Knee Brace Research Articles

A Biomechanical Comparison Shows No Difference Between Two Knee Braces used for Medial Collateral Ligament Injuries

PurposeThe purpose of this study was to assess the ability of 2 commonly used knee braces to control knee valgus motion and subsequent strain on the medial collateral ligament (MCL) in a laboratory-controlled environment.MethodsTwenty healthy individuals (6 male, 14 female; mean age, 23 ± 3 years) with no history of knee injury or brace use performed a jump landing task while wearing either no brace or 1 of 2 braces: the Playmaker and Total Range of Motion . Three-dimensional joint kinematics and kinetics were measured in our biomechanics laboratory.ResultsSignificantly less knee dynamic valgus angulation was noted when using either brace (−0.51° ± 3.9° and −1.3° ± 3.2°) compared no brace (4.8° ± 3.0°). Dynamic valgus angulation did not differ significantly between the 2 braces tested, which were both not statistically different from baseline alignment. There were significant differences seen in peak knee flexion angle between each brace (77.9° ± 8.8°and 83.1° ± 8.4°), as well as between both braces and no brace (90.6° ± 11.1°). There was no significant difference in knee frontal plane moment or peak vertical ground reaction force loading among all 3 testing conditions.ConclusionsCompared to no brace, both braces allowed significantly less dynamic valgus angulation of the knee under physiological vertical loads but were not significantly different from one another.Clinical RelevanceKnee braces are commonly used to protect the MCL when placed under physiological loads. It is important to know which braces effectively reduce valgus stress to provide the best outcomes.

The acute effect of knee brace on the electromyography activity of lower limb muscles in individuals with genu valgus during walking

Background: Different factors affect walking biomechanics disturb the postural control. Genu valgus is one of the most important lower limb malalignments that affects the postural control and disrupts the posture. The purpose of the present study was to investigate the acute effect of knee brace on the electromyography activity of lower limb muscles in individuals with genu valgus during walking. Methods: In this semi-experimental and a laboratory typ study,. 24 boys with genu valgum (20-30 years old) volunteered to participate in the study. The electrical activity of the selected muscles was recorded by an electromyography system during walking with and without knee brace. Paired t-test was used for statistical analysis at a significance level of 0.05. Results: There was a significant increase in electrical activity of the semitendinosus muscle during walking with knee brace compared to walking without it (p = 0.037, d = 0.89). The electrical activity of other lower limb muscles did not show any significant differences during acute use of knee brace (P >0.05). Conclusion: The semitendinosus muscle in individuals with genu valgus is weak. Therefore, significant increase in the electrical activity of the semitendinosus muscle during wearing of knee brace means delaying the fatigue and indicating improvement in the muscular function.

Valgus knee bracing for medial knee osteoarthritis and varus malalignment: a pilot study

Purpose: Knee bracing is inconsistently recommended in clinical guidelines for the management of knee osteoarthritis (OA). Knee OA progression may be related to altered mechanical knee loads, particularly in those with varus malignment. Valgus knee bracing is thought to alleviate symptoms by reducing loads borne through the medial tibiofemoral compartment during walking. However, the effect of valgus knee bracing on medial tibiofemoral compartment mechanical loads is not well understood. Investigations on valgus knee bracing to date have largely used the external knee adduction moment as a surrogate to infer medial tibiofemoral compartment mechanical loads.

Magnetic resonance imaging of medial collateral ligament avulsion fractures of the knee in children: a potentially underestimated injury.

Literature regarding medial collateral ligament (MCL) injuries is focused on adults with superficial MCL disruptions. However, children follow different injury patterns, with avulsion fractures at ligament attachment sites occurring commonly. Such avulsions have not been characterized for pediatric MCL injuries. To elucidate imaging findings, and review management and outcomes of pediatric MCL avulsion fractures. We conducted a 10-year retrospective review of knee magnetic resonance (MR) imaging reports for patients younger than 16years old diagnosed with acute MCL avulsion fracture. MR imaging was reviewed to confirm and characterize the components of the avulsion (perichondrium without or with cartilage, and/or bone) and to identify additional knee injuries. Radiographs, if available, from the time of injury were reviewed. Clinical management and patient outcomes were recorded. Eighteen patients (13 boys, 5 girls) incurred an acute MCL avulsion fracture. All avulsions involved the deep MCL attachment: 17 meniscofemoral and 1 meniscotibial component. Two avulsions also included the superficial MCL attachment. Nine boys had non-osseous avulsions, all radiographically occult. All girls had radiographically apparent avulsions. Three girls and three boys sustained associated knee derangements, most commonly anterior cruciate ligament (ACL) injury (n=4). All MCL avulsions were initially treated conservatively; one child required subsequent surgery for ongoing pain. Pediatric MCL avulsion fractures in this study uniformly involve the attachment of the deep MCL and can be entirely non-osseous, particularly in boys who lag in skeletal maturity, making these injuries radiographically occult. MR imaging may be required to recognize these avulsions, which can impact the duration of rest and knee bracing.

