Knee Varus Angle Research Articles

Prospective validity of a clinical prediction rule for response to non-surgical multidisciplinary management of knee osteoarthritis in tertiary care: a multisite prospective longitudinal study

ObjectivesWe tested a previously developed clinical prediction tool—a nomogram consisting of four patient measures (lower patient-expected benefit, lower patient-reported knee function, greater knee varus angle and severe medial knee radiological...

Analysis on the risk of degenerative knee arthritis in the elderly during regular exercise

<p>目的：經由退化性膝關節炎 (knee osteoarthritis, KOA) 風險角度檢測，探討規律參與運動的中年人與中老年人是否有較高的 KOA 罹患風險。方法：招募規律運動習慣的實驗參與者共 14 位，分為中年組 7 位 (年齡為44.1 ± 4.7歲)，以及中老年組 7 位 (年齡為59.0 ± 8.8歲)。使用 2 台高速攝影機拍攝膝關節內外翻角度，以及Noraxon無線肌電感測系統分析股內側肌與股外側肌之肌肉活化特徵，使用描述性統計分析兩組實驗參與者是否有 KOA 風險的角度特徵，以及經由獨立樣本 t-test 比較中年組與中老年組在膝關節內外翻角度與肌肉活化特徵之差異，顯著水準設 α = .05。結果：中年組膝內翻角度為 0.71 ± 2.9˚，中老年組為 2.14 ± 4.4˚，以上皆小於罹患 KOA 之風險角度 (內翻 3˚)，兩組間無顯著差異。兩組實驗參與者在步行時，股內側肌與股外側肌的活化程度相似，無顯著差異。股內側肌與股外側肌之活化比例與活化時間差值，在兩組之間皆未達顯著差異。結論：在本研究中未發現長期規律運動的中年人與中老年人有較高的退化性膝關節炎罹患風險，膝內翻角度皆未超過罹患 KOA 的風險角度值，平均年齡接近 60 歲的中老年組，KOA 風險角度的平均值仍低於 3°，因此適度的運動對膝關節健康應有正面的效益。</p><p>Purpose: Through detecting Knee Osteoarthritis (KOA) risk perspective, to explore whether middle-aged and middle-aged people who regularly participate in sports have a higher risk of KOA. Methods: Fourteen participants with regular exercise habits were recruited and divided into the middle-aged group (seven participants aged 44.1 ± 4.7 years old) and the pre-elderly group (59.0 ± 8.8 years old). Two high-speed cameras were used to capture the varus and valgus angles of the knee joint, and the Noraxon wireless electromyography system was used to analyze the muscle activation characteristics of the vastus medialis and vastus lateralis muscles. Descriptive statistics were used to analyze the angle characteristics of whether the two groups of experiment participants were at risk of KOA. And through the independent sample t-test to compare the differences between the middle-aged group and the pre-elderly group in the varus angle and muscle activation characteristics of the middle-aged group, the significance level was set at α = .05. Results: The knee varus angle was 0.71 ± 2.9° in the middle-aged group, and 2.14 ± 4.4° in the middle-aged and elderly group, all of which were smaller than the risk angle of KOA (varus 3°) and there was no significant difference between the two groups. The activation of the vastus medialis and vastus lateralis was similar between the two groups of participants during walking, with no significant difference. There was no significant difference between the two groups in the activation ratio and activation time difference of vastus medialis and vastus lateralis. Conclusion: In this study, it was not found that middle-aged people and pre-elderly people who exercise regularly for a long time have a higher risk of degenerative knee arthritis, and the angle of knee varus does not exceed the risk angle value of KOA, and the average age is close to 60 years old in the pre-elderly group, the average KOA risk angle was still lower than 3°; therefore moderate exercise should have a positive effect on knee joint health.</p> <p> </p>

Correlational between the gap contact force and the degree of lower limb alignment correction in Oxford mobile bearing unicompartmental knee arthroplasty

