To evaluate 1) the relationship between the knee contact force (KCF) and knee adduction and flexion moments (KAM and KFM) during normal gait in people with medial knee osteoarthritis (KOA), 2) the ...effects on the KCF of walking with a modified gait pattern and 3) the relationship between changes in the KCF and changes in the knee moments.
We modeled the gait biomechanics of thirty-five patients with medial KOA using the AnyBody Modeling System during normal gait and two modified gait patterns. We calculated the internal KCF and evaluated the external joint moments (KAM and KFM) against it using linear regression analyses.
First peak medial KCF was associated with first peak KAM (R2 = 0.60) and with KAM and KFM (R2 = 0.73). Walking with both modified gait patterns reduced KAM (P = 0.002) and the medial to total KCF ratio (P < 0.001) at the first peak. Changes in KAM during modified gait were moderately associated with changes in the medial KCF at the first peak (R2 = 0.54 and 0.53).
At the first peak, KAM is a reasonable substitute for the medial contact force, but not at the second peak. First peak KFM is also a significant contributor to the medial KCF. At the first peak, walking with a modified gait reduced the ratio of the medial to total KCF but not the medial KCF itself. To determine the effects of gait modifications on cartilage loading and disease progression, longitudinal studies and individualized modeling, accounting for motion control, would be required.
To compare changes in knee pain, function, and loading following a 4-month progressive walking program with or without toe-out gait modification in people with medial tibiofemoral knee ...osteoarthritis.
Individuals with medial knee osteoarthritis were randomized to a 4-month program to increase walking activity with (toe-out) or without (progressive walking) concomitant toe-out gait modification. The walking program was similar between the two groups, except that the gait modification group was trained to walk with 15° more toe-out. Primary outcomes included: knee joint pain (WOMAC), foot progression angles and knee joint loading during gait (knee adduction moment (KAM)). Secondary outcomes included WOMAC function, timed stair climb, and knee flexion moments during gait.
Seventy-nine participants (40 in toe-out group, 39 in progressive walking group) were recruited. Intention-to-treat analysis showed no between-group differences in knee pain, function, or timed stair climb. However, the toe-out group exhibited significantly greater changes in foot progression angle (mean difference = −9.04° (indicating more toe-out), 95% CI: −11.22°, −6.86°; P < 0.001), late stance KAM (mean difference = −0.26 %BW*ht, 95% CI: −0.39 %BW*ht, −0.12 %BW*ht, P < 0.001) and KAM impulse (−0.06 %BW*ht*s, 95% CI: −0.11 %BW*ht*s, −0.01 %BW*ht*s; P = 0.031) compared to the progressive walking group at follow-up. The only between-group difference that remained at a 1-month retention assessment was foot progression angle, with greater changes in the toe-out group (mean difference = −6.78°, 95% CI: −8.82°, −4.75°; P < 0.001).
Though both groups experienced improvements in self-reported pain and function, only the toe-out group experienced biomechanical improvements.
NCT02019108.
The relationship between knee moments and markers of knee osteoarthritis progression has not been examined in different knee osteoarthritis subtypes. The objective was to examine relationships ...between external knee moments during gait and tibiofemoral cartilage thickness in patients with nontraumatic and posttraumatic knee osteoarthritis. For this cross‐sectional study, participants with knee osteoarthritis were classified into two groups: nontraumatic (n = 22; mean age 60 years) and posttraumatic (n = 19; mean age 56 years, history of anterior cruciate ligament rupture). Gait data were collected with a three‐dimensional motion capture system sampled at 100 Hz and force plates sampled at 2000 Hz. External knee moments were calculated using inverse dynamics. Cartilage thickness was determined with magnetic resonance imaging (T1‐weighted, 3D sagittal gradient‐echo sequence). Linear regression analyses examined relationships between cartilage thickness with knee moments, group, and their interaction. A higher knee adduction moment impulse was negatively associated with medial to lateral cartilage thickness ratio (B = −1.97). This relationship differed between participants in the nontraumatic osteoarthritis group (r = −0.56) and posttraumatic osteoarthritis group (r = −0.30). A higher late stance knee extension moment was associated with greater medial femoral condyle cartilage thickness (B = −0.86) and medial to lateral cartilage thickness (B = −0.73). These relationships also differed between participants in the nontraumatic osteoarthritis group (r = −0.61 and r = −0.51, respectively) and posttraumatic osteoarthritis group (r = 0.10 and r = 0.25, respectively). Clinical Significance: The relationship between knee moments with tibiofemoral cartilage thickness differs between patients with nontraumatic and posttraumatic knee osteoarthritis. The potential influence of mechanical knee loading on articular cartilage may also differ between these subtypes.
