PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2235301

Accelerations due to impact at heel strike using below-knee prosthesis.

H W Van Jaarsveld·H J Grootenboer·J De Vries
View original source ↗Export metadata ↓

Abstract

The acceleration in the sagittal plane of the prosthetic tube at heel strike in normal walking was measured in five healthy amputees with their definitive below-knee prosthesis, every subject using six different prosthetic feet, wearing sport shoes as well as leather shoes. The experiments were carried out in the rehabilitation centre "Het Roessingh", Enschede, The Netherlands. Maximum accelerations were extracted from the acceleration-time-signal. Mean acceleration maxima of all subjects were calculated for each foot-shoe combination to eliminate the individual influence of the subjects. In the axial direction the maximal accelerations demonstrate a clear difference among the prosthetic feet and the shoes, while in dorsoventral (tangential) direction the inter-individual variation in the acceleration extremes dominates the difference between the types of footwear. In comparison with non-amputees the magnitude of the maximal axial acceleration at heel strike does not differ significantly.

Explore related subjects

AmputeesArtificial LimbsBiomechanical PhenomenaGaitHumansLegMaleProsthesis DesignJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

H W Van Jaarsveld, H J Grootenboer, J De Vries. 1990. Accelerations due to impact at heel strike using below-knee prosthesis.. https://doi.org/10.3109/03093649009080323

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Real-time patient-specific finite element analysis of internal stresses in the soft tissues of a residual limb: a new tool for prosthetic fitting.

Fitting of a prosthetic socket is a critical stage in the process of rehabilitation of a trans-tibial amputation (TTA) patient, since a misfit may cause pressure ulcers or a deep tissue injury (DTI: necrosis of the muscle flap under intact skin) in the residual limb. To date, prosthetic fitting typically depends on the subjective skills of the prosthetist, and is not supported by biomedical instrumentation that allows evaluation of the quality of fitting. Specifically, no technology is presently available to provide real-time continuous information on the internal distribution of mechanical stresses in the residual limb during fitting of the prosthesis, or while using it and this severely limits patient evaluations. In this study, a simplified yet clinically oriented patient-specific finite element (FE) model of the residual limb was developed for real-time stress analysis. For this purpose we employed a custom-made FE code that continuously calculates internal stresses in the residual limb, based on boundary conditions acquired in real-time from force sensors, located at the limb-prosthesis interface. Validation of the modeling system was accomplished by means of a synthetic phantom of the residual limb, which allowed simultaneous measurements of interface pressures and internal stresses. Human studies were conducted subsequently in five TTA patients. The dimensions of bones and soft tissues were obtained from X-rays of the residual limb of each patient. An indentation test was performed in order to obtain the effective elastic modulus of the soft tissues of the residual limb. Seven force sensors were placed between the residual limb and the prosthetic liner, and subjects walked on a treadmill during analysis. Generally, stresses under the shinbones were approximately threefold higher than stresses at the soft tissues behind the bones. Usage of a thigh corset decreased the stresses in the residual limb during gait by approximately 80%. Also, the stresses calculated during the trial of a subject who complained about pain and discomfort were the highest, confirming that his socket was not adequately fitted. We conclude that real-time patient-specific FE analysis of internal stresses in deep soft tissues of the residual limb in TTA patients is feasible. This method is promising for improving the fitting of prostheses in the clinical setting and for protecting the residual limb from pressure ulcers and DTI.

Amputees↗
PubMed2006

A method for analyzing joint symmetry and normalcy, with an application to analyzing gait.

A new method for analyzing symmetry and normalcy of gait patterns is explained. This method utilizes eigenvectors to compare waveforms. The right and left limbs of a single subject are compared to determine symmetry. To determine normalcy, a single limb from a subject is compared to a normative file created from the average of healthy control subjects. The analysis method provides four measures of symmetry and normalcy: trend phase, trend symmetry/normalcy, range amplitude ratio, and range offset. The trend symmetry/normalcy is a comparison of the shapes of the waveforms for each limb. The range amplitude ratio is a comparison of the range of motion of each limb. The range offset is a comparison of the range in which each limb operates. The exact methods and clinical applications are provided.

Amputees↗
PubMed2006

The Locomotor Capability Index in diagram form: the Stanmore-Kingston Splat.

The Stanmore-Kingston Splat is a graphical display of the goals and achievements of amputee rehabilitation patients using the Locomotor Capability Index. The chart is in a radial polygram form with the sectors coloured and shaded. Three scores can be shown: The patient's capability at delivery of the prosthesis, the goals set for rehabilitation, and the final achievement after the programme. The main advantages are rapid, easy reading for a therapist and convenient use when discussed with the patient at goal setting or progress review. The Splat is being used at Stanmore Disablement Services Centre and an extension to other centres is planned.

Amputees↗