Search

Inertial measurement units and normative values enable clinicians to quantify clinical walking tests and set rehabilitation goals. Objectives of this study were (1) to compare time- and distance-based walking tests in individuals with lower limb amputation (iLLA) and normative values following rehabilitation discharge (T1) and 6 weeks after discharge (T2) and (2) to investigate spatiotemporal and foot kinematic parameters over a 6-minute walk test using inertial measurement units. Twelve iLLA participated in this study. Distance, cadence, stance ratio, loading rate ratio, push-up ratio, path length, and minimum toe clearance were analyzed during 6-minute walk test. Nonparametric repeated-measures analysis of variance tests, Bonferroni corrections, were performed. Time of distance-based walking tests diminished at T2 (P < .02). Compared with normative values, walking performance in iLLA was reduced. Cadence at T2 increased significantly (P = .026). Stance ratio increased in both legs at T2 (P < .05). Push-up ratio tended to decrease at T2 in the amputated leg (P = .0003). Variability of path length and minimum toe clearance at T2 were less than at T1 in the nonamputated leg (P < .05). Spatiotemporal improvement at T2 could be due to prosthesis adaptation in iLLA. The lower performance of the functional walk test compared with normative values could be due to amputation and pain-related fatigue. [ABSTRACT FROM AUTHOR]

Context: Decreased flexibility in muscles and joints of lower extremities is commonly observed in runners. Understanding the effect of decreased flexibility on knee walking kinematics in runners is important because, over time, altered gait patterns can make runners vulnerable to overuse injuries or degenerative pathologies. Objectives: To compare hamstring and iliotibial-band (ITB) flexibility and knee kinematics in runners and nonrunners. Design: A descriptive, comparative laboratory study. Setting: Hamstring and ITB flexibility were measured with the active knee-extension test and the modified Ober test, respectively, in both groups of participants. Three-dimensional (3D) walking kinematic data were then recorded at the knee using a motion-tracking system. Participants: 18 runners and 16 nonrunners. Main Outcome Measures: Knee-extension angle (hamstring flexibility) and hip-adduction angle (ITB flexibility). Knee kinematic parameters of interest included knee angle at initial contact, peak knee angles, and knee-angle range in all planes of movement. Results: The runners had a significantly less flexible ITB than the nonrunners (hip adduction [-] and adduction [+] angles, 3.1° ± 5.6° vs -6.4° ± 4.5°; P < .001). The runners demonstrated a greater mean tibial external-rotation angle at initial contact (7.3° ± 5.8° vs 2.0° ± 4.0°; P = .01) and a smaller mean peak tibial internal-rotation angle (-1.6° ± 3.0° vs -4.2° ± 3.2°; P = .04) than the nonrunners. Conclusion: This study provides new insight into the relationship between muscle flexibility and 3D knee kinematics in runners. This supports the premise that there is an association between muscle flexibility and transverse-plane knee kinematics in this population. [ABSTRACT FROM AUTHOR]

Background: Toe-out foot positioning is increasingly analyzed as a compensatory body-mechanical strategy to reduce pain and joint constraints in people with degenerative joint disease during gait. However, its influence during functional tasks, such as sit-to-stand, has not been reported.Research Question: How uni- and bilateral toe-out foot positioning influence body-dynamics during a STS task?Methods: The study was conducted on 15 healthy participants. Seven feet conditions were tested: neutral (N); right toe-out angle of 10° (U10), 20° (U20), and 30° (U30); bilateral toe-out angle of 10° (B10), 20° (B20), and 30° (B30). Execution time, trunk kinematic, vertical ground reaction force ratio as well as maximal knee and hip joint moments were analyzed and compared.Results: A significant difference was found across conditions in the STS execution time (p = 0.036) showing a main effect on temporal parameters using both uni- and bilateral toe-out foot positioning. A significant difference between conditions was also obtained for the vertical force ratio (p = 0.018) and the maximal knee flexion moment (p = 0.008). Post-hoc tests demonstrated a significant difference on force ratio and on knee flexion moment only while using a more pronounced unilateral toe-out foot positioning.Significance: The influence of toe-out foot positioning on body-dynamics during STS supports the idea of an alteration of body-mechanical strategy, as reported in literature gait studies. The results could have an impact on the management of patients using these strategies in order to reduce the onset of secondary joint diseases such as osteoarthritis. [ABSTRACT FROM AUTHOR]