ABSTRACT
Purpose
Greater articular cartilage T1ρ magnetic resonance imaging relaxation times indicate less proteoglycan density and are linked to posttraumatic osteoarthritis development after ...anterior cruciate ligament reconstruction (ACLR). Although changes in T1ρ relaxation times are associated with gait biomechanics, it is unclear if excessive or insufficient knee joint loading is linked to greater T1ρ relaxation times 12 months post-ACLR. The purpose of this study was to compare external knee adduction (KAM) and flexion (KFM) moments in individuals after ACLR with high versus low tibiofemoral T1ρ relaxation profiles and uninjured controls.
Methods
Gait biomechanics were collected in 26 uninjured controls (50% females; age, 22 ± 4 yr; body mass index, 23.9 ± 2.8 kg·m
−2
) and 26 individuals after ACLR (50% females; age, 22 ± 4 yr; body mass index, 24.2 ± 3.5 kg·m
−2
) at 6 and 12 months post-ACLR. ACLR-T1ρ
High
(
n
= 9) and ACLR-T1ρ
Low
(
n
= 17) groups were created based on 12-month post-ACLR T1ρ relaxation times using a k-means cluster analysis. Functional analyses of variance were used to compare KAM and KFM.
Results
ACLR-T1ρ
High
exhibited lesser KAM than ACLR-T1ρ
Low
and uninjured controls 6 months post-ACLR. ACLR-T1ρ
Low
exhibited greater KAM than uninjured controls 6 and 12 months post-ACLR. KAM increased in ACLR-T1ρ
High
and decreased in ACLR-T1ρ
Low
between 6 and 12 months, both groups becoming more similar to uninjured controls. There were scant differences in KFM between ACLR-T1ρ
High
and ACLR-T1ρ
Low
6 or 12 months post-ACLR, but both groups demonstrated lesser KFM compared with uninjured controls.
Conclusions
Associations between worse T1ρ profiles and increases in KAM may be driven by the normalization of KAM in individuals who initially exhibit insufficient KAM 6 months post-ACLR.
To examine the nature of differences in the relationship between frontal plane rearfoot kinematics and knee adduction moment (KAM) magnitudes.
Cross-sectional study resulting from a combination of ...overground walking biomechanics data obtained from participants with medial tibiofemoral osteoarthritis at two separate sites. Statistical models were created to examine the relationship between minimum frontal plane rearfoot angle (negative values = eversion) and different measures of the KAM, including examination of confounding, mediation, and effect modification from knee pain, radiographic disease severity, static rearfoot alignment, and frontal plane knee angle.
Bivariable relationships between minimum frontal plane rearfoot angle and the KAM showed consistent negative correlations (r = −0.411 to −0.447), indicating higher KAM magnitudes associated with the rearfoot in a more everted position during stance. However, the nature of this relationship appears to be mainly influenced by frontal plane knee kinematics. Specifically, frontal plane knee angle during gait was found to completely mediate the relationship between minimum frontal plane rearfoot angle and the KAM, and was also an effect modifier in this relationship. No other variable significantly altered the relationship.
