Increased Knee Adduction Moment Research Articles

Influence of Internal and External Foot Rotation on Peak Knee Adduction Moments and Ankle Moments during Gait in Individuals with Knee Osteoarthritis: A Cross-Sectional Study.

The aim of the study was to verify the effects of foot progression angle (FPA) modification during walking on the internal moments of the ankle and knee joints in individuals with knee osteoarthritis (OA). Biomechanical changes such as increased knee adduction moment (KAM) during walking are known to be involved in the development and severity of knee OA. Although various FPA modifications during gait have been applied to reduce peak KAM, few studies have investigated the effects of applying toe-in or toe-out walking modifications for knee OA on peak KAM and three-dimensional (3D) moments of the ankle joint. Kinetic moment variables were acquired from 35 individuals with medial knee compartment OA. A 3D motion analysis system and two force platforms were used to acquire KAM and 3D moments of both ankle joints during gait. Visual3D was used to obtain final moment data for statistical processing. Repeated-measures analysis of variance with Bonferroni adjustment was used to compare kinetic and kinematic values for each FPA walking condition. There was a significant decrease (p < 0.01) in first peak KAM when walking with an internal rotation foot position compared to normal foot position walking. Also, there was a significant decrease (p < 0.01) in second peak KAM when walking with an external rotation foot position compared to normal foot position walking. Compared to a normal foot position, peak ankle inversion moment of the external rotation foot position walking showed a significant decrease (p < 0.05). There were no interactive effects between FPA condition and limb sides for any KAM values (p > 0.05). The results showed no significant increase in the ankle joint moment value during gait for FPA modification conditions. Thus, the clinical implications of this study suggest that modification of the FPA in patients with OA to reduce KAM does not negatively impact the 3D ankle moments.

Restoration of the native tibial joint line obliquity in total knee arthroplasty with inverse kinematic alignment does not increase knee adduction moments.

Patient-specific alignment in total knee arthroplasty (TKA) has shown promising patient-reported outcome measures; however, the clinical and biomechanical effects of restoring the native knee anatomy remain debated. The purpose of this study was to compare the gait pattern between a mechanically aligned TKA cohort (adjusted mechanical alignment-aMA) and a patient-specific alignment TKA cohort (inverse kinematic alignment-iKA). At two years postoperatively, the aMA and iKA groups, each with 15 patients, were analyzed in a retrospective case-control study. All patients underwent TKA with robotic assistance (Mako, Stryker) through an identical perioperative protocol. The patients' demographics were identical. The control group comprised 15 healthy participants matched for age and gender. Gait analysis was performed with a 3D motion capture system (VICON). Data collection was conducted by a blinded investigator. The primary outcomes were knee flexion during walking, knee adduction moment during walking and spatiotemporal parameters (STPs). The secondary outcomes were the Oxford Knee Score (OKS) and Forgotten Joint Score (FJS). During walking, the maximum knee flexion did not differ between the iKA group (53.0°) and the control group (55.1°), whereas the aMA group showed lower amplitudes of sagittal motion (47.4°). In addition, the native limb alignment in the iKA group was better restored, and although more in varus, the knee adduction moments in the iKA group were not increased (225Nmm/kg) compared to aMA group (276Nmm/kg). No significant differences in STPs were observed between patients receiving iKA and healthy controls. Six of 7 STPs differed significantly between patients receiving aMA and healthy controls. The OKS was significantly better in patients receiving iKA than aMA: 45.4 vs. 40.9; p = 0.05. The FJS was significantly better in patients receiving iKA than aMA: 84.8 vs. 55.5; p = 0.002. At two years postoperatively, the gait pattern showed greater resemblance to that in healthy controls in patients receiving iKA rather than aMA. The restoration of the native coronal limb alignment does not lead to increased knee adduction moments due to the restoration of the native tibial joint line obliquity. Level III.

MOVEMENT STARTEGIES ADOPTED BY INDIVIDUALS WITH MEDIAL KNEE OA IN RESPONSE TO PRESSURE-BASED AUDITORY FEEDBACK GAIT RERAINING

Purpose: Structural progression of medial knee osteoarthritis (OA) is associated with an increased knee adduction moment (KAM), a surrogate measure of the compartmental knee loads. The KAM is thus a target for mechanical intervention. Based on real-time pressure data and individualized training thresholds, the use of plantar pressure-based auditory feedback to shift weight medially was found to reduce the KAM in individuals with medial knee OA. However, its potential mechanisms remain unclear. Thus, this study aimed to elucidate movement strategies adopted by individuals with medial knee OA in response to pressure-based feedback gait retraining and compare movement strategies of substantial and partial responders of the intervention.

