Greater Knee Adduction Moment Research Articles

Early Gait Biomechanics Linked to Daily Steps Following Anterior Cruciate Ligament Reconstruction.

Gait biomechanics and daily steps are important aspects of knee joint loading that change following anterior cruciate ligament reconstruction (ACLR). Understanding their relationship during the first 6 months post-ACLR could help develop comprehensive rehabilitation interventions that promote optimal joint loading following injury, thereby improving long-term knee joint health. Our primary objective was to compare biomechanical gait waveforms throughout stance at early timepoints post-ACLR in individuals with different daily step behaviors at 6 months post-ACLR. The secondary aim was to examine how these gait waveforms compare to those of uninjured controls. Case-Control Study. Laboratory. Individuals with primary ACLR assigned to a low (LSG) (n=13) or high step group (HSG) (n=19) based on their average daily steps at 6 months post- ACLR, and uninjured matched controls (n=32). Gait biomechanics were collected at 2, 4, and 6 months post-ACLR in ACLR individuals and at a single session for controls. Knee adduction moment (KAM), knee extension moment (KEM), and knee flexion angle (KFA) waveforms were calculated during gait stance and then compared via functional waveform analyses. Mean differences and corresponding 95% confident intervals between groups were reported. Primary results demonstrated lesser KFA (1-45%, 79-92% of stance) and greater KEM (65-93% of stance) at 2 months and greater KAM (14-20%, 68-92% of stance) at 4 months post-ACLR for the HSG compared to the LSG. KEM, KAM, and KFA waveforms differed across various proportions of stance at all timepoints between step groups and controls. Differences in gait biomechanics are present at 2 and 4 months post-ACLR between step groups, with the LSG demonstrating an overall more flexed knee and more profound stepwise underloading throughout stance than the HSG. The results indicate a relation between early gait biomechanics and later daily steps behaviors following ACLR.

IS REMOTE ACTIVE FEEDBACK GAIT RETRAINING COMPARABLE TO IN-PERSON RETRAINING 2 YEARS POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION?

Purpose: Anterior cruciate ligament (ACL) tear greatly increases the risk of osteoarthritis, a leading cause of chronic pain and disability. At 2 years post ACLR, altered knee mechanics have been associated with structural changes and longitudinal patient-reported outcomes (PROs). Specifically, increased knee adduction moment (KAM) correlated with cartilage deep tissue matrix degeneration, and greater KAM and flexion moment (KFM) predicted worse PROs in 8 years. In-person laboratory based active feedback gait retraining to produce medial weight shift under the foot has been shown to reduce KAM without increasing KFM in healthy and osteoarthritic knees.

Higher 12-month t1rho relaxation times associate with lower external knee adduction moment during walking in anterior cruciate ligament reconstruction patients

Purpose: Aberrant gait biomechanics following anterior cruciate ligament reconstruction (ACLR) are associated with the development of posttraumatic osteoarthritis (PTOA). External knee adduction moment (KAM) is used to estimate medial compartment loading during gait and greater KAM is associated with more severe idiopathic knee osteoarthritis progression. However, there is conflicting evidence regarding the association between KAM and PTOA development. Lesser KAM is associated with worse joint tissue metabolism and articular cartilage composition at 6 months post-ACLR.

Immediate Effects of Medially Posted Insoles on Lower Limb Joint Contact Forces in Adult Acquired Flatfoot: A Pilot Study.

Flatfoot is linked to secondary lower limb joint problems, such as patellofemoral pain. This study aimed to investigate the influence of medial posting insoles on the joint mechanics of the lower extremity in adults with flatfoot. Gait analysis was performed on fifteen young adults with flatfoot under two conditions: walking with shoes and foot orthoses (WSFO), and walking with shoes (WS) in random order. The data collected by a vicon system were used to drive the musculoskeletal model to estimate the hip, patellofemoral, ankle, medial and lateral tibiofemoral joint contact forces. The joint contact forces in WSFO and WS conditions were compared. Compared to the WS group, the second peak patellofemoral contact force (p < 0.05) and the peak ankle contact force (p < 0.05) were significantly lower in the WSFO group by 10.2% and 6.8%, respectively. The foot orthosis significantly reduced the peak ankle eversion angle (p < 0.05) and ankle eversion moment (p < 0.05); however, the peak knee adduction moment increased (p < 0.05). The reduction in the patellofemoral joint force and ankle contact force could potentially inhibit flatfoot-induced lower limb joint problems, despite a greater knee adduction moment.