Integrating a Potentiometer into a Knee Brace Shows High Potential for Continuous Knee Motion Monitoring.

Continuous monitoring of knee motion can provide deep insights into patients’ rehabilitation status after knee injury and help to better identify their individual therapeutic needs. Potentiometers have been identified as one possible sensor type for continuous monitoring of knee motion. However, to verify their use in monitoring real-life environments, further research is needed. We aimed to validate a potentiometer-embedded knee brace to measure sagittal knee kinematics during various daily activities, as well as to assess its potential to continuously monitor knee motion. To this end, the sagittal knee motion of 32 healthy subjects was recorded simultaneously by an instrumented knee brace and an optoelectronic reference system during activities of daily living to assess the agreement between these two measurement systems. To evaluate the potentiometer’s behavior during continuous monitoring, knee motion was continuously recorded in a subgroup (n = 9) who wore the knee brace over the course of a day. Our results show a strong agreement between the instrumented knee brace and reference system across all investigated activities as well as stable sensor behavior during continuous tracking. The presented potentiometer-based sensor system demonstrates strong potential as a device for measuring sagittal knee motion during daily activities as well as for continuous knee motion monitoring.

The Effect of a Course of Up-cholugi and Yup-chagi Exercises on the Kinematic Indices of the Knee and the Incidence of Bow-leggedness (Genu Varum) in Professional Taekwondo Practitioners

Objective: Knee brace is one of the lower limb abnormalities. This study aimed to investigate the effect of knee kinematical parameters on the development of knee Genu Varum. Methods: This study’s statistical sample was 32 taekwondo practitioners with red and black belts of sports clubs in the northeast of Tehran, determined using G-Power software and in two groups of 16 people in terms of gender, age, and membership in the field. The 8-week training intervention, which included 3session of 1-hour training sessions emphasizing performing the techniques of up-chulogi and yup-chaggy, was performed for the experimental group. The control group did not have any specific activity during this period. Knee kinematic indices include naval drop size tests, tibial torsion, Q angle, androgen enterogen, internal and external hip rotation, and knee hyperextension in the two groups of healthy and injured in pre and posttest was evaluated. The data were statistically analyzed using descriptive analysis using t-test and SPSS V. 23 software. Results: According to the study results, a significant positive relationship was observed between the variables of the selected technique of up-chology and the technique of up-chugi on the incidence of knee Genu Varum. Also, there was a significant difference between the indices of naval drop (P=0.003), torsion (P=0.006), Q angle (P=0.005) and knee hyperextension (P=0.001) in pre-test to post-test results. Conclusion: The selected exercises have increased the distance between the knees and functional disorders. Because the braced knee may play a role in influencing athletes’ negative performance and injury in training and competition, it is necessary to consider it in studies related to the prevention of potential injuries.

Clinical and cost-effectiveness of bracing in symptomatic knee osteoarthritis management: protocol for a multicentre, primary care, randomised, parallel-group, superiority trial

BackgroundBrace effectiveness for knee osteoarthritis (OA) remains unclear and international guidelines offer conflicting recommendations. Our trial will determine the clinical and cost-effectiveness of adding knee bracing (matched to patients’ clinical...

The effect of asymmetrical gait induced by unilateral knee brace on the knee flexor and extensor muscles.

