Search Results (688)

Background/Objectives: this study describes the development of a novel three-dimensional electrogoniometer for the quantitative assessment of knee mobility and stability during gait. The primary objective is to determine whether real-time measurements obtained during dynamic activity provide more clinically relevant information than traditional static assessments. Methods: the device employs angular position encoders to capture knee joint kinematics—specifically flexion, extension, rotation, and tibial translation—during locomotion. Data are transmitted in real time to an Android-based application, enabling immediate graphical visualization. A descriptive observational study was conducted involving healthy participants and individuals with anterior cruciate ligament (ACL) injuries to evaluate the device’s performance. Results: results showed that the electrogoniometer captured knee flexion-extension with a range of up to 90°, compared to 45° typically recorded using conventional systems. The device also demonstrated enhanced sensitivity in detecting variations in tibial translation during gait cycles. Conclusions: this electrogoniometer provides a practical tool for clinical assessment of knee function, enabling real-time monitoring of joint behavior during gait. By capturing functional mobility and stability more accurately than static methods, it may enhance diagnostic precision and support more effective rehabilitation planning in orthopedic settings. Full article

Background: While mechanical alignment total knee arthroplasty (TKA) has long been the conventional surgical technique in patients with advanced osteoarthritis, kinematic alignment TKA has emerged as a promising alternative, designed to restore the knee’s native pre-arthritic anatomy. Since superiority of either technique remains inconclusive, we aimed to compare immediate and short-term postoperative outcomes of kinematic versus mechanical alignment TKA. Methods: This prospective cohort study was conducted at a tertiary care centre between January 2020 and August 2022, enrolling kinematic and mechanical alignment TKA patients. Outcomes were assessed during hospitalization and at 14 days postoperatively. Data collected included patient-reported outcome measures (PROMs), functional performance evaluations, pain scores, discharge disposition and hospital length of stay. Both univariate and multivariate regression analyses were conducted, adjusting for potential confounders. Results: The study included 103 patients, with 77 who underwent kinematic alignment and 26 mechanical alignment TKA. Patients in the kinematic alignment group demonstrated statistically significant better postoperative outcomes compared to those in the mechanical alignment group. Kinematic alignment TKA patients demonstrated superior functional performance on the Timed Up and Go test immediately postoperatively and were more frequently discharged home rather than to a rehabilitation facility. Hospital stay length and short-term PROMs also favoured the Kinematic alignment TKA group, showing statistically significant higher scores in the Oxford Knee Score, short form-12 Mental Component Summary, and the Knee Injury and Osteoarthritis Outcome Score Symptoms subscale. Conclusions: Kinematic alignment TKA offers superior immediate and short-term outcomes compared to mechanical alignment TKA, with benefits in functional recovery, hospitalization duration, and discharge disposition. This evidence supports kinematic alignment TKA as a viable alternative, aiding in patient and surgeon decision-making. Full article

The barbell back squat, a prevalent lower-limb resistance exercise characterized by a closed kinetic chain and multi-joint movement, results in the greatest knee joint range of motion. Variations in thigh and shank lengths and their ratios may influence knee joint mechanics. This study investigated the effects of thigh and shank lengths and their ratios on knee kinematics and kinetics during the barbell back squat. Fifty resistance-trained adult men participated. Kinematic and kinetic data were collected using an eight-camera motion capture system and two force plates. Correlation and simple linear regression analyses were conducted to evaluate the relationships between thigh and shank length parameters and knee joint mechanics. Greater thigh length was significantly associated with increased anterior knee displacement and knee extension moment. Additionally, longer shank length and a higher shank-to-thigh ratio were associated with greater knee abduction and internal rotation angles. Consequently, increased thigh length may contribute to greater anterior knee displacement, while increased shank length may be associated with increased knee abduction and internal rotation. Accordingly, trainers and trainees should evaluate individual thigh and shank lengths. For participants with relatively longer shank and thigh segments, compensatory knee movements should be closely monitored to mitigate the risk of musculoskeletal injuries. Full article

