Peak External Knee Adduction Moment Research Articles

Higher knee flexion moment during walking is associated with a lower risk of knee pain developing among the elderly after 24 months.

Knee pain is one of the main problems associated with knee osteoarthritis. The peak external knee adduction moment (KAM) in gait is commonly used to estimate medial knee loading, and elevated KAM has been related to a higher risk of developing knee pain in older adults. Although knee flexion moment (KFM) also contributes to medial knee loading, its role in the development of knee pain remains unclear. To investigate the association between knee moments and the incidence of knee pain in 24 months in asymptomatic older adults. Prospective cohort study. University laboratory. Community-dwelling adults aged 60-80 years were recruited. We excluded participants with knee pain/known arthritis, knee injury, knee/hip joint replacement, cognitive impairment, or neurological conditions. Three-dimensional gait analysis was conducted to compute the peak KFM and KAM. Telephone surveys were conducted 12 and 24 months after the baseline assessment. Self-reported knee pain and its intensity and frequency were captured. Logistic regression with generalized estimating equations was used to examine associations between knee moments and the risk of knee pain. Of the 162 eligible participants who completed the baseline assessment (age: 65.8±4.0 years, 61.1% females), 157 and 138 were also assessed for incident knee pain after 12 and 24 months, respectively. Compared with the lowest tertile, the highest tertile of KFM was significantly related to a lower incidence of frequent knee pain (RR=0.25, 95% CI: 0.08-0.85, P=0.027) in 24 months. In addition, a higher KFM was significantly associated with the lower intensity of incident knee pain after 24 months (β=-1.513; 95% CI: -2.879, -0.147; P=0.030). We also observed trends showing that a higher peak KAM was related to higher risks of developing any (RR=2.48, 95% CI: 0.99-6.20, P=0.053) and frequent (RR=3.82, 95% CI: 0.96-15.1, P=0.057) knee pain in 24 months. A higher sagittal knee moment is associated with a lower risk of knee pain developing in 24 months in older adults. Interventions for promoting sagittal knee moment may be considered in preventative training programs for reducing knee pain among older adults.

The effect of foot position during static calibration trials on knee kinematic and kinetics during walking

BackgroundGait analysis has been used extensively for computing knee kinematics and kinetics, in particular, in healthy and impaired individuals. One variable assessed is the external knee adduction moment (EKAM). Variations in EKAM values between investigations may be caused by changes in static standing position, especially foot placement angles which may increase or reduce any differences seen. Purpose of the studyThe current study aimed to explore the influence of static trial foot position on knee kinematic and kinetic variables during walking. MethodsTwelve healthy male participants completed three different static standing trials; 1) 20-degrees toe-in, 2) 0° and 3) 20-degrees toe-out before walking at their own pace during a lower limb kinematics and kinetics assessment. First and second peak EKAM was compared between static foot position trials, as well other knee kinematic and kinetic outcomes. Repeated measures ANOVA was used with post hoc pairwise comparison to determine the differences between static foot position trials. ResultsThe first peak of EKAM was significantly smaller in the 20o toe-out angle, than the 20o toe-in angle (p = 0.04–8.16% reduction). Furthermore, significant changes were found in peak knee kinematics and kinetics variables (adduction angle, external rotation angle, knee flexion moment external rotation moment, abduction angle and internal rotation angle) in the different positions. ConclusionModification in static foot position between study visits may result in changes especially in the 1st peak EKAM and other kinematics and kinetics variables during walking. Therefore, standardisation of static foot position should be utilised in longitudinal studies to ensure changes in EKAM are not masked or accentuated between assessments.

Gait Improvement in Patients with Knee Osteoarthritis after Proximal Fibular Osteotomy.