NOVEL ‘APP’ AND WEARABLE INSOLE BASED REMOTE GAIT RETRAINING SHOW POTENTIAL TO ALTER GAIT MECHANICS TWO YEARS AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Purpose: Anterior cruciate ligament (ACL) injury substantially increases the risk for developing post-traumatic osteoarthritis (PTOA). While ACL reconstruction (ACLR) surgery is successful at stabilizing the knee, abnormal gait mechanics may develop and persist, establishing altered loading conditions that contribute to the development of OA. Increased knee adduction moment (KAM) in individuals 2 years following ACLR has been associated with increased cartilage matrix degeneration and reduced patient reported outcomes (PRO).

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.

IMMEDIATE EFFECTS OF SEMI-CUSTOM INSOLES AND STRUCTURED KNEE SLEEVES ON LOWER EXTREMITY KINETICS AND KINEMATICS IN RECREATIONAL MALE ATHLETES WITH PATELLOFEMORAL PAIN

The aim of this experiment was to provide insight into the immediate influence of both semi-custom insoles and knee sleeves in recreational male runners/athletes suffering from patellofemoral pain and also to explore the association between the extent of patellofemoral pain and psychological wellbeing. Experiment 1 examined 17 male recreational runners with patellofemoral pain, in semi-custom insole and no-insole conditions. Experiment 2 examined 13 male recreational athletes with patellofemoral pain, undertaking run, [Formula: see text] cut and single-leg hop movements in knee sleeve and no-sleeve conditions. In both experiments, motion capture and ground reaction forces were collected, allowing kinetics and three-dimensional kinematics to be calculated alongside patellofemoral joint loading quantified using musculoskeletal modeling. In both experiments, patellofemoral pain symptoms were examined using the KOOS patellofemoral pain subscale and psychological wellbeing using the COOP-WONCA questionnaire. The findings from both experiments showed that pain symptoms significantly predicted psychological wellbeing ([Formula: see text] in experiment 1 and [Formula: see text] in experiment 2). Experiment 1 showed that orthoses significantly reduced tibial internal rotation range of motion (no-[Formula: see text] and [Formula: see text]) whilst also increasing the peak knee adduction moment (no-[Formula: see text][Formula: see text]N[Formula: see text]m/kg and [Formula: see text][Formula: see text]N[Formula: see text]m/kg). The findings from experiment 2 revealed that the knee sleeve reduced the peak patellofemoral force (no-[Formula: see text][Formula: see text]BW and [Formula: see text][Formula: see text]BW) in the run movement and the patellofemoral load rate in the cut movement (no-[Formula: see text][Formula: see text]BW/s and [Formula: see text][Formula: see text]BW/s). Overall, the findings confirm that pain symptoms are predictive of psychological wellbeing in recreational male athletes with patellofemoral pain. Furthermore, the findings suggest that both insoles and knee sleeves may provide immediate biomechanical benefits in recreationally active individuals with patellofemoral pain, although when wearing insoles this may be at the expense of an increased knee adduction moment during running.

Compensatory gait deviations in patients with increased outward tibial torsion pre and post tibial derotation osteotomy

BackgroundTibial torsion describes the rotation between the proximal and distal joint axis along the shaft, which can be, as rotational deformity, pathologically increased or decreased. Some patients might increase hip internal rotation during walking to compensate increased outward tibial torsion. Research questionThe aim of this study was to assess the effect of tibial derotation osteotomy on gait deviations in patients with increased outward tibial torsion. MethodsThirteen patients (13.5 ± 1.4 yrs, 22 limbs) with increased tibial torsion (CT confirmed 49.2 ± 4.8°) were analyzed pre and post tibial derotation osteotomy and compared with 17 typically developing children (TDC, 13.5 ± 2.3 yrs, 32 limbs). Kinematic and kinetic data were recorded. Subgroup analyses were performed whether patients showed compensatory hip internal rotation (Comp) or not (NoComp). Principal component (PC) analysis was used to achieve data transformation. A linear mixed model was used to estimate the main effect of PC-scores of retained PCs explaining 90% of the cumulative variance. ResultsCompensatory hip internal rotation (Comp, present in 45.5% of limbs analyzed) led to a lower external foot progression angle compared to patients without compensatory hip internal rotation (NoComp). In both patient groups foot progression angle was normalized after tibial derotation osteotomy. Post-operative NoComp had normalized frontal plane joint loadings, while Comp showed an increased hip and knee adduction moment. SignificanceFuture studies should investigate if more time is needed for Comp to normalize gait patterns post-operative or if a pre and post-operative gait training might help. Otherwise the increased knee adduction moment might be clinically relevant due to previous studies reporting a possible association with knee osteoarthritis.

