Predicting dynamic knee joint load with clinical measures in people with medial knee osteoarthritis

Knee joint loading, as measured by the knee adduction moment (KAM), has been implicated in the pathogenesis of knee osteoarthritis (OA). Given that the KAM can only currently be accurately measured in the laboratory setting with sophisticated and expensive equipment, its utility in the clinical setting is limited. This study aimed to determine the ability of a combination of four clinical measures to predict KAM values.Three-dimensional motion analysis was used to calculate the peak KAM at a self-selected walking speed in 47 consecutive individuals with medial compartment knee OA and varus malalignment. Clinical predictors included: body mass; tibial angle measured using an inclinometer; walking speed; and visually observed trunk lean toward the affected limb during the stance phase of walking. Multiple linear regression was performed to predict KAM magnitudes using the four clinical measures. A regression model including body mass (41% explained variance), tibial angle (17% explained variance), and walking speed (9% explained variance) explained a total of 67% of variance in the peak KAM.Our study demonstrates that a set of measures easily obtained in the clinical setting (body mass, tibial alignment, and walking speed) can help predict the KAM in people with medial knee OA. Identifying those patients who are more likely to experience high medial knee loads could assist clinicians in deciding whether load-modifying interventions may be appropriate for patients, whilst repeated assessment of joint load could provide a mechanism to monitor disease progression or success of treatment.     

The association of external knee adduction moment with biomechanical variables in osteoarthritis: A systematic review

ContextOsteoarthritis (OA) is a musculoskeletal disorder primarily affecting the older population and resulting in chronic pain and disability. Biomechanical variables, associated with OA severity such as external knee adduction moment (KAM) and joint malalignment, may affect the disease process by altering the bone-on-bone forces during gait.ObjectiveTo investigate the association between biomechanical variables and KAM in knee OA.MethodA systematic search for published studies' titles and abstracts was performed on Ovid Medline^®, Cumulative index to Nursing and Allied Health, PREMEDLINE, EBM reviews and SPORTDiscus. Fourteen studies met the inclusion criteria and were considered for the review.ResultsThe magnitude and time course of KAM during gait appeared to be consistent across laboratories and computational methods. Only two of the included studies that compared patients with OA to a control group reported a higher peak KAM for the OA group. Knee adduction moment increased with OA severity and was directly proportional to varus malalignment. Classifying the patients on the basis of disease severity decreased the group variability, permitting the differences to be more detectable.ConclusionsBiomechanical variables such as varus malalignment are associated with KAM and therefore may affect the disease process. These variables should be taken into considerations when developing therapeutic interventions for individuals suffering from knee OA.     

Knee adduction moment is correlated with the increase in medial meniscus extrusion by dynamic ultrasound in knee osteoarthritis

BackgroundAn increase in medial meniscus extrusion (MME) due to abnormal biomechanical stress leads to knee osteoarthritis (OA) progression. MME evaluation during walking is a key method of detecting dynamic changes in the meniscus, and in combination with motion analysis, can provide a deeper understanding of the mechanisms involved in the increase of MME.ObjectiveTo validate the feasibility of MME dynamic evaluation in combination with a motion analysis system based on the correlation between the increase in MME and biomechanical factors.MethodsTwenty-three knees from 23 patients with mild to moderate knee OA were analysed in this study. The medial meniscus during walking was evaluated by ultrasound. The increase in MME was calculated as the difference between the minimum and maximum MME during walking. A three-dimensional motion analysis system was synchronised with the ultrasound and then, biomechanical factors such as knee moment and ground reaction force were evaluated.ResultsThe wave patterns of the mediolateral and vertical components of ground reaction forces and knee adduction moment were similar to those in the MME based on a high cross-correlation coefficient (>0.8). The increase in MME was significantly correlated with the peak value of the knee adduction moment (r = 0.54, P = 0.0073) but not with the mediolateral and vertical components of the ground reaction force.ConclusionThe findings show that knee adduction moment is correlated with an increase in MME during walking and indicates the validity and feasibility of the dynamic evaluation of MME in combination with a motion analysis system.     

Gait retraining using real-time feedback in patients with medial knee osteoarthritis: Feasibility and effects of a six-week gait training program

Background

The knee adduction moment (KAM) is often elevated in medial knee osteoarthritis (KOA). The aim of this study was to evaluate effects on KAM and patient-reported outcomes of a six-week gait training program.

