Postural Lower Limb Research Articles

Effect of Soft Knee Brace on Shank Movement in Running

Background: Soft knee braces are used for the protection and treatment of knee injuries in light-intensity activities of daily life. Soft knee braces have several functions, such as stabilizing and supporting the lower limb posture. However, previous studies did not investigate the effects of a soft knee brace on the lower limbs during vigorous-intensity activities. Aims: The objective of this study was to investigate the effect of a soft knee brace on the physical load and stability of the lower limb during running as a vigorous-intensity activity. Methods: Participants were asked to run with or without a soft knee brace, and lower-limb movements during running were measured using an inertial sensor on the shank. Results: The result showed that soft knee brace significantly reduced the magnitude and mediolateral standard deviation of shank acceleration. Conclusion: The results of this study indicate the possibility that wearing a soft knee brace can improve the physical load and stability of the lower limbs during running.

Correlation between physical activity and anthropometric measurements among children and adolescents

ObjectivesThe purpose of this study was to measure the association between the level of physical activity and sedentary conditions with anthropometric measurements of children and adolescents. MethodsThis cross-sectional descriptive study consisted of a convenience sample of 400 children and adolescents from public schools in Itapevi-SP, Brazil. The Physical Activity Checklist Interview or LAF “Lista de Atividades Físicas” in a Brazilian version, was administered in a face-to-face interview on a school day and allowed assessment of sedentary behavior and physical activity on the previous day. Anthropometric measurements included body weight, sex, age, and lower limb posture. The participants were photographed in the frontal and sagittal planes, and the photos were analyzed using postural assessment software (PAS/SAPO). Pearson's tests were applied to analyze correlations. ResultsChildren and adolescents show a greater tendency toward valgus knees with increasing body mass (r = ‒0.33). On average, girls have a larger Q angle. Ankles are less likely to become valgus with increasing age and mass (r = ‒0.18 and ‒0.23, respectively). The horizontal alignment of the pelvis is mostly in anteversion with a significant increase with age (r = 0.27) and a slight increase with mass (r = 0.15). The knee and ankle tend to be less hyperextended and more dorsiflexed from the age of 10, with no correlation with the other variables. It was not possible to observe a clear relationship between the time spent in physical activity and sedentary behavior and the postural angles mentioned above. ConclusionAlthough correlations were found between age, sex and body mass, and postural angles, notably pelvis alignment, Q angle, knee, ankle, sex, and body weight, there was no correlation between the time spent in physical activity, sedentary behavior, and lower limb posture.

Abnormal lower limb posture recognition based on spatial gait feature dynamic threshold detection

Lower limb rehabilitation training often involves the use of assistive standing devices. However, elderly individuals frequently experience reduced exercise effectiveness or suffer muscle injuries when utilizing these devices. The ability to recognize abnormal lower limb postures can significantly enhance training efficiency and minimize the risk of injury. To address this, we propose a model based on dynamic threshold detection of spatial gait features to identify such abnormal postures. A human-assisted standing rehabilitation device platform was developed to build a lower limb gait depth dataset. RGB data is employed for keypoint detection, enabling the establishment of a 3D lower limb posture recognition model that extracts gait, time, spatial features, and keypoints. The predicted joint angles, stride length, and step frequency demonstrate errors of 4 %, 8 %, and 1.3 %, respectively, with an average confidence of 0.95 for 3D key points. We employed the WOA-BP neural network to develop a dynamic threshold algorithm based on gait features and propose a model for recognizing abnormal postures. Compared to other models, our model achieves a 96 % accuracy rate in recognizing abnormal postures, with a recall rate of 83 % and an F1 score of 90 %. ROC curve analysis and AUC values reveal that the WOA-BP algorithm performs farthest from the pure chance line, with the highest AUC value of 0.89, indicating its superior performance over other models. Experimental results demonstrate that this model possesses a strong capability in recognizing abnormal lower limb postures, encouraging patients to correct these postures, thereby reducing muscle injuries and improving exercise effectiveness.

The TACOs (time-based assessment computerized strategy) approach to evaluating occupational working postures.