Cycling with Low Saddle Height is Related to Increased Knee Adduction Moments in Healthy Recreational Cyclists

Bicycle saddle height configurations have been shown to affect knee joint biomechanics. Research suggests that an excessively low saddle height may lead to Patellofemoral Pain Syndrome, which is thought to be caused by the knee adduction moment during cycling. However, how saddle heights affect frontal plane knee biomechanics was not clear. We aimed to compare different saddle heights on frontal plane knee biomechanics during cycling. Twenty healthy young recreational cyclists (23.4 ± 0.5 years) performed 3 min of cycling at four different saddle heights (Medium [25° knee flexion angle], Preferred [a height chosen by cyclists], Low [Preferred + 15°], High [Preferred - 15°] measured at the bottom-dead-center). Cycling workload and cadence were set at 60 w and 60 RPM, respectively, since our project was focused on rehabilitation. A motion analysis system and a custom instrumented pedal were used to collect three-dimensional kinematics d (200 Hz) and pedal reaction force (1000 Hz). Results showed that, compared with other saddle heights, Low saddle height produced greater adduction knee moments (11.9 ± 1.9 Nm, P < 0.05), a longer duration (0.15 ± 0.01 s, P < 0.05), larger knee flexion (58.5 ± 2.6°, P < 0.05) and larger abduction angles (−4.5 ± 0.8°, P < 0.05). We showed that Low saddle height resulted in increased knee adduction moments with longer duration. In contrast, High saddle height reduced both knee moments and time duration. The results suggest that increased saddle heights may provide a safe and efficient cycling strategy for healthy young recreational cyclists.

The Effects of Yoga and Medial Thrust Gait Training and Conventional Physiotherapy on Gait Biomechanics, Pain, and Function in Individuals with Knee Osteoarthritis: A Randomized Clinical Trial Protocol

Background: Literatures indicate a strong association between biomechanical factors, i.e., increased knee adduction moment (KAM) and knee osteoarthritis. Laboratory studies showed that yoga exercises and medial thrust (MT) gait pattern could reduce the KAM. However, there is a lack of clinical evidence to support their efficacy compared to current exercise therapy regimens. Objectives: This randomized control trial will compare the effects of combined yoga and the MT gait training and conventional knee exercises on gait biomechanics, pain, and function in people with knee OA. Methods: Forty patients with knee OA will be randomly allocated to two treatment groups: (1) the yoga and MT gait group (YogaMT), and (2) the conventional physiotherapy group. Exercise therapy for the YogaMT group includes the MT gait training, and the yoga exercises, and for the conventional physiotherapy group, conventional knee strengthening exercises. The amount of KAM during gait, pain severity, and the functional score will be assessed at baseline, two days and one month after 12 sessions of treatment. Conclusions: Physiotherapists should explore etiology-based interventions targeting the contributing factors to the development and progression of OA. The results of this RCT may help suggest a more effective treatment for patients with knee OA.

Comparing Anterior Cruciate Ligament Injury Risk Variables Between Unanticipated Cutting and Decelerating Tasks

To examine the relationship between anterior cruciate ligament injury risk factors in unanticipated cutting and decelerating. Three-dimensional kinematics and ground reaction forces were collected on 11 females (22 [2]y, 1.67 [0.08]m, and 68.5 [9.8]kg) during 2 unanticipated tasks. Paired samples t tests were performed to compare dependent variables between tasks. Spearman rank correlation coefficients were calculated to analyze the relationship between peak internal knee adduction moment and peak anterior tibial shear force (ASF) during 2 unanticipated tasks. Significantly greater knee abduction angles, peak knee adduction moments, and peak ASFs were observed during cutting (P ≤ .05). A strong positive correlation existed between decelerating ASF and cutting ASF (ρ = .67), while correlations between decelerating knee adduction moment and cutting knee adduction moment and decelerating ASF and cutting knee adduction moment were not significant. In situations where time management is a necessity and only one task can be evaluated, it may be more appropriate to utilize an unanticipated cutting task rather than an unanticipated deceleration task because of the increased knee adduction moment and ASF. These data can help future clinicians in better designing more effective anterior cruciate ligament injury risk screening methods.

