Effect Of Leg Length Discrepancy Research Articles

The Effect of Leg Length Discrepancy on Paraspinal Muscles Activation Using Surface Electromyography.

The aim of the study is to assess the effects of leg length discrepancy on paraspinal muscle activity and kinematic variables during gait. Thirty-nine healthy participants aged 5-12 yrs performed the 10-m walk test using the surface electromyography and G-walk sensor for the following conditions: (1) non-leg length discrepancy condition (leg length discrepancy 0 cm) and (2) leg length discrepancy condition with an insole on the right leg at three different heights (leg length discrepancy 0.5 cm, 1.0 cm, and 1.5 cm). The root mean square was normalized using maximal voluntary contraction and reference voluntary contraction methods (RMS_MVC and RMS_ref) and compared between the sides. The mean RMS_MVC of the 12th thoracic erector spinae on the right side was significantly higher at a leg length discrepancy 0.5 cm and 1 cm. Regarding the 3rd lumbar multifidus, the mean RMS_MVC on the right side was significantly higher at a leg length discrepancy 1.5 cm. The mean RMS_ref exhibited similar patterns. Pelvic obliquity and rotation showed asymmetry at a leg length discrepancy 1.5 cm compared with a leg length discrepancy 0 cm. A small leg length discrepancy significantly affected the asymmetric hyperactivation of the 3rd lumbar multifidus and 12th thoracic erector spinae muscles during gait. Considering the action of these muscles, asymmetric hyperactivation might result in rotation and bending of the lumbar spine and the bending of the thoracolumbar spine.

Effect of Leg Length Discrepancy on Dynamic Gait Stability

: It is unclear whether the increased center of mass lateral shift during gait induced by leg length difference induces lateral instability. The purpose of this study was to investigate the effect of leg length discrepancy (LLD) on dynamic gait stability and the compensatory kinematic and dynamic strategies for this effect by using the extrapolated center of mass and margin of stability. : Nineteen healthy male participants walked without insoles (no LLD condition; 0 cm) and with added insoles (LLD condition; 3 cm). Kinematic and kinetic data were analyzed using a three-dimensional motion analyzer and force plates; the values were compared between the two conditions. Correlation analysis was performed on the parameters and the margin of stability and significant changes were identified. Compared with the no-LLD condition, in the LLD condition, lateral stability was maintained on both the short leg side and the long leg side. Nonetheless, changes in joint angles and muscle activity on the frontal plane were observed on the short leg side, although the correlations were not significant. On the long leg side, a moderate negative correlation was found between the lateral flexion angle of the trunk and the margin of stability (r=-0.56, P=0.011). The short leg side may compensate for lateral stability by complex changes in joint angles and muscle activity, and the long leg side may compensate for lateral stability by actively adjusting the trunk lateral flexion angle.

Effect of Leg Length Discrepancy on Lateral Center-edge Angle Measurement.

In patients with leg length discrepancy (LLD) and consequent pelvic obliquity, either the longitudinal axis of the pelvis or a line perpendicular to the ground may be used as the longitudinal reference line for measuring the lateral center-edge angle (LCEA). We aimed to (1) systematically inspect which longitudinal reference line has been used for measuring the LCEA in previous studies; (2) evaluate the frequency of change in the radiographical classification of acetabular overcoverage or undercoverage per the longitudinal reference line; and (3) validate the trigonometric method, predicting the change in the LCEA according to the LLD. Studies investigating the LCEA published between January 1976 and July 2019 in the MEDLINE database were categorized according to the longitudinal reference line used. Further, in a retrospective analysis of 238 patients surgically treated for LLD, the LCEA was first measured on standing pelvic radiographs using the longitudinal axis of the pelvis (pLCEA) and measured again using a line perpendicular to the ground (gLCEA). Femoral head coverage was categorized as undercoverage, normal, or overcoverage based on the pLCEA and gLCEA. The theoretically calculated difference between the pLCEA and gLCEA (dLCEA) as determined using a trigonometric method was compared with the dLCEA measured on radiographs. Of 229 previous studies, 188 did not specify the longitudinal reference line. The number of patients who were diagnosed with acetabular overcoverage using the pLCEA and gLCEA was one and fourteen, respectively (P<0.001). The number of patients who were diagnosed with acetabular undercoverage using the pLCEA and gLCEA was one and zero, respectively (P=1.000). There was no difference (P=0.433) between the theoretically calculated (9±5 degrees) and measured (9±5 degrees) dLCEAs. The definition of the longitudinal reference line should be clarified when measuring the LCEA. The trigonometric method can accurately predict the change in the LCEA according to LLD in concentric hips without proximal femoral and pelvic deformities. Level IV-diagnostic study.