Many investigations of biomechanical overload concentrate on upper limbs and manual handling: certain jobs require an evaluation on spinal and lower limb postures. While existing methodologies adequately describe postures, they often poorly consider the organisation. This shortcoming prompted the development of TACOs for spinal and lower limb postures, using organisational factors to adjust the risk indexes. The TACOs is set out in steps: task identification, posture assessment, duration, and a final evaluation also for complex cycles. Given the complexity, tools have been devised, free downloadable, to facilitate evaluation. Studies on the TACOs reliability indicate excellent intra-observer and moderate interobserver agreement. TACOs, defining the task as a measurement unit, offers the advantage of assessing postures more easily and, considering duration, provides precise evaluation of the final risk. While the method does not demonstrate predictive validity regarding related diseases, it nonetheless enables the classification of exposure levels, even in complex multitask scenarios.

Comparison of human injury differences in vehicle-riding/pushing bicycle accidents

To support regulations related to cyclists dismounting and pushing across motor vehicle lanes, this study first extracted posture parameters for riding/pushing through physical experiments, then simplified the posture parameters and extracted typical postures with distinguishability. Finally, simulated experiments were designed to compare the differences in human injury between riding and pushing in collision accidents. The physical experiment found that the bicycle controller’s (individuals who ride or push bicycles) forward leaning angle of the back (referred to as the ‘back angle’) when riding can be estimated by the ratio of saddle height to bicycle handlebar height, but the back angle when pushing is not affected by other parameters. Eight typical postures containing only lower limb posture parameters were then identified, and statistical analysis showed significant differences in over 80% of parameters among the postures. Through simulated experiments, the rider’s tolerable saddle height was identified. Even at this saddle height, the injury in riding state was still significantly higher than that in the pushing state, indicating that pushing the bicycle across the motor vehicle lane can reduce the injury to the bicycle controller. The research results not only support relevant regulations, but also provide typical postures for the bicycle controller in vehicle-bicycle collision experiments in the future, and have certain theoretical and practical value.

Reductions in rearfoot eversion posture due to proximal muscle strengthening are dependent on foot-ankle varus alignment

BackgroundStrengthening the hip and trunk muscles may decrease foot pronation in upright standing due to expected increases in hip passive torque and lower-limb external rotation. However, considering the increased pronation caused by a more varus foot-ankle alignment, subjects with more varus may experience smaller or no postural changes after strengthening. ObjectiveTo investigate the effects of hip and trunk muscle strengthening on lower-limb posture during upright standing and hip passive torque of women with more and less varus alignment. MethodsThis nonrandomized controlled experimental study included 50 young, able-bodied women. The intervention group (n = 25) performed hip and trunk muscle strengthening exercises, and the control group (n = 25) maintained their usual activities. Each group was split into two subgroups: those with more and less varus alignment. Hip, shank, and rearfoot-ankle posture and hip passive external rotation torque were evaluated. Mixed analyses of variance and preplanned contrasts were used to assess prepost changes and between-group differences (α = 0.05). ResultsThe less-varus subgroup of the intervention group had a reduced rearfoot eversion posture (P = 0.02). No significant changes were observed in the less-varus subgroup of the control group (P = 0.31). There were no significant differences in posture between the control and intervention groups when varus was not considered (P ≥ 0.06). The intervention group had increased hip passive torque (P = 0.001) compared to the control group, independent of varus alignment. ConclusionDespite the increases in hip passive torque, the rearfoot eversion posture was reduced only in women with a less-varus alignment. Having more foot-ankle varus may prevent eversion reductions.

Investigation on vehicle occupant dummy applicability for under-foot impact loading conditions

PurposeUnder-foot impact loadings can cause serious lower limb injuries in many activities, such as automobile collisions and underbody explosions to military vehicles. The present study aims to compare the biomechanical responses of the mainstream vehicle occupant dummies with the human body lower limb model and analyze their robustness and applicability for assessing lower limb injury risk in under-foot impact loading environments. MethodsThe Hybrid III model, the test device for human occupant restraint (THOR) model, and a hybrid human body model with the human active lower limb model were adopted for under-foot impact analysis regarding different impact velocities and initial lower limb postures. ResultsThe results show that the 2 dummy models have larger peak tibial axial force and higher sensitivity to the impact velocities and initial postures than the human lower limb model. In particular, the Hybrid III dummy model presented extremely larger peak tibial axial forces than the human lower limb model. In the case of minimal difference in tibial axial force, Hybrid III's tibial axial force (7.5 KN) is still 312.5% that of human active lower limb's (2.4 KN). Even with closer peak tibial axial force values, the biomechanical response curve shapes of the THOR model show significant differences from the human lower limb model. ConclusionBased on the present results, the Hybrid III dummy cannot be used to evaluate the lower limb injury risk in under-foot loading environments. In contrast, potential improvement in ankle biofidelity and related soft tissues of the THOR dummy can be implemented in the future for better applicability.