Bracing of the Reconstructed and Osteoarthritic Knee during High Dynamic Load Tasks.

Lateral compartment osteoarthritis accompanied by abnormal knee biomechanics is frequently reported in individuals with knee osteoarthritis after anterior cruciate ligament reconstruction (ACLR). The aim of this study was to evaluate changes in knee biomechanics produced by an adjusted and unadjusted varus knee brace during high dynamic loading activities in individuals with lateral knee osteoarthritis after ACLR and valgus malalignment. Nineteen participants who had undergone ACLR 5 to 20 yr previously and had symptomatic and radiographic lateral knee osteoarthritis with valgus malalignment were assessed. Quantitative motion analysis experiments were conducted during hopping, stair ascent, and descent under three test conditions: (i) no brace, (ii) unadjusted brace with sagittal plane support and neutral frontal plane alignment, and (iii) adjusted brace with sagittal plane support and varus realignment (valgus to neutral). Sagittal, frontal, and transverse plane knee kinematics, external joint moment, and angular impulse data were calculated. Relative to an unbraced knee, braced conditions significantly increased knee flexion and adduction angles during hopping (P = 0.003 and P = 0.005; respectively), stair ascent (P = 0.003 and P < 0.001, respectively), and descent (P = 0.009 and P < 0.001, respectively). In addition, the brace conditions increased knee flexion (P < 0.001) and adduction (P = 0.001) angular impulses and knee stiffness (P < 0.001) during hopping, as well as increased knee adduction moments during stair ascent (P = 0.008) and flexion moments during stair descent (P = 0.006). There were no significant differences between the adjusted and the unadjusted brace conditions (P > 0.05). A knee brace, with or without varus alignment, can modulate knee kinematics and external joint moments during hopping, stairs ascent, and descent in individuals with predominant lateral knee osteoarthritis after ACLR. Longer-term use of a brace may have implications in slowing osteoarthritis progression.

Analysis of the factors that correlate with increased knee adduction moment during gait in the early postoperative period following total knee arthroplasty

BackgroundAnalysis of dynamic knee loading during gait is essential to prevent mechanical failures following total knee arthroplasty. External knee adduction moment during gait is the primary factor producing medial joint reaction force, and an increase in the moment is directly related to an increase in the medial compartment load on the knee. MethodsKnee adduction moment during gait in 39 knees of 32 female patients following a posterior stabilized knee replacement with a single surgeon was evaluated at 1.3months following surgery. A cut-off moment was determined as mean+1 standard deviation (SD) of the moment from 10 healthy subjects, and patients' knees were divided into high- and normal-moment groups. Significant differences in clinical assessments and gait parameters between the two groups were assessed. ResultsBased on the cut-off moment, 23 knees were grouped into normal knees and 16 knees were grouped into high-moment knees. High-moment knees showed identical femorotibial angles and knee society scores but had greater toe-out angles and medially directed ground reaction forces compared to normal-moment knees. High-moment knees showed strong correlations between peak moment and knee adduction angle, and frontal plain moment arm. ConclusionsThe clinical significance of a high knee adduction moment following total knee arthroplasty remains unclear, but dynamic frontal alignment during gait is one of the key factors for residual high-moment knees following surgery.

Knee joint moments during high flexion movements: Timing of peak moments and the effect of safety footwear

