Do Transfemoral Prostheses With Powered Prosthetic Knee Flexion and Extension Improve Mobility? A Biomechanical Evaluation of the Ossur Power Knee
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- Walking speed
研究概览
简要总结
Microprocessor-controlled knees (MPKs) do not typically utilize motors to power joint rotation, but they automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the prosthesis user during gait. The Ossur Power Knee is the only commercially-available MPK that uses a motor to provide active power generation during walking and other activities. The purpose of this proposed investigation is to perform and compare biomechanical evaluations of the Power Knee and Ossur Rheo XC, a passive MPK, during walking and other activities by prosthesis users. Furthermore, mobility between male and female subjects will be compared to determine if there are differences in prosthetic knee usage on the basis of sex.
详细描述
The anatomical knee is a complex, polycentric joint characterized by a large range of motion in the sagittal plane and limited mobility in the coronal and transverse planes. The sagittal plane motion is used for progression in stance phase, and limb clearance and advancement in swing. Limb prostheses are intended to restore function and cosmesis in persons with limb loss. The complexity and function of prosthetic components have advanced significantly as technology has improved, but a state-of-the-art artificial limb is still a relatively poor substitute for an anatomical one. Microprocessor-controlled knees (MPKs) do not typically utilize motors to power joint rotation, but they automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the user during gait. The Ossur Power Knee, which was first introduced in 2006, is the only MPK that uses a motor to provide active power generation during walking and other activities involving knee flexion and extension. Last year, Ossur released the 3rd generation of its Power Knee and appears to have addressed many of the previous shortcomings in terms of reduced weight, less noise, lower cost and longer battery life. Therefore, the newest version of the Power Knee warrants a fresh evaluation since it is, in essence, substantially different in design and function from previous models.
The purpose of this proposed investigation is to perform biomechanical evaluations of the new Ossur Power Knee during walking and other activities by transfemoral prosthesis users. Using a cross-over experimental design, approximately 20 unilateral, transfemoral amputee subjects (10 men and 10 women) will be evaluated in the Jesse Brown VAMC Motion Analysis Research Laboratory (MARL) while wearing the Ossur Power Knee and Ossur Rheo XC, which is a passive MPK device. Furthermore, the Ossur Power Knee may offer distinct advantages to female prosthesis users, so mobility will be compared between men and women to determine if differences exist on the basis of sex. The specific aims and hypotheses of this project are:
Aim 1: To compare the effects of the Ossur Power Knee and Ossur Rheo XC on the gait of unilateral, transfemoral prosthesis users during level walking. Kinematic and kinetic data will be collected as subjects walk in the MARL. Hypothesis--the active knee flexion and extension provided by the Ossur Power Knee will (1) improve walking performance, and (2) reduce metabolic energy cost during ambulation.
Aim 2: To compare the effects of the Ossur Power Knee and Ossur Rheo XC on stairs, slopes and during sit-to-stand/stand-to-sit activities of unilateral, transfemoral prosthesis users. Kinematic data will be collected as subjects perform these activities. Hypothesis--subjects will have improved performance when using the Ossur Power Knee.
Aim 3: To analyze and compare gender specific data between subjects using the Ossur Power Knee and the Ossur Rheo XC. Hypothesis--male and female subjects will demonstrate substantially different abilities to use the two knee components, indicating that gender specific components should be further investigated and developed. Research focusing on the unique prosthetic needs of women Veterans is currently a special emphasis area of the VA RR&D Service.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 45 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Unilateral, transfemoral amputation (any etiology).
- •Age from 45-75 years.
- •Residual limb length classified as standard (i.e., medium) to long.
- •Prosthesis user for at least 1 year prior to enrolling in the study.
- •K3 or K4 level ambulator.
- •Good sensation on their residual limb(s) (upon routine clinical examination).
- •Good skin integrity upon visual inspection.
- •Does not require the use of assistive devices to walk for short distances.
- •Not currently taking medications that are known to affect balance or gait.
- •Presents with good socket fit based upon a standard assessment by the study prosthetist.
排除标准
- •Bilateral amputations
- •Individuals with a knee disarticulation
结局指标
主要结局
Walking speed
时间窗: To be measured after the 1-month accommodation period of wearing each prosthetic knee component
Walking speed will be measured as participants walk on level ground at slow, normal and fast speeds.
Sit-to-stand/stand-to-sit symmetry
时间窗: To be measured after the 1-month accommodation period of wearing each prosthetic knee component
Knee kinematics and load distribution between the sound and prosthetic sides will be measured as participants stand up and sit down in a chair.
Metabolic energy cost
时间窗: To be measured after the 1-month accommodation period of wearing each prosthetic knee component
The metabolic energy rate will be measured as subjects walk at their freely selected speed on a level treadmill, which will be converted to metabolic energy cost (energy expended per unit distance).
次要结局
- Sound leg loading rate(To be measured after the 1-month accommodation period of wearing each prosthetic knee component)
- Kinematics of pelvic motion(To be measured after the 1-month accommodation period of wearing each prosthetic knee component)
- Step length(To be measured after the 1-month accommodation period of wearing each prosthetic knee component)
- Toe clearance during swing phase(To be measured after the 1-month accommodation period of wearing each prosthetic knee component)