Abstract: Background: Patients with knee osteoarthritis present an altered gait pattern. Amongst many factors, the lower limb alignment (varus, valgus) has been identified as an important risk factor for the progression of knee osteoarthritis. Among the large number of studies on knee osteoarthritis gait, only a few have included patients with a valgus deformity. The aims of this study were to determine how knee alignment influences full-body gait in patients with knee osteoarthritis and if knee malalignment is associated with pain and functional capacity. Methods: Sixty patients with severe knee osteoarthritis scheduled for a total knee arthroplasty were included in this study. Twenty-six subjects were recruited as the control group. The spatio-temporal parameters, three-dimensional full-body kinematics, and lower body kinetics were evaluated during a comfortable gait and compared between the groups. Pain and function were assessed with the WOMAC questionnaire. Findings: The full-body gait analysis demonstrated substantially different gait patterns and compensation mechanisms between the three groups. Patients with varus knee alignment significantly augmented their trunk movements in sagittal and frontal planes compared to patients with a valgus knee. In addition, patients with a valgus knee reported lower pain and lower functional deficits compared to patients with a varus knee. Interpretation: We found that gait compensations were significantly influenced by lower limb alignment. These new insights related to different knee osteoarthritis gait patterns might help in the understanding of gait compensation behaviours prior to total knee arthroplasty and better manage the strategies of rehabilitation following surgery. [Copyright &y& Elsevier]

• An algorithm to improve kinematics accuracy in markerless gait analysis is presented. • This algorithm refines AI-driven skeletons in a subject-specific geometric manner. • It preserves skeleton links' length during walking, using intra-frame modelization. • It benefits from gait phases information in between-frames adjustments. • It smooths lower limb joints' trajectory in between-frames adjustments. Despite the advancements in developing markerless gait analysis systems, they still demonstrate lower accuracy compared to gold-standard systems. Hence, in this research, a novel approach is presented to improve the lower limb kinematics accuracy in markerless gait analysis. This approach refines the 3D lower-limb skeletons obtained by AI-based pose estimation algorithms in a subject-specific geometric manner, preserves skeleton links' length, benefits from gait phases information that adds biomechanical awareness to the algorithm, and utilizes an embedded trajectory smoothing. Validation of the proposed method shows that it reduces 12.6–43.5 % of root mean square error (RMSE) and significantly improves kinematic curves' similarity to the gold-standard ones. Results also prove the feasibility of more accurate lower limb kinematics calculation using a single (2.02–7.57° RMSE) or dual RGB-D camera (1.66–7.25° RMSE). Development of such algorithms could result in requirement of fewer cameras that deliver comparable or even superior measurement accuracy compared to multi-camera approaches. [ABSTRACT FROM AUTHOR]

Background: A recent amputation leads to decreased functional capacities in the lower limb amputees (LLA), especially during walking. Assessments of LLA's gait in clinical settings are used to provide feedback on their evolution without quantifying gait parameters distinctly, unlike new technologies, such as inertial sensors (IMUs), which have demonstrated their effectiveness in different environments and populations.Research Question: How do the spatial-temporal gait parameters and kinematics of the LLA evolve quantitatively over a six-minute walk test (6MWT) and is the use of inertial sensors relevant in clinical practice to quantify those parameters?Methods: Fifteen LLA from a study cohort performed a 6MWT post-rehabilitation, wearing inertial sensors on both feet to provide gait parameters (i.e., minimum toe clearance (minTC), speed, cadence, stance time and foot flat ratio (FFr)) over this test. A non-parametric ANOVA was conducted comparing the evolution of each parameter over the 6MWT (12 intervals of 30 s). Significance level was set at P ≤  0.05. Post-hoc Wilcoxon signed-rank tests were performed if a main effect was detected.Results: MinTC and stance phase variability along the 6MWT were significantly different over time. Cadence variability and speed variation were significantly different between both feet (amputated and non-amputated leg).Significance: The increased variability in gait parameters along the 6MWT suggests a greater risk of future mobility problems following a return in community. The data provided by the IMUs reflect the potential of the clinical rehabilitation programme and could, therefore, help clinicians to refine their interventions. [ABSTRACT FROM AUTHOR]