Knee Biomechanical Deficits During a Single-Leg Landing Task Are Addressed With Neuromuscular Training in Anterior Cruciate Ligament-Reconstructed Athletes.

Faulty neuromuscular and biomechanical deficits of the knee are nearly ubiquitous in athletes after anterior cruciate ligament (ACL) reconstruction (ACLR). Knee biomechanical deficits are directly associated with an increased risk of second ACL injury, which typically occurs during a sports-related movement on a single limb. To date, the biomechanical effects of a neuromuscular training (NMT) program on knee biomechanics during a single-leg landing task have not been investigated. Prospective Cohort Study. Controlled laboratory setting. Eighteen ACLR and 10 control athletes. Neuromuscular training. Knee kinematics and kinetics. There were no significant interactions of session and limb (P > 0.05) for the athletes with ACLR after training. However, there were several significant main effects of session (P < 0.05) for knee kinematics and kinetics during the single-leg landing task. After training, the athletes with ACLR landed with greater knee flexion angles, decreased knee abduction angles, increased knee flexion range of motion, and decreased knee excursion. Also, the ACLR athletes landed with lower knee flexion moments, greater knee adduction moments, and lower peak vertical ground reaction force. Post-training comparison of the ACLR and control cohorts found no significant interactions of group and limb (P > 0.05) and only a significant main effect of group (P < 0.05) for frontal plane knee angle at initial contact. The athletes with ACLR landed with greater knee adduction angles than the control group. Deficits in knee biomechanics that are associated with an increased risk of ACL injury are attenuated after completion of this NMT program.

Position of the non-stance leg during the single leg squat affects females and males differently

BackgroundKinematic differences between females and males for the single leg squat (SLS) have been identified. However, kinetic differences between sexes and how variations of the non-stance leg position during the SLS may affect kinematics and kinetics differently in females and males have not been examined. ObjectivesExamine sex-specific kinematic and kinetic differences during the SLS task with 3 different non-stance leg positions. DesignControlled laboratory study, cross-sectional design. MethodsThirty-two healthy adults (16 females, 16 males) performed the 3 SLS tasks while data were collected using a motion capture system and force plates. At 60 degrees of knee flexion (60KF) and peak knee flexion (PKF), kinematics and joint moments were compared between sexes and SLS tasks using a linear regression analysis. ResultsFemales exhibited less ipsilateral trunk flexion (P < 0.001) and greater anterior pelvic tilt (P ≤ 0.021) and hip adduction (P < 0.001) than males across tasks at 60KF and PKF. Across tasks, females had a smaller knee flexion moment than males at PKF (P = 0.001). Females had a greater hip abduction moment during SLS-Front than SLS-Middle (P = 0.044) and SLS-Back (P = 0.003) at PKF, but males had similar hip abduction moments across tasks (P ≥ 0.299). At 60KF, males had a greater knee adduction moment during SLS-Front compared to the other tasks (P ≤ 0.019) while females had similar hip abduction moments across tasks (P ≥ 0.459). ConclusionAltering the non-stance leg position during the SLS affects the kinematics and kinetics of both females and males. The position of the non-stance leg can be modified for assessment and treatment purposes and should be reported in research.

The effect of surface inclination and limb on knee loading measures in transtibial prosthesis users

