Search Results (64)

Accurate gait assessment is essential for managing pathological locomotion, especially in elderly patients recovering from hip joint surgeries. Inertial measurement units (IMUs) provide real-time, objective data in clinical settings. This study examined pelvic oscillations in sagittal, frontal, and transverse planes using a wearable IMU system in two groups: Group A (n = 15, osteosynthesis metallica) and Group B (n = 34, arthroplasty), all over age 65. Gait analysis was conducted during assisted and unassisted walking. In the frontal plane, both groups showed statistically significant improvements: Group A from 46.4% to 75.2% (p = 0.001) and Group B from 52.6% to 72.2% (p = 0.001), reflecting enhanced lateral stability. In the transverse plane, Group A improved significantly from 47.7% to 80.2% (p = 0.001), while Group B showed a non-significant increase from 73.0% to 80.5% (p = 0.068). Sagittal plane changes were not statistically significant (Group A: 68.8% to 71.1%, p = 0.313; Group B: 76.4% to 69.1%, p = 0.065). These improvements correspond to better pelvic symmetry and postural control, which are critical for a safe and stable gait. Improvements were more pronounced during unassisted walking, indicating better pelvic control. These results confirm the clinical utility of IMUs in capturing subtle gait asymmetries and monitoring recovery progress. The findings support their use in tailoring rehabilitation strategies, particularly for enhancing frontal and transverse pelvic stability in elderly orthopedic patients. Full article

Achieving energy-efficient, human-like gait remains a major challenge in bipedal humanoid robotics, as traditional serial actuation architectures often lead to high instantaneous power peaks and uneven load distribution. This study addresses the lack of research on how mechanical symmetry, achieved through parallel actuation, can improve power management in lower-limb joints. We developed a 14-degree-of-freedom (DOF) hip-sized bipedal robot model and conducted simulations comparing a conventional serial configuration—using single-DOF rotary actuators—with a novel parallel configuration that employs paired linear actuators at the hip pitch, hip roll, ankle pitch, and ankle roll joints. Simulation results over a standardized walking cycle show that the parallel configuration reduces peak hip-pitch power by 80.4% and peak ankle-pitch power by 53.5%. These findings demonstrate that incorporating actuator symmetry through parallel joint design significantly reduces actuator stress, improves load sharing, and enhances overall energy efficiency in bipedal locomotion. Full article

Background/Objectives: Total hip arthroplasty (THA) is a widely performed procedure to alleviate pain and improve function in patients with hip disorders. However, leg length discrepancy (LLD) remains a prevalent complication. LLD can cause gait disturbances, back pain, postural imbalance, and patient dissatisfaction, along with significant medico-legal implications. This review examines the evaluation, management, and medico-legal aspects of LLD. Methods: The review analyzed literature on the prevalence, evaluation methods, and management strategies for LLD in THA. Radiographic and clinical assessment tools were considered, alongside factors such as pelvic obliquity and pre-existing conditions. The importance of preoperative planning, intraoperative techniques (including computer-assisted methods), and comprehensive documentation was evaluated to address both clinical and legal challenges. Results: The review shows that leg length discrepancy (LLD) following total hip arthroplasty (THA) occurs in 3% to 30% of cases, with mean values ranging from 3 to 17 mm. LLD may result from anatomical or procedural factors, and effective evaluation requires both radiographic imaging and clinical assessment. Preoperative planning plays a critical role in accurately assessing anatomical parameters and selecting appropriate prosthetic components to preserve or restore limb length symmetry. Advanced intraoperative techniques, including computer-assisted surgery, help reduce LLD incidence. While some complications may be unavoidable, proper documentation and patient communication, particularly regarding informed consent, are essential to mitigate medico-legal risks Conclusions: LLD after THA requires a multidimensional approach incorporating clinical, radiological, biomechanical, and legal considerations. Effective preoperative and intraoperative strategies, combined with robust communication and documentation, are essential to minimize LLD and its associated risks. A focus on precision and patient-centered care can improve outcomes and reduce litigation. Full article