Objective: To study the correlation between joint contact force and postoperative lower extremity alignment in Oxford unicompartmental knee arthroplasty (OUKA) and provide reference data for predicting the lower extremity alignment after OUKA. Methods: It was a retrospective case series study. A total of 78 patients (92 knees) who underwent OUKA surgery from January 2020 to January 2022 in the Department of Orthopedics and Joint Surgery of China-Japan Friendship Hospital were included in this study, including 29 males and 49 females, aged (68.8±6.9) years. A custom-designed force sensor was used to measure gap contact force in the medial gap of OUKA. The patients were divided into groups according to the varus degree of lower limb alignment after operation. Relationship between the gap contact force and the alignment of the lower limbs after operation was analyzed with Pearson correlation analysis, and the gap contact force was compared between patients with different lower limbs alignment correcting results. Results: The mean contact force measured during the operation at 0° of knee extension was 81.7 N±57.8 N, and it was 96.1 N±54.5 N at 20° of knee flexion. The average postoperative knee varus angle was 2.9°±2.7°. The gap contact force at the 0° and 20° positions of the knee joint was negatively correlated with the varus degree of the postoperative lower limb alignment (r=-0.493, -0.331, both P<0.001). The distribution of gap contact force at 0° was different in each group, the contact force [M (Q1, Q3)] of the neutral position group(n=24) was 117.4 N (31.7 N, 233.0 N), and it was 63.7 N (11.3 N, 209.0 N), 31.5 N (8.3 N, 87.7 N) in the mild varus group (n=51) and the significant varus group (n=17), respectively, and the difference was statistically significant (P<0.001); while at 20°, only the difference between the significant varus group and the neutral position group was statistically significant (P=0.040). The gap contact force of the alignment satisfactory group at 0° and 20° was greater than those in the significant varus group (both P<0.05). The gap contact force measured at 0° and 20° was significantly greater in patients with preoperative significant flexion deformity than in patients without flexion deformity (or mild flexion deformity) (both P<0.05). Conclusions: OUKA gap contact force is related to the degree of lower limb alignment correction after the operation. In patients with well-corrected lower limb alignment after surgery, the median intraoperative knee joint gap contact force at 0° and 20° is 117.4 N and 92.5 N, respectively.

Effect of foot strike patterns and cutting angles on knee kinematics and kinetics during side-cutting maneuvers

Purpose Cutting maneuvers are important actions in multidirectional sports but associated with noncontact anterior cruciate ligament (ACL) injuries. This study aimed to investigate the effect of different foot strike patterns and cutting angles on knee kinematics and kinetics. Methods Twenty healthy male team sports athletes performed cuts with maximum speed at three angles (45°, 90°, and 135°) with different foot strike patterns (rearfoot strike [RFS] and forefoot strike [FFS]). A three-dimensional motion capture system combined with a force plate was used to collect makers trajectory and ground reaction force (GRF). Vertical GRF, and knee joint angles and moments were compared among these cutting tasks. Results Regardless of foot strike patterns, increased knee flexion angle, knee valgus moment, and knee internal rotation moment were observed during cutting to sharper angles (p &lt; 0.001). At 90° and 135°, the FFS condition remained in a varus position and showed lower knee flexion moment than the RFS condition (p ≤ 0.004). However, no significant differences in knee kinematic and kinetic variables were found between foot strike patterns during cutting to 45°. Conclusions These findings suggest that sharper cutting angles potentially increase the risk of ACL injury. Compared with the RFS pattern, the FFS pattern induces a slight knee varus angle and a lower knee flexion moment at sharper angles, which might further reduce the load placed on the knee.

Effects of total knee arthroplasty on balance and fall risk in elderly patients with severe gonarthrosis: An age- and sex-matched comparative study.

Falls are a severe cause of morbidity and mortality in elderly patients, and gonarthrosis causes a tendency to fall. Total knee arthroplasty (TKA) is a widely used successful surgical procedure for end-stage gonarthrosis. To investigate whether there is a difference in the frequency of falls, balance and fall risk, and clinical and radiological results in patients with end-stage gonarthrosis with and without TKA. This was a single-center, retrospective, case-control study with age- and gender-matched groups. A total of 100 patients over 60 years of age, with end-stage gonarthrosis and who met the inclusion criteria were included in the study. Fall risk was analyzed using the Berg Balance Scale (BBS), TUG tests, and the ITAKI Fall Risk Test. Knee varus angles were measured using standing long-leg radiographs, and radiological gonarthrosis grading was performed. Pain levels and quality of life were assessed using the VAS and WOMAC. Each patient's knee extensor muscle strength and range of motion were measured. WOMAC, ITAKI, TUG test, and VAS scores were significantly higher in the control group than in the TKA group. BBS scores were significantly lower in the control group. Although the number of falls was high in the control group, there was no statistically significant difference between the two groups. The results of this study showed that total knee arthroplasty provided statistically significant improvement in the clinical, radiological, and fall risk results of the patients. Although there was a decrease in the frequency of falls compared to the control group, it was statistically insignificant. In addition, in our study, it was evaluated that the most important risk factor for falling was advanced age.