BackgroundOsteoarthritis (OA) is a degenerative disease caused by the wearing of joint cartilage and bone. Literature has established that a prosthesis user’s intact limb is at greater risk of developing OA. This study analyzed the effect of commonly encountered surface inclinations on knee joint loading measures in able-bodied and transtibial prosthesis users.Methods12 transtibial prosthesis users and 12 able-bodied participants walked across level ground, up slope, down slope, and cross slope (further divided into top and bottom slope depending on the location of the limb being analyzed). First and second peak external knee adduction moment (KAM), external knee adduction moment rate, and external knee adduction moment impulse were extracted from the stance phase of gait. Mixed ANOVA statistics with Bonferonni post hoc analyses were performed.ResultsSignificant limb differences were only found for KAM rate and first peak KAM. When compared to all other surfaces up slope had the significantly lowest KAM rate and was not significantly lower for all other tested variables. Down slope had significantly greater KAM rate than all surfaces except bottom slope. KAM second peak and KAM impulse analysis resulted in no significant differences.ConclusionsIndividuals at risk for developing, or currently dealing with, knee OA could avoid walking for extended periods on down slope. Walking up moderate slopes may be considered as a complementary activity to level walking for rehabilitation and delaying OA progression.The lack of significant limb differences suggests that second peak KAM and KAM impulse may not be appropriate load-related indicators of OA initiation among prosthesis users without OA. KAM rate was the most sensitive joint loading variable and therefore should be investigated further as an appropriate variable for identifying OA risk in individuals with transtibial amputations.

Biomechanical characteristics of lower limb gait waveforms: Associations with body fat in children

BackgroundChildhood obesity is associated with musculoskeletal dysfunction and altered lower limb biomechanics during gait. Few previous studies have explored relationships between childhood obesity measured by body fat and lower limb joint waveform kinematics and kinetics. Research questionWhat is the association between body fat and hip, knee and ankle joint angles and moments during gait and in 7 to 11 year-old boys? MethodsFifty-five boys participated in the study. Body fat was measured by air displacement plethysmography. Hip, knee and ankle 3D waveforms of joint angles and moments were recorded during gait. Principle component analysis was used to reduce the multidimensional nature of the waveform into components representing parts of the gait cycle. Multiple linear regression analysis determined the association between the components with body fat. ResultsHigher body fat predicted greater hip flexion, knee flexion and knee internal rotation during late stance and greater ankle external rotation in late swing/early stance. Greater hip flexion and adduction moments were found in early stance with higher body fat. In mid-stance, greater knee adduction moments were associated with high body fat. Finally, at the ankle, higher body fat was predictive of greater internal rotation moments. SignificanceThe study presents novel information on relationships between body fat and kinematic and kinetic waveform analysis of paediatric gait. The findings suggest altered lower limb joint kinematics and kinetics with high body fat in young boys. The findings may help to inform research in to preventing musculoskeletal comorbidities and promoting weight management.

The influence of sex and obesity on gait biomechanics in people with severe knee osteoarthritis scheduled for arthroplasty

BackgroundSex and body mass may influence knee biomechanics associated with poor total knee arthroplasty (TKA) outcomes for knee osteoarthritis (OA). This study aimed to determine if gait differed between men and women, and overweight and class I obese patients with severe knee OA awaiting TKA. Methods34 patients with severe knee OA (average age 70.0 (SD 7.2) years, body mass index 30.3 (4.1kg/m2)) were recruited from a TKA waiting list. Three-dimensional gait analysis was performed at self-selected walking speed. Comparisons were made between men and women, and overweight (body mass index (BMI) 25.0–29.9kg/m2) and class I obese (BMI 30.0–34.9kg/m2) participants. Biomechanical outcomes included absolute and body size-adjusted peak knee adduction moment (KAM), KAM impulse, peak knee flexion moment, as well as peak knee flexion and varus-valgus angles, peak varus-valgus thrust, and peak vertical ground reaction force (GRF). FindingsMen had a higher absolute peak KAM, KAM impulse and peak GRF compared to women, and this sex-difference in frontal plane moments remained after adjusting for body size. However, when additionally adjusting for static knee alignment, differences disappeared. Knee biomechanics were similar between obesity groups after adjusting for the greater body weight of those with class I obesity. InterpretationMen had greater KAM and KAM impulse even after adjustment for body size; however adjustment for their more varus knees removed this difference. Obesity group did not influence knee joint kinematics or moments. This suggests sex- and obesity-differences in these variables may not be associated with TKA outcomes.

Knee muscle strength after recent partial meniscectomy does not relate to 2-year change in knee adduction moment.