The Effect of Simulated Leg-Length Discrepancy on the Dynamic Parameters of the Feet during Gait-Cross-Sectional Research.

Background: The effect of Leg-Length Discrepancy (LLD) on dynamic gait parameters has been extensively discussed. Podobarography is the study of foot-to-ground pressure distribution. It has been used to test plantar footprint deviations that could reveal pathology. Purpose: The aim of this study is to determine the effects of simulated LLD on dynamic gait parameters measured with a pressure platform in healthy subjects. Methods: Thirty-seven healthy subjects participated in observational cross-sectional research. A procedure was performed to capture the dynamic parameters of each participant under five different simulated LLD conditions. Support time, mean pressure, and peak pressure measures were registered on three trials for each foot and LLD level per session. An analysis of variance (ANOVA) test for repeated measures was performed to check for differences between the different simulated LLD levels. Results: The stance time of the short leg had no significant changes. The stance time of the long leg increased by 3.51% (p < 0.001), mean pressure of the short leg increased by 1.23% (p = 0.005), and decreased by 5.89% in the long leg (p < 0.001). Peak pressure of the short leg decreased by 2.58% (p = 0.031) and the long leg decreased by 12.11% (p < 0.001). Conclusions: This study demonstrates that increasing LLD causes an asymmetrical foot-loading pattern, with decreased mean and peak pressure on the longer limb, and consequently an overload on the short side. Furthermore, an increasing LLD causes increased stance time on the long leg.

Leg Length Discrepancy to Influence on Kinematic Changes of the Pelvis and the Hip during Gait

Purpose: The purpose of this study was to investigate the effects of leg length discrepancy on kinematic changes of the pelvis and hip during gait. Methods: A total of ten healthy women with no history of neurological, musculoskeletal surgery or injuries, or pain in the lower limbs were recruited. They were assigned to two groups; the experimental group (LLD) consisting of five subjects leg length discrepancy of 10mm to 18mm and the control group (CON) consisting of five subjects leg length discrepancy of<10 mm. All participants were in ­structed to perform three walking trials for further analysis by using the Cortex 3.0 software program. Independent T-test and Mann-Whitney test were used to examine the effects of mild LLD on kinematic changes of the pelvis and hip during gait. Results: Angles of hip flexion, hip abduction, pelvic obliquity, and pelvic tilt in the experimental group were not significantly different compared to those of the control group. Conclusion: Mild leg length discrepancy induces kinematic changes in the lower limbs, including decreased hip flexion, increased hip ab­ duction, and increased pelvic obliquity in the shorter limb, and increased hip adduction and increased pelvic obliquity in the longer limb. However, those changes were not significant.

Effect of leg-length discrepancy following total hip arthroplasty on collapse of the contralateral hip in bilateral non-traumatic osteonecrosis of the femoral head.