Aging often leads to a decline in intersegmental coordination, particularly in the lower limbs, which can negatively impact gait stability and symmetry. While fear of falling (FoF) and a history of falls (HoF) increase fall risk in older adults, their relationship with intra- and intersegmental coordination during gait remains understudied. This cross-sectional observational study involved 60 participants aged 60 and older. The three-dimensional range of motion of lower limb joints during gait was assessed using an optoelectronic system. Intra- and intersegmental coordination were evaluated via the Continuous Relative Phase (CRP) variable, including its mean, standard deviation, and coefficient of variation. The results showed that the HoF and FoF groups had higher mean CRP values in the left hip-knee (HOF, p = 0.004) and hip-ankle (FOF, p = 0.030) in the sagittal plane, as well as higher standard deviation values in the left knee-ankle (HOF, p = 0.006) and right hip-ankle (HOF, p = 0.004). Inter-segmental coordination differences were also observed, with higher mean CRP values between the knee joints in the sagittal plane (HOF, p = 0.046) and lower mean and standard deviation values between the ankle joints (FOF, p = 0.048 and p = 0.038, respectively). This study concludes that fear of falling and history of falling are significantly associated with altered intra- and intersegmental coordination in older adults, which may contribute to fall risk. Understanding these altered coordination patterns is crucial, as it underscores the therapeutic significance of targeting these changes, which could lead to interventions aimed at improving gait stability and reducing fall risk in elderly individuals. Full article

Femoral head and neck excision (FHNE) remains a common orthopedic surgical procedure in many countries. However, data on postoperative outcomes regarding changes in hindlimb function are limited. This study aimed to evaluate hindlimb function after FHNE in dogs of different weights. Twenty-seven dogs that underwent FHNE were block-randomly assigned to two groups based on weight (≤20 kg and >20 kg). Hindlimb function was evaluated using force plate gait analysis to measure peak vertical force (PVF), alongside other orthopedic evaluations and a composite orthopedic assessment score at 1, 2, 3, 4, 5, 6, 9, and 12 months after surgery. Kaplan–Meier survival analysis and the log-rank test were used for statistical comparisons. The findings demonstrated no significant difference in PVF between the operated and non-operated limbs in either weight groups (≤20 kg and >20 kg) at four and three months postoperatively (median functional recovery time) (p = 0.33), nor were there significant differences in lameness scores at trot between weight groups five and three months after FHNE (p = 0.64). These results indicate that FHNE provides satisfactory functional outcomes and can be considered a suitable orthopedic intervention for medium- to large-breed dogs. Full article

Post-stroke hemiplegia often leads to gait asymmetry, mobility reduction, and increased fall risk. Foot Drop Stimulation (FDS) is used in rehabilitation to improve dorsiflexion and gait patterns. Through cyclogram-based analysis, this retrospective study evaluated the effectiveness of FDS in enhancing inter-limb gait symmetry in 21 post-stroke hemiplegic individuals following 10 sessions of treadmill training combined with FDS. Participants underwent 3D gait analysis pre- and post-intervention, performed by means of optical motion capture system, from which spatiotemporal and cyclogram features of the hip, knee, and ankle were computed. FDS was found to significantly improve dynamic range of motion (ROM) of the affected side at hip (+5%) and knee (+9%) joints. Cyclogram analysis showed that FDS reduced inter-limb hip asymmetry (orientation: 13.35° to 10.65°, Trend Symmetry Index: 19.09° to 15.46°), though no improvements were observed at the ankle. FDS with treadmill training improved hip and knee symmetry, supporting cyclogram-based assessments for gait rehabilitation and highlighting the need for targeted ankle interventions. Further research is needed to explore long-term effects and optimize rehabilitation strategies. Full article