Gait in children with achondroplasia \u2013 a cross-sectional study on joint kinematics and kinetics

BackgroundChildren with achondroplasia have extreme short stature due to short limbs, as well as several other clinical features that may affect their gait. The purpose of this cross-sectional study was to provide a detailed description of gait in children with achondroplasia compared to age-matched controls.MethodsBetween the years 2007 and 2010, 16 children with achondroplasia [mean age 9.6 years (range 5–16; six female)] with no previous history of orthopaedic lower limb surgery and 19 age-matched controls conducted three-dimensional (3D) gait analysis at one occasion. The gait analysis rendered pelvis and lower limb joint kinematics and kinetics, and time and distance data. Descriptive statistics, independent samples t-tests, and Fisher’s exact test were used to describe the cohort including gait data and participant characteristics.ResultsChildren with achondroplasia had kinematic gait pattern deviations in all three planes, especially in the sagittal plane, when compared to the control group. Peak anterior pelvic tilt and peak ankle dorsiflexion were found to be increased. Increased knee flexion was noted at initial contact and again at terminal stance. During stance, children with achondroplasia had a higher peak hip abduction angle and a higher peak knee varus angle in the frontal plane. In the sagittal plane, kinetic gait pattern deviations were found at the hip, knee, and ankle, consistent with a flexion pattern. Compared to the control group, children with achondroplasia walked with reduced walking speed and step length, and increased cadence. There was no difference in walking speed when leg length was taken into account. Normalised step length and normalised cadence, on the other hand, were found to be increased in children with achondroplasia.ConclusionsThe observed gait characteristics in children with achondroplasia are related to anatomical attributes and strategies to increase step length, and hence walking speed.

Effects of a 1-mm difference in bearing thickness on intraoperative bearing movement and kinematics in Oxford unicompartmental knee arthroplasty

BackgroundThe choice of mobile bearing (MB) thickness is essential for obtaining successful results after mobile-bearing Oxford unicompartmental knee arthroplasty (UKA). This study aimed to investigate the effects of a 1-mm difference in bearing thickness on intraoperative MB movement and intraoperative knee kinematics in Oxford UKAs.MethodsWe prospectively investigated the effects of a 1-mm difference in bearing thickness on intraoperative MB movement and knee kinematics in 25 patients who underwent Oxford UKAs when surgeons didn’t know which bearing thickness to choose with 1-mm difference. A trial tibial component that was scaled every 2 mm was used to measure the intraoperative MB movement, and the tibial internal rotation relative to the femur and the knee varus angle was simultaneously evaluated using the navigation system as the knee kinematics. We separately evaluated sets of two MB thicknesses with 1-mm differences, and we compared the intraoperative parameters at maximum extension; 30º, 45º, 60º, and 90º flexion; and maximum flexion between the thicker MB (thick group) and the thinner MB (thin group).ResultsThe MB in the thin group was located significantly posteriorly at 90º flexion compared with that in the thick group; however, there were no differences at the other flexion angles. There was significantly less tibial internal rotation in the thin group at 90º flexion than that in the thick group; however, there were no differences at the other flexion angles. The knee varus angles in the thick group were significantly smaller than those in the thin group by approximately one degree at all angles other than at 30º and 45º flexion.ConclusionThe thicker MB could bring the less posterior MB movement and the more tibial internal rotation at 90º flexion, additionally the valgus correction angle in the thicker MB should be paid attention. These results could help surgeons to decide the thickness of MBs when they wonder the thickness of MB.