The purpose of this study was to examine whether leg-length discrepancy (LLD) following unilateral total hip arthroplasty (THA) affects the incidence of contralateral head collapse and subsequent THA in patients with bilateral osteonecrosis, and to determine factors associated with subsequent collapse. We identified 121 patients with bilateral non-traumatic osteonecrosis who underwent THA between 2003 and 2011 to treat a symptomatic hip, and who also exhibited medium-to-large lesions (necrotic area ≥ 30%) in an otherwise asymptomatic non-operated hip. Of the 121 patients, 71 were male (59%) and 50 were female (41%), with a mean age of 51 years (19 to 71) at the time of initial THA. All patients were followed for at least five years and were assessed according to the presence of a LLD (non-LLD vs LLD group), as well as the LLD type (longer non-operated side vs shorter non-operated side group). Overall, 68 hips (56%) became painful and progressed to collapse at a mean of 2.6 years (0.2 to 13.8), resulting in 59 THAs (49%). The five-year collapse-free survival rate for the non-LLD group was 59% (95% confidence interval (CI) 46.8 to 71.8) compared with 45% (95% CI 32.9 to 57.5) for the LLD group (p = 0.036), and 66% (95% CI 55.2 to 77.2) for the longer non-operated side group compared with 32% (95% CI 19.1 to 44.9) for the shorter non-operated side group (p < 0.001). Multivariate regression analyses found that large lesions had a higher risk of collapse than medium-size lesions (odds ratio (OR) 4.19, 95% confidence interval (CI) 1.69 to 10.38; p = 0.002). Meanwhile, patients with a LLD < 3 mm (OR 0.20, 95% CI 0.08 to 0.52; p = 0.001) or a longer non-operated leg (OR 0.11, 95% CI 0.04 to 0.28; p < 0.001) after THA were less likely to experience a subsequent collapse. We found that LLD may be a modifiable risk factor for femoral head collapse. Minimizing LLD and particularly avoiding a shorter non-operated limb after THA may lead to a lower risk of collapse of the asymptomatic hip in patients with bilateral non-traumatic osteonecrosis. Cite this article: Bone Joint J 2019;101-B:303-310.

Finite Element Analysis on Knee Joint with Leg Length Inequality

This study aims to investigate the effect of leg length discrepancy (LLD) on the joint reaction stress and strain of femur particularly in the knee joint. The knee joint model was developed using CATIA and imported into ANSYS to simulate the LLD case based on the value of the joint reaction force from the previous experimental study. The analysis was done under a linear static condition. The knee components were divided on three; bone (femur and tibia), cartilage (femoral cartilage and tibial plateau cartilage) and menisci. The effect of LLD on the knee joint was determined by observing the contour of equivalent stress and strain distribution on the knee joint components and the maximum equivalent von-Mises stress and strain. The result shows a higher value of stress and strain was found on the short leg compared to the long leg due to the LLD. The pattern of overall results shows that the magnitude of stress-strain is proportional to the level of increments in LLD. Since the short leg demonstrate the greater in stress and strain value, it is prone to experience failure in the future such as wear in cartilage.

Leg Length Discrepancy Effects on Range of Motion in Lower Limb During Walking

Leg length discrepancy (LLD) refers to the medical condition where both legs are noticeable unequal length that could affect the gait and posture, thus may lead to various orthopedic disorders that can have serious repercussions on the individual. In order to ameliorate the rehabilitation of individuals with LLD, it is important to understand the biomechanics of LLD in these individuals. This paper presents a study to investigate on the effect of LLD on the hip and knee joint range of motion. Sandal with insoles was used to simulate the artificial LLD. The sandal’s thickness was increased starting from 0.5 cm up to 4.0 cm with 0.5 cm increment. Eighteen healthy subject need to walk over two force plates. Visual 3D and Qualisys Track Manager (QTM) system were employed for data processing. ROM was compared using the one-way blocked analysis of variance and paired t-test. The results showed that a statistically significance difference in hip and knee ROM for long leg in frontal and sagittal direction, respectively. The ROM for hip was found significance at the minimum LLD level of 2.5 cm while for knee at 1.0 cm. No significance difference found in hip and knee ROM for short leg.

Correlation between Gait Asymmetry and Leg Length Discrepancy—What Is the Role of Clinical Abnormalities?