Proximal fibula osteotomy (PFO) is a relatively new surgery to treat medial compartment knee osteoarthritis (KOA), which can improve varum deformity and relieve knee joint pain. However, the gait alterations in KOA patients after PFO are still poorly understood. The purpose of this study was to evaluate the gait patterns change in patients of medial compartment KOA after PFO. Gait data were collected for 9 females with unilateral medial compartment KOA before and at 6 months after PFO and also for 9 healthy age-matched females. Paired t-test was used to determine the effect of PFO within the KOA group, and independent t-test were performed to compare between KOA and control groups for spatiotemporal, kinematic, and kinetic variables. The results showed that patients with KOA had significantly increased knee peak flexion angle, knee sagittal range of motion, and peak external hip adduction moment but decreased knee frontal range of motion in the affected limb after PFO. The gait symmetry was improved postoperatively confirmed by single support and swing phases, knee peak flexion angle and sagittal range of motion, peak external hip and knee adduction moments, and peak anterior and peak posterior ground reaction forces. These findings provided evidence of a biomechanical benefit and gait improvement following PFO to treat medial compartment KOA.

Influence of using knee sleeve and lateral wedge insole on knee loading among healthy individuals during stair negotiation

BackgroundFor individuals with knee osteoarthritis (OA), stair negotiation is a challenging task and the first task during which they report pain due to the high knee loading required. The use of lateral wedge insole (LWI) has been found to reduce loading in patients with OA but not to reduce pain, whereas the use of knee sleeve has been shown to result in good pain reduction. Understanding the effect of combining LWI and knee sleeve use on healthy individuals before testing on individuals with knee OA is an important step. Research questionThe current study aimed to evaluate the effect of combining the use of LWI and knee sleeve and compare the results with the application of each treatment separately and with the control condition. MethodsThis randomised cross-over study included 17 healthy participants who underwent 3D gait analysis. Participants performed ascending and descending stair activities with the following four treatment conditions: five-degree LWI, off-the-shelf knee sleeve, both LWI and knee sleeve and control condition. External knee adduction moment (EKAM) and knee frontal plane range of motion (ROM) were evaluated as primary outcomes. Repeated measure ANOVA or the Friedman test was selected based on meeting the assumption followed by multiple pairwise comparisons with Bonferroni correction. ResultsIn general, the use of LWI reduced the first peak EKAM significantly (p < 0.001) compared to the control condition in stir ascending (12% reduction) but not in stair descending (p > 0.05). Interestingly, knee sleeve use did not result in any reduction in the first peak EKAM compared to the control or any other condition. However, knee sleeve use led to a significant reduction in the knee frontal plane ROM during stair descending. The combined treatment was not superior to the LWI use when compared to control in the EKAM reduction. SignificanceCombined knee sleeve and LWI use was not superior to LWI use alone in reducing the knee loading, but it may be beneficial for individuals with knee OA since it helped in reduction of the knee frontal plane ROM during stair descending. Importantly, the effect of LWI use or any other treatment must be investigated for each different activity, and the results found in one activity must not be generalised across other activities.

Running kinetics and femoral trochlea cartilage characteristics in recreational and collegiate distance runners

ABSTRACT Recreational running can benefit knee cartilage, but the relationship between competitive running and knee cartilage is unclear. We compared femoral cartilage between collegiate runners, recreational runners, and controls; and evaluated the association between running amount, running kinetics and femoral cartilage characteristics. Thirty collegiate runners, 30 recreational runners, and 30 controls completed ultrasound imaging of the femoral cartilage and running gait analysis. Outcomes included cartilage thickness, and echo-intensity from the medial and lateral femoral condyles; and the peak external knee flexion (KFM) and knee adduction moments. Cartilage outcomes were compared via one-way MANOVA. The associations between running kinetics, running amount, and femoral cartilage characteristics were assessed via linear regression models adjusted for sex. No differences were found in cartilage outcomes between groups (p = 0.067). Among recreational runners, a larger peak KFM was associated with lower medial femoral cartilage echo-intensity (ΔR2 = 0.176, Δp = 0.014). In collegiate runners, a greater self-reported running amount was associated with higher medial femoral cartilage (ΔR2 = 0.117, Δp = 0.046) and lateral cartilage (ΔR2 = 0.121, Δp = 0.042) echo-intensity. Cartilage did not differ between groups, but the association between running kinetics, running amount, and knee cartilage may vary between collegiate and recreational runners.