Differences in gait kinetics and kinematics between patients with rotating hinge knee and cruciate-retaining prostheses: a cross-sectional study.

[Purpose] Rotating hinge knee prostheses are often used in primary total knee arthroplasty. However, the biomechanics resulting from this treatment remain unexplored. This cross-sectional study compared patient data on gait kinetics and kinematics to assess the efficacy of primary total knee arthroplasty using a rotating hinge knee or other prostheses. [Participants and Methods] Thirty-three participants were assigned to the following groups: rotating hinge knee (n=7); cruciate-retaining prosthesis (n=7); untreated osteoarthritis (n=10); and young adults as a reference group (n=9). Participant data on biomechanical and spatiotemporal parameters were analyzed. [Results] The postoperative course of the rotating hinge knee group was not significantly longer than that of the cruciate-retaining prosthesis group. The knee varus angle and adduction moment of the rotating hinge knee group were significantly smaller than those of the untreated osteoarthritis group. Gait kinetics and kinematics were not different between the rotating hinge knee and cruciate-retaining prosthesis groups. [Conclusion] Participants who had undergone primary total knee arthroplasty with a rotating hinge knee prosthesis had worse preoperative conditions and demonstrated a similar postoperative gait as those who had undergone total knee arthroplasty with other prostheses. Our findings may be used to tailor rehabilitation programs for participants who have undergone total knee arthroplasty with a rotating hinge knee implant.

Exploring the relationship between pain intensity and knee moments in participants with medial knee osteoarthritis: a cross-sectional study

BackgroundHigh biomechanical loading is believed to be a risk factor to pain in people with knee osteoarthritis (OA), but controversial findings have been reported on the relationship between external knee adduction moment (KAM) and pain. A more comprehensive analysis considering other factor such as external knee flexion moment (KFM) could help better reveal this relationship. This study explored the relationship between external knee adduction moment and pain intensity in participants with knee osteoarthritis (OA) using an integrated path analysis model.MethodsThis was a cross-sectional study based on laboratory setting. Forty-seven participants with clinical and radiographic medial knee OA were analyzed for their external knee adduction moment (KAM) and knee flexion moment (KFM) during walking using a motion analysis system. Pain intensity was measured by visual analogue scale (VAS) and the pain subscale of the Knee Injury and Osteoarthritis Outcome Score. Varus/valgus alignment was captured and quantified using a bi-planar X-ray system. Using a path analysis model, the relationships between pain intensity, KAM, KFM, OA radiographic severity, knee varus angle and walking speed were examined.ResultsThe proposed path model met the goodness-of-fit criteria. Based on this model, KAM had a negative effect on VAS pain indirectly through the mediation of KFM. The model indicated KAM and KFM were negatively related to one another; and KFM was positively related to VAS. The KAM index, defined as (KAM/ (KAM + KFM)), was negatively related to VAS.ConclusionsPath analysis enabled the construction of a more integrated pathokinematic framework for people with knee OA. The KAM index which reflected the load sharing on the frontal and sagittal planes also revealed its relationship with pain. Re-distribution of mechanical loading from frontal to sagittal plane might be a strategy for pain avoidance associated with mechanical irritation.

Loaded Hex Bar Jump Landing Does Not Increase Frontal Plane Knee Angles And Torques