Reducing the effect of leg length discrepancy (LLD) on gait abnormalities while other abnormal conditions such as spasticity, joint contractures or weak muscle strength are exhibited is challenging. This study aimed to evaluate the impact of mild LLD on lower limb biomechanics, on participants with anatomic LLD with and without other clinical abnormalities. A motion capture system was utilized on 32 participants to measure lower limb kinematics and dynamic leg length (DLL) throughout the gait cycle, calculated as the absolute distance from the hip joint center, either to the heel, ankle joint center, or forefoot. The Pearson correlation coefficient found that LLD was associated with 5 kinematic variables only when LLD appeared with no other clinical abnormalities present (r = 0.574 – 0.846, p &lt; 0.05). When clinical abnormalities were present, the random forest classification accuracy was lower (64% versus 80%), implying that the used kinematics are low predictors for anatomic LLD, revealing a higher asymmetrical clearance index (the difference between the maximal stance phase and the minimal contra-lateral swing phase DLL) and a different kinematic variable importance index. Clinical abnormalities in pathological gait will in all probability significantly affect gait deviations, affirming mild anatomic LLD as inconsequential. A functional measurement can offer a better estimate as to the side and extent of the functional discrepancy.

The Effects of Leg Length Discrepancy on Stability and Kinematics-Kinetics Deviations: A Systematic Review.

Various studies have examined body posture stability, including postural sway and associated biomechanical parameters, to assess the severity effects of leg length discrepancy (LLD). However, various viewpoints have been articulated on the results of these studies because of certain drawbacks in the comprehensive analysis of the effect of variations in LLD magnitude. Therefore, this systematic review was performed to help focus on the current findings to help identify which biomechanical parameters are most relevant, commonly used, and able to distinguish and/or have specific clinical relevance to the effect of variations in LLD magnitude during static (standing) and dynamic (walking) conditions. Several electronic databases containing studies from the year 1983 to 2016 (Scopus, ScienceDirect, PubMed, PMC, and ProQuest) were obtained in our literature search. The search process yielded 22 published articles that fulfilled our criteria. We found most of the published data that we analyzed to be inconsistent, and very little data was obtained on the correlation between LLD severity and changes in body posture stability during standing and walking. However, the results of the present review study are in line with previous observational studies, which describe asymmetry in the lower limbs corresponding to biomechanical parameters such as gait kinematics, kinetics, and other parameters described during static (standing) postural balance. In future investigations, we believe that it might be useful to use and exploit other balance-related factors that may potentially influence body posture stability.

Leg Length Discrepancy: Dynamic Balance Response during Gait.

Balance in the human body's movement is generally associated with different synergistic pathologies. The trunk is supported by one's leg most of the time when walking. A person with poor balance may face limitation when performing their physical activities on a daily basis, and they may be more prone to having risk of fall. The ground reaction forces (GRFs), centre of pressure (COP), and centre of mass (COM) in quite standing posture were often measured for the evaluation of balance. Currently, there is still no experimental evidence or study on leg length discrepancy (LLD) during walking. Analysis of the stability parameters is more representative of the functional activity undergone by the person who has a LLD. Therefore, this study hopes to shed new light on the effects of LLD on the dynamic stability associated with VGRF, COP, and COM during walking. Eighteen healthy subjects were selected among the university population with normal BMIs. Each subject was asked to walk with 1.0 to 2.0 ms−1 of walking speed for three to five trials each. Insoles of 0.5 cm thickness were added, and the thickness of the insoles was subsequently raised until 4 cm and placed under the right foot as we simulated LLD. The captured data obtained from a force plate and motion analysis present Peak VGRF (single-leg stance) and WD (double-leg stance) that showed more forces exerted on the short leg rather than long leg. Obviously, changes occurred on the displacement of COM trajectories in the ML and vertical directions as LLD increased at the whole gait cycle. Displacement of COP trajectories demonstrated that more distribution was on the short leg rather than on the long leg. The root mean square (RMS) of COP-COM distance showed, obviously, changes only in ML direction with the value at 3 cm and 3.5 cm. The cutoff value via receiver operating characteristic (ROC) indicates the significant differences starting at the level 2.5 cm up to 4 cm in long and short legs for both AP and ML directions. The present study performed included all the proposed parameters on the effect of dynamic stability on LLD during walking and thus helps to determine and evaluate the balance pattern.