Asymmetrical stiff knee gait is a mechanical pathology that can disrupt lower extremity muscle coordination. A better understanding ofthis condition can help identify potential complications. This study proposes the use ofdynamic musculoskeletal modelling simulation to investigate theeffect of induced mechanical perturbation onthe kneeand to examine the musclebehaviour without invasive technique. Thirty-eighthealthy participants were recruited. Asymmetrical gait was simulated using knee brace. Knee joint angle, jointmoment and knee flexor and extensor muscle forces were computed using OpenSim. Differences inmuscle force between normal and abnormal conditions were investigated using ANOVA and Tukey-Kramer multiple comparison test.The results revealed that braced knee experienced limited range of motion withsmallerflexion momentoccuring atlate swing phase. Significant differences were found in all flexormuscle forces and in several extensor muscle forces (p<0.05). Normal knee produced larger flexormuscle force than braced knee. Braced knee generated the largest extensormuscle force at early swing phase. In summary, musculoskeletalmodelling simulation can be a computational tool to map and detect thedifferences between normal and asymmetrical gaits.

Finite Element Analysis of a Novel Approach for Knee and Ankle Protection during Landing

There is a high risk of serious injury to the lower extremities during a human drop landing. Prophylactic knee and ankle braces are commonly used to reduce injury by restraining the motion of joints. However, braces that restrain joint range of motion (ROM) may have detrimental effects on the user’s kinematical performance and joint function. The present study aimed to propose a novel set of double-joint braces and to evaluate its protective performance in terms of the ankle and knee. Accordingly, the finite element method was performed to investigate the biomechanical responses of the ankle and knee in braced and unbraced conditions. The results showed that the semi-rigid support at the ankle joint can share the high impact force that would otherwise be inflicted on one’s lower extremity, thereby reducing the peak stress on the inferior articular surface of the tibia, menisci, and articular cartilages, as well as the horizontal force on the talus. Moreover, with knee bending, the elongated spring component at the knee joint can convert the impact kinetic energy into elastic potential energy of the spring; meanwhile, the retractive force generated by the spring also provides a more balanced interaction between the menisci and articular cartilages. This biomechanical analysis can accordingly provide inspiration for new approaches to place human lower extremities at lower risk during landings.

Development, testing and performance evaluation of steel beam-through framed connections with curved knee braces for improving seismic performance

An innovative beam-through framed connection equipped with curved knee braces is presented in this article. Curved knee braces with pinned connections are employed in semi-rigid beam-to-column joints. The proposed connection is expected to exhibit great deformability and energy dissipating capacity. The working mechanism and the theoretical behavior of the connection are firstly introduced, followed by an experimental study on three full-scale specimens under quasi-static cyclic tests. The test specimens exhibited stable behavior and great ductility. Damages were mainly concentrated on the knee braces within 0.02 rad drift ratio. The failure appeared when loading amplitude was above 0.07 rad drift ratio. The proposed connection is then introduced into beam-through steel frames (BTFs) which use strip braces as lateral force resisting system. To evaluate the contribution from knee braces, nonlinear response history analyses were performed on four demonstration BTFs. Based on the results of analyses, it is found that traditional BTF would exhibit high mode effect due to compressive buckling of strip braces, the inter-story drift is nonuniform along building height. Employing knee braces on traditional BTF stabilizes hysteretic behaviors and improves post-yielding strength for the system, global response of the system is reduced obviously and soft-story mechanism is mitigated. Moreover, results also indicate that satisfying peak transient inter-story drift and deformation uniformity can be achieved when strength demand from knee braces is adopted as 25% of total design inter-story strength demand.

Novel velocity estimation for symmetric and asymmetric self-paced treadmill training

