Dataset Information

Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

ABSTRACT: This study was a randomized crossover of stair ambulation of Transfemoral Amputees (TFAs) using the Genium and C-Leg prosthetic knees. TFAs typically have difficulty ascending and descending stairs, limiting community mobility. The objective of this study was to determine the relative efficacy of the Genium and C-Leg prostheses for stair ascent and descent, and their absolute efficacy relative to non-amputees. Twenty TFAs, and five non-amputees participated in the study. TFAs were randomized to begin the study with the Genium or C-Leg prosthesis. Informed consent was obtained from all participants prior to data collection and the study was listed on clinicaltrials.gov (#NCT01473662). After fitting, accommodation, and training, participants were asked to demonstrate their preferred gait pattern for stair ascent and descent and a step-over-step pattern if able. TFAs then switched prosthetic legs and repeated fitting, accommodation, training, and testing. An eight camera Vicon optical motion analysis system, and two AMTI force plates were used to track and analyze the participants' gait patterns, knee flexion angles, knee moment normalized by body weight, and swing time. For stair descent, no significant differences were found between prostheses. For stair ascent, Genium use resulted in: increased ability to use a step-over-step gait pattern (p=0.03), increased prosthetic side peak knee flexion (p<0.01), and increased swing duration (p<0.01). Changes in contralateral side outcomes and in knee moment were not significant. Overall the Genium knee decreased deficiency in gait patterns for stair ascent relative to the C-Leg, by enabling gait patterns that more closely resembled non-amputees.

SUBMITTER: Lura DJ

PROVIDER: S-EPMC5645229 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

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Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

Lura Derek J DJ Wernke Matthew W MW Carey Stephanie L SL Kahle Jason T JT Miro Rebecca M RM Highsmith M Jason MJ

Gait & posture 20170725

This study was a randomized crossover of stair ambulation of Transfemoral Amputees (TFAs) using the Genium and C-Leg prosthetic knees. TFAs typically have difficulty ascending and descending stairs, limiting community mobility. The objective of this study was to determine the relative efficacy of the Genium and C-Leg prostheses for stair ascent and descent, and their absolute efficacy relative to non-amputees. Twenty TFAs, and five non-amputees participated in the study. TFAs were randomized to ...[more]

PMID: 28763712

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Project description:PurposeTo investigate the differences of patellofemoral joint pressure and contact area between the process of stair ascent and stair descent.MethodsThe finite element models of 9 volunteers without disorders of knee (9 males) to estimate patellar cartilage pressure during the stair ascent and the stair descent. Simulations took into account cartilage morphology from magnetic resonance imaging, joint posture from weight-bearing magnetic resonance imaging, and ligament model. The three-dimension models of the patella, femur and tibia were developed with the medical image processing software, Mimics 11.1. The ligament was established by truss element of the non-linear FE solver. The equivalent gravity direction (-z direction) load was applied to the whole end of femur (femoral head) according to the body weight of the volunteers, and the force of patella was observed. A paired-samples t-test or Wilcoxon rank sum test to make comparisons between stair ascent and stair descent. Statistical analyses were performed using SPSS 22.0 using a P value of 0.05 to indicate significance.ResultsDuring the stair descent (knee flexion at 30°), the contact pressure of the patella was 2.59 ± 0.06Mpa. The contact pressure of femoral trochlea cartilage was 2.57 ± 0.06Mpa. During the stair ascent (knee flexion at 60°), the contact pressure with patellar cartilage was 2.82 ± 0.08Mpa. The contact pressure of the femoral trochlea cartilage was 3.03 ± 0.11Mpa. The contact area between patellar cartilage and femoral trochlea cartilage was 249.27 ± 1.35mm2 during the stair descent, which was less than 434.32 ± 1.70mm2 during the stair ascent. The area of high pressure was located in the lateral area of patella during stair descent and the area of high pressure was scattered during stair ascent.ConclusionThere are small change in the cartilage contact pressure between stair ascent and stair descent, indicating that the joint adjusts the contact pressure by increasing the contact area.

Project description:BackgroundAlthough total knee arthroplasty improves functional mobility in persons with end-stage knee osteoarthritis, many subjects have reported continued difficulty with stair ascent and descent after surgery. The purpose of the present study was to determine preoperative predictors of handrail use during stair ascent and descent following primary unilateral total knee arthroplasty.MethodsOne hundred and five adults who were scheduled for unilateral total knee arthroplasty participated in the study. Postoperative handrail use during stair ascent or descent was predicted on the basis of preoperative functional measures. Preoperative age, body mass index, knee strength, knee flexion active range of motion, Knee Outcome Survey scores, time to complete a stair-climbing task, and previous handrail use were entered as covariates into a binary logistic regression. Forward logistic regression was performed to determine which preoperative factors best predicted handrail use at three months and two years after surgery. Handrail use in a control group was also evaluated at baseline and at the time of the two-year follow-up.ResultsPrior to surgery, sixty-three of the 105 subjects required a handrail. Two years after surgery, sixty of the 105 subjects required a handrail. In the control group, nineteen of the sixty-four subjects required a handrail at baseline and ten of thirty-one required a handrail at the time of the two-year follow-up. At two years, the preoperative ability to ascend and descend stairs without a handrail was the best predictor of individuals who would not require a handrail after surgery, followed by younger age and greater quadriceps strength. Collectively, these variables correctly predicted the ability of ninety of 105 persons to negotiate stairs without a handrail at two years after surgery (p < 0.001).ConclusionsYounger, stronger patients who do not use a handrail prior to unilateral total knee arthroplasty can expect the best outcomes in terms of ascending and descending stairs following surgery. This information may provide patients with more realistic expectations after surgery and allow them to make more appropriate discharge plans.

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Project description:Present knowledge of how the microcirculation is altered by prolonged exposure to hypoxia at high altitude is incomplete and modification of existing analytical techniques may improve our knowledge considerably. We set out to use a novel simplified method of measuring in vivo capillary density during an expedition to high altitude using a CytoCam incident dark field imaging video-microscope. The simplified method of data capture involved recording one-second images of the mucosal surface of the inner lip to reveal data about microvasculature density in ten individuals. This was done on ascent to, and descent from, high altitude. Analysis was conducted offline by two independent investigators blinded to the participant identity, testing conditions and the imaging site. Additionally we monitored haemoglobin concentration and haematocrit data to see if we could support or refute mechanisms of altered density relating to vessel recruitment. Repeated sets of paired values were compared using Kruskall Wallis Analysis of Variance tests, whilst comparisons of values between sites was by related samples Wilcoxon Signed Rank Test. Correlation between different variables was performed using Spearman's rank correlation coefficient, and concordance between analysing investigators using intra-class correlation coefficient. There was a significant increase in capillary density from London on ascent to high altitude; median capillaries per field of view area increased from 22.8 to 25.3 (p=0.021). There was a further increase in vessel density during the six weeks spent at altitude (25.3 to 32.5, p=0.017). Moreover, vessel density remained high on descent to Kathmandu (31.0 capillaries per field of view area), despite a significant decrease in haemoglobin concentration and haematocrit. Using a simplified technique, we have demonstrated an increase in capillary density on early and sustained exposure to hypobaric hypoxia at thigh altitude, and that this remains elevated on descent to normoxia. The technique is simple, reliable and reproducible.

Dataset Information

Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

Publications

Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

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