Background: Soft tissue sarcomas (STSs) are rare and heterogeneous malignancies requiring a multidisciplinary approach to diagnosis and treatment. Advances in surgical techniques, chemotherapy, and radiotherapy have improved survival rates but often result in significant functional impairments, particularly in patients undergoing limb-sparing procedures. Rehabilitation is crucial for restoring mobility and independence, with recent studies emphasizing the importance of personalized rehabilitation protocols tailored to specific surgical interventions. Quantitative assessments, such as 3D motion capture and surface electromyography, provide objective insights into gait performance and motor function, enabling more precise rehabilitation strategies to optimize recovery. Methods: This study evaluated gait performance in 21 patients with lower-limb impairment following limb-sparing surgery for STS. Patients underwent two instrumented gait assessments using marker-based 3D motion capture and surface electromyography to measure spatiotemporal gait parameters, joint kinematics, and muscle activity. Independence in the activity of daily living was assessed with the modified Barthel Index in both timepoints. Results: Following rehabilitation, patients demonstrated significant improvements in functional independence, as reflected by an increase in the modified Barthel Index (p < 0.001). Gait analysis revealed increased walking speed, stride length, cadence, and improved joint range of motion at the hip, knee, and ankle, though electromyographic analysis showed no statistically significant differences in muscle activation patterns or co-contraction indices. Conclusions: These findings underscore the importance of a rehabilitation programs personalized on gait strategies. A deeper understanding of motor adaptations based on sarcoma location and surgical approach could further refine rehabilitation protocols, ultimately enhancing patient outcomes and quality of life. Full article

Biomechanical analyses of technique are essential for performance improvement in athletic jumps, but scarce evidence exists for adolescent athletes in the literature. The purpose of this study was to examine the sex differences in the high jump biomechanics of U18 athletes. Twenty-one women (15.2 ± 1.0 yrs) and twenty-one men (15.2 ± 1.2 yrs) Greek U18 high jumpers were recorded in regional competitions using two cameras (sampling frequency: 60 fps). The kinematic parameters of the last step, the take-off, and the crossbar clearance were calculated using 3D-DLT analysis. The independent samples t-test was used to detect significant (p < 0.05) differences between groups. Results revealed that men had significantly (p < 0.05) better performance, with larger last step angle and length, body center of mass (BCM) height at the final touchdown and take-off, approach and vertical BCM take-off velocity, touchdown lateral inclination of the take-off leg, and swing leg knee angle at take-off. Women had significantly (p < 0.05) higher vertical BCM velocity at touchdown. No differences (p > 0.05) were observed for take-off angle, the support leg knee angle, the inclination of the torso at touchdown, or the vertical BCM displacement during the take-off phase. The anthropometric and physical conditioning differences between sexes contributed to the findings of the study. Coaches should consider the age and sex differences of adolescent athletes when designing training programs to optimize high jump performance. Full article

Background/Objectives: Although considerable progress has been made in understanding lateral ankle sprains (LAS) and chronic ankle instability (CAI), recurrent injury rates remain high. This highlights the need to explore additional contributors such as comprehensive lower-limb gait analysis, including multisegmented foot models and proximal joint kinematics and strength. This study aimed to assess multisegmented foot and lower-limb kinematics throughout the gait cycle in individuals with CAI compared to healthy controls. Additionally, associations between hip abductor strength and frontal plane ankle kinematics were examined. Methods: Fifty males (25 with CAI and 25 healthy controls) participated in this cross-sectional study. Gait analysis was conducted using a BTS SMART 3D motion capture system to assess multisegmented foot and proximal joint kinematics. Isometric hip strength was measured using a Biodex dynamometer. Statistical Parametric Mapping (SPM) was used to assess group differences, and correlations were calculated between hip abductor strength and ankle kinematics. Results: The CAI group demonstrated significantly greater calcaneus abduction relative to the shank in the transverse plane between 88% and 93% of the gait cycle (MD = −3.50°, 95% CI [−5.60, −1.40], d = −0.95, p = 0.037). No other statistically significant between-group differences in hip, knee, or foot segment kinematics were detected. Furthermore, correlations between hip abductor strength and ankle frontal plane kinematics were not significant. Conclusions: Males with CAI demonstrated altered rearfoot kinematics in the transverse plane during the terminal swing phase. The multisegmented foot model was valuable in detecting subtle deviations and emphasized the importance of including the swing phase. Hip abductor strength was not associated with ankle kinematics, suggesting that its potential role in CAI may involve other mechanisms. These findings may support clinical gait assessment and rehabilitation planning by highlighting the importance of evaluating all foot segments and the entire lower limb, rather than focusing solely on the ankle joint. Segment-specific deviations, particularly those emerging during the swing phase, may help guide targeted interventions aimed at improving foot positioning in males with CAI. Full article