Quantifying varus thrust in knee osteoarthritis using wearable inertial sensors: A proof of concept

BackgroundVarus thrust during walking, visualized as excessive frontal plane knee motion during weight acceptance, is a modifiable risk factor for progression of knee osteoarthritis. However, visual assessment does not capture thrust severity and quantification with optical motion capture is often not feasible. Inertial sensors may provide a convenient alternative to optical motion capture. This proof-of-concept study sought to compare wearable inertial sensors to optical motion capture for the quantification of varus thrust. MethodsTwenty-six participants with medial knee osteoarthritis underwent gait analysis at self-selected and fast speeds. Linear regression with generalized estimating equations assessed associations between peak knee adduction velocity or knee adduction excursion from optical motion capture and peak thigh or shank adduction velocity from two inertial sensors on the lower limb. Relationships between inertial measures and peak external knee adduction moment were assessed as a secondary aim. FindingsBoth thigh and shank inertial sensor measures were associated with the optical motion capture measures for both speeds (P < 0.001 to P = 0.020), with the thigh measures having less variability than the shank. After accounting for age, sex, body mass index, radiographic severity, and limb alignment, thigh adduction velocity was also associated with knee adduction moment at both speeds (both P < 0.001). InterpretationAn inertial sensor placed on the mid-thigh can quantify varus thrust in people with medial knee osteoarthritis without the need for optical motion capture. This single sensor may be useful for risk screening or evaluating the effects of interventions in large samples.

Comparing walking biomechanics of older females in maximal, minimal, and traditional shoes

BackgroundKnee osteoarthritis (OA) is a degenerative joint disease that affects millions of individuals each year. Several biomechanical variables during walking have been identified as risk factors for developing knee OA, including the peak external knee adduction moment (KAM) and the knee flexion angle at initial contact. Many interventions have been studied to help mitigate these risk factors, including footwear. However, it is largely unknown how varying shoe cushioning may affect walking biomechanics related to knee OA risk. Research QuestionWhat is the effect of maximally and minimally cushioned shoes on walking biomechanics compared to a traditionally cushioned shoe in older females? MethodsWalking biomechanics in three shoes (maximal, traditional, minimal) were collected on 16 healthy females ages 50–70 using an 8-camera 3D motion capture system and two embedded force plates. Key biomechanical variables related to knee OA disease risk were compared between shoes using repeated measures ANOVAs. ResultsThe KAM was significantly larger in the maximal shoe (p = 0.005), while the knee flexion angle at initial contact was significantly larger in both the maximal and minimal shoe compared to the traditional shoe (p = .000). Additionally, the peak knee flexion angle (p = .000) and the loading rates of the vertical ground reaction force were (instantaneous: p = 0.001; average: p = .010) were significantly higher in the minimal shoe. SignificanceWhile these results are specific to the shoes used in this study, clinicians should exercise caution in prescribing maximal or minimal shoes to females in this age group who may be at risk of knee OA given these results. Research is needed on the effect of these shoes in patients with knee OA.

Hallux Valgus And Walking Speed Influence Frontal Plane Net Joint Moments In Older Adults