Assessment of dental ergonomics among dental students: A retrospective study.

Musculoskeletal (MSK) disorders account for 11%-98% of occupational health issues for dental professionals, with an onset as early as in dental school. Dental ergonomics is among the risk factors; thus, a prompt assessment is crucial in preventing future MSK pain. The aim of this study was to retrospectively assess dental ergonomics of second-year dental students after dedicated lectures were introduced in the predoctoral curriculum. Three cohorts of second-year dental students were evaluated during preclinical activity in July 2019, January 2022, and December 2022 by an Occupational Therapy (OT) faculty and calibrated OT students. Dental ergonomics was assessed with the Rapid Upper Limb Assessment (RULA). Dental student cohorts were compared with one-way analysis of variance (ANOVA). The average RULA final score of 409 participants was 5.1±0.9, with no difference between the three cohorts (p=0.676). The January 2022 cohort scored significantly lower in wrist-arm score than that of 2019 (p=0.001) and December 2022 (p=0.046). Neck and lower limb posture were significantly higher in January 2022 cohort than in 2019 (p=0.001 and 0.013) and December 2022 (p=0.001 and 0.005) cohorts. The December 2022 cohort revealed a medium, high and extremely high risk of developing MSK of 40.2%, 37.1%, and 21.6%, respectively, with no difference between sexes. The risk of developing MSK pain was medium-high in predoctoral dental students and was not related to sex. The overall dental ergonomics required attention and rapid change. Further implementation of varied forms of teaching and monitoring of dental ergonomics from the early years of education is recommended to prevent development of MSK pain at young age and foster better postural habits.

Dual Predictive Quaternion Kalman Filter and its Application in Seamless Wireless Mobile Human Lower Limb Posture Tracking

Dual Predictive Quaternion Kalman Filter and its Application in Seamless Wireless Mobile Human Lower Limb Posture Tracking

Femoral posture during embryonic and early fetal development: An analysis using landmarks on the cartilaginous skeletons of ex vivo human specimens.

The pre-axial border medially moves between the fetal and early postnatal periods, and the foot sole can be placed on the ground. Nonetheless, the precise timeline when this posture is achieved remains poorly understood. The hip joint is the most freely movable joint in the lower limbs and largely determines the lower-limb posture. The present study aimed to establish a timeline of lower-limb development using a precise measurement of femoral posture. Magnetic resonance images of 157 human embryonic samples (Carnegie stages [CS] 19-23) and 18 fetal samples (crown rump length: 37.2-225 mm) from the Kyoto Collection were obtained. Three-dimensional coordinates of eight selected landmarks in the lower limbs and pelvis were used to calculate the femoral posture. Hip flexion was approximately 14° at CS19 and gradually increased to approximately 65° at CS23; the flexion angle ranged from 90° to 120° during the fetal period. Hip joint abduction was approximately 78° at CS19 and gradually decreased to approximately 27° at CS23; the average angle was approximately 13° during the fetal period. Lateral rotation was greater than 90° at CS19 and CS21 and decreased to approximately 65° at CS23; the average angle was approximately 43° during the fetal period. During the embryonic period, three posture parameters (namely, flexion, abduction, and lateral rotation of the hip) were linearly correlated with each other, suggesting that the femoral posture at each stage was three-dimensionally constant and exhibited gradual and smooth change according to growth. During the fetal period, these parameters varied among individuals, with no obvious trend. Our study has merits in that lengths and angles were measured on anatomical landmarks of the skeletal system. Our obtained data may contribute to understanding development from anatomical aspects and provide valuable insights for clinical application.

Lower limb postures resembling sitting and standing alter lumbar angles along the passive stiffness curve.