PURPOSE: To determine if loaded Hexagonal Barbell (HB) jump-landings elicit hip/knee kinematics and kinetics patterns typical of ACL injury during the landing phase of this exercise. METHODS: 10 male NCAA athletes (20.4 + 2.4 y; 108.8 + 14.0 kg) performed 5 maximal HB jumps at 0% (control), 20%, 40%, and 60% of their HB deadlift 1-repetition maximum (mean: 216.6 ± 10.9 kg). A 45 marker full body model was utilized to collect the dominant limb landing phase of the maximal HB jumps using a 10 camera Vicon motion + AMTI force plate capture system (200 Hz/1000 Hz). Plug in Gait analysis yielded peak hip, knee flexion and adduction angles as well as and peak hip, knee sagittal and frontal plane torques. A RMANOVA with Fisher’s post hoc was used to evaluate differences (p < 0.05). RESULTS: Loads in peak hip adduction angle decreased (0%: -10.516° + 4.001, 20%: -5.089° + 3.600, 40%: -4.853° + 4.071, 60%: -4.846° + 4.538; p ≤ 0.0001); with post hoc noting 20, 40 and 60 were lower than the control (p = 0.0001) but not between loaded conditions. Peak knee flexion angle decreased with increased loads (0%: -69.723° + 13.231, 20%: -69.884° + 11.282, 40%: -66.103° + 9.902, 60%: -64.558° + 9.757; p = 0.03); with differences noted 60% lower than the control (p = 0.01) and 20% (p = 0.01). Peak sagittal knee torque increased (0%: 2.511 N.mm/kg + .616, 20%: 2.646 N.mm/kg + .728, 40%: 2.314 N.mm/kg + .668, 60%:2.233 N.mm/kg + .516; p = 0.43); with 20% exhibiting lower values than 40% (p = 0.03) and 60% (p = 0.01). Peak sagittal hip torque increased (0%: 3.390 N.mm/kg + 1.518, 20%: 2.946 N.mm/kg + 1.515, 40%: 2.293 N.mm/kg + 1.038, 60%: 1.727 N.mm/kg + .869; p = <0.0001) with lower values for 40% compared to 20% (p = 0.03) and control (p = 0.0009) and significantly lower hip torque values for 60% compared to 20% (p = 0.0003) and control (p < 0.0001). No significant differences were found in peak hip flexion angle, peak knee varus angle, peak frontal plane knee torque, and peak frontal plane hip torque (p > 0.251). CONCLUSIONS: Higher loads during the landing portion of a hex bar jump result in decreased hip peak hip adduction and a more erect, less flexed knee. However, increased HB loads did not appear to incite the representative ACL injury factors of higher frontal plane knee valgus angles or torques.

Greater knee varus angle and pelvic internal rotation after landing are predictive factors of a non-contact lateral ankle sprain

ObjectivesThis study aimed to clarify the kinematic, kinetic characteristics associated with lateral ankle sprain. DesignA 16-month prospective cohort study. SettingLaboratory. ParticipantsA total of 179 college athletes. Main outcome measuresJoint kinematics, moment during single-leg landing tasks, and ankle laxity were measured. The attendance of each participating team, injury mechanism, existence of body contact, presence of orthosis, with or without medical diagnosis, and periods of absence were recorded. ResultsTwenty-nine participants incurred lateral ankle sprain during non-contact motion. The Cox regression analysis revealed that greater knee varus peak angle (hazard ratio: 1.16 [95% confidence interval: 1.10–1.22], p < 0.001) and greater pelvic internal rotation peak angle toward the support leg were associated with lateral ankle sprain (hazard ratio: 1.08 [95% confidence interval: 1.02–1.15], p = 0.009). The cut-off values for each predictive factor were −0.17° (area under the curve = 0.89, p < 0.001) and 6.63° (area under the curve = 0.74, p < 0.001), respectively. ConclusionsA greater knee varus peak angle and pelvic internal rotation peak angle after single-leg landing are predictive factors for lateral ankle sprain.

The Study of Correlation between Genu Anklebone Varus Angle and Plantar Pressure

Yang, W.B.; Yang, Z., and Dong, J.Y., 2020. The study of correlation between genu anklebone varus angle and plantar pressure. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 972–977. Coconut Creek (Florida), ISSN 0749-0208.In this paper, data acquisition is carried out with the help of Codamotion three-dimensional motion capture system and footscan plantar pressure acquisition system. The lower limb posture characteristics and plantar pressure data of subjects walking at different walking speeds of slow, medium and fast speed are collected and analyzed. Spearman correlation analysis method is used to analyze the correlation of the pressure knee and ankle joint valgus angle in ten areas of the sole of the foot in the process of walking, to judge whether there is a correlation between the characteristics and analyze the strength of the correlation. Through the analysis, in the process of walking, there is a good correlation between the knee varus angle and the pressure of the first metatarsal area, the second metatarsal area, the third metatarsal area, and the ankle varus angle and the pressure of the fourth metatarsal area, the fifth metatarsal area. Secondly, there is a certain correlation between the varus angle of the knee and ankle and the pressure of the thumb area, and the pressure of the heel inside and outside, while the correlation between the varus angle of the knee and ankle is poor. The correlation coefficients between the pressure of the first metatarsal area and the angle of the ankle varus, the third metatarsal area and the angle of the knee and ankle varus, the fifth metatarsal area and the angle of the ankle varus are small when the speed increases or decreases. Speed has little effect on the correlation between these features. The correlation coefficients of thumb area pressure and genu varus angle, second metatarsal area pressure and genu varus angle, fifth metatarsal area pressure and genu varus angle are different when the speed increases or decreases. Speed has a great influence on the correlation between these features.