BackgroundSelf-paced treadmills (SPT) can provide an engaging setting for gait rehabilitation by responding directly to the user’s intent to modulate the external environment and internal effort. They also can improve gait analyses by allowing scientists and clinicians to directly measure the effect of an intervention on walking velocity. Unfortunately, many common SPT algorithms are not suitable for individuals with gait impairment because they are designed for symmetric gait patterns. When the user’s gait is asymmetric due to paresis or if it contains large accelerations, the performance is diminished. Creating and validating an SPT that is suitable for asymmetric gait will improve our ability to study rehabilitation interventions in populations with gait impairment. The objective of this study was to test and validate a novel self-paced treadmill on both symmetric and asymmetric gait patterns and evaluate differences in gait kinematics, kinetics, and muscle activity between fixed-speed and self-paced treadmill walking.MethodsWe collected motion capture, ground reaction force data, and muscle activity from 6 muscles in the dominant leg during walking from 8 unimpaired subjects. In the baseline condition, the subjects walked at 3 fixed-speeds normalized to their leg length as Froude numbers. We developed a novel kinematic method for increasing the accuracy of the user’s estimated walking velocity and compared our method against other published algorithms at each speed. Afterward, subjects walked on the SPT while matching their walking speed to a given target velocity using visual feedback of the treadmill speed. We evaluated the SPT by measuring steady-state error and the number of steps to reach the desired speed. We split the gait cycle into 7 phases and compared the kinematic, kinetic, and muscle activity between the fixed speed and self-paced mode in each phase. Then, we validated the performance of the SPT for asymmetric gait by having subjects walk on the SPT while wearing a locked-knee brace set to 0° on the non-dominant leg.ResultsOur SPT enabled controlled walking for both symmetric and asymmetric gait patterns. Starting from rest, subjects were able to control the SPT to reach the targeted speeds using visual feedback in 13–21 steps. With the locked knee brace, subjects controlled the treadmill with substantial step length and step velocity asymmetry. One subject was able to execute a step-to gait and halt the treadmill on heel-strikes with the braced leg. Our kinematic correction for step-length outperformed the competing algorithms by significantly reducing the velocity estimation error at the tested velocities. The joint kinematics, joint torques, and muscle activity were generally similar between fixed-speed and self-paced walking. Statistically significant differences were found in 5 of 63 tests for joint kinematics, 2 of 63 tests for joint torques, and 9 of 126 tests for muscle activity. The differences that were statistically significant were not found across all speeds and were generally small enough to be of limited clinical relevance.ConclusionsWe present a validated method for implementing a self-paced treadmill for asymmetric and symmetric gaits. As a result of the increased accuracy of our estimation algorithm, our SPT produced controlled walking without including a position feedback controller, thereby reducing the influence of the controller on measurements of the user’s true walking speed. Our method relies only on a kinematic correction to step length and step time which can support transfer to systems outside of the laboratory for symmetric and asymmetric gaits in clinical populations.

Isolating the energetic and mechanical consequences of imposed reductions in ankle and knee flexion during gait

BackgroundWeakness of ankle and knee musculature following injury or disorder results in reduced joint motion associated with metabolically expensive gait compensations to enable limb support and advancement. However, neuromechanical coupling between the ankle and knee make it difficult to discern independent roles of these restrictions in joint motion on compensatory mechanics and metabolic penalties.MethodsWe sought to determine relative impacts of ankle and knee impairment on compensatory gait strategies and energetic outcomes using an unimpaired cohort (N = 15) with imposed unilateral joint range of motion restrictions as a surrogate for reduced motion resulting from gait pathology. Participants walked on a dual-belt instrumented treadmill at 0.8 m s−1 using a 3D printed ankle stay and a knee brace to systematically limit ankle motion (restricted-ank), knee motion (restricted-knee), and ankle and knee motion (restricted-a + k) simultaneously. In addition, participants walked without any ankle or knee bracing (control) and with knee bracing worn but unrestricted (braced).ResultsWhen ankle motion was restricted (restricted-ank, restricted-a + k) we observed decreased peak propulsion relative to the braced condition on the restricted limb. Reduced knee motion (restricted-knee, restricted-a + k) increased restricted limb circumduction relative to the restricted-ank condition through ipsilateral hip hiking. Interestingly, restricted limb average positive hip power increased in the restricted-ank condition but decreased in the restricted-a + k and restricted-knee conditions, suggesting that locking the knee impeded hip compensation. As expected, reduced ankle motion, either without (restricted-ank) or in addition to knee restriction (restricted-a + k) yielded significant increase in net metabolic rate when compared with the braced condition. Furthermore, the relative increase in metabolic cost was significantly larger with restricted-a + k when compared to restricted-knee condition.ConclusionsOur methods allowed for the reproduction of asymmetric gait characteristics including reduced propulsive symmetry and increased circumduction. The metabolic consequences bolster the potential energetic benefit of targeting ankle function during rehabilitation.Trial registrationN/A.

Effect of Prophylactic Knee Bracing on Anterior Cruciate Ligament Agonist and Antagonist Muscle Forces During Perturbed Walking.

