two publications. MPK use may significantly reduce uncontrolled falls by up to 80% as well as significantly improve indicators of fall risk. Performance-based outcome measures suggest that persons with MFCL-2 mobility grade may be able to walk about 14% to 25% faster on level ground, be around 20% quicker on uneven surfaces, and descend a slope almost 30% faster when using an MPK. The results of this systematic review suggest that trial fittings may be used to determine whether or not individuals with TFA and MFCL-2 mobility grade benefit from MPK use. Criteria for patient selection and assessment of trial fitting success or failure are proposed.