Vibration improves gait biomechanics linked to posttraumatic knee osteoarthritis following anterior cruciate ligament injury.

Anterior cruciate ligament reconstruction (ACLR) incurs a high risk of posttraumatic knee osteoarthritis (PTOA). Aberrant gait biomechanics contribute to PTOA and are attributable in part to quadriceps dysfunction. Vibration improves quadriceps function following ACLR, but its effects on gait biomechanics are unknown. The purpose of this study was to evaluate the effects of whole-body vibration (WBV) and local muscle vibration (LMV) on gait biomechanics in individuals with ACLR. Seventy-five volunteers (time since ACLR 27 ± 16 months) were randomized to WBV, LMV, or Control interventions. Walking biomechanics were assessed prior to and following a single exposure to the interventions. Outcomes included pre-post change scores in the ACLR limb for the peak vertical ground reaction force (vGRF) and its loading rate, peak internal knee extension (KEM) and abduction moments, and peak knee flexion and varus angles. LMV produced a significant decrease in the vGRF loading rate (-3.6 BW/s) that was greater than the changes in the WBV (-0.3 BW/s) and Control (0.5 BW/s) groups. Additionally, WBV produced an increase in the peak KEM (0.27% BW × Ht) that was greater than the change in the Control group (-0.17% BW × Ht) but not the LMV group (0.01% BW × Ht). Lower KEM and greater loading rates have been linked to declines in joint health following ACLR. WBV acutely increased the peak KEM and LMV decreased loading rates. These data suggest that vibration has the potential to mitigate aberrant gait biomechanics, and may represent an effective approach for reducing PTOA risk following ACLR.

Gait Biomechanics Linked To Post-traumatic Osteoarthritis Following Anterior Cruciate Ligament Reconstruction Are Improved With Vibration

PURPOSE: Anterior cruciate ligament reconstruction (ACLR) incurs a high risk of post-traumatic knee osteoarthritis (PTOA). Aberrant gait biomechanics contribute to PTOA and are attributable in part to quadriceps dysfunction. Vibration improves quadriceps function following ACLR, but its effects on gait biomechanics are unknown. The purpose of this study was to evaluate the effects of whole body vibration (WBV) and local muscle vibration (LMV) on gait biomechanics in individuals with ACLR. METHODS: 75 volunteers with primary unilateral ACLR (72% females; age 21 ± 3 yr; time since ACLR 27 ± 16 mo) were randomized to WBV, LMV, or Control interventions. WBV and LMV were applied 6 x 1 minute (30Hz, 2g). Walking biomechanics were assessed prior to and following the interventions. Outcomes included the peak vertical ground reaction force (vGRF) and its loading rate, peak internal knee extension and valgus moments, and peak knee flexion and varus angles during the first 50% of stance. vGRF magnitude and rate were normalized to body weight (BW) and moments were normalized as % body weight∗height (%BW∗Ht). ACLR limb change scores (post-pre) for each outcome were compared across groups via one-way ANCOVA controlling for gait speed, time since ACLR, and baseline values. RESULTS: Change scores did not differ across groups for peak knee flexion (p = 0.374) or varus (p = 0.801) angles, vGRF (p = 0.656), or internal valgus moment (p = 0.866). However, changes in vGRF loading rate differed across groups (p = 0.024), with a significant decrease in the LMV group (-3.6 BW/s) that was greater than the changes in the WBV (-0.3 BW/s; p = 0.035) and Control (0.5 BW/s; p = 0.010) groups. Additionally, the change in peak internal extension moment differed across groups (p = 0.016), with a significant increase in the WBV group (0.27 %BW∗Ht) that was greater than the change in the Control group (-0.17 %BW∗Ht; p = 0.005) but not the LMV group (0.01 %BW∗Ht; p = 0.101). CONCLUSIONS: Lower knee extension moments and greater loading rates during gait have been linked to declines in joint health following ACLR. WBV acutely increased the peak knee extension moment and LMV decreased loading rates. These data suggest that vibration has the potential to mitigate aberrant gait biomechanics, and may represent an effective approach for mitigating PTOA risk following ACLR.