Background:Anterior cruciate ligament (ACL) injuries most commonly occur after a perturbation. Prophylactic knee braces (PKBs) are off-the-shelf braces designed to prevent and reduce the severity of knee injuries during sports, yet their effectiveness has been debated.Purpose:To identify differences in ACL agonist and antagonist muscle forces, during braced and unbraced conditions, while walking with the application of unexpected perturbations.Study Design:Controlled laboratory study.Methods:A total of 20 recreational athletes were perturbed during walking at a speed of 1.1 m/s, and motion analysis data were used to create patient-specific musculoskeletal models. Static optimization was performed to calculate the lower-limb muscle forces. Statistical parametric mapping was used to compare muscle forces between the braced and unbraced conditions during the stance phase of the perturbed cycle.Results:The brace reduced muscle forces in the quadriceps (QUADS), gastrocnemius (GAS), and soleus (SOL) but not in the hamstrings. The peak QUADS muscle force was significantly lower with the brace versus without at 49% to 60% of the stance phase (28.9 ± 12.98 vs 14.8 ± 5.06 N/kg, respectively; P < .001) and again at 99% of the stance phase (1.7 ± 0.4 vs 3.6 ± 0.13 N/kg, respectively; P = .049). The SOL muscle force peak was significantly lower with the brace versus without at 25% of the stance phase (1.9 ± 1.7 vs 4.6 ± 3.4 N/kg, respectively; P = .031) and at 39% of the stance phase (1.9 ± 1.4 vs 5.3 ± 5.6 N/kg, respectively; P = .007). In the GAS, there were no significant differences between conditions throughout the whole stance phase except between 97% and 100%, where the braced condition portrayed a smaller peak force (0.23 ± 0.13 vs 1.4 ± 1.1 N/kg for unbraced condition; P = .024).Conclusion:These findings suggested that PKBs that restrict knee hyperextension and knee valgus/varus motion can alter neuromuscular patterns, which result in a reduction of QUADS force.Clinical Relevance:Understanding the way PKBs alter muscle function and knee mechanics can provide invaluable information that will help in making decisions about their use. Further studies should investigate different types of braces and perturbations to evaluate the effectiveness of PKBs.

High Prevalence of Hip and Knee Arthroplasty in Former Professional American Style Football Players: A Call to Action.

High Prevalence of Hip and Knee Arthroplasty in Former Professional American Style Football Players: A Call to Action.

Effectiveness, safety, and cost–utility of a knee brace in medial knee osteoarthritis: the ERGONOMIE randomized controlled trial

This pragmatic, multicenter, open-label, randomized controlled trial (RCT) aimed to compare the effectiveness, safety, and cost-utility of a custom-made knee brace versus usual care over 1 year in medial knee osteoarthritis (OA). 120 patients with medial knee OA (VAS pain at rest >40/100), classified as Kellgren-Lawrence grade II-IV, were randomized into two groups: ODRA plus usual care (ODRA group) and usual care alone (UCA group). The primary effectiveness outcome was the change in VAS pain between M0 and M12. Secondary outcomes included changes over 1 year in KOOS (function) and OAKHQOL (quality of life) scores. Drug consumption, compliance, safety of the knee brace, and cost-utility over 1 year were also assessed. The ODRA group was associated with a higher improvement in: VAS pain (adjusted mean difference of-11.8; 95% CI:-21.1 to-2.5); all KOOS subscales (pain:+8.8; 95% CI: 1.4-16.2); other symptoms (+10.4; 95% CI: 2.7-18); function in activities of daily living (+9.2; 95% CI: 1.1-17.2); function in sports and leisure (+12.3; 95% CI: 4.3-20.3); quality of life (+9.9; 95% CI: 0.9-15.9), OAKHQOL subscales (pain:+14.8; 95% CI: 5.0-24.6); and physical activities (+8.2; 95% CI: 0.6-15.8), and with a significant decrease in analgesics consumption at M12 compared with the UCA group. Despite localized side-effects, observance was good at M12 (median: 5.3h/day). The ODRA group had a more than 85% chance of being cost-effective for a willingness-to-pay threshold of €45 000 per QALY. The ERGONOMIE RCT demonstrated significant clinical benefits of an unloader custom-made knee brace in terms of improvements in pain, function, and some aspects of quality of life over 1 year in medial knee OA, as well as its potential cost-utility from a societal perspective.