Background/Objectives: Hip-level amputees face ambulatory challenges due to the lack of a lower limb and prosthetic hip power. Some hip-level amputees restore mobility by using a prosthesis with hip, knee, and ankle joints. Powered prosthetic joints contain an actuator that provides external flexion-extension moments to assist with movement. Powered knee and powered ankle-foot units are on the market, but no viable powered hip unit is commercially available. This research details the development of a novel powered four-bar prosthetic hip joint that can be integrated into a full-leg prosthesis. Methods: The hip joint design consisted of a four-bar linkage with a harmonic drive DC motor placed in the inferior link and an additional linkage to transfer torque from the motor to the hip center of rotation. Link lengths were determined through engineering optimization. Device strength was demonstrated with force and finite element analysis and with ISO 15032:2000 A100 static compression tests. Walking tests with a wearable hip-knee-ankle-foot prosthesis simulator, containing the novel powered hip, were conducted with three able-bodied participants. Each participant walked back and forth on a level 10 m walkway. Custom hardware and software captured joint angles. Spatiotemporal parameters were determined from video clips processed in the Kinovea software (ver. 0.9.5). Results: The powered hip passed all force and finite element checks and ISO 15032:2000 A100 static compression tests. The participants, weighing 96 ± 2 kg, achieved steady gait at 0.45 ± 0.11 m/s with the powered hip. Participant kinematic gait profiles resembled those seen in transfemoral amputee gait. Some gait asymmetries occurred between the sound and prosthetic legs. No signs of mechanical failure were seen. Most design requirements were met. Areas for powered hip improvement include hip flexion range, mechanical advantage at high hip flexion, and device mass. Conclusions: The novel powered four-bar hip provides safe level-ground walking with a full-leg prosthesis simulator and is viable for future testing with hip-level amputees. Full article

The ageing of the global population, especially in developed countries, is driving significant societal changes. In Portugal, demographic data reflect a marked increase in the ageing index. Understanding gait alterations associated with ageing is essential for the early detection of mobility decline and fall risk. This study aimed to analyse gait patterns in older adults to contribute to a biomechanical ageing profile. Thirty-six community-dwelling older adults (29 female, 7 male; mean age: 74 years) participated. Gait data were collected using the Xsens full-body motion capture system, which combines inertial sensors with biomechanical modelling and sensor fusion. Spatiotemporal and kinematic parameters were analysed using descriptive statistics. Compared to younger adult norms, participants showed increased stance and double support phases, reduced swing phase, and lower gait speed, stride length, and cadence, with greater step width. Kinematic data showed reduced peak plantar flexion, knee flexion, and hip extension, but increased dorsiflexion peaks—adaptations aimed at stability. Despite a limited sample size and lack of clinical subgroups, results align with age-related gait literature. Findings support the utility of wearable systems like Xsens in capturing clinically relevant gait changes, contributing to normative biomechanical profiling and future mobility interventions. Full article

Background and Objectives: Knee Osteoarthritis affects about 10% of people over 50, causing pain and functional limitation. Hyaluronic acid (HA) is crucial in regulating the osteocartilaginous matrix. Patients are usually assessed using clinical scores to examine symptoms and quality of life, and in this context, gait analysis could provide an objective assessment of walking patterns to identify any deficits. This systematic review investigates the short and long-term effects of intra-articular HA injections on gait kinematics, pain and activities of daily living (ADL), investigating the correlation between outcomes. Materials and Methods: The review followed PRISMA guidelines. The PICO model included patients with radiographic knee osteoarthritis who received intra-articular HA injections, comparing them to healthy controls or those receiving corticosteroids or placebo. Outcomes included gait kinetics and functional scales at baseline and during follow-ups. Results: From 342 identified articles, 13 were included, comprising a total of 321 patients. The gait analysis utilized optoelectronic systems, inertial sensors, and electromyographic sensors pre- and post-HA treatment. Clinical parameters were assessed using the Visual Analogue Scale, WOMAC OA, Knee Society Score, Lequesne Score, and SF-36. The data showed significant improvement in speed (p = 0.001) and step cadence (p < 0.005) 30 days post-treatment and improvements in knee adduction moment (p < 0.001) and sagittal ground reaction force vectors (p < 0.01) up to six months post-treatment. Pain reduction and improvements in VAS (p < 0.001) and Lequesne score (p < 0.001) were observed in short-term follow-ups. Conclusions: Our study suggests an improvement in pain and knee function after hyaluronic acid injection. Moreover, gait analysis is an important tool for objectively assessing deficits and developing personalized rehabilitation programs. Furthermore, combining infiltrative treatment with rehabilitation could extend the effects of hyaluronic acid and improve results. Full article