Aim(1) Characterize knee joint moments and peak knee flexion moment timing during kneeling transitions, with the intent of identifying high-risk postures. (2) Determine whether safety footwear worn by kneeling workers (construction workers, tile setters, masons, roofers) alters high flexion kneeling mechanics. MethodsFifteen males performed high flexion kneeling transitions. Kinetics and kinematics were analyzed for differences in ascent and descent in the lead and trail legs. ResultsMean±standard deviation peak external knee adduction and flexion moments during transitions ranged from 1.01±0.31 to 2.04±0.66% body weight times height (BW∗Ht) and from 3.33 to 12.6% BW∗Ht respectively. The lead leg experienced significantly higher adduction moments compared to the trail leg during descent, when work boots were worn (interaction, p=0.005). There was a main effect of leg (higher lead vs. trail) on the internal rotation moment in both descent (p=0.0119) and ascent (p=0.0129) phases. ConclusionPeak external knee adduction moments during transitions did not exceed those exhibited during level walking, thus increased knee adduction moment magnitude is likely not a main factor in the development of knee OA in occupational kneelers. Additionally, work boots only significantly increased the adduction moment in the lead leg during descent. In cases where one knee is painful, diseased, or injured, the unaffected knee should be used as the lead leg during asymmetric bilateral kneeling. Peak flexion moments occurred at flexion angles above the maximum flexion angle exhibited during walking (approximately 60°), supporting the theory that the loading of atypical surfaces may aid disease development or progression.

Comparison of the static tibia-hindfoot angle and arch height between the Oxford Foot Model (OFM) and a full weight bearing 3D-imaging (PedCAT)

Tibial torsion describes the rotation between the proximal and distal joint axis along the shaft, which can be, as rotational deformity, pathologically increased or decreased. Some patients might increase hip internal rotation during walking to compensate increased outward tibial torsion.The aim of this study was to assess the effect of tibial derotation osteotomy on gait deviations in patients with increased outward tibial torsion.Thirteen patients (13.5 ± 1.4 yrs, 22 limbs) with increased tibial torsion (CT confirmed 49.2 ± 4.8°) were analyzed pre and post tibial derotation osteotomy and compared with 17 typically developing children (TDC, 13.5 ± 2.3 yrs, 32 limbs). Kinematic and kinetic data were recorded. Subgroup analyses were performed whether patients showed compensatory hip internal rotation (Comp) or not (NoComp). Principal component (PC) analysis was used to achieve data transformation. A linear mixed model was used to estimate the main effect of PC-scores of retained PCs explaining 90% of the cumulative variance.Compensatory hip internal rotation (Comp, present in 45.5% of limbs analyzed) led to a lower external foot progression angle compared to patients without compensatory hip internal rotation (NoComp). In both patient groups foot progression angle was normalized after tibial derotation osteotomy. Post-operative NoComp had normalized frontal plane joint loadings, while Comp showed an increased hip and knee adduction moment.Future studies should investigate if more time is needed for Comp to normalize gait patterns post-operative or if a pre and post-operative gait training might help. Otherwise the increased knee adduction moment might be clinically relevant due to previous studies reporting a possible association with knee osteoarthritis.

Ipsilateral and contralateral foot pronation affect lower limb and trunk biomechanics of individuals with knee osteoarthritis during gait

BackgroundLateral wedges have been suggested for the treatment of individuals with knee osteoarthritis, but it may have undesirable effects on the biomechanics of gait through increased foot pronation. This study investigated the effects of increased unilateral foot pronation on the biomechanics of individuals with knee osteoarthritis during gait. MethodsBiomechanical data of twenty individuals with knee osteoarthritis were collected while they walked in three conditions: i) flat sandals; ii) wedged sandal on the knee osteoarthritis limb and flat sandal on the healthy limb; and iii) flat sandal on the osteoarthritis and wedged sandal on the healthy limb. Knee pain and comfort were evaluated. Principal Component Analysis followed by ANOVA was implemented to identify differences between conditions. FindingsThe wedged sandal on the osteoarthritis limb increased rearfoot eversion (P<0.001; ES=0.79); increased shank rotation range of motion (P<0.001; ES=0.70); reduced knee internal rotation moment (P<0.001; ES=0.83); reduced hip internal rotation moment (P=0.001; ES=0.66); increased ipsilateral trunk lean (P=0.031; ES=0.47); and increased trunk rotation range of motion (P=0.001; ES=0.69). Walking with the wedged sandal on the healthy limb increased hip (P=0.003; ES=0.61) and knee (P=0.002; ES=0.63) adduction moments. Individuals reported greater comfort walking with the flat sandals (P=0.004; ES=0.55). InterpretationIncreased unilateral foot pronation of the knee osteoarthritis and healthy limbs causes lower limb and trunk mechanical changes that may overload the knee and the lower back, such as increased knee adduction moment, shank rotation and trunk lateral lean. Foot motion of both lower limbs should be evaluated and care must be taken when suggesting lateral wedges for individuals with knee osteoarthritis.