Online Rehabilitation Protocols for Medial Patellofemoral Ligament Reconstruction With and Without Tibial Tubercle Osteotomy Are Variable Among Institutions

PurposeTo compare and contrast the various rehabilitation protocols for medial patellofemoral ligament (MPFL) reconstruction and MPFL reconstruction plus tibial tubercle osteotomy (TTO) published online by academic orthopaedic surgery residency programs and private practice institutions throughout the United States.MethodsWe performed a systematic electronic search of MPFL reconstruction rehabilitation protocols in academic orthopaedic surgery residency programs in the United States using Google’s search engine (www.google.com) based on the Fellowship and Residency Electronic Interactive Database Access System (FREIDA). Private practice organizations publishing MPFL reconstruction or MPFL reconstruction–TTO rehabilitation protocols that were found on the first page of search results were also included, but no comprehensive search for private practice protocols was performed. Protocols specifying an MPFL reconstruction with TTO were included for separate review because of altered weight-bearing status postoperatively. A list of comparative criteria was created to assess the protocols for the presence and timing of the various rehabilitation components.ResultsFrom the list of 189 U.S. academic residency programs, as well as additional private practice protocols found in the Google search, 38 protocols were included for review (31 protocols for isolated MPFL reconstruction and 7 protocols for MPFL reconstruction plus TTO). A return to full range of motion by week 6 was recommended by 15 (48.4%) of the isolated MPFL reconstruction protocols and 6 (85.7%) of the MPFL reconstruction–TTO protocols. Six weeks of knee brace wear was recommended by 13 isolated MPFL reconstruction protocols (43.3%) and 4 MPFL reconstruction–TTO protocols (57.1%). Moreover, 6 isolated MPFL reconstruction protocols (19.4%) and 3 MPFL reconstruction–TTO protocols (42.9%) recommended use of a patellar stabilizing brace postoperatively.ConclusionsThere is substantial variability among rehabilitation protocols after MPFL reconstruction, as well as MPFL reconstruction plus TTO, including postoperative range of motion, weight-bearing status, and time until return to sport. Furthermore, many online protocols from academic orthopaedic surgery residency programs and private practices in the United States fail to mention several of these parameters, most notably functional testing to allow patients to return to sport.Clinical RelevanceProper rehabilitation after MPFL reconstruction with or without TTO is an important factor to a patient’s postoperative outcome. This study outlines the variability in online rehabilitation protocols after MPFL reconstruction with or without TTO published online by academic residency programs and private practice institutions.

Effect of biomechanical footwear on upper and lower leg muscle activity in comparison with knee brace and normal walking

AimTo evaluate the activity of knee stabilizing muscles while using custom-made biomechanical footwear (BF) and to compare it when walking barefoot and with a knee brace (Unloader®). MethodsSeventeen healthy working-aged (mean age: 29 years; standard deviation: 8 years) individuals participated. The knee brace was worn on the right knee and BF in both legs. Surface electromyography (sEMG) data was recorded bilaterally from vastus medialis (VM), semitendinosus (ST), tibialis anterior (TA) and lateral gastrocnemius (LG) muscles during walking, and repeated-measures ANOVA with a post-hoc t-test was used to determine differences between the different walking modalities (barefoot, brace and BF). ResultsAveraged sEMG was significantly higher when walking with BF than barefoot or knee brace in the ST muscles, in the right LG, and left TA muscle. It was significantly lower when walking with the brace compared to barefoot in the right ST and LG muscles, and left TA muscle. Analysis of the ensemble-averaged sEMG profiles showed earlier activation of TA muscles when walking with BF compared to other walking modalities. ConclusionBF produced greater activation in evaluated lower leg muscles compared to barefoot walking. Thus BF may have an exercise effect in rehabilitation and further studies about its effectiveness are warranted.