Increased trunk flexion may underlie elevated knee flexor activity in people with knee osteoarthritis

BackgroundPrevious research has demonstrated elevated activation of the knee flexor muscles in people with knee osteoarthritis. People with this condition have also been observed to walk with increased trunk flexion; this may alter biomechanical loading patterns and change muscle activation profiles. Therefore, the aim of this study was to understand the biomechanical effect of increasing trunk flexion during walking.MethodsKinetic and EMG data were collected from a sample of 20 people with knee osteoarthritis and a sample of 20 healthy matched controls during normal walking. Using a biofeedback protocol, participants were subsequently instructed to walk with a 5° increase in trunk flexion. Sagittal moments, muscle activations and co-contractions were then compared across a window in early stance with a two-way ANOVA test.ResultsWhen trunk flexion was increased, there was a corresponding increase in activity of the medial and lateral hamstrings and gastrocnemius muscles as well as a rise in medial co-contraction. This effect was consistent across the two groups. The most pronounced effect was observed for semitendinosus, which showed a dramatic change in activation profile in the healthy group and a 127% increase in activation during early stance.ConclusionsThis is the first study to demonstrate that increased trunk flexion in people with knee osteoarthritis may explain, to some degree, the elevated knee flexor activity and medial co-contraction which is associated with this disease. These findings motivate further work to understand the therapeutic potential of interventions designed to improve postural alignment.     

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

Background

Analysis of dynamic knee loading during gait is essential to prevent mechanical failures following total knee arthroplasty. External knee adduction moment during gait is the primary factor producing medial joint reaction force, and an increase in the moment is directly related to an increase in the medial compartment load on the knee.

不同硬度楔形鞋垫对膝关节内翻力矩的影响

目的研究不同硬度楔形鞋垫在步行状态下对膝关节内翻力矩的影响。方法 15名健康成年男性受试者穿着不同硬度楔形鞋垫进行步态测试,通过光学运动捕捉系统和地面测力板收集运动学和动力学数据,经Visual3D软件计算得出膝关节内翻力矩,分析在3种不同步行状况下(仅穿鞋、鞋中放入软、硬楔形鞋垫)膝关节内翻力矩峰值的差异。结果与较软的楔形鞋垫相比,较硬的楔形鞋垫可使膝关节内翻力矩的第1个峰值降低9.3%,第2个峰值降低9.7%,差异具有统计学意义。结论楔形鞋垫增加一定的硬度能更多降低膝关节内侧间室的压力,减轻关节面的磨损,从而可能缓解膝关节炎症状。     

Inter-laboratory comparison of knee biomechanics and muscle activation patterns during gait in patients with knee osteoarthritis

BackgroundGait analysis has been used for decades to quantify knee function in patients with knee osteoarthritis; however, it is unknown whether and to what extent inter-laboratory differences affect the comparison of gait data between studies. Therefore, the aim of this study was to perform an inter-laboratory comparison of knee biomechanics and muscle activation patterns during gait of patients with knee osteoarthritis.MethodsKnee biomechanics and muscle activation patterns from patients with knee osteoarthritis were analyzed, previously collected at Dalhousie University (DAL: n = 55) and Amsterdam UMC, VU medical center (VUmc: n = 39), using their in-house protocols. Additionally, one healthy male was measured at both locations. Both direct comparisons and after harmonization of components of the protocols were made. Inter-laboratory comparisons were quantified using statistical parametric mapping analysis and discrete gait parameters.ResultsThe inter-laboratory comparison showed offsets in the sagittal plane angles, moments and frontal plane angles, and phase shifts in the muscle activation patterns. Filter characteristics, initial contact identification and thigh anatomical frame definitions were harmonized between the laboratories. After this first step in protocol harmonization, the offsets in knee angles and sagittal plane moments remained, but the inter-laboratory comparison of the muscle activation patterns improved.ConclusionsInter-laboratory differences obstruct valid comparisons of gait datasets from patients with knee osteoarthritis between gait laboratories. A first step in harmonization of gait analysis protocols improved the inter-laboratory comparison. Further protocol harmonization is recommended to enable valid comparisons between labs, data-sharing and multicenter trials to investigate knee function in patients with knee osteoarthritis.     