Kinetics features changes before and after intra-articular hyaluronic acid injections in patients with knee osteoarthritis

To examine the kinetic features in patients with knee osteoarthritis (OA) after intra-articular hyaluronic acid (IAHA) injections in different time periods. A single group repeated measures study. Gait laboratory in a tertiary hospital. Twenty-five subjects with bilateral symptomatic knee OA and 15 healthy control subjects. Gait analyses were performed in both control and OA groups before (baseline), and after the completion of IAHA injections (1 week, 3 months, and 6 months). Knee pain and functional indices were assessed using a visual analogue scale (VAS) and the Lequesne function Index (LI). Joint kinetic changes were analyzed in the frontal and sagittal planes with 6-camera motion analysis system and two AMTI force plates. VAS and LI scores were both improved in OA group after IAHA injections (p<0.001). In the frontal plane, increased knee adduction moment (p<0.001) after IAHA treatment was observed and would last up to a period of 6 months. In the sagittal plane, lower knee extension moments at early stance, and larger knee flexion moments at terminal stance were demonstrated after the completion of IAHA injections (p<0.05). This study revealed that IAHA injections can provide significant pain relief and improvement in activity of daily living function for patients with knee OA. However, the reduction in pain and the increase in knee adduction moment may last up to 6 months. This may cause excessive loading on the knee joints, which may further accelerate the rate of knee degeneration. As a result, longer study time is needed to determine whether the observed kinetic findings in this study are associated with detrimental outcomes on the knee joints.

Mechanisms underpinning longitudinal increases in the knee adduction moment following arthroscopic partial meniscectomy

BackgroundKnee osteoarthritis is common following arthroscopic partial meniscectomy and a higher external peak knee adduction moment is believed to be a contributor. The peak knee adduction moment has been shown to increase over 2years (from 3-months post-arthroscopic partial meniscectomy). The aim of this study was to evaluate mechanisms underpinning the increase in peak knee adduction moment over 2years observed in people 3-months following arthroscopic partial meniscectomy. MethodsSixty-six participants with medial arthroscopic partial meniscectomy were assessed at baseline and again 2years later. Parameters were evaluated at time of peak knee adduction moment as participants walked barefoot at their self-selected normal and fast pace for both time points. FindingsFor normal pace walking, an increase in frontal plane ground reaction force-to-knee lever arm accounted for 30% of the increase in peak knee adduction moment (B=0.806 [95% CI 0.501–1.110], P<0.001). For fast pace walking, an increase in the frontal plane ground reaction force magnitude accounted for 21% of the increase in peak knee adduction moment (B=2.343 [95% CI 1.219–3.468], P<0.001); with an increase in tibia varus angle accounting for a further 15% (B=0.310 [95% CI 0.145–0.474], P<0.001). InterpretationOur data suggest that an increase in lever arm and increase in frontal plane ground reaction force magnitude are contributors to the increased knee adduction moment observed over time in people following arthroscopic partial meniscectomy.

Gait neuromechanics in women with and without joint hypermobility

s / Gait & Posture 39S (2014) S1–S141 S7 legs, dependent on affected side, and three trials of participants were considered. Linear MixedModels were used to determine the main effects within retained principal components (PCs). Results: PatientsmeanAntetorsionwas38.6◦(SD6.1◦), basedon CT-scans. There were no significant group differences in sex, age, BMI and walking speed, but patients showed significant less hip external rotation in clinical examination. Group effects based on LinearMixedModels revealed that patientswalkedwith significant more internal foot progression angle (FPA) andmore external ankle rotation (ARA) than controls. There were no alterations observed in knee kinematics. Patients walked with significant more anterior pelvic tilt (SPA) and at hip joint level with more internally rotated (THA) and flexed (SHA) hips. Group effects in kinetics revealed that patients showed a significant lower knee adductionmoment (FKM) andhip adductionmoment (FHM).Differentiation into primary and secondary passive effects was derived from clinical considerations. Discussion and conclusions: Deviations in FPA and THA were stated as primary deviations. Due to the reduced hip external rotation patientswere not able to counterbalance for primary deviations. Passive secondary effects were detected in ARA, SHA, SPA, FKM and FHM. In order to achieve normal gait, patients walked with external ankle rotation, flexed hips and more anterior pelvic tilt. During gait internal hip rotation induced anterior pelvic tilt andmore hip flexion by straining iliofemoral ligaments. Moreover, anterior pelvic tilt may have wide-ranging consequences as it may induce increased lordosis of the lumbar spine and extension of the thoracic spine. Although in the current study FKM mean gait waveform indicated a tendency for an increased knee adduction moment in patients, the application of Linear Mixed Models on PC-scores of retained PCs showed a significant group effect in PC3 (explaining 16.74% of total variance), representing a lower knee adduction moment in patients. In hip the only significant group effect corresponded to a lower hip adduction moment in patients (PC2, explaining 15.32% of total variance), whereas mean gait waveform indicated a higher hip adduction moment. In summary coxa antetorta is not mainly a cosmetic problem in general. Modifications in kinematics and kinetics may cause physical complaints and osteoarthritis in future. Therefore, conducting 3DGA is recommended for individual clinical decision-making and planning surgical corrections in patients with coxa antetorta.