Hallux valgus (HV) is often comorbid with knee osteoarthritis (OA) in older adults. Both these conditions are known to adversely affect walking mechanics, but the biomechanical link between these conditions has not been established. Peak external knee adduction moment is a surrogate measure of knee OA severity and progression. However, this variable is sensitive to changes in walking speed. PURPOSE: To examine the effects of HV on peak external knee adduction moment while walking at controlled slow and fast speeds. METHODS: Nineteen older adults (65-80 years) with moderate-to-severe HV and 19 healthy older controls completed five walking trials at controlled slow (1.0 m·s-1) and fast (1.3 m·s-1) speeds. Three-dimensional lower extremity marker position and ground reaction force data were collected at 100 and 1000 Hz, respectively. External knee adduction moment was calculated using an inverse dynamics approach. Peak moments were identified for the more affected leg for the HV group and dominant leg for the control group for each trial. Two-way mixed model ANOVAs were used to examine the effects of group (HV vs. control) and speed (1.0 vs. 1.3 m·s-1) on peak external knee adduction moment. RESULTS: For peak knee adduction moment a group x speed interaction (p=0.035) was observed. With increase in walking speed external knee adduction moment increased (p<0.001), however, the HV group had twice as much of an increase in net peak knee adduction moment (16.6% greater; 0.53 ± 0.21 vs. 0.62 ± 0.25 Nm/kg) as compared to the control group (8.6% greater; 0.51 ± 0.13 vs. 0.56 ± 0.13 Nm/kg). CONCLUSIONS: Older adults with HV show altered knee joint mechanics at faster walking speeds. Knee adduction moment data suggest that older adults with HV may be at a greater risk for developing knee osteoarthritis.

Long-term use of minimal footwear in older adult women with knee osteoarthritis: Mechanisms of action in the knee adduction moment

Studies have shown the short- and long-term effects of wearing minimalist footwear in reducing knee loads in patients with knee osteoarthritis (OA). This study aimed to investigate the mechanisms underpinning the reduction in external knee adduction moment (EKAM) in older adult women who wore this type of footwear through a randomized controlled trial. Fifty-six participants with medial compartment knee OA were equally allocated to either an intervention group (IG) that wore minimalist footwear (Moleca®) or to a control group (CG) that continued regular clinical treatment for OA for six months. The influence of lower limb joint kinematics and joint frontal moments, center of pressure displacement, and foot progression angle in predicting the reduction of EKAM were assessed after a six-month intervention. Surprisingly, none of the seven independent variables predicted the first peak EKAM in the multiple regression model for the IG. For the CG, the increase of one unit in the first peak of the hip adduction moment resulted in a 1.01 units increase in the first peak EKAM. Additionally, a one-unit reduction in the ankle eversion angle resulted in an increase of 0.16 units in the percent change in the first peak EKAM. Thus, wearing the Moleca® shoe for six months helped the participants keep a natural gait pattern without increasing the hip moment or the ankle inversion angle compared to the women who did not wear the Moleca® footwear.ClinicalTrials.gov (NCT01342458)

Body mass index moderates the association between gait kinetics, body composition, and femoral knee cartilage characteristics.

This study compared femoral cartilage characteristics between age- and sex-matched individuals with (n = 48, age = 22.8 ± 3.5 years; body mass index [BMI] = 33.1 ± 4.1 kg/m2 ) and without obesity (n = 48 age = 22.0 ± 2.6 years; BMI = 21.7 ± 1.7 kg/m2 ) and evaluated the associations between body composition, quadriceps function, and gait kinetics with femoral cartilage characteristics. Medial and lateral femoral cartilage thickness, medial:lateral thickness ratio and medial and lateral cartilage echo intensity were measured using ultrasound imaging. Body composition was assessed using air displacement plethysmography. Quadriceps function was assessed via maximal isometric knee extension. Three-dimensional gait biomechanics were recorded to extract peak external knee flexion and adduction moments, and peak loading rate of the vertical ground reaction force. Cartilage outcomes were compared between groups using one-way multivariate analysis of variance. Stepwise moderated regression evaluated the association between body composition, quadriceps function, and gait kinetics with femoral cartilage outcomes in individuals with and without obesity. Medial (75.24 vs 65.84; P < .001, d = 1.02) and lateral (58.81 vs 52.22; P < .001, d = 0.78) femoral cartilage echo intensity were higher in individuals with compared with those without obesity. A higher body fat percentage was associated with higher medial and lateral cartilage echo intensity (ΔR2 = 0.09-0.12) in individuals with obesity. A higher knee adduction moment was associated with a larger medial:lateral thickness ratio (ΔR2 = 0.09) in individuals without obesity. No associations were found between quadriceps function and cartilage outcomes. These findings suggest that high body fat in adults with obesity is associated with cartilage echo intensity. The obese body mass index was also associated with a lack of a positive relationship between cartilage thickness and joint loading during walking.