In vivo lumbar passive stiffness is often used to assess time-dependent changes in lumbar tissues and to define the neutral zone. We tested the hypothesis that flexing the hips would alter tension in hip and spine musculature, leading to a more extended passive stiffness curve (i.e., right-shifted), without changes in lumbar stiffness. Twenty participants underwent side-lying passive testing with the lower limbs positioned in Stand, Kneel, and Sit representative postures. Moment-angle curves were constructed from the lumbar angles and the moment at L4/5 and partitioned into three zones. Partially supporting our hypothesis, lumbar stiffness within the low and transition stiffness zones was similar between the Stand and Sit. Contrary to our hypothesis, lumbar angles were significantly larger in the Sit compared to the Stand and Kneel postures at the first and second breakpoints, with average differences of 9.3° or 27.2% of passive range of motion (%PassRoM) in flexion and 5.6° or 16.6 %PassRoM in extension. Increased flexion in the Sit may be linked to increased posterior pelvic tilt and associated lower lumbar vertebrae flexion. Investigators must ensure consistent pelvis and hip positioning when measuring lumbar stiffness. Additionally, the adaptability of the neutral zone to pelvis posture, particularly between standing and sitting, should be considered in ergonomic applications.

Retracted: Research on the Design of Bright Clothing for the Elderly Based on Intelligent Detection of Lower Limb Posture Antifall Sensors

Retracted: Research on the Design of Bright Clothing for the Elderly Based on Intelligent Detection of Lower Limb Posture Antifall Sensors

작업 자세 부하 평가를 위한 모션 데이터 기반 자동 인간공학적 평가 프로그램 개발 및 검증

Objective: This study aims to develop a simultaneous automatic evaluation program for three evaluation tools using motion data of wearable IMU sensors that can be used in the field, and to present various measures for the results of each evaluation tool of the entire work.BRBRBackground: Work-related musculoskeletal diseases have been on the rise over the past four years, and improvement based on the results of work posture evaluation is needed to prevent such musculoskeletal diseases. Recently, various automation evaluation methods have been proposed in consideration of the limitations of the existing observation method, but the image processing technology is difficult to apply on-site, and the motion data-based has a limitation using a small number of evaluation tools mainly focused on the upper and lower limbs.BRBRMethod: In the research procedure, after designing algorithms for each of the three ergonomic assessment tools, algorithm reliability was verified through analysis of the agreement between the manual evaluation results and automatic evaluation results, and simultaneous automatic evaluation programs were developed. Finally, the results of each assessment tool and evaluation scale were derived and compared by applying motion data of two types of work to the developed program.BRBRResults: Measurement items and criteria of motion data for 3 angles of 5 upper limbs and 3 lower limb postures were derived and based on algorithms for each of the 3 ergonomic assessment tools were designed. As a result of analyzing the degree of agreement between manual evaluation and automatic evaluation, the Kappa coefficient corresponded to a very high degree of agreement in all ergonomic assessment tools. The developed program presented the angles of major body parts according to time for each frame of the entire data, risk levels according to all assessment tools and individual assessment tools, and various evaluation scales such as Max, Min, Mode, Mean, Most posture, and Worst postures for each analyzed data.BRBRConclusion: As a result of Cohen

Dry needling in triceps surae muscles and its influence on pressure pain threshold and lower limb posture in active elderly women: a randomized, blinded controlled clinical trial