The effect of simulated leg length discrepancy on lower limb biomechanics during gait

Understanding the effects of leg length discrepancy (LLD) on the biomechanics of gait and determining as to what extent of LLD alters gait is essential. A total of 91 biomechanical data were assessed from 14 lower limbs of healthy individuals walking under random conditions: shod only and with a 5, 10, 15, 20, 30 and 40 mm sole lift. Lower limb kinematics and dynamic leg length (DLL) were measured by a motion capture system. Hotelling's T-Square test was used to evaluate the differences in DLLs throughout the gait cycle in conjunction with differences between the sides based on the maximal stance phase and minimal swing phase DLLs. Kinematics were compared using the one-way blocked analysis of variance and Post-hoc analysis by the paired t-test. Significant dynamic shortening of the longer limb, mainly during the swing phase, and significant change in maximal stance and minimal swing phase DLL relationship started at a 10 mm lift condition (p < 0.05). Thirteen kinematic variables produced a significant angular main effect (p < 0.05), with a more flexed position of the longer limb and extended shorter limb beginning at a 5 mm lift. An increase in hip abduction and external foot rotation during the swing phase was also found. This study demonstrates that simulated LLD, as low as 5 mm, causes biomechanical changes in the lower limbs during gait revealed in both kinematics and dynamic leg length, suggesting that LLD, as small as 5–10 mm, should not be ignored.

Combined effects of leg length discrepancy and the addition of distal mass on gait asymmetry

Asymmetries in gait often arise due to some form of physical impairment. For example, a leg length discrepancy (LLD) or the change of limb mass can result in asymmetric gait patterns. Although adding mass and LLD have been studied separately, this research studies how gait patterns change as a result of asymmetrically altering both leg length and mass at a leg's distal end. Spatio-temporal and kinetic gait measures are used to study the combined asymmetric effects of placing LLD and mass on the opposite and same side. There were statistically significant differences for the amount of mass and leg length added for all five parameters. Contrary to our hypothesis, there was no significant interaction between the amount of mass and leg length added. There were cases in all perturbations where a combination of mass and LLD make a gait parameter more symmetric than a single effect. These cases exhibit the potential for configurations with lower overall asymmetries even though each parameter has a slight asymmetry as opposed to driving one parameter to symmetry and other parameters to a larger asymmetry.

Effect of Leg Length Discrepancy to the Hip Function on Post Hemiarthroplasty Patients in Jember

Hip fractures in elderly patient are often treated with hemiarthroplasty. Hemiarthroplasty can cause various complications, one of which is leg legth descrepancy (LLD). The function of the hip joint is reduced due to these complications. Previous studies have shown contradictive results regarding the relationship of LLD to the function of the hip joint in post-arthroplasty patient's. This type of research is observational with retrospective study. The population in this study came from 2 hospitals in Jember was 53 patients and the sample was 30 people. LLD is measured by true leg length and apparent leg length, whereas hip joint function is measured by Oxford Hip Score (OHS). The data were tested by using Spearman correlation test. In conclusion, there was a moderate relationship between LLD true leg length to the function of the hip joint. This study does not support the implications of the LLD to the hip function because of weak relationship between LLD true leg to the hip function and moderate relasionship between LLD apparent leg length to the hip function.