The condition of the contralateral knee may induce different degrees of knee extensor strength asymmetry and affect functionality in individuals with unilateral or bilateral osteoarthritis

BackgroundLoss of knee extensor strength in individuals with knee osteoarthritis (KOA) may induce inter-limb strength asymmetries and alter functionality. The aims were to analyse whether the condition of the uninvolved knee (advanced to severe KOA or no affection) may induce different degrees of knee extensor strength asymmetry in individuals with KOA and to study whether functionality may differ in cases of unilateral or bilateral KOA.MethodsSixty-eight subjects with advance-to-severe KOA were categorized into two groups (unilateral or bilateral KOA). The knee extensor strength ratio (KESR), and self-reported and performance-based functionality were analysed and compared. Sex and age were independent factors. One- and two-way analysis of variance assessed for significant between-group differences (95% confidence interval (CI)).ResultsParticipants with unilateral KOA presented with 20% knee extensor strength asymmetry. The mean difference with the bilateral KOA group in terms of Knee Extensors Strength Ratio was 0.2 (95% CI 0–0.3; P = 0.021), of the Oxford Knee Scale score was 4.2 (95% CI 3.4–5.1; P = 0.037), and of the Timed Up and Go was 1.3 s (95% CI 0.5–2.2; P > 0.05). There were significant sex and age interactions (P < 0.05).ConclusionsIndividuals with unilateral or bilateral KOA present with different degrees of knee extensor strength asymmetry. The non-affected knee seems to help to better develop functional tasks in cases of unilateral condition. The findings may help the design of tailored strengthening interventions in which each knee condition in individuals with KOA should be considered.     

Changes of gait patterns and muscle activity after intraarticular treatment of patients with osteoarthritis of the knee: A prospective, randomised, doubleblind study

Evaluation of gait performance and muscle activity patterns as well as clinical efficacy and safety after intraarticular injections with hyaluronan (Ostenil) compared with triamcinolone (Volon A10) injections in patients with knee osteoarthritis.This was a prospective, randomised, double-blind clinical trial evaluating the influence of five injections of hyaluronan or triamcinolone on gait pattern and muscle activity. For the clinical evaluation visual analogue scale, Lequesne index, and Knee Society Score were used. Quality of life was estimated with the SF-36.The definitive analysis was performed on the population who received all five injections and were examined in the two follow-up visits. Fifteen patients were treated with triamcinolone and 20 with hyaluronan. Significant improvement could be demonstrated for pain scale and clinical scores in both groups. Gait patterns showed significant differences only for Knee Abduction Moment (p = 0.007) in the hyaluronan group and for Maximum Vertical Force 1 and 2 between the both groups in the follow up visit (p = 0.018) (p = 0.019). In both groups there was no significant difference regarding to muscle activity. Quality of life showed no changes in all visits between the groups.Hyaluronan was not superior to triamcinolone. The results suggest that treatment with hyaluronan can reduce pain and improve knee function. A significant short term improvement in gait and muscle activity patterns, however, was not observed, in either hyaluronan or triamcinolone.     

CR假体与PS假体全膝关节置换治疗膝骨性关节炎合并膝外翻畸形的疗效分析

目的 比较后交叉韧带保留型（CR）假体与后方稳定型（PS）假体行人工全膝关节置换术（TKA）治疗膝骨性关节炎合并膝外翻畸形的临床疗效。方法 回顾性分析南昌大学附属赣州医院关节外科2019年5月至2021年5月收治的60例（60膝）膝骨性关节炎合并膝外翻畸形患者资料,均为单侧置换。30例采用CR假体行TKA治疗（CR组）,30例采用PS假体行TKA治疗（PS组）。比较两组患者的手术时间、术中失血量、术后引流量、术后3 d血红蛋白（Hb）下降量及深静脉血栓发生情况;比较两组患者手术前后膝外翻角;比较两组患者术后1周、1个月、3个月、6个月、1年疼痛视觉模拟评分（VAS）、膝关节活动度（ROM）、美国特种外科医院膝关节评分（HSS）。结果 60例患者均顺利完成TKA手术,所有患者随访13 ～ 28个月,平均（18.51±0.90）个月。CR组术中出血量、术后引流量、术后3 d的Hb下降量较PS组减少（P＜0.05）;两组手术时间相当、术后均无深静脉血栓发生,差异无统计学意义（P＞0.05）;两组手术前后膝外翻角的比较差异无统计学意义（P＞0.05）;CR组术后1周、1个月VAS评分较PS组更低（P＜0.05）,两组术后3个月、6月、1年VAS评分比较差异无统计学意义（P＞0.05）;CR组术后1周、1个月、3个月膝关节ROM和HSS评分优于PS组（P＜0.05）,两组术后6个月、1年膝关节ROM和HSS评分比较差异无统计学意义（P＞0.05）。结论 采用CR或PS假体行TKA手术治疗膝骨性关节炎合并膝外翻畸形均可有效纠正膝关节畸形、减轻膝关节疼痛、改善膝关节活动度及功能,取得满意临床疗效;但相对PS假体,CR假体保留了后交叉韧带,减少了股骨髁部截骨量,从而减少手术出血,更好减轻早期术后疼痛,有助于TKA术后早期功能康复。     