Knee muscle weakness and a greater external knee adduction moment are suggested risk factors for medial tibiofemoral knee osteoarthritis. Knee muscle weakness and a greater knee adduction moment may be related to each other, are potentially modifiable, and have been observed after arthroscopic partial meniscectomy. The aim of this exploratory study was to determine if knee muscle weakness 3 months after arthroscopic partial meniscectomy (baseline) is associated with an increase in external knee adduction parameters during the subsequent 2 years. Eighty-two participants undergoing medial arthroscopic partial meniscectomy were assessed at baseline, and 66 participants who were reassessed 2 years later were included in our study. Isokinetic muscle strength and external adduction moment parameters (peak and impulse) during normal and fast walking were measured at baseline and followup. Multiple linear regression models were used to examine the association between baseline muscle strength and 2-year change in adduction moment parameters. A post hoc power calculation showed we had 80% power to detect a correlation of 0.31 between baseline muscle strength and change in the external knee adduction, with an alpha error of 0.05 and two-sided significance. Maximal isokinetic muscle strength 3 months after arthroscopic partial meniscectomy was not associated with change in adduction moment parameters (p value range from 0.12 to 0.96). No evidence was found to suggest that improving maximal knee muscle strength after a recent arthroscopic partial meniscectomy would reduce change in knee adduction moment observed during the subsequent 2 years. As muscle function is modifiable, future investigation of other aspects of muscle function that may relate to change in knee adduction moment is warranted.

Knee joint loading during gait in healthy controls and individuals with knee osteoarthritis

People with knee osteoarthritis (OA) are thought to walk with high loads at the knee which are yet to be quantified using modeling techniques that account for subject specific electromyography (EMG) patterns, kinematics and kinetics. The objective was to estimate medial and lateral loading for people with knee OA and controls using an approach that is sensitive to subject specific muscle activation patterns. Sixteen OA and 12 control (C) subjects walked while kinematic, kinetic and EMG data were collected. Muscle forces were calculated using an EMG-Driven model and loading was calculated by balancing the external moments with internal muscle and contact forces. OA subjects walked slower and had greater laxity, static and dynamic varus alignment, less flexion and greater knee adduction moment (KAM). Loading [normalized to body weight (BW)] was no different between the groups but OA subjects had greater absolute medial load than controls and maintained a greater %total load on the medial compartment. These patterns were associated with body mass, sagittal and frontal plane moments, static alignment and close to significance for dynamic alignment. Lateral compartment unloading during mid-late stance was observed in 50% of OA subjects. Loading for control subjects was similar to data from instrumented prostheses. Knee OA subjects had high medial contact loads in early stance and half of the OA cohort demonstrated lateral compartment lift-off. Results suggest that interventions aimed at reducing BW and dynamic malalignment might be effective in reducing medial compartment loading and establishing normal medio-lateral load sharing patterns.

Control of frontal plane knee laxity during gait in patients with medial compartment knee osteoarthritis

Objective Patients with medial compartment knee osteoarthritis (OA) adopt an abnormal gait pattern, and often develop frontal plane laxity at the knee. The purpose of this study was to quantify the extent of frontal plane knee joint laxity in patients with medial knee OA and genu varum and to assess the effect of joint laxity on knee joint kinetics, kinematics and muscle activity during gait. Design Twelve subjects with genu varum and medial compartment knee osteoarthritis (OA group) and 12 age-matched uninjured subjects underwent stress radiography to determine the presence and magnitude of frontal plane laxity. All subjects also went through gait analysis with surface electromyography of the medial and lateral quadriceps, hamstrings, and gastrocnemius to calculate knee joint kinematics and kinetics and co-contraction levels during gait. Results The OA group showed significantly greater knee instability ( P=0.002), medial joint laxity ( P=0.001), greater medial quadriceps–medial gastrocnemius (VMMG) co-contraction ( P=0.043), and greater knee adduction moments ( P=0.019) than the control group. Medial joint laxity contributed significantly to the variance in both VMMG and the knee adduction moment during early stance. Conclusion The presence of medial laxity in patients with knee OA is likely contributing to the altered gait patterns observed in those with medial knee OA. Greater medial co-contraction and knee adduction moments bodes poorly for the long-term integrity of the articular cartilage, suggesting that medial joint laxity should be a focus of interventions aimed at slowing the progression of disease in individuals with medial compartment knee OA.