Assessing in vivo articular cartilage mechanosensitivity as outcome of high tibial osteotomy in patients with medial compartment osteoarthritis: Experimental protocol

To propose an experimental protocol for using high tibial osteotomy (HTO) as a model for studying in vivo biological effects of large permanent changes in ambulatory load. This study is a prospective multimodal (clinical, biomechanical, biological) data collection without randomization. The study will examine a cohort of 40 patients with medial compartment knee OA undergoing opening wedge HTO. Before planned HTO, patients will be clinically assessed (including mechanical axis measurement from radiographs) and complete questionnaires on physical function. Patients will complete a walking stress test with blood sampling (30min walking, 5.5h sitting), and undergo gait analysis. Six weeks after HTO (at the time of full weight bearing), the mechanical axis will be measured from radiographs. Patients will complete the questionnaires and a walking stress test with blood sampling, and undergo gait analysis 6 months after HTO. The peak external knee adduction moment, knee external knee adduction moment impulse and peak external knee flexion moment will be used as surrogates of ambulatory load. Load-induced changes in cartilage biomarkers will be used as surrogates of metabolic changes in response to ambulatory load. At the 12-month follow-up, subjects will complete the questionnaires. The results of this study can be considered as proof-of-concept of a potential diagnostic test (walking stress test) for cartilage degeneration and its prognostic value. A direct relationship between ambulatory load and cartilage metabolism assessed as degradation to synthesis ratio would allow developing novel load-modifying interventions and evaluating the efficacy of existing interventions.

Knee Joint Load Reduction by using Lateral Wedge Insole in Different Body Mass Index Level Females

Background: The higher body mass index is a risk factor that associated with onset and progression of knee osteoarthritis by increasing the knee adduction moment. Lateral wedge insoles are used for reducing the knee adduction moment which may prevent the occurrence of knee osteoarthritis in healthy population.Purpose: The purpose of this study was to assess the effectiveness of the lateral wedge insole among normal, overweight, obese I and obese II female while walking.Methods: A cross-sectional experimental design study was used to investigate 80 females who aged between 18 – 40 years using 3-D Motion Analysis. The peak external knee adduction moment was collected in walking shoes and walking shoes with 5-degree lateral wedge insoles conditions. The significant difference was determined using Paired-T test (p = 0.05).Results: The peak external knee adduction moment was significantly decreased by the effect of shoes with lateral wedge insoles in normal, overweight and obese I (22.12%, 18.34% and 24.15%). However, it did not change in the obese II.Conclusion: The peak external knee adduction moment was decreased by the immediate effect of lateral wedge insoles. It may prevent the onset of knee osteoarthritis in normal, overweight, and obese I. Further study should investigate long term effect of lateral wedge insoles on the knee joint load and the effect of dose in higher body mass index.

Real-Time Three-Dimensional Knee Moment Estimation in Knee Osteoarthritis: Toward Biodynamic Knee Osteoarthritis Evaluation and Training.

We investigated differences in knee kinetic variables (external knee adduction, flexion, internal rotation moments, and impulses) between patients with knee osteoarthritis (KOA) and healthy controls during stepping on a custom elliptical trainer; and searched knee kinetic variable candidates for real-time biofeedback and for complementing diagnosis/evaluation on the elliptical trainer based on the knee kinetic variables' associations with the knee injury and osteoarthritis outcome score (KOOS). Furthermore, we explored potential gait re-training strategies on the elliptical trainer by investigating the knee kinetic variables' associations with 3-D ankle angles. The knee kinetic variables and ankle angles were determined in real-time in a patient group of 10 patients with KOA and an age-and sex-matched control group of 10 healthy subjects. The mean peak external knee adduction moment of the patient group was 47% higher than that of the control group. The KOOS-Sports and Recreational Activities and KOOS-Pain scores were found to be significantly associated with the knee kinetic variables. All the ankle angles were associated with the knee kinetic variables. The findings support the use of the knee kinetic variables on the elliptical trainer to complement KOA diagnosis quantitatively and provide potential real-time KOA gait re-training strategies/guides.