Effect of whole body vibration exercise on muscle strength and proprioception in females with knee osteoarthritis

The purpose of this study was to assess the effect of whole body vibration (WBV) exercise on muscle strength and proprioception in female patients with osteoarthritis in the knee (knee-OA). A single blinded, randomised, controlled trial was performed in an outpatient clinic on 52 female patients diagnosed with knee-OA (mean age 60.4 years ± 9.6). They were randomly assigned to one of 3 groups: 1. WBV-exercise on a stable platform (VibM; n = 17 (mean age, 61.5 ± 9.2)), WBV-exercise on a balance board (VibF; n = 18 (mean age, 58.7 ± 11.0)), or control group (Con; n = 18 (mean age, 61.1 ± 8.5)).The WBV groups trained twice a week for 8 weeks, with a progressively increasing intensity. The WBV groups performed unloaded static WBV exercise.The following were measured: knee muscle strength (extension/flexion) and proprioception (threshold for detection of passive movement (TDPM)). Self-reported disease status was measured using WOMAC.It was found that muscle strength increased significantly (p < 0.001) in VibM compared to Con. Isometric knee-extension significantly increased (p = 0.021) in VibM compared to Con. TDPM was significantly improved (p = 0.033) in VibF compared to Con, while there was a tendency (p = 0.051) for VibM to perform better compared to Con. There were no effects in the self-reported disease status measures.This study showed that the WBV-exercise regime on a stable platform (VibM) yielded increased muscle strength, while the WBV-exercise on a balance board (VibF) showed improved TDPM. The WBV-exercise is a time-saving and safe method for rehabilitation of women with knee-OA.     

膝骨性关节炎关节周围肌肉功能改善的治疗评价

背景：膝骨性关节炎患者存在膝关节周围肌肉萎软无力,综合治疗辅助膝关节周围肌力训练,可以明显缓解症状,恢复膝关节周围肌肉力量。 目的：用等速肌力测试膝骨性关节炎患者综合治疗前后膝关节周围肌肉的功能变化与膝关节功能的相关性,探讨膝骨性关节炎的病理机制,为临床康复及治疗提供依据。 方法：筛选Ⅱ期及Ⅲ期30例单侧膝骨性关节炎患者,用美国特种外科医院膝关节评分系统判定膝关节的功能情况,标准目测类比量表评分评定患者疼痛情况;测定治疗前膝骨性关节炎患者膝关节周围肌肉功能状况;对Ⅱ期及Ⅲ期膝骨性关节炎患者进行最少1个月的主动股四头肌等长性肌肉收缩运动及口服塞来昔布并关节腔内注射透明质酸钠的综合治疗,测定治疗后的膝关节肌肉功能状况,随访评价美国特种外科医院膝关节评分及标准目测类比量表评分。 结果与结论：与健侧相比,Ⅱ期及Ⅲ期膝骨关节炎患者屈伸肌峰力矩与作功量在60 (°)/s测试及180 (°)/s测试时,患侧肌力明显下降(P < 0.05)。经综合治疗后,膝骨性关节炎患者美国特种外科医院膝关节评分明显增加(P < 0.05),而标准目测类比量表疼痛评分明显下降(P < 0.05),患侧肌力明显增强(P < 0.05);且治疗后膝骨关节炎患者患侧肌力与健侧的差异无显著性意义(P > 0.05),但综合治疗前后膝骨性关节炎患者患侧膝腘绳肌股四头肌峰力矩比值在60 (°)/s测试中差异无显著性意义(P > 0.05),而在180 (°)/s测试测试中差异有显著性意义(P < 0.05)。提示膝骨性关节炎患者存在膝关节周围肌力下降,通过肌肉功能锻练配合有效的止痛、营养关节药物的综合治疗,可以明显缓解症状,提高肌肉力量,恢复患者膝关节功能。     

A mathematical modelling study investigating the influence of knee joint flexion angle and extension moment on patellofemoral joint reaction force and stress