While there does appear to be a moderate relationship between frontal plane rearfoot angle and the KAM, any differences in the magnitude of this relationship can likely be explained through an examination of frontal plane knee angle during walking. This finding suggests that interventions derived distal to the knee should account for the effect of frontal plane knee angle to have the desired effect on the KAM.
An increased external knee adduction moment has been identified as a factor contributing to the progression of medial knee osteoarthritis. Interventions that reduce knee adduction moment may help ...prevent knee osteoarthritis onset and progression. While exercise interventions have been commonly used to treat knee osteoarthritis, whether exercises can modulate knee adduction moment in knee osteoarthritis patients remains unknown. This systematic review and meta-analysis aimed to determine if exercise interventions are effective in reducing knee adduction moment during gait.
Study reports published through May 2023 were screened for pre-specified inclusion/exclusion criteria. Nine studies met the eligibility criteria and yielded 24 effect sizes comparing the reduction in knee adduction moment of the exercise intervention groups to the control groups. Moderator/experimental variables concerning characteristics of the exercise interventions and included subjects (e.g., sex, BMI, type of exercise, muscle group targeted, training volume, physical therapist supervision) that may contribute to variation among studies were explored through subgroup analysis and meta-regression.
The effect of exercise intervention on modulating knee adduction moment during gait was no better than control (ES = -0.004, P = 0.946). Sub-group analysis revealed that the effect sizes of studies containing only females (positive exercise effect) were significantly greater than studies containing both males and females.
Exercise may not be effective in reducing knee adduction moment during gait. Clinicians aiming to decrease knee adduction moment in patients with medial knee osteoarthritis should consider alternative treatment options. Exploring the underlying mechanism(s) regarding a more positive response to exercises in females may help design more effective exercise interventions.
•Exercises may not reduce knee adduction moment in knee osteoarthritis patients.•Type, muscles targeted, or volume does not alter exercise effects on knee loading.•Women may benefit more from exercises in reducing knee adduction moment than men.•Exercise benefits for osteoarthritis patients are not from knee loading modulation.
The knee adduction moment (KAM) can inform treatment of medial knee osteoarthritis; however, measuring the KAM requires an expensive gait analysis laboratory. We evaluated the feasibility of ...predicting the peak KAM during natural and modified walking patterns using the positions of anatomical landmarks that could be identified from video analysis.
Using inverse dynamics, we calculated the KAM for 86 individuals (64 with knee osteoarthritis, 22 without) walking naturally and with foot progression angle modifications. We trained a neural network to predict the peak KAM using the 3-dimensional positions of 13 anatomical landmarks measured with motion capture (3D neural network). We also trained models to predict the peak KAM using 2-dimensional subsets of the dataset to simulate 2-dimensional video analysis (frontal and sagittal plane neural networks). Model performance was evaluated on a held-out, 8-person test set that included steps from all trials.
The 3D neural network predicted the peak KAM for all test steps with r2( Murray et al., 2012) 2 = 0.78. This model predicted individuals’ average peak KAM during natural walking with r2( Murray et al., 2012) 2 = 0.86 and classified which 15° foot progression angle modifications reduced the peak KAM with accuracy = 0.85. The frontal plane neural network predicted peak KAM with similar accuracy (r2( Murray et al., 2012) 2 = 0.85) to the 3D neural network, but the sagittal plane neural network did not (r2( Murray et al., 2012) 2 = 0.14).
Using the positions of anatomical landmarks from motion capture, a neural network accurately predicted the peak KAM during natural and modified walking. This study demonstrates the feasibility of measuring the peak KAM using positions obtainable from 2D video analysis.
Highlights • Tibiofemoral contact forces increased from walking, to running, to sidestepping. • Tibiofemoral joint was stabilized primarily by muscle forces. • Sidestepping resulted in equal ...medial-to-lateral contact loading. • External measures were poor correlates of the tibiofemoral contact forces. • Relationships between external measures and contact forces were gait-task specific.
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