Background: Aging leads to the loss of anatomical structures and physiological processes such as postural stability. Poor postural control leads to a shift in the center of gravity, thus overloading the musculature. Muscles overloaded due to postural changes do not show enough muscle contraction, causing the appearance of trigger points (TP). Among the PG deactivation methods, the Dry Needling (DN) has been shown to be a good response method in clinical practice. Objective: To analyze the immediate effect of DN on pressure pain threshold (PPT) of latent trigger points of the sural triceps muscles, in order to verify whether there is improvement in the posture of the lower limbs of active elderly women. Methods: A randomized, controlled and blind clinical trial (patients) was carried out. The sample consisted of physically active elderly women from the community. Divided into two groups: DN Group (DNG) and Control Group (CG). Both groups underwent an initial assessment, treatment (DNG) or sham (CG), and reassessment. The tests were: pressure algometer and biophotogrammetry. Data were analyzed from Normality using the Shapiro-Wilk test. The characterization of the sample was analyzed by multivariate analysis of variance (MANOVA) for comparison between groups. For inter and intragroup analysis, mixed Anova with post hoc Bonferroni was used. The level of significance used was p<0.05. Results: The PPT showed an increase in the intragroup analysis for the right (14.03%) and left (14.92%) sides in the GDN group, as for the intergroup analysis, the results of the reassessment were higher in the DNG group compared to the GC. Regarding the posture of the lower limbs, there was no significant improvement in the intergroup and intragroup analyses. Conclusion: The present study demonstrated that the application of Dry Needling in PG in the sural triceps musculature presents an increase in the pressure pain threshold, however, only one session of the technique application was not enough to present a significant improvement in the posture of the lower limbs. of active elderly women. Search registered on the ReBEC (Brazilian Registry of Clinical Trials) platform under the number RBR-97sqsb.

Research on the Design of Bright Clothing for the Elderly Based on Intelligent Detection of Lower Limb Posture Antifall Sensors

In this paper, we construct a model for intelligent detection of lower limb posture fall prevention sensors, conduct an in-depth study of bright clothing for the elderly with smart detection of fall prevention, and design an article of colorful clothing for the elderly based on intelligent detection of lower limb posture fall prevention sensors. In this paper, the overall system scheme is determined according to the application, including the characteristic position of the device to be worn, the establishment of the reference coordinate system, and the setting of the overall system architecture. The data acquisition, transmission, and saving functions are realized, and the two-step extended Kalman filter, complementary filter, and DMP-Kalman filter are used to solve the posture angle of the measured object. The feasibility of the prototype was verified by testing the daily behavioral activity data and fall behavior data of the elderly, and the collected data were processed and analyzed by three data fusion algorithms, which proved the effectiveness of the algorithms, among which the DMP-Kalman filter algorithm has better performance. From the test results, the design of this paper can detect the posture angle of the human body more accurately, which provides a practical reference for fall detection equipment. Using clothing as a carrier, the fall detection and warning module is integrated with clothing to study an article of intelligent clothing for fall detection and warning for the elderly. A core issue in the integration process is the influence of the clothing on the detection module when the human body is moving. The effect of the material and loft of the clothing on the model is studied through experiments. The results of the two indexes, i.e., sensitivity and specificity, of the integrated model and the model not integrated with the clothing are around 98%. The experimental results of the material and loft of the clothing within a specific range have little influence on the model. The final intelligent garment design scheme was determined on this basis.

Measurement of Functional Stability Limits in Squatting Position and the Estimation Technique Based on Considering Lower Limb Posture

Measurement of Functional Stability Limits in Squatting Position and the Estimation Technique Based on Considering Lower Limb Posture

Sagittal femoral bowing contributes to distal femoral valgus angle deviation in malrotated preoperative radiographs

BackgroundThe coronal whole-leg radiograph is generally used for preoperative planning in total knee arthroplasty. The distal femoral valgus angle (DFVA) is measured for distal femoral bone resection using an intramedullary guide rod. The effect of coronal and sagittal femoral shaft bowing on DFVA measurement in the presence of malrotation or knee flexion contracture has not been well reported. The objectives of this study were: (1) to investigate the effects of whole-leg malrotation and knee flexion contracture on the DFVA in detail, (2) to determine the additional effect of coronal or sagittal femoral shaft bowing.MethodsWe studied 100 consecutive varus and 100 valgus knees that underwent total or unicompartmental knee arthroplasty. Preoperative CT scans were used to create digitally reconstructed radiography (DRR) images in neutral rotation (NR, parallel to the surgical epicondylar axis), and at 5° and 10° external rotation (ER) and internal rotation (IR). The images were also reconstructed at 10° femoral flexion. The DFVA was evaluated in each DRR image, and the angular variation due to lower limb malposition was investigated.ResultsThe DFVA increased as the DRR image shifted from IR to ER, and all angles increased further from extension to 10° flexion. The DFVA variation in each position was 1.3° on average. A larger variation than 2° was seen in 12% of all. Multivariate regression analysis showed that sagittal femoral shaft bowing was independently associated with a large variation of DFVA. Receiver operating characteristic analysis showed that more than 12° of sagittal bowing caused the variation.ConclusionIf femoral sagittal bowing is more than 12°, close attention should be paid to the lower limb position when taking whole-leg radiographs. Preoperative planning with whole-leg CT data should be considered.