BackgroundPatellofemoral pain (PFP) is the most common orthopaedic condition among runners. Individuals with PFP exhibit greater patellofemoral joint (PFJ) reaction force and stress when compared with pain-free controls. However, it is not clear whether PFJ reaction force and stress are the highest (or lowest) when knee joint flexion angle and extension moment are in which combinations. We aimed to investigate the influence of knee joint flexion angle and extension moment on PFJ reaction force and stress.MethodsA PFJ sagittal model was used to quantify PFJ reaction force and stress. Based on the public dataset of the previous study, peak knee joint flexion angle and extension moment at various running speeds was calculated. Based on the calculated peak value, simulation ranges were set to knee joint flexion angle of 10–45° and extension moment of 0–240 Nm. The quadriceps force, effective lever arm length at quadriceps muscle, and PFJ contact area were determined as a function of the knee joint flexion angle and extension moment, and finally PFJ forces and stress were estimated.ResultsPFJ reaction force increased as the knee flexion angle and extension moment increased. Although PFJ stress also increased as the knee extension moment increased, it was at the highest and lowest at 10° and about 30° knee joint flexion angles, respectively.ConclusionsIncorporating knee flexion posture (approximately 30°) during running may help in reducing PFJ stress, which would be useful in the prevention of pain and act as an optimal treatment program for PFP.     

单髁置换术与全膝关节置换术在治疗膝内侧单间室骨性关节炎术后早期关节遗忘度中的比较

目的 比较膝关节单髁置换术（unicompartmental knee arthroplasty, UKA）与全膝人工关节置换术（total knee arthroplasty, TKA）治疗膝内侧单间室骨性关节炎的早期膝关节功能评分与关节遗忘度评分,评价并分析两类术式在早期关节遗忘度评分方面的差异。方法 回顾性分析上海中医药大学附属光华医院关节外科2016年10月至2020年10月期间行全膝关节置换术及膝关节单髁置换术患者共296例,根据不同手术方式进行分组,其中TKA组共144例,UKA组共152例。出院后对患者术后1、3、6、12、24个月进行门诊复查,进行关节遗忘度评分、膝关节功能HSS评分、目测类比评分（VAS评分）。结果 (1)296例患者获得24～37个月的随访,平均随访（30.41±6.93）个月;(2)术后24个月TKA组与UKA组的HSS评分与VAS评分均明显好于术前,组内比较差异具有统计学意义（P<0.05）;(3)两组患者术后24个月膝关节VAS评分的改善程度差异无统计学意义（P>0.05）,UKA组的HSS评分改善程度好于TKA组,且差异有统计学意...     

Isokinetic strengthening and neuromuscular electrical stimulation protocol impact on physical performances,functional status and quality of life in knee osteoarthritis overweight/obese women

BackgroundKnee muscle weakness associated with overweight/obesity can lead to impairment of vital daily function in knee osteoarthritis patients. This study investigated the effect of a knee eccentric isokinetic muscle strength (IMS) training program combined with neuromuscular electrical stimulation (NMES) on muscle strength and flexibility, joint ROM, functional status, physical performance, and quality of life in knee osteoarthritis overweight/obese women.MethodsThirty-six women were randomized into three groups, two experimental groups (EG) and a control group following a classic rehabilitation program. During 6 weeks of two sessions/week, one of the two EGs performed an IMS program (ISO.G); the other underwent combined IMS and NMES training (ISO + NMES.G). All patients were evaluated with clinical examination, isokinetic test at 60°/s and 240°/s speeds, physical performance tests related to activities of daily living, and Knee injury and Osteoarthritis Outcome Score (KOOS) quality of life questionnaire, before and after the intervention.ResultsIn the 10-m walk, chair stand, stair climb and monopodal stance tests, muscle flexibility and quality of life scores showed significant improvement for ISO.G (P = 0.000) and ISO + NMES.G (P = 0.000). Concentric strength at 240°/s was improved in ISO + NMES.G (P = 0.000) unlike the muscle strength at 60°/s (quadriceps, P = 0.104; hamstrings, P = 0.171), force asymmetry (P = 0.481) and post-intervention joint ROM (P = 0.309).ConclusionsThe combination of IMS and NMES shows significant superiority over the usual rehabilitation program for the majority of the parameters measured for optimal management of knee osteoarthritis.     

