Inertial sensor-based measures of gait symmetry and repeatability in people with unilateral lower limb amputation (original) (raw)
Related papers
Identifying gait quality metrics sensitive to changes in lower limb constraint
2021
Background Manual tuning of robotic lower limb prostheses can be time consuming for both the patient and the clinician and requires in-person visits to a clinic. An automated process for the tuning parameters of a robotic lower limb prosthesis could result in a substantial savings in healthcare resources. A critical challenge to an automated parameter tuning algorithm is the quantification of a person’s gait quality. There is not good agreement in the literature of an objective outcome measure that can rapidly assess gait quality in lower limb amputees. As a first step, we investigated the ability of four common gait quality metrics to detect differences in gait quality: Prosthetic Observational Gait Score (POGS), Gait Deviation Index (GDI), Lateral Sway, and Impulse Asymmetry. Methods We systematically applied four unilateral lower limb joint constraint conditions (baseline/no constraint, ankle constraint, knee constraint, and knee + ankle constraint) to nine able-bodied participan...
Are wearable insoles a validated tool for quantifying transfemoral amputee gait asymmetry
Prosthetics and Orthotics International, 2019
Walking with a prosthesis is challenging, particularly when the amputation is proximal to the knee joint. To cope with the loss of functionality of prosthetic joints compared to physiologic joints, people with lower limb amputations often modify the kinematics of their contralateral or residual limbs, which results in gait deviations, such as vaulting or pelvic hiking. 1-4 These deviations could be quantified through biomechanical parameters derived from motion capture systems, but the use of such techniques in a clinical environment cannot be considered due to the complexity
Journal of neuroengineering and rehabilitation, 2012
Background: Symmetry and regularity of gait are essential outcomes of gait retraining programs, especially in lower-limb amputees. This study aims presenting an algorithm to automatically compute symmetry and regularity indices, and assessing the minimum number of strides for appropriate evaluation of gait symmetry and regularity through autocorrelation of acceleration signals. Methods: Ten transfemoral amputees (AMP) and ten control subjects (CTRL) were studied. Subjects wore an accelerometer and were asked to walk for 70 m at their natural speed (twice). Reference values of step and stride regularity indices (Ad1 and Ad2) were obtained by autocorrelation analysis of the vertical and antero-posterior acceleration signals, excluding initial and final strides. The Ad1 and Ad2 coefficients were then computed at different stages by analyzing increasing portions of the signals (considering both the signals cleaned by initial and final strides, and the whole signals). At each stage, the difference between Ad1 and Ad2 values and the corresponding reference values were compared with the minimum detectable difference, MDD, of the index. If that difference was less than MDD, it was assumed that the portion of signal used in the analysis was of sufficient length to allow reliable estimation of the autocorrelation coefficient. Results: All Ad1 and Ad2 indices were lower in AMP than in CTRL (P < 0.0001). Excluding initial and final strides from the analysis, the minimum number of strides needed for reliable computation of step symmetry and stride regularity was about 2.2 and 3.5, respectively. Analyzing the whole signals, the minimum number of strides increased to about 15 and 20, respectively. Conclusions: Without the need to identify and eliminate the phases of gait initiation and termination, twenty strides can provide a reasonable amount of information to reliably estimate gait regularity in transfemoral amputees.
—The prosthetic activity monitor (PAM) is an instrument to assess over the long-term the duration and spatio–tem-poral characteristics of walking of amputees, during normal daily life. In this study, the validity of PAM-derived measurements was investigated. Twelve transtibial amputees performed an activity protocol, consisting of stationary and walking activities, and activities associated with nonlocomotor movements. The protocol also included potential sources of error and activities assumed to be prone to misde-tection. Measurements consisted of the PAM and video recordings. Agreement between video analysis and PAM output was the main outcome measure. The PAM generally correctly classified stationary activities (100% inactive, 0% active, 0% locomotion), nonlocomotor activities (45% inactive, 55% active, 0% locomotion) and walking activities (0% inactive, 1.8% active, 98.2% locomotion). When walking, the number of strides taken was slightly underestimated (1.0%). The underestimation of distance travelled (6.2%) and walking speed (5.8%) was greater. The agreement with video output decreased when the PAM was misaligned, when persons walked at a speed below the defined minimum speed, and when persons walked with crutches. The PAM provides valid data on activity classes and number of strides. Although the majority of the distance data was satisfactory , in some cases considerable differences were found between the PAM and the video data. The impact of alignment, walking speed, and use of assistive devices on the PAM's operation should be considered.