Abstract: Background: Interpreting gait data is challenging due to intersubject variability observed in the gait pattern of both normal and pathological populations. The objective of this study was to investigate the impact of using principal component analysis for grouping knee osteoarthritis (OA) patients'' gait data in more homogeneous groups when studying the effect of a physiotherapy treatment. Methods: Three-dimensional (3D) knee kinematic and kinetic data were recorded during the gait of 29 participants diagnosed with knee OA before and after they received 12weeks of physiotherapy treatment. Principal component analysis was applied to extract groups of knee flexion/extension, adduction/abduction and internal/external rotation angle and moment data. The treatment''s effect on parameters of interest was assessed using paired t-tests performed before and after grouping the knee kinematic data. Findings: Increased quadriceps and hamstring strength was observed following treatment (P <0.05). Except for the knee flexion/extension angle, two different groups (G1 and G2) were extracted from the angle and moment data. When pre- and post-treatment analyses were performed considering the groups, participants exhibiting a G2 knee moment pattern demonstrated a greater first peak flexion moment, lower adduction moment impulse and smaller rotation angle range post-treatment (P <0.05). When pre- and post-treatment comparisons were performed without grouping, the data showed no treatment effect. Interpretation: The results of the present study suggest that the effect of physiotherapy on gait mechanics of knee osteoarthritis patients may be masked or underestimated if kinematic data are not separated into more homogeneous groups when performing pre- and post-treatment comparisons. [Copyright &y& Elsevier]

Background: Most previous studies reported biomechanical deficits in individuals with a trans-tibial amputation (TTA) during gait using zero-dimensional analyses. However, these analyses do not allow to precisely determine during which part of the gait cycle these deficits occur. There is a need to use more appropriate methods to map the differences, such as one-dimensional statistical parametric mapping.Research Question: What are the most relevant phases of the gait cycle during which the biomechanical deficits in TTA occur?Methods: Eight TTA and 15 healthy counterparts (CON) underwent one biomechanical gait analysis. Pelvis, hip, knee and ankle kinematics, total support moment (TSM) and gastrocnemius lateralis, vastus lateralis and tibialis anterior muscle activity were compared between the amputated (AmLL), the intact (InLL) and the control (CnLL) lower limbs using one-dimensional statistical parametric mapping.Results: More ankle dorsiflexion and knee flexion were observed for the AmLL compared to the InLL and CnLL (ankle only) from the end of the stance phase to the beginning of the swing phase. Less knee flexion was also found for the AmLL during early stance phase. More pelvis posterior tilt and rotation toward the contralateral limb was observed during most of the gait cycle for the AmLL compared to the InLL. TSM was smaller for the AmLL compared to the CnLL during early stance phase.Significance: Using a one-dimensional statistical parametric mapping approach for TTA gait analysis, this study provides novel insights on their biomechanical gait deficits compared to CON. Greater reliance on the InLL was observed in TTA as suggested by the asymmetric kinematic and kinetic profiles. [ABSTRACT FROM AUTHOR]

Individuals with a lower limb amputation use compensatory strategies during essential tasks such as sit-to-stand and stair ascent leading to secondary physical conditions. The ensuing biomechanical parameters outlining the motion strategies they put in place need to be identified and described. We searched three databases (Embase, IEEE Xplore and PubMed) for articles on the spatiotemporal, the kinematics and the kinetics that compared the amputated, the intact lower limbs, or the trunk of individuals with a unilateral transtibial or transfemoral amputation with the limbs of a control group. We found twenty articles. During sit-to-stand, individuals with a lower limb amputation increased the trunk inclination angle toward the intact lower limb, explaining higher ground reaction forces and peak knee sagittal power generation. During stair ascent, individuals with a lower limb amputation increased the stance phase duration on the intact lower limb. Moreover, individuals with a lower limb amputation increased both lower limbs hip extension moment and power, and the amputated lower limb knee extension moment. In both tasks, the individuals with a transfemoral amputation presented larger differences than those with transtibial compared to the control group. Both lower limbs intact joint moment and power were increased to compensate for the prosthesis passive joint and to ensure stability. Stair gait studies mainly focused on the lower limbs' biomechanical changes in the sagittal plane, while sit-to-stand studies focused on asymmetries without comparing the lower limbs independently. Better methodological descriptions are essential to enhance the external validity of previous results. • Stair gait and sit-to-stand are crucial for individuals with lower limb amputation. • Trunk and lower limbs need to be investigated during both tasks. • This review identified the most relevant parameters underlying movement strategies. • Moment and power show that residual joints compensate for the prosthetic joint. • Trunk and lower limb need to be more investigated during both tasks. [ABSTRACT FROM AUTHOR]