The Influence Of Maximal And Minimal Shoes On Walking Biomechanics In Older Individuals

Older individuals frequently walk as a means for exercise and often wear running shoes during this activity. Recently there has been increased popularity in older individuals wearing maximal running shoes during walking. Maximal running shoes are unique because they are comprised of a highly cushioned midsole in both the rearfoot and forefoot that is supposed to improve shock attenuation. Minimal running shoes with little cushioning are also used in this population to improve proprioception and balance. Loading in the frontal plane is of particular interest for older individuals since it has been associated with increased risk of knee osteoarthritis. Little is currently known about how maximal and minimal shoes influence walking biomechanics in any age group. PURPOSE: To examine the influence of maximal and minimal running shoes on walking biomechanics in older individuals. METHODS: Walking biomechanics were collected on 16 female participants (age range: 51 – 64 years) using an 8-camera Vicon motion capture system and two embedded force plates. 3D kinematics and kinetics were collected while subjects walked along a 10-meter runway in three different footwear conditions (MAX, MIN, TRAD). Variables of interest included the 1st and 2nd peak of the vertical ground reaction force (Fz1, Fz2), the instantaneous vertical loading rate (IVLR), peak ankle eversion and knee varus angles, and the peak external ankle eversion and knee varus moments. Differences were determined using a repeated measures ANOVA. RESULTS: The external knee varus moment was significantly higher in the maximal shoe compared to the traditional shoe (MAX: 0.55 ± 0.16 Nm/kg, TRAD: 0.49 ± 0.14 Nm/kg, p = .005). The IVLR was significantly higher in the minimal shoe compared to the traditional shoe (MIN: 30.4 ± 3.4 BW/s, TRAD: 21.8 ± 1.8 BW/s, p < .001). No other significant differences were found for the variables of interest. CONCLUSION: The maximal shoe was found to increase the external knee varus moment, which has been linked to increased pain and disease progression in knee osteoarthritis. The IVLR was significantly higher in the minimal shoe, which has also been linked to injury. Based on these findings, there are no clear advantages to wearing a maximal or minimal shoe during walking, and doing so may be detrimental to injury risk. No grant support was provided.

Somatosensory Function Influences Aberrant Gait Biomechanics Following Anterior Cruciate Ligament Reconstruction.

Osteoarthritis is common following anterior cruciate ligament reconstruction (ALCR), and aberrant gait biomechanics are considered a primary contributor. Somatosensory dysfunction potentially alters gait biomechanics, but this association is unclear. Therefore, the purposes of this investigation were to compare somatosensory function between limbs and evaluate associations between somatosensory function and gait biomechanics linked to osteoarthritis development in individuals with ALCR. Seventy-three volunteers with ALCR participated. Gait biomechanics (peak vertical ground reaction force magnitude and loading rate, peak internal knee extension and valgus moments, peak knee flexion and varus angles, and quadriceps/hamstrings co-activation) were assessed as subjects walked at their preferred speed. The somatosensory function was assessed via joint position sense error (knee flexion) and vibratory perception threshold (femoral epicondyles, malleoli, and first metatarsal). Though somatosensory function did not differ between the ACLR and contralateral limbs, poorer joint position sense in the ACLR limb was associated with lower loading rates and internal knee extension moments, and greater co-activation. Poorer vibratory perception at the medial and lateral malleoli and first metatarsal head in the ACLR limb was associated with lower loading rates, greater internal knee valgus moments and varus angles, and greater co-activation. Poorer vibratory perception at the medial malleolus and first metatarsal head in the contralateral limb was associated with greater peak knee varus angles and internal knee valgus moments. These results suggest that future research evaluating rehabilitation approaches for improving somatosensory function is warranted as a potential approach for restoring normal gait biomechanics and reducing osteoarthritis risk. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:620-628, 2020.