Predictors and Functional Implications of Change in Leg Length After Total Knee Arthroplasty

BackgroundLeg lengthening occurs in 83% of primary total knee arthroplasty (TKA). The effects of leg length discrepancy (LLD) on THA patients are well established. However, patient function and satisfaction associated with LLD after primary TKA has not been analyzed. This study aimed to quantify the magnitude of limb lengthening, identify radiographic and perceived LLD, and correlate these with predictive factors and functional outcomes in a series of TKA patients. MethodsPatients undergoing primary TKA who met inclusion criteria were prospectively enrolled in this study. Leg length measurements were measured on standardized preoperative and postoperative long leg radiographs. Patients completed preoperative and 6-month postoperative Knee Society Score and functional Knee Injury and Osteoarthritis Outcome Score, as well as a postoperative satisfaction and customized leg length–specific functional questionnaire. ResultsNinety-one patients undergoing TKA surgeries were included. Mean overall lengthening was 3.5 mm (range, −31.0 to 21.4 mm; SD, 8.4) with 77% of limbs lengthened; 89% of patients had no LLD (defined as ≥10 mm) after TKA. Postoperative radiographic LLD was associated with increased preoperative LLD (P < .001). Perceived postoperative LLD was associated with female gender (P = .02), decreased satisfaction (18% vs 84%; P < .001), and poorer functional score changes. Perceived LLD was not associated with radiographic LLD. ConclusionRadiographic lengthened LLD is uncommon after primary TKA (11%) and does not correlate with perceived LLD. Patients with perceived LLD have decreased satisfaction and functional score improvements after TKA surgery.

Effect of Leg Length Discrepancy on Gait and Cobb's Angle

Effect of Leg Length Discrepancy on Gait and Cobb's Angle

The effect of leg length discrepancy on clinical outcome after TKA and identification of possible risk factors.

This study was investigated on the leg length discrepancy (LLD) after computer-assisted total knee arthroplasty (TKA), and its effects on the post-operative function and patient satisfaction. It is hypothesized that LLD after computer-assisted TKA would affect the clinical outcomes for knee scores. A total of 148 cases were analysed retrospectively with a minimum of 2years of follow-up. Eighty-one knees involved a <15-mm LLD, and 67 knees involved more than a 15-mm LLD. The radiographic outcomes, clinical outcomes, patients' satisfaction, and perception of LLD were also evaluated. There was a significant difference in the Knee Society function score and the score for the difficulty with ascending the stairs in the Western Ontario and McMaster Universities score between the groups. There was a statistically significant difference between the two groups in the results of their perception questionnaires, but no difference in the results of their satisfaction questionnaires. The odds ratio for the risk of post-operative LLD increased with the increased pre-operative LLD and the unilateral TKA. In conclusion, the functional outcomes of more than 15-mm post-operative LLD after computer-assisted TKA were lower than those of the <15-mm LLD. Thus, the reduced post-operative LLD should be considered to improve the functional outcomes of primary TKA. A careful treatment plan for degenerative arthritis should be considered and discussed with patients, especially in unilateral TKAs. IV.

Effect of leg length discrepancy on the dynamics of stride interval during self-paced walking

Effect of leg length discrepancy on the dynamics of stride interval during self-paced walking

補高による脚長差歩行が下肢筋活動に及ぼす影響

補高による脚長差歩行が下肢筋活動に及ぼす影響

The effect of leg length discrepancy upon load distribution in the static phase (standing)

Leg length discrepancy (LLD) is commonly recognised as a complication of total hip arthroplasty. Some patients with only minor LLD complain of major difficulties. The effect of LLD has been described in the dynamic phase, but not static phase. The aim of this project was to investigate the effect of leg length discrepancy on static limb loading (i.e. Standing). A pedobarograph was used to measure the limb loading of 20 normal volunteers whilst changing the height of the other foot thus simulating a LLD. With both feet at the same level, the left limb took 54% of the load. When the right foot was lower, (simulating a long left leg), the left leg took 39% of the load. When the right foot was higher, (simulating a long right leg), the left leg took 65% of the load. A paired t-test comparison of the simulation with the level load showed a significant difference with P=0.002. Our results show that weight distribution increased in the shorter limb when LLD was simulated. This uneven distribution is likely to lead to premature fatigue when standing and may explain why some patients with LLD post hip arthroplasty have poorer outcomes.