Transfemoral amputee intact limb loading and compensatory gait mechanics during down slope ambulation and the effect of prosthetic knee mechanisms.

Background: Intact limb knee osteoarthritis is a prevalent secondary disability in transfemoral amputees. Walking down a ramp may increase this risk due to excessive limb loading. We sought to determine whether intact limb loading differed between transfemoral amputees and controls during down slope ambulation, and the compensatory strategies transfemoral amputees used to modify intact limb loading.

Preliminary evaluation of variable compliance joystick for people with multiple sclerosis.

Upper-limb fatigue is a common problem that may restrict people with multiple sclerosis (MS) from using their electric powered wheelchair effectively and for a long period of time. The objective of this research is to evaluate whether participants with MS can drive better using a variable compliance joystick (VCJ) and customizable algorithms than with a conventional wheelchair joystick. Eleven participants were randomly assigned to one of two groups.

Beyond componentry: How principles of motor learning can enhance locomotor rehabilitation of individuals with lower limb loss--a review.

Relatively little attention has been given to the use of well-established motor learning strategies to enable individuals with lower limb loss to effectively and safely learn to walk with their prostheses in the home and community. Traditionally, such outcomes have been pursued by focusing on the design and function of a patient's prosthesis, rather than on how he or she should learn to use it. The use of motor learning strategies may enhance physical rehabilitation outcomes among individuals with lower limb loss.

New resource for the computation of cartilage biphasic material properties with the interpolant response surface method.

Cartilage material properties are important for understanding joint function and diseases, but can be challenging to obtain. Three biphasic material properties (aggregate modulus, Poisson's ratio and permeability) can be determined using an analytical or finite element model combined with optimisation to find the material properties values that best reproduce an experimental creep curve. The purpose of this study was to develop an easy-to-use resource to determine biphasic cartilage material properties.

Manual wheelchair stroke characteristics during an extended period of propulsion.

Study Design: Cross-sectional study.

Objectives: The purpose of this study was to examine stroke characteristics of long-term manual wheelchair users during an extended manual wheelchair propulsion trial and the extent to which changes in propulsion biomechanics occurred.

Setting: Human Engineering Research Laboratories, VA Rehabilitation Research and Development Center, VA Pittsburgh Healthcare Systems, Pittsburgh, PA, USA.

Shoulder biomechanics during the push phase of wheelchair propulsion: a multisite study of persons with paraplegia.

Objectives: To present a descriptive analysis and comparison of shoulder kinetics and kinematics during wheelchair propulsion at multiple speeds (self-selected and steady-state target speeds) for a large group of manual wheelchair users with paraplegia while also investigating the effect of pain and subject demographics on propulsion.

Design: Case series.

Setting: Three biomechanics laboratories at research institutions.

Clinical evaluation of Guido robotic walker.

The Guido is a robotic walker that provides navigation and obstacle-avoidance assistance. Engineering tests have found that the device performs adequately and presents no hazard to the user. The performance of the Guido was compared with a low-tech mobility aid, the Assistive Mobility Device (AMD) developed at the Atlanta Department of Veterans Affairs Medical Center, in trials involving older adults with visual impairments.

Shoulder joint kinetics and pathology in manual wheelchair users.

Background: Manual wheelchair users rely heavily on their upper limbs for independent mobility which likely leads to a high prevalence of shoulder pain and injury. The goal of this study was to examine the relationship between shoulder forces and moments experienced during wheelchair propulsion and shoulder pathology.

Methods: Kinetic and kinematic data was recorded from 33 subjects with paraplegia as they propelled their wheelchairs at two speeds (0.

Effect of a vitamin D analog on leg bone mineral density in patients with chronic spinal cord injury.

A randomized, placebo-controlled trial was performed to determine the effect of a vitamin D analog (1-alpha-hydroxyvitamin D(2) [1-alpha D(2)]) on the bone mineral density (BMD) in patients with chronic spinal cord injury (SCI). Forty subjects with chronic complete motor SCI were enrolled. The mean plus or minus standard deviation age and duration of injury were 42 plus or minus 12 yr and 11 plus or minus 10 yr, respectively.

Evaluation of the safety and durability of low-cost nonprogrammable electric powered wheelchairs.

Objective: To evaluate whether a selection of low-cost, nonprogrammable electric-powered wheelchairs (EPWs) meets the American National Standards Institute (ANSI)/Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) Wheelchair Standards requirements.

Design: Objective comparison tests of various aspects of power wheelchair design and performance of 4 EPW types.

Specimens: Three of each of the following EPWs: Pride Mobility Jet 10 (Pride), Invacare Pronto M50 (Invacare), Electric Mobility Rascal 250PC (Electric Mobility), and the Golden Technologies Alanté GP-201-F (Golden).

A modeling framework to estimate patellofemoral joint cartilage stress in vivo.

Purpose: Patellofemoral (PF) pain is common among athletes and may be caused by increased subchondral bone stress as a result of increased stress in the cartilage of the femur or patella. This article presents a modeling pipeline to estimate in vivo cartilage stress in the PF joint.

Methods: The modeling pipeline uses the finite element method to calculate stresses and strains in the PF joint cartilage.

Patellofemoral joint contact area increases with knee flexion and weight-bearing.

Patellofemoral pain is a common and debilitating disorder. Elevated cartilage stress of the patellofemoral joint is hypothesized to play a role in the onset of pain. Estimating cartilage stress requires accurate measurements of contact area.

Evaluation of selected electric-powered wheelchairs using the ANSI/RESNA standards.

