Knee Muscle Research Articles

ACL Reconstruction: Which Additional Physiotherapy Interventions Improve Early-Stage Rehabilitation? A Systematic Review

Despite the restoration of the mechanical stability of the knee joint after