Gait & posture最新文献

Background: A causal link exists between structural differences in the foot and alterations in the lower limb biomechanics, which might predispose an individual to develop characteristic musculoskeletal disorders.

Research question: This study aimed to determine how the foot structural characteristics, as represented by the medial longitudinal arch flexibility, affect lower limb joint coupling coordination and anterior-posterior ground reaction impulses (GRIs) during walking and running.

Methods: Following the calculation of arch height flexibility, a total of fifty-four physically active males were grouped and completed gait experiments to collect kinematic and kinetic data synchronously. Inter-joint coordination and variability were calculated from the angle-angle plots of knee-hip, ankle-knee, and metatarsophalangeal (MTP)-ankle couplings based on an optimized vector coding technique.

Results: Our results indicate that coupling coordination of interest and its variability, as well as anterior-posterior GRIs, could potentially be influenced due to differences in arch height flexibility. Notably, the individuals with stiff arches exhibited significantly greater coordination variabilities during the early stance for both ankle-knee and MTP-ankle coordination yet significantly smaller for MTP-ankle coordination variabilities during the mid-stance phase. Furthermore, combining the statistical parametric mapping analysis results, the flexible arches experienced a greater proportion of GRIs in the anterior-posterior direction.

Significance: In conclusion, these observations demonstrated that variations in arch flexibility led to differences in lower limb joint coordination variabilities and GRIs during gait. This fresh insight into inter-joint coordinative function may be useful for enhancing foot motion strategies based on arch structural characteristics.

Background: Middle-aged adults represent the transition between younger and older adults, where some of the characteristic gait differences due to aging begins to surface. However, the gait characteristics of middle-aged adults across the whole gait cycle remains an understudied topic. As speed is a sensitive indicator of health, characterizing the effects of speed on the gait of middle-aged adults and differentiating it from the response of young adults will provide insights into the effects of aging on gait speed modulation mechanisms.

Research question: What are the mechanisms of gait speed changes that are employed by middle-aged adults, and how are they different from younger adults?

Methods: A cohort of healthy young and middle-aged adults completed 60 second trials at three different speeds. Joint kinematics, kinetics, and surface electromyography data were analyzed and compared between the speed levels and age groups. Statistical Parametric Mapping along with a nonlinear curve registration algorithm was used to simultaneously assess the changes in both magnitude and timing of different metrics.

Results: When compared to the younger cohort, the middle-aged cohort had significantly lower ankle range of motion, dorsiflexion moment during loading response and plantarflexion moment during push-off. At the knee joint, the middle-aged adults had significantly lower knee flexion moment during stance. At the hip joint, the middle-aged adults had lower extension moment during terminal stance.

Significance: Time-continuous analysis showed that primary differences due to age were related to decreased joint range of motion and joint moment production capability in the middle-aged adults. Faster walking appears a safe method for middle-aged adults to increase joint range of motion and joint moment expression. However, targeted interventions that focus on improving capability are likely also needed. Suggested targets being improving ankle and knee joint moment capability, and increased range of motion at all joints.

Background: Children with reduced motor competence (MC) have reported differences in their walking performance when compared to their typically developed peers, albeit, with inconsistent results.

Research questions: What is the effect of reduced balance on walking performance in adolescent boys and girls under cognitive-motor interference conditions?

Methods: This cross-sectional study assessed motor competence, in adolescents aged 13-14 years, using the Movement Assessment Battery for Children 2nd edition and walking performance from gait parameters derived from an inertial measurement unit placed over the estimated centre of mass. Each participant performed two 10 m straight-line walks at their self-selected speed. These consisted of a walk with no distractions and a cognitive-motor interference walk (reciting the alternate letters of the alphabet out loud). A two-way mixed ANOVA was used to assess for significant interactions.

Results: 365 adolescents, (low balance = 58, typical balance = 307) participated in this study (boys = 204, girls = 161). Significant interactions were reported between MC groups and walking condition for walking speed in boys (F_(1,195) = 5.23, p= 0.02, η_p² = 0.03) and girls (F_(1,154) = 4.05, p= 0.046, η_p² = 0.03). Both sexes with low balance reduced their walking speed to a greater extent than their typically developed peers under cognitive-motor interference conditions compared to the single-task walk. In addition, boys with low balance reported increased stride length variability (F_(1,198)= 4.40, p= 0.037, η_p²= 0.02) compared to typically developed peers.

Significance: Adolescents with low balance report altered walking. Our data could support a better understanding of the relationship between balance and gait and may help the development of interventions to support those with difficulties.

Background: Biplanar radiography displays promising results in the production of subject-specific (S.specific) biomechanical models. However, the focus has predominantly centred on methodological investigations in gait analysis. Exploring the influence of such models on the analysis of high range of motion tasks linked to hip pathologies is warranted. The aim of this study is to investigate the effect of S.Specific modelling techniques on the reliability of deep squats kinematics in comparison to generic modelling.

Methods: 8 able-bodied male participants attended 5 motion capture sessions conducted by 3 observers and performed 5 deep squats in each. Prior to each session a biplanar scan was acquired with the reflective-markers attached. Inverse kinematics of pelvis and thigh segments were calculated based on S.specific and Generic model definition. Agreement between the two models femoropelvic orientation in standing was assessed with Bland-Altman plots and paired t- tests. Inter-trial, inter-session, inter-observer variability and observer/trial difference and ratio were calculated for squat kinematic data derived from the two modelling approaches.

Results: Compared to the Generic model, the S.Specific model produced a calibration trial that is significantly offset into more posterior pelvis tilt (-2.8±2.7), hip extension (-2.2±3.8), hip abduction (-1.2±3.6) and external rotation (-13.8±11.4). The S.specific model produced significantly different squat kinematics in the sagittal plane of the pelvis (entire squat cycle) and hip (between 40 % and 60 % of the squat cycle). Variability analysis indicated that the error magnitude between the two models was comparable (difference<2°). The S.specific model exhibited a lower variability in the observer/trial ratio in the sagittal pelvis and hip, the frontal hip, but showed a higher variability in the transverse hip.

Significance: S.specific modelling appears to introduce a calibration offset that primarily translates into an effect in the sagittal plane kinematics. However, the clinical added value of S.specific modelling in terms of reducing experimental sources of kinematic variability was limited.