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.

Relations between external moment and movement of the knee joint during the stance phase in patients with severe knee osteoarthritis

BackgroundThe relations between external knee moment and the knee joint movement during stance phase of the patients with knee osteoarthritis is unknown well. This study try to clarify the relations between external knee moment and the knee joint movement during stance phase of the patients with knee osteoarthritis. MethodsSubjects comprised 15 patients who had 23 knees with severe osteoarthritis. The knee joint movements and external knee moments while walking were measured using a motion analysis system and a floor-mounted force plate. We then calculated the change in knee joint angles, first and second peak external knee adductions, and maximum flexion−extension moments during the stance phase. Pearson's product−moment correlation coefficient was used to confirm the relation between the external moments and knee movements. ResultsThe first peak external knee adduction moment was moderately positively correlated with the maximum knee varus angle at the early stance phase and was moderately negatively correlated with the amount of change in the knee valgus direction angle at mid-stance. The peak external knee extension moment at the early stance phase was strongly positively correlated with the knee flexion angle at foot-strike and the maximum knee flexion angle at the early stance phase and was negatively correlated with the external rotation angle at foot-strike. ConclusionAn effective rehabilitation approach to decrease the load of knee joint must combine both to strength the muscles around the knee joint, particularly quadriceps, and to device for controlling the knee movement.

MODIFYING STANCE ALTERS THE PEAK KNEE ADDUCTION MOMENT DURING A GOLF SWING

The knee joint is one of the most frequently injured regions in the game of golf, and the loads experienced by the knee during the golf swing are typically greater than during other activities of daily living. Altering movement patterns is a common strategy that can be used to reduce loading on the knee joint but has received little attention during studies of the golf swing. The primary aim of this study was to examine the effect altering golf stance has on the lead limb peak external knee adduction moment. Laboratory based, quasi-experimental. Twenty healthy participants were recruited for a 3-dimensional biomechanical analysis wherein participants hit three golf shots with a driver using the following stance conditions: self-selected, bilateral 0 º foot angle, bilateral 30 º foot angle, wide stance width, and narrow stance width. Both the 30 º foot angle (0.80 ± 0.51 Nm) and wide stance width (0.89 ± 0.49 Nm) conditions significantly decreased (p < 0.001) the lead limb peak external knee adduction moment compared to the self-selected (1.15 ± 0.58 Nm) golf stance. No significant differences (p = 0.109) in swing speed were found between any of the stance conditions. The externally rotated foot position and wider stance width decreased the lead limb peak external knee adduction moment without hindering swing speed. Modifying stance could be a viable option for golfers who wish to continue playing the sport at a high level, while reducing potentially detrimental loads at the knee joint.Levels of Evidence: 2b-Individual cohort study.

Kinematic and kinetic effect during stair descending in knee osteoarthritis treated with electro-acupuncture