Human gait analysis is essential for clinical evaluation and rehabilitation monitoring, particularly in post-stroke individuals, where joint kinematics provide valuable insights into motor recovery. While optical motion capture (OMC) is the gold standard, its high cost and restricted use in laboratory settings limit its accessibility. This study aimed to evaluate the accuracy of REEV SENSE, a novel magnetometer-free inertial measurement unit (IMU), in capturing knee and ankle joint angles during overground walking in post-stroke individuals using assistive devices. Twenty participants with chronic stroke walked along a 10-m walkway with their usual assistive device (cane or walker), while joint kinematics were simultaneously recorded using OMC and IMUs. Agreement between the systems was assessed using the mean absolute error, root mean square error, 95% confidence intervals, and Pearson’s correlation coefficient. Knee angles measured with the IMUs showed a strong correlation with the OMC (r > 0.9) and low errors (MAE < 5°), consistent with clinical acceptability. Ankle angle accuracy was lower for participants using walkers, while knee measurements remained stable regardless of the assistive device. These findings demonstrate that REEV SENSE IMUs provide clinically relevant kinematic data and support their use as a practical wearable tool for gait analysis in real-world or remote clinical settings. Full article

The purpose of this study was to identify differences between patellofemoral joint stress (PFJS), patellofemoral joint reaction force (PFJRF), quadriceps force, trunk and knee flexion angles, and horizontal position of applied load relative to the knee and heel between the front squat (FS) and back squat (BS) exercises at two depths (60 and 80% of leg length, where 60% represents a lower squat depth). Twenty-two healthy college-aged females (age: 22.23 ± 1.86 years, mass: 67.65 ± 9.60 kg, height: 171.34 ± 6.38 cm) participated in this study. Mechanical variables were measured or estimated using a 15-camera 3D motion analysis (180 Hz) system and force platforms (1800 Hz). Five repetitions of each squatting technique at each depth were performed. Multivariate testing showed a difference in patellofemoral loading variables, trunk and knee kinematics, and bar position relative to the heel and knee (p = 0.00) between squat depths. There was no difference between techniques, no interaction between depth and techniques (p > 0.05). Follow-up univariate analyses showed differences in PFJS, PFJRF, quadriceps force, horizontal bar position relative to the heel and knee, and knee and trunk flexion between squat depths. The similar joint stress observed between FS and BS may be explained by compensatory trunk mechanics or the use of a light external load. Full article

Introduction: Octogenarians undergoing unicompartmental knee arthroplasty (UKA) face increased risks of complications due to reduced bone support following osteoporosis. The aim of this study was to describe our preferred technique to balance robotic-assisted UKA in this specific patient population and to present its results. Methods: This retrospective analysis of prospectively collected data examined 121 consecutive octogenarian patients (median age 84 years, IQR 82–86) who underwent robotic-assisted medial UKA between September 2018 and December 2022 with ≥24 months follow-up. Patients aged ≤80 years, with ≤2 years of follow-up, or without informed consent were excluded. Data collection included radiographic measurements (HKA, LDFA, MPTA, joint line height), patient-reported outcome measures (Oxford Knee Score, Knee Society Score), and complications. Statistical analysis employed descriptive statistics, paired t-tests, Cohen’s d for effect sizes, and the McNemar test for categorical variables. Results: The hip–knee–ankle angle improved significantly from 174.43° to 178.04° (mean difference 3.61°, 95% CI 3.13–4.09, p < 0.001). Patient-reported outcomes demonstrated substantial improvements: the Knee Society Score increased by 83.09 points (95% CI 79.76–86.42, p < 0.001, Cohen’s d = 4.53), and the Oxford Knee Score increased by 17.09 points (95% CI 15.42–18.76, p < 0.001), with both exceeding minimal clinically important differences. Only 7.4% (9/121) of cases exhibited joint line lowering of >2 mm, with 1.7% (2/121) having both post-operative HKA <175° and joint line lowering of >2 mm. The implant survival rate was 100% with minimal complications, including two conservatively managed tibial plateau fractures and two cases of wound dehiscence with no further surgery needed. Conclusions: Robotic-assisted medial UKA can consistently preserve joint line height while achieving excellent alignment correction and clinical outcomes in octogenarians, potentially addressing failure risks in this specific population. Full article