Gait deviations and compensations in adolescents with coxa antetorta

s / Gait & Posture 39S (2014) S1–S141 S7 legs, dependent on affected side, and three trials of participants were considered. Linear MixedModels were used to determine the main effects within retained principal components (PCs). Results: PatientsmeanAntetorsionwas38.6◦(SD6.1◦), basedon CT-scans. There were no significant group differences in sex, age, BMI and walking speed, but patients showed significant less hip external rotation in clinical examination. Group effects based on LinearMixedModels revealed that patientswalkedwith significant more internal foot progression angle (FPA) andmore external ankle rotation (ARA) than controls. There were no alterations observed in knee kinematics. Patients walked with significant more anterior pelvic tilt (SPA) and at hip joint level with more internally rotated (THA) and flexed (SHA) hips. Group effects in kinetics revealed that patients showed a significant lower knee adductionmoment (FKM) andhip adductionmoment (FHM).Differentiation into primary and secondary passive effects was derived from clinical considerations. Discussion and conclusions: Deviations in FPA and THA were stated as primary deviations. Due to the reduced hip external rotation patientswere not able to counterbalance for primary deviations. Passive secondary effects were detected in ARA, SHA, SPA, FKM and FHM. In order to achieve normal gait, patients walked with external ankle rotation, flexed hips and more anterior pelvic tilt. During gait internal hip rotation induced anterior pelvic tilt andmore hip flexion by straining iliofemoral ligaments. Moreover, anterior pelvic tilt may have wide-ranging consequences as it may induce increased lordosis of the lumbar spine and extension of the thoracic spine. Although in the current study FKM mean gait waveform indicated a tendency for an increased knee adduction moment in patients, the application of Linear Mixed Models on PC-scores of retained PCs showed a significant group effect in PC3 (explaining 16.74% of total variance), representing a lower knee adduction moment in patients. In hip the only significant group effect corresponded to a lower hip adduction moment in patients (PC2, explaining 15.32% of total variance), whereas mean gait waveform indicated a higher hip adduction moment. In summary coxa antetorta is not mainly a cosmetic problem in general. Modifications in kinematics and kinetics may cause physical complaints and osteoarthritis in future. Therefore, conducting 3DGA is recommended for individual clinical decision-making and planning surgical corrections in patients with coxa antetorta.

Balance and gait adaptations in patients with early knee osteoarthritis

Gait adaptations in people with severe knee osteoarthritis (OA) have been well documented, with increased knee adduction moments (KAM) the most commonly reported parameter. Neuromuscular adaptations have also been reported, including reduced postural control. However these adaptations may be the result of morphological changes in the joint, rather than the cause. This study aimed to determine if people with early OA have altered gait parameters and neuromuscular adaptations. Gait and postural tasks were performed by 18 people with early medial knee OA and 18 age and gender-matched control subjects. Parameters measured were kinematics and kinetics during gait and postural tasks, and centre of pressure and electromyographic activity during postural tasks. OA subjects showed no differences in the gait parameters measured, however they demonstrated postural deficits during one-leg standing on both their affected and unaffected sides and altered hip adduction moments compared with controls. Increased activity of the gluteus medius of both sides (p<0.05), and quadriceps and hamstrings of the affected side (p<0.05) during one-leg standing compared with controls were also noted. This study has demonstrated that gait adaptations commonly associated with OA do not occur in the early stages, while neuromuscular adaptations are evident. These results may be relevant for early interventions to delay or prevent osteoarthritis in its early stages.