Acupuncture's mechanism keeps unclear especially from biomechanical perspective though its effect on knee osteoarthritis (KOA) has been proved. Seventeen KOA cases in electro-acupuncture (EA) group and 18 cases in minimal acupuncture (MA) have done gait analysis motion analysis during stair climbing before and after EA or MA treatment. (1) Less pain and higher velocity of stairs descending ( P < 0.05) after EA treatment. (2) Second peak knee adduction angle (PKAA2) increased after EA treatment ( P < 0.05). (3) At first peak external knee adduction moment (PEKAM1) event after EA, knee adduction angle, vertical (Z-axis) ground reaction force (GRFZ), knee extensor torque and ankle eversor torque increased; hip external rotation angle decreased ( P < 0.05 or P < 0.01). Same event after MA treatment, hip external rotation angle, lateral (X-axis) ground reaction force (GFRX), hip extensor and ankle internal rotators torque became lower ( P < 0.05 or P < 0.01). (4) At PEKAM2 event after EA treatment, knee adduction angle increased; hip adductor, hip extensor and hip internal rotators torque decreased ( P < 0.05 or P < 0.01). Same event after MA treatment, GRFX was higher; hip flexion angle, ankle internal rotator, hip extensor and hip internal rotator torque was lower ( P < 0.05 or P < 0.01). (5) Hip flexion angle was smaller in EA than in MA at PEKAM2 and PKKAA2 events. Ankle eversor torque was higher in EA group than in MA group at PKKAA1 event ( P < 0.05 or P < 0.01). EA increased velocity of descending stairs, may improve loading capacity in hip, knee and ankle joints, indicating less compensatory strategy of lower limbs with less pain. MA showed different effect.

Differences in Hip and Knee Running Moments across Female Pubertal Development.

This study aimed to investigate whether knee and hip running moments differ across stages of female pubertal development. This was a cross-sectional study comparing the barefoot running moments of 91 prepubertal (n = 31, Tanner stage I), early/midpubertal (n = 30, Tanner stages II and III), and late/postpubertal (n = 30, Tanner stages IV and V) girls. External peak moments for knee abduction (KAbM), knee adduction (KAM), knee flexion (KFM), and knee internal rotation (KIRM) were analyzed. Secondary measures of hip adduction moment at the time of peak KAbM and hip flexion moment at the time of peak KFM were also derived. Between-group differences were analyzed using a series of one-way ANOVAs and ANCOVAs. At the knee, the late/postpubertal girls displayed a higher peak KFM and KAM compared with the prepubertal group (P < 0.05), and the early/midpubertal group exhibited a higher peak KFM than the prepubertal group (P = 0.034). No between-group differences were found for peak KAbM or KIRM (P > 0.05). At the hip, both the late/postpubertal (P = 0.03) and early/midpubertal girls (P = 0.039) ran with a lower hip adduction moment at the time of peak KAbM than the prepubertal girls. The hip flexion moment at the time of peak KFM in late/postpubertal girls was also significantly lower than both the early/mid- and prepubertal girls (P < 0.001). Girls at the latter stages of puberty exhibit higher peak external knee flexion and adduction moments, but not abduction or internal rotation moments. This may be partly attributed to a lower hip flexion but higher hip abduction moment at the time of peak knee moments. Future research should examine whether these differences in knee kinetics between pubertal stages have implications for knee injuries such as patellofemoral pain syndrome.

Differences in the coordination of gait based on body mass index in sedentary young adults