Genu valgum (GV) is a common lower limb deformity that may increase the risk of anterior cruciate ligament (ACL) injury. This study used OpenSim musculoskeletal modeling and kinematic analysis to investigate the mechanical responses of the ACL under fatigue in females with GV. Eight females with GV and eight healthy controls completed a running-induced fatigue protocol. Lower limb kinematic and kinetic data were collected and used to simulate stress and strain in the anteromedial ACL (A–ACL) and posterolateral ACL (P–ACL) bundles, as well as peak joint angles and knee joint stiffness. The results showed a significant interaction effect between group and fatigue condition on A–ACL stress. In the GV group, A–ACL stress was significantly higher than in the healthy group both before and after fatigue (p < 0.001) and further increased following fatigue (p < 0.001). In the pre-fatigued state, A–ACL strain was significantly higher during the late stance phase in the GV group (p = 0.036), while P–ACL strain significantly decreased post-fatigue (p = 0.005). Additionally, post-fatigue peak hip extension and knee flexion angles, as well as pre-fatigue knee abduction angles, showed significant differences between groups. Fatigue also led to substantial changes in knee flexion, adduction, abduction, and hip/knee external rotation angles within the GV group. Notably, knee joint stiffness in this group was significantly lower than in controls and decreased further post-fatigue. These findings suggest that the structural characteristics of GV, combined with exercise-induced fatigue, exacerbate A–ACL loading and compromise knee joint stability, indicating a higher risk of ACL injury in fatigued females with GV. Full article

It is well established that combining exercise with medication may benefit functionality in individuals with PD (Parkinson’s disease). However, the long-term evolution of gait biomechanics under this combination remains poorly understood. Objectives: This study aims to analyze the evolution of spatiotemporal gait parameters, kinetics, and kinematics throughout a long-term exercise program conducted in water and on dry land. Methods: We have compared the trajectories of biomechanical variables across the treatment phases using statistical parametric mapping (SPM). A cohort of fourteen individuals with PD (mean age: 65.6 ± 12.1 years) participated in 24 sessions of aquatic exercises over three months, followed by a three-month retention phase, and then 24 additional sessions of land-based exercises. Three-dimensional gait data and spatiotemporal parameters were collected before and after each phase. Two-way ANOVA with repeated measures was used to compare spatiotemporal parameters. Results: The walking speed increased while the duration of the double support phase decreased. Additionally, the knee extensor moment consistently increased in the entire interval from midstance to midswing (20% to 70% of the stride period), approaching normal gait patterns. Regarding kinematics, significant increases were observed in both hip and knee flexion angles. Furthermore, the abnormal ankle dorsiflexion observed at the foot strike disappeared. Conclusions: These findings collectively suggest positive adaptations in gait biomechanics during the observation period. Full article

Background: Residual deficits after early treatment of developmental dysplasia of the hip (DDH) using osteotomy often led to asymmetrical gait deviations with increased repetitive rates of ground reaction force (GRF) in both hips, resulting in a higher risk of early osteoarthritis. This study investigated lower limb inter-joint coordination and swing foot control during level walking in adolescents with early-treated unilateral DDH. Methods: Eleven female adolescents treated early for DDH using Pemberton osteotomy were compared with 11 age-matched healthy controls. The joint angles and angular velocities of the hip, knee, and ankle were measured, and the corresponding phase angles and continuous relative phase (CRP) for hip–knee and knee–ankle coordination were obtained. The variability of inter-joint coordination was quantified using the deviation phase values obtained as the time-averaged standard deviations of the CRP curves over multiple trials. Results: The DDH group exhibited a flexed posture with increased variability in knee–ankle coordination of the affected limb throughout the gait cycle compared to the control group. In contrast, the unaffected limb compensated for the kinematic alterations of the affected limb with reduced peak angular velocities but increased knee–ankle CRP over double-limb support and trajectory variability over the swing phase. Conclusions: The identified changes in inter-joint coordination in adolescents with early treated DDH provide a plausible explanation for the previously reported increased GRF loading rates in the unaffected limb, a risk factor of premature OA. Full article