Biomechanical Study of a Tricompartmental Unloader Brace for Patellofemoral or Multicompartment Knee Osteoarthritis

Objective: Off-loader knee braces have traditionally focused on redistributing loads away from either the medial or lateral tibiofemoral (TF) compartments. In this article, we study the potential of a novel “tricompartment unloader” (TCU) knee brace intended to simultaneously unload both the patellofemoral (PF) and TF joints during knee flexion. Three different models of the TCU brace are evaluated for their potential to unload the knee joint.Methods: A sagittal plane model of the knee was used to compute PF and TF contact forces, patellar and quadriceps tendon forces, and forces in the anterior and posterior cruciate ligaments during a deep knee bend (DKB) test using motion analysis data from eight participants. Forces were computed for the observed (no brace) and simulated braced conditions. A sensitivity and validity analysis was conducted to determine the valid output range for the model, and Statistical Parameter Mapping was used to quantify the effectual region of the different TCU brace models.Results: PF and TF joint force calculations were valid between ~0 and 100 degrees of flexion. All three simulated brace models significantly (p < 0.001) reduced predicted knee joint loads (by 30–50%) across all structures, at knee flexion angles >~30 degrees during DKB.Conclusions: The TCU brace is predicted to reduce PF and TF knee joint contact loads during weight-bearing activity requiring knee flexion angles between 30 and 100 degrees; this effect may be clinically beneficial for pain reduction or rehabilitation from common knee injuries or joint disorders. Future work is needed to assess the range of possible clinical and prophylactic benefits of the TCU brace.

Development and experimental study of steel beam-through framed connections with T-type curved knee braces for improving seismic performance

This paper introduces beam-through framed connections (BTFCs) with innovative T-type curved knee braces (TCKBs). Beam-through steel frame (BTF) is an emerging system using strip braces as lateral force-resisting components. Even though strip braces can provide high strength and stiffness, they will get slack after yielding since compressive buckling, and dynamic characteristics of the system will be unstable. Innovative T-type curved knee braces are intended to provide stable strength and full energy dissipating capacity. By equipping a BTF with TCKBs, seismic performance of the system can be improved, and architectural space can be released. In order to verify the reasonability of construction details, investigate failure modes and damage sequences, a total of three full-scale specimens with different TCKBs were designed and tested under incremental cyclic loading. Results of tests demonstrated the expected stable hysteretic behaviors, controllable damage sequences and superior ductility. Damages were mainly concentrated on knee braces within 2.0% drift ratio. With subsequent increase of the loading amplitude, plasticity was observed on beam-to-column connection area. Tested knee braces started to be fractured when drift ratio reached 7.0% approximately which was treated as the failure mode. In the final stage of loading, webs of knee braces fractured one after another. After web of four knee braces fractured, specimen could still exhibit partial strength derived from damaged braces and semi-rigid beam-to-column connection which indicated the safety storage after failure mode.

Immediate Effect of Valgus Knee Brace and Lateral Wedge Insole on Gait Parameters in Medial Compartment Osteoarthritis of Knee: A Cross-sectional Study

Introduction: Orthoses have been reported to improve function and symptom reduction in knee Osteoarthritis (OA) of the medial compartment. Biomechanical changes introduced instantly in the gait with the use of orthoses can be evaluated to understand their effectiveness. Aim: To determine and compare the immediate effect of valgus knee brace and Lateral Wedge Insole (LWI) on gait parameters in medial compartment OA knee patients. Materials and Methods: This was a cross-sectional study conducted in the Department of Physical Medicine and Rehabilitation at a tertiary centre from August 2018 to July 2019. A 56 patients of knee OA (Kellgren-Lawrence system grades 2 or 3) were assessed by instrumented gait analysis before and just after orthotic fitment. Gait parameters related to External Knee Adduction Moment (EKAM) (e.g., maximum Ground Reaction Force (mGRF), vertical Ground Reaction Forces (vGRF), Varus Angle (VA) were assessed via motion capture during walking, in all four conditions: barefoot (B), LWI, valgus Knee brace (KB), Combined (C) i.e., (LW+KB). Statistical analysis was done using International Business Machines (IBM) Statistical Package for Social Sciences (SPSS) version 24.0. To find the significant difference in given parameters, repeated measure Analysis of Variance (ANOVA) was applied taking p-value &lt;0.05. Results: A total of 56 patients (13 men, 43 women) mean age of 58.04±5.8 years and a mean Body Mass Index (BMI) of 27.4±3.5 kg/m2 were analysed. A 35 patients had OA grade 2 and 21 were classified as grade 3. No significant difference in mean vGRF and VA values was found among LW, KB and C (p=0.118) and (p=0.894) throughout the stance phase. The significant difference was in mean mGRF values during initial stance phase (0-20% of gait cycle) (p=0.036). Conclusion: The orthoses may not swiftly provide beneficial biomechanical changes in gait parameters of medial OA knee patients.