Validity and reliability of smartphones in measuring joint position sense among asymptomatic individuals and patients with knee osteoarthritis: A cross-sectional study

BackgroundQuantifying proprioception deficit in patients with osteoarthritis (OA) may be important in evaluating treatment effectiveness. This study investigated the concurrent and known-groups validity as well as test–retest reliability of a smartphone application in assessing joint position sense (JPS) in asymptomatic individuals and patients with knee OA.MethodsSixty-four knees, from 16 asymptomatic controls and 16 patients with bilateral OA, were assessed twice with a 1-week interval in between. The smartphone Goniometer Pro application and isokinetic dynamometer simultaneously quantified JPS, in terms of absolute repositioning error (RE) angle, during active and passive limb movements at selected angles.ResultsBoth devices showed moderate to almost perfect correlations in measuring JPS; whether active (intra-class correlation coefficient (ICC) >0.87) or passive (ICC >0.97). The mean RE angle differences between the two devices were <0.77° (passive JPS) and <2.76° (active JPS). Both devices were capable of distinguishing patients and asymptomatic controls at 55° and 80°. The smartphone showed moderate test–retest reliability of active JPS measurement (ICC = 0.51) in the two groups, similar to that of the isokinetic dynamometer (ICC = 0.62), but with a high measurement error.ConclusionsSmartphone application is a valid alternative to the isokinetic dynamometer in assessing JPS in patients with knee OA and asymptomatic controls. The two devices could distinguish patients and asymptomatic volunteers during passive JPS measured at 55° and 80°. Both devices have moderate reliability in quantifying active JPS, but reliability results should be considered with caution.     

右归丸对膝骨关节炎模型鼠软骨组织显微结构及热休克蛋白90α蛋白表达的影响

目的:观察右归丸对膝骨关节炎(knee osteoarthritis,KOA)模型大鼠软骨组织显微结构和热休克蛋白90α(heat shock protein 90α,Hsp90α)蛋白表达的影响,进一步揭示右归丸防治KOA的机制。方法:将大鼠随机分为假手术对照组、KOA模型组、硫酸氨基葡萄糖组和右归丸(高、中、低剂量)组,每组10只。采用改良Hulth法制备大鼠KOA模型,分别予相应药物灌胃8周。HE染色法观察软骨组织的形态学变化,并进行Makin评分;应用免疫组化法检测各组大鼠软骨组织Hsp90α、纤连蛋白(fibronectin,Fn)和Ⅱ型胶原(collagen typeⅡ,COL-Ⅱ)的表达;RT-qPCR法检测各组大鼠软骨组织Hsp90α、白细胞介素1β(interleukin-1β,IL-1β)、基质金属蛋白酶3(matrix metalloproteinase-3,MMP-3)和MMP-13的mRNA表达水平,应用Western blot法检测各组大鼠软骨组织Hsp90α和COL-Ⅱ的表达。结果:与假手术组比较,KOA模型组大鼠软骨组织Makin评分明显升高,软骨组织H...     

The role of the patellar tendon angle and patellar flexion angle in the interpretation of sagittal plane kinematics of the knee after knee arthroplasty: A modelling analysis

Background

Many different measures have been used to describe knee kinematics. This study investigated the changes of two measures, the patellar tendon angle and the patellar flexion angle, in response to variations in the geometry of the knee due to surgical technique or implant design.

Mechanical-based therapies may reduce pain and disability in some patients with knee osteoarthritis: A systematic review with meta-analysis

BackgroundMechanical-based therapies are not yet recommended to manage osteoarthritis (OA). This systematic review and meta-analysis aim to assess the effects of passive mechanical-based therapies (isolated or combined with other therapies) on patients with knee OA compared to placebo, other isolated or combined interventions.MethodsPubmed, Cochrane, Web of Science and EMBASE were searched up to December 2020. We included randomized and non-randomized trials using therapeutic ultrasound, phonophoresis, extracorporeal shockwave therapy (ESWT) and vibration (single or combined with other therapies) compared to placebo, and/or other physical therapies groups. Biochemical, patient-reported, physical and imaging outcome measures were retrieved. We judged risk of bias using the RoB2 tool for randomized studies, the ROBINS-I tool for non-randomized studies, and the GRADE to interpret certainty of results.ResultsWe included 77 clinical studies. Ultrasound and ESWT statistically improved pain and disability comparing to placebo (combined or not with other therapies), and when added to other therapies versus other therapies alone. Ultrasound was statistically inferior to phonophoresis (combined or not with other therapies) in reducing pain and disability for specific therapeutic gels and/or combined therapies. Vibration plus exercise statistically improved pain relief and function versus exercise alone. All meta-analyses showed very-low certainty of evidence, with 15 of 42 (38%) pooled comparisons being statistically significant (weak to large effect).ConclusionsDespite the inconsistent evidence with very-low certainty, the potential benefits of passive mechanical-based therapies should not be disregard and cautiously recommended that clinicians might use them in some patients with knee OA.