Journal of Orthopaedic Surgery, 2019
Gait variability is a determinant of qualified locomotion and is useful for monitoring the effects of therapeutic interventions. The aim of this study was to compare gait variability and symmetry in trained individuals with transtibial (TT) amputation and transfemoral (TF) amputation. Methods: The design of this study was planned as observational. Eleven individuals with TF amputation, 14 individuals with TT amputation, and 14 healthy individuals (HI) were evaluated with a motorized treadmill. The mean step length, the step length variability, an ambulation index, and the time on each foot (stance phase symmetry) of participants were recorded. Results: There were differences between the three groups in the residual/non-preferred limb (RNp) step length (p ¼ 0.031), the intact/preferred (IP) limb step length variability (p ¼ 0.001), the RNp step length variability (p < 0.001), the time on each foot (p < 0.001), and the ambulation index score (p < 0.001). There was a similarity between the groups (TF, TT, HI) in IP limb step lengths (p ¼ 0.127) and duration of prosthesis usage since amputation in individuals with lower limb loss (p ¼ 0.224). Conclusions: This study provided basic data about gait variability and symmetry in individuals with traumatic lower limb loss. The results of the study showed that the variability of gait increased with the level of loss, and individuals with TT amputation showed partially equivalent performance with the healthy group. Similarities in gait characteristics may have resulted from effective prosthetic usage or effective gait rehabilitation.
Acta Universitatis Palackianae …, 2009
Human gait is a genetically fixed motion model. The use of prosthesis changes the structure of the gait, the distribution of energy increases. The aim of this study was to compare the intra and inter individual variability of the basic dynamic gait parameters of physically active persons with unilateral trans-tibial amputation. A group of 11 males (age 46.1 ± 12.0 years, body weight 82.5 ± 13.9 kg) with unilateral trans-tibial amputation was analysed. The basic dynamic parameters (AMTI) of the gait of each subject with conventional and dynamic prosthetic foot were measured. The interindividual variability in the group of the evaluated person is higher in comparison with the intraindividual variability. The sizes of the coefficients of reliability are exceeded for measured parameters (time, force, force impulse) in anteroposterior and in vertical direction the value 0.976. The extent of these values depends on the individual properties of evaluated person (for example the instability of the knee etc.).
JPO Journal of Prosthetics and Orthotics, 2010
Asymmetric gait, commonly referred to as "limping," is frequently seen in individuals with a variety of musculoskeletal and neurologic conditions. Asymmetric gait impacts the metabolic cost of ambulation and the development of osteoarthritis and also affects the cosmetic appearance of gait. This is especially true for individuals with lower limb amputations who ambulate with prosthetic limbs. The Lower Extremity Ambulation Feedback System (LEAFS) is a shoe-insert device that uses force sensors to evaluate asymmetries in gait and provide auditory feedback when an asymmetric gait threshold is reached. The aim of this study was to validate the ability of the LEAFS to accurately measure stance time and detect asymmetries in stance time. A prospective, consecutive case series study design was used. The study population consisted of individuals with lower limb amputations at the transtibial level. Data were collected simultaneously using both the LEAFS and a force plate and markers on the foot in a clinical motion analysis laboratory as subjects ambulated at their self-selected walking speed. The methods comparison approach of Bland and Altman was used to validate the measurement of stance time, and two-sample t-tests were used to validate the detection of asymmetry. The LEAFS determined the stance time with a bias error of Ϫ10.4 Ϯ 37.2 ms, when compared with the clinical motion laboratory, and detected the same asymmetries in stance time for subjects with unilateral amputation (a shorter stance time on the limb with the prosthetic, when compared with the intact limb) as the clinical motion laboratory.