Objectives: To compare the performance characteristics of different electric-powered wheelchairs (EPWs) and to evaluate the effectiveness of the American National Standards Institute/Rehabilitation Engineering and Assistive Technology Society of North America (ANSI/RESNA) wheelchair standards.

Design: Five types of EPWs were selected. Three wheelchairs of each type were tested according to the ANSI/RESNA wheelchair standards.

Intelligent walkers for the elderly: performance and safety testing of VA-PAMAID robotic walker.

A walker that could help navigate and avoid collisions with obstacles could help reduce health costs and increase the quality of care and independence of thousands of people. This study evaluated the safety and performance of the Veterans Affairs Personal Adaptive Mobility Aid (VA-PAMAID). We performed engineering tests on the VA-PAMAID to determine safety factors, including stability, energy consumption, fatigue life, and sensor and control malfunctions.

Mechanobiological predictions of growth front morphology in developmental hip dysplasia.

Developmental dysplasia of the hip (DDH) is the most common orthopedic problem of newborn children. Most clinicians and researchers agree that the primary cause of DDH is abnormal mechanical forces on the head of the femur due to limb position, pressure from the womb, or ligament laxity. The abnormal mechanical forces result in altered growth and bony deformities, in particular large neck-shaft and anteversion angles in the proximal femur and a shallow acetabulum.

Measuring functional change in children with acquired brain injury (ABI): comparison of generic and ABI-specific scales using the Pediatric Evaluation of Disability Inventory (PEDI).

Background And Purpose: The Pediatric Evaluation of Disability Inventory (PEDI) subscales are hierarchic in nature, with item placements within each subscale reflecting the general order of skill attainment in children without disabilities. The purpose of this study was to determine whether a hierarchical subscale developed in this study for children with acquired brain injuries (ABIs) corresponds to the generic PEDI subscales, and, if not, whether condition-specific (ABI-specific) PEDI subscales are more sensitive for measuring change.

Subjects: Eighty-seven children and adolescents (mean age=9.

Driving characteristics of electric-powered wheelchair users: how far, fast, and often do people drive?

Objectives: To determine the driving characteristics of electric-powered wheelchair users during unrestricted community activities and to compare the activity levels among an active group and a group of regular users.

Design: Multisite engineering evaluation of electric-powered wheelchair driving activity during unrestricted community mobility.

Setting: Data were collected in the communities of Pittsburgh, PA, and the National Veterans Wheelchair Games (NVWG) in San Antonio, TX.

Reliability of hearing thresholds: computer-automated testing with ER-4B Canal Phone earphones.

This study was conducted to document test-retest reliability of hearing thresholds using our computer-automated tinnitus matching technique and Etymotic ER-4B Canal Phone insert earphones. The research design involved repeated threshold measurements both within and between sessions, and testing to evaluate the potential effect of eartip removal and reinsertion. Twenty normal-hearing subjects were evaluated over two testing sessions with the use of a fully automated protocol for determining thresholds with 1-dB precision.

Analysis of vibrations induced during wheelchair propulsion.

Little is known about how dynamic acceleration affects wheelchair-rider comfort. The current study was to test both the operation of an instrumented wheelchair by a wheelchair user over a Simulated Road Course (SRC) and the operation of the same instrumented wheelchair during normal daily activities (a field test) by test subjects. Sixteen subjects participated in the protocol.

Effects of oral estrogen and progestin on the lower urinary tract among female nursing home residents.

Objective: To examine the effects of oral estrogen/progestin on incontinence and related lower urinary tract conditions among female nursing home (NH) residents.

Design: Randomized placebo-controlled trial.

Setting: Five NHs.

Urinary incontinence treatment preferences in long-term care.

Objective: To elicit preferences for different urinary incontinence (UI) treatments in long-term care (LTC) from groups likely to serve as proxy decision makers for LTC residents.

Design: A descriptive, comparative study of preference for UI treatments of frail older adults, family members of nursing home (NH) residents, and LTC nursing staff. Surveys were mailed to families and self-administered by staff.

Prompted voiding for nighttime incontinence in nursing homes: is it effective?

Objectives: To determine whether prompted voiding (PV) is effective for nighttime urinary incontinence in nursing home (NH) residents and whether residents who respond well to daytime PV also respond well at night.

Design: Prospective case series.

Setting: Four community NHs.

Dynamic calibration of a wheelchair dynamometer.

The inertia and resistance of a wheelchair dynamometer must be determined in order to compare the results of one study to another, independent of the type of device used. The purpose of this study was to describe and implement a dynamic calibration test for characterizing the electro-mechanical properties of a dynamometer. The inertia, the viscous friction, the kinetic friction, the motor back-electromotive force constant, and the motor constant were calculated using three different methods.

Road loads acting on manual wheelchairs.

A barrier to performing more in-depth analyzes during the wheelchair design process is a lack of dynamic reaction force and moment data, and the instrumentation to collect this data. Instrumentation was developed to collect the dynamic force and moment data. New data collections methodologies and analysis techniques were implemented to facilitate computer-aided-engineering for wheelchair designs.

Arginine vasopressin levels in nursing home residents with nighttime urinary incontinence.

Objectives: To examine the relationship between diurnal urine volume and plasma arginine vasopressin levels (AVP) in nursing home residents with nighttime urinary incontinence and a comparison group of frail but nondemented, continent geriatric board and care residents.

Design: Case series.

Setting: Four nursing homes and two board and care facilities.