Lower limb posture and joint mobility in young Soccer players

Soccer practice can induce marked changes in the lower limbs with dreaded short and long term consequences. We evaluated the possible effects of sport practice on lower limb posture and their relationships with ankle joint mobility (AJM). In 61 male Soccer players mean age 11.6±1.8 years, and in 50 Volleyball and Basketball players matched for age, sex and body mass index, lower limb posture and AJM in both plantar flexion and dorsiflexion were evaluated on the sagittal plane in supine position using, respectively, images analysis and an inclinometer. A multivariate analysis of variance was carried out to assess if the practice of different sports affects the leg posture (FP: angle between foot and leg) and foot posture (LP: angle between the foot and the line perpendicular to the ground). The sport practiced showed a significant multivariate effect on the lower limb posture. Soccer players showed a greater LP angle (169.2±4.3° vs 164.9±4.5°; p<0.001) and a lesser FP angle in both Basketball and Volleyball players (298.0±12.6° vs 305.6±10.9°; p<0.002). These differences were not present between the Basketball and Volleyball players. Soccer players showed a reduced AJM (127.6±15.7° vs. 138.8±21.6°; p<0.002) compared to the other subjects evaluated. The AJM was found directly correlated to the FP angle (p<0.005). The results of this study indicate that young Soccer players could show an altered posture of the leg and foot and a reduced AJM. The alterations of these parameters seem to be a consequence of the sport practice.

Using a Passive Back Exoskeleton During a Simulated Sorting Task: Influence on Muscle Activity, Posture, and Heart Rate.

To evaluate using a back exoskeleton in a simulated sorting task in a static forward bent trunk posture on muscle activity, posture, and heart rate (HR). Potentials of exoskeletons for reducing musculoskeletal demands in work tasks need to be clarified. Thirty-six healthy males performed the sorting task in 40°-forward bent static trunk posture for 90seconds, in three trunk orientations, with and without exoskeleton. Muscle activity of the erector spinae (ES), biceps femoris (BF), trapezius descendens (TD), rectus abdominis (RA), vastus laterals (VL), and gastrocnemius medialis was recorded using surface electromyography normalized to a submaximal or maximal reference electrical activity (%RVE (reference voluntary electrical activity)/%MVE). Spine and lower limb postures were assessed by gravimetric position sensors, and HR by electrocardiography. Using the exoskeleton resulted in decreased BF muscle activity [-8.12%RVE], and minor changes in ES [-1.29%MVE], RA [-0.28%RVE], VL [-0.49%RVE], and TD [+1.13%RVE] muscle activity. Hip and knee flexion increased [+8.1°; +6.7°]. Heart rate decreased by 2.1 bpm. Trunk orientation had an influence on BF muscle activity. Using the back exoskeleton in a short sorting task with static trunk posture mainly reduced hip extensor muscle activity and changed lower limb but not spine posture. Implications of using a back exoskeleton for workers' musculoskeletal health need further clarification. The detected changes by using the Laevo® illustrate the need for further investigation prior to practical recommendations of using exoskeletons in the field. Investigating various work scenarios in different kind of workers and long-term applications would be important elements.

Systematic Comparison of OWAS, RULA, and REBA Based on a Literature Review.

This study aimed to systematically compare three representative observational methods for assessing musculoskeletal loadings and their association with musculoskeletal disorders (MSDs): Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA). The comparison was based on a literature review without time limitations and was conducted on various factors related to observational methods. The comparisons showed that although it has a significant limitation of comprising only two classifications for the leg postures, (1) the RULA is the most frequently used method among the three techniques; (2) many studies adopted the RULA even in evaluation of unstable lower limb postures; (3) the RULA assessed postural loads as higher risk levels in most studies reviewed in this research; (4) the intra- and inter-reliabilities for the RULA were not low; and (5) the risk levels assessed by the RULA were more significantly associated with postural load criteria such as discomfort, MHTs and % capable at the trunk, and MSDs.