Background: The pelvic girdle is an important component of the human stabilization system, both during the maintenance of an upright standing position and during motor activities. Frequent functional and structural asymmetries within it can affect the structure and function of many organs and systems of the human body. The mechanism of their occurrence is not fully explained. The objective of the present study was to verify the hypothesis regarding the relationship between the value of pelvic asymmetry and the functional state of muscles that stabilize the lumbo–pelvic–hip complex, as measured by changes in their stiffness. Methods: The study group consisted of 40 young women aged from 19 to 29 years. The observational cross-sectional study incorporated the following elements: an interview, an anthropometric test, an inclinometric assessment of the magnitude of hip girdle rotation utilizing a duometer and tensiomyography. Results: Analysis of the variables examined in subjects with symmetric or rotated pelvises did not show significant differences between the studied sides in the two groups. Evaluation of associations between the magnitude of pelvic rotation and tensiomyography findings showed that with increased pelvic rotation, the stiffness of the back extensor muscles and the rectus thigh muscles increased only slightly bilaterally, and the contraction rate of the rectus abdominis and biceps thigh muscles decreased. Conclusions: The results of the tensiomyography study did not unequivocally demonstrate that changes in pelvic symmetry in the transverse plane are associated with dysfunction of the muscles that stabilize the pelvic girdle. Full article

Standardizing socket design and maintaining a default socket alignment in transtibial prostheses are innovations that aim to simplify fitting procedures and reduce prosthetic service costs, particularly in low-income countries. Objectives: This study evaluated the Mercer Universal Prosthesis (MUP) with a standardized “neutral alignment” against custom-made conventional prostheses (CVPs). Methods: Twenty transtibial amputees (n = 20) completed gait assessments using their CVP and immediately after fitting with an MUP. Temporal–spatial and sagittal plane kinematics (hip, knee, and ankle angles) were analyzed, along with a gait symmetry index. Results: the MUP group reported a significant difference between the prosthetic and the intact limb for both hip and knee kinematics (p < 0.05), but there was no change in the CVP group. When compared with the sound limb in the MUP group, post hoc analysis showed that both hip flexion and the hip range of motion (ROM) in the MUP limb significantly increased by 5.7° and 7.3° (p = 0.002 and p < 0.001, respectively). Spatial and temporal gait parameters were comparable between the MUP and CVP groups, and gait symmetry showed no significant differences. The CVP showed greater symmetry in terms of hip (19%, p = 0.012) and knee flexion (8%, p = 0.026) compared to the MUP, while the MUP had higher plantarflexion symmetry (24.4%, p = 0.013). Conclusions: Immediately post fitting, MUP improved joint mobility in the prosthetic limb, potentially enhancing kinematics. While short-term benefits are evident, further research is needed to assess long-term gait adaptation and quality of life impacts. Full article

Total hip arthroplasty (THA) is commonly performed for conditions like osteoarthritis, avascular necrosis, hip fractures, and hip dysplasia. Complications following THA can result in major proximal femoral defects (MPFD), which are challenging to manage. Megaprostheses provide a solution, offering stability and early weight-bearing, though they present their own challenges. However, maintaining hip symmetry with megaprostheses is challenging in accurately restoring femoral offset, acetabular orientation, and soft tissue tension. These factors can contribute to instability, altered biomechanics, and functional impairment. Therefore, achieving hip symmetry through femoral and acetabular offset, limb length discrepancy (LLD), and center of rotation (COR) is an important consideration. Achieving proper symmetry may improve gait, quality of life, and overall outcomes. This case series includes 10 patients with non-tumoral pathology treated with megaprostheses for complications after THA between 2014 and 2024. Megaprosthesis conversion was performed for sepsis (n = 2), aseptic loosening (n = 4), and periprosthetic fracture (n = 4). Dislocation occurred in 20%, with one case showing restored hip symmetry but dislocating due to trauma and noncompliance. Another case had an LLD of 3 cm, contributing to dislocation. Periprosthetic infection was observed in 20%, managed with a two-stage approach. Although hip symmetry was not fully restored in all patients, strict follow-up and rehabilitation were essential for improving functionality and quality of life. Megaprosthesis is an effective solution for MPFD in non-oncological patients when performed correctly. Restoring hip symmetry is challenging and depends on patient care and compliance, though it is an important factor influencing outcomes. Full article