Effects of treadmill running and limb immobilization on knee cartilage degeneration and locomotor joint kinematics in rats following knee meniscal transection

This study examined the effects of reduced and elevated weight bearing on post-traumatic osteoarthritis (PTOA) development, locomotor joint kinematics, and degree of voluntary activity in rats following medial meniscal transection (MMT). Twenty-one adult rats were subjected to MMT surgery of the left hindlimb and then assigned to one of three groups: (1) regular (i.e., no intervention), (2) hindlimb immobilization, or (3) treadmill running. Sham surgery was performed in four additional rats. Voluntary wheel run time/distance was measured, and 3D hindlimb kinematics were quantified during treadmill locomotion using biplanar radiography. Rats were euthanized 8weeks after MMT or sham surgery, and the microstructure of the tibial cartilage and subchondral bone was quantified using contrast enhanced micro-CT. All three MMT groups showed signs of PTOA (full-thickness lesions and/or increased cartilage volume) compared to the sham group, however the regular and treadmill-running groups had greater osteophyte formation than the immobilization group. For the immobilization group, increased volume was only observed in the anterior region of the cartilage. The treadmill-running group demonstrated a greater knee varus angle at mid-stance than the sham group, while the immobilization group demonstrated greater reduction in voluntary running than all the other groups at 2 weeks post-surgery. Elevated weight-bearing via treadmill running at a slow/moderate speed did not accelerate PTOA in MMT rats when compared to regular weight-bearing. Reduced weight-bearing via immobilization may attenuate overall PTOA but still resulted in regional cartilage degeneration. Overall, there were minimal differences in hindlimb kinematics and voluntary running between MMT and sham rats.

Relationship between surgical balancing and outcome measures in total knees.

BackgroundThe purpose of the study was to investigate the accuracy of balancing which could be achieved at total knee surgery and its relation to functional outcomes.MethodsDuring surgery, the forces on the medial and lateral plateaus were measured at 10-15 degrees flexion in 101 patients, using an instrumented tibial trial, with equal forces being targeted. Of the initial 101 cases, 71 cases completed all follow-up visits to 1 year. At each follow-up visit, the function was measured using the Knee Society Scoring System, and varus and valgus laxity angles were measured.ResultsThe mean medial/(medial + lateral) compartmental force ratio was 0.52, with a standard deviation of 0.09. The total contact force was 217 Newtons, with a standard deviation of 72 Newtons. No correlations were found between the functional scores and the compartmental force ratio or total contact force. However, the mean varus and valgus laxity angles, 2.8 and 2.3 degrees, respectively, were very close to the angles of normal intact knees.ConclusionsThe likely reason for the lack of correlation of function was that the large majority of the balancing ratios were within the range 0.4-0.6 but with a wide spread of functional scores typical of total knee study groups. However, the normal varus and valgus angles achieved at follow-up indicated that equal balancing in early flexion was a reasonable surgical target. Using instrumented tibial trials enabled accurate and consistent balancing values to be achieved, as well as normal varus and valgus laxity angles, which may be important in obtaining optimal outcomes.

Relationship between the Femur-tibia and Knee Varus Angles during Gait One Year after Open-wedge High Tibial Osteotomy

〔目的〕本研究の目的は内側楔状開大式高位脛骨骨切り術（OWHTO）術後のFTAと歩行中の膝関節内反角度との関係と，膝関節のアライメントの変化が，歩行中の股関節と足関節の前額面の角度に及ぼす影響を明らかにすることである．〔対象と方法〕当院にて，OWHTOが施行された49名を対象とした．術前と術後1年時に歩行分析を行い，FTAと立脚期50％時点の膝関節内反角度との関係を検討した．また，股関節，膝関節，足関節の立脚期50％の時点の値を術前後で比較した．〔結果〕FTAと立脚期50％時点の膝関節内反角度との間には中等度の正の相関関係を示した．〔結語〕術後はFTAと歩行中の膝関節内反角度は完全に一致しないことを留意する必要があると考えられた．

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.