Purpose: Obesity is a known risk factor for knee osteoarthritis (kOA), yet there is a paucity of research investigating movement in obese individuals prior to the development of kOA. Previous studies have found very few differences in gait when comparing normal and obese young adults, yet likely differences in physical activity levels of participants have not been accounted for. Therefore, the purpose of this study was to assess knee health, gait and physical function in normal and obese sedentary young adults. Methods: Eighteen (9 normal weight (N): 21.9 ± 2.9 years, BMI 21.9 ± 1.4, 24.2 ± 4.8% body fat; and 9 obese (Ob): 24.2 ± 3.2, BMI 31.9 ± 1.2, 40.8 ± 4.8% body fat) sedentary, otherwise healthy college-aged individuals were recruited to participate in this study. Participants completed measures of physical function and knee health, including the six-minute walk test and KOOS questionnaire. Additionally, participants completed a biomechanical gait analysis at both a preferred walking velocity and a “fast” walking velocity. For this investigation, key lower extremity variables were selected for group comparison: peak external knee adduction moment (normalized to participants’ fat-free weight and height); sagittal plane knee and ankle range of motion; and sagittal plane movement coordination between the thigh and shank, and the shank and foot. A modified vector coding technique was used to assess sagittal plane movement coordination for the ankle and knee, providing a metric of segmental contribution to overall motion. Coordination was categorized into different patterns (exclusive distal segment, exclusive proximal segment, in-phase, or anti-phase motion) and the percentage of stance spent with each coordination pattern was compared across groups. A 2 × 2 (group × velocity) ANOVA statistically assessed each variable. Results: Groups were similar (P > 0.05) in preferred walking velocity (N: 1.26 m/s, Ob: 1.27 m/s), 6MW (N: 554 m, Ob: 529 m) and KOOS (N: 474.1, Ob: 478.6). There was no interaction between group and velocity, or group differences, for ankle range of motion, knee flexion excursion or peak knee adduction moment (P > 0.05, Table1). All gait variables significantly increased from preferred to fast walking (Table 1). There were no differences in sagittal plane movement coordination of the thigh and shank (P > 0.05). At the fast walking velocity, N spent a greater portion of stance with exclusive shank motion (N: 33.4%, Ob: 20.1%; P = 0.006) and significantly less time with exclusive foot motion (N: 14.8%, Ob: 33.7%; P < 0.001). Conclusions: In line with previous research, we saw an increase in range of motion at the ankle and knee joints and an increase in joint loading from preferred to fast walking velocity. Contrary to previous findings, our groups did not differ in performance on physical function tests, yet both groups were similar to obese participants in the literature. This depressed physical function is likely related to the inclusion criteria to that of sedentary individuals. Despite overall group similarities, we observed differences in the coordination of movement at the ankle, especially during fast walking. Ob walked with a greater reliance on motion of the foot to achieve ankle motion than N. This difference in coordination demonstrates that regardless of similarities in typical measures, the groups are organizing movement differently. Our findings suggest that coordination may be influenced by body mass index, not activity level. In these young healthy adults, overall movement and function do not appear to be influenced by body mass. These findings suggest a sedentary lifestyle may importantly influence research findings on kOA risk. Therefore, it is important to consider physical activity levels of participants for future studies. Furthermore, observed differences in coordination may elucidate group differences that could go unnoticed using traditional measures.Tabled 1Preferred velocityFastNormalObeseNormalObeseAnkle ROM (°)*12.18 ± 2.6211.26 ± 5.029.87 ± 3.479.19 ± 5.24Knee ROM (°)*18.63 ± 3.9219.92 ± 4.1222.30 ± 4.9024.25 ± 3.70Knee adduction moment (Nm/ffw*ht)*0.042 ± 0.0090.042 ± 0.0140.046 ± 0.0090.049 ± 0.015*There was not a significant interaction of goup and velocity, nor a significant group effect for any variable (p > 0.05). There was a significant velocity effect for each variable (p < 0.05). Open table in a new tab *There was not a significant interaction of goup and velocity, nor a significant group effect for any variable (p > 0.05). There was a significant velocity effect for each variable (p < 0.05).

The effects of a simulated occupational kneeling exposure on squat mechanics and knee joint load during gait

Occupational kneeling is associated with an increased risk for tibiofemoral knee osteoarthritis. Forces on the knee in the kneeling posture, as well as the greater incidence of meniscus tears among workers, likely contribute to the increased risk. We hypothesise that an additional mechanism may contribute – altered neuromuscular control due to prolonged high knee flexion. Forty participants (20 male, 20 female) completed an evaluation of gait and squatting before, immediately following, and 30 min following a 30 min simulated occupational kneeling exposure. An increase in the peak external knee adduction moment and a delay in vastus medialis activation onset during walking were observed post-kneeling, as well as increased frontal plane knee motion during squatting. This was the first investigation to find changes in high flexion transitions as a result of kneeling. Greater frontal plane knee motion may increase the risk for meniscal tears, and subsequently, knee osteoarthritis.Practitioner Summary: A 30 min simulated occupational kneeling exposure resulted in small but significant gait changes. The greatest effect was on frontal plane knee movement during squatting, which is especially relevant to occupations requiring frequent kneeling/squatting. This increased motion may indicate an increased risk of injury, which supports a link to knee osteoarthritis.