Objective: This study aimed to establish a dominant and non-dominant limb muscle strength evaluation model to evaluate the asymmetry of lower extremity muscle strength. Methods: The hip, knee, ankle flexors and extensors of 86 runners were evaluated separately in different contraction modes and at different movement speeds. A principal component analysis was used to establish a model for evaluating dominant and non-dominant lower extremity muscle strength and to comprehensively evaluate the asymmetry of lower extremity muscle strength. Results: Six main factors were present in both dominant and non-dominant indicators of lower extremity muscle strength, with dominant indicators of lower extremity muscle strength explaining 80.413% of the total variance and non-dominant indicators explaining 78.607% of the total variance. Conclusions: In a population of healthy male runners, there were differences in the symmetry of lower limbs in the comprehensive assessment model. The main contribution of the non-dominant side was the knee muscles, and the dominant side was the hip and knee muscles, so this difference should be considered in constructing future muscle strength evaluation models. It is critical to understanding the design and function of the human muscle system, and can reduce the number of meaningful tests we perform on diverse populations and help us reduce asymmetry. Full article

Background: Postural symmetry ensures balanced alignment and equal weight distribution, promoting optimal function and minimizing stress on muscles and joints. This study aimed to evaluate lower limb movement symmetry in response to mechanical perturbations. Methods: Twelve healthy young women were subjected to mechanical perturbation tests while standing on the Motek GRAIL system treadmill. Maximum values of kinematic and kinetic parameters and symmetry indices were counted to compare the responses of dominant and non-dominant limbs. Results: The study identified symmetrical and asymmetrical features in lower limb dynamics. Symmetry nearness was observed in the ankle joint angle (SI = 0.03), the hip torque (SI = 0.03), and the vertical component of the ground reaction force (SI = 0.04). However, significant asymmetries were found in the medio-lateral component of the ground reaction force (SI = 1.84), ankle torque (SI = 0.23), knee torque (SI = 0.19), hip angle (SI = 0.15), and knee angle (SI = 0.08). The anterior–posterior component of the ground reaction force (SI = 0.14) showed asymmetry but was not statistically significant. Conclusions: Perturbations impact lower limb dynamics, revealing dominance- and joint-specific asymmetries. Bilateral assessment is crucial for understanding postural control, guiding rehabilitation to restore symmetry, and reducing the risk of injuries, falls, and musculoskeletal strain, particularly in athletes and older adults. These findings emphasize the value of symmetry indices in optimizing therapy and prevention strategies. Full article

Rehabilitation of gait function in post-stroke hemiplegic patients is critical for improving mobility and quality of life, requiring a comprehensive understanding of individual gait patterns. Previous studies on gait analysis using unsupervised clustering often involve manual feature extraction, which introduces limitations such as low accuracy, low consistency, and potential bias due to human intervention. This cross-sectional study aimed to identify and cluster gait patterns using an end-to-end deep learning approach that autonomously extracts features from joint angle trajectories for a gait cycle, minimizing human intervention. A total of 74 sub-acute post-stroke hemiplegic patients with lower limb impairments were included in the analysis. The dataset comprised 219 sagittal plane joint angle and angular velocity trajectories from the hip, knee, and ankle joints during gait cycles. Deep temporal clustering was employed to cluster them in an end-to-end manner by simultaneously optimizing feature extraction and clustering, with hyperparameter tuning tailored for kinematic gait cycle data. Through this method, six optimal clusters were selected with a silhouette score of 0.2831, which is a relatively higher value compared to other clustering algorithms. To clarify the characteristics of the selected groups, in-depth statistics of spatiotemporal, kinematic, and clinical features are presented in the results. The results demonstrate the effectiveness of end-to-end deep learning-based clustering, yielding significant performance improvements without the need for manual feature extraction. While this study primarily utilizes sagittal plane data, future analysis incorporating coronal and transverse planes as well as muscle activity and gait symmetry could provide a more comprehensive understanding of gait patterns. Full article

This study aims to (1) assess the inter-limb asymmetry in hip, knee, and ankle strength and countermovement jump (CMJ) performance among adolescent basketball players and (2) examine the relationship between inter-limb asymmetry and CMJ performance. Moreover, 30 adolescent basketball players (15 boys and 15 girls) aged 14 to 15 years participated in this study. The strength of the lower limb joints was measured using an isokinetic dynamometer at a speed of 60 degrees per second. Three maximal CMJs were performed, and the highest jump was used for the final analysis. The subjects were median-split into high-asymmetry (n = 15) and low-asymmetry (n = 15) groups based on the calculated strength asymmetry scores. The asymmetry scores were calculated using the formula: (dominant–non-dominant)/dominant* 100%. The inter-limb asymmetry data ranged from 12.2% to 21.6%. A Spearman correlation analysis showed that only the inter-limb asymmetry of the ankle plantar flexor was significantly correlated with the CMJ heights (ρ = −0.56, p = 0.001). An independent t-test revealed no significant differences in strength asymmetry between boys and girls (all p > 0.05). The low-asymmetry group demonstrated significantly greater CMJ performance compared to the high-asymmetry group (ES = 1.11, 95% CI = 0.34–1.87, p = 0.007), indicating that inter-limb asymmetry of the ankle plantar flexor has a significant negative impact on CMJ performance. Coaches should focus on enhancing both the strength and symmetry of the ankle joints to improve athletic performance and prevent injuries in sports, where jumping is a common movement. Full article

Background: Augmenting auditory feedback through an error-augmentation paradigm could facilitate the perception and correction of gait asymmetry in stroke survivors, but how such a paradigm should be tailored to individual asymmetry profiles remains unclear. Before implementing the paradigm in rehabilitation, we need to investigate the instantaneous effects of distorted footstep sound feedback on gait symmetry in healthy young adults. Methods: Participants (n = 12) walked on a self-paced treadmill while listening to their footstep sounds, which were distorted unilaterally according to five conditions presented randomly: small delay; small advance; large delay; large advance; or unmodified (control). The primary outcomes were swing time ratio (SWR) and step length ratio (SLR). Secondary outcomes included walking speed, bilateral swing time, step length, and maximum toe height, as well as hip, knee, and ankle angle excursions. Results: SWR (p < 0.001) but not SLR (p ≥ 0.05) was increased in all distorted feedback conditions compared to the control condition. Increased swing time on the perturbed side ipsilateral to feedback distortion was observed in the advanced conditions (p < 0.001), while swing time increased bilaterally in the delayed conditions (p < 0.001) but to a larger extent on the unperturbed side contralateral to feedback distortion. Increases in swing time were accompanied by larger maximum toe height as well as larger hip and knee joint excursions (p < 0.05 to p < 0.001). No differences in any outcomes were observed between small and large feedback distortion magnitudes. Conclusions: Distorted footstep sound feedback successfully elicits adaptation in temporal gait symmetry (SWR), with distinct modulation patterns for advanced vs. delayed footstep sounds. Spatial symmetry (SLR) remains unaltered, likely because auditory feedback primarily conveys temporal information. This research lays the groundwork to implement personalized augmented auditory feedback in neurorehabilitation. Full article

Background: Racehorses commonly train and race in one direction, which may result in gait asymmetries. This study quantified gait symmetry in two cohorts of Thoroughbreds differing in their predominant exercising direction; we hypothesized that there would be significant differences in the direction of asymmetry between cohorts. Methods: 307 Thoroughbreds (156 from Singapore Turf Club (STC)—anticlockwise; 151 from Hong Kong Jockey Club (HKJC)—clockwise) were assessed during a straight-line, in-hand trot on firm ground with inertial sensors on their head and pelvis quantifying differences between the minima, maxima, upward movement amplitudes (MinDiff, MaxDiff, UpDiff), and hip hike (HHD). The presence of asymmetry (≥5 mm) was assessed for each variable. Chi-Squared tests identified differences in the number of horses with left/right-sided movement asymmetry between cohorts and mixed model analyses evaluated differences in the movement symmetry values. Results: HKJC had significantly more left forelimb asymmetrical horses (Head: MinDiff p < 0.0001, MaxDiff p < 0.03, UpDiff p < 0.01) than STC. Pelvis MinDiff (p = 0.010) and UpDiff (p = 0.021), and head MinDiff (p = 0.006) and UpDiff (p = 0.017) values were significantly different between cohorts; HKJC mean values indicated left fore- and hindlimb asymmetry, and STC mean values indicated right fore- and hindlimb asymmetry. Conclusion: the asymmetry differences between cohorts suggest that horses may adapt their gait to their racing direction, with kinematics reflecting reduced ‘outside’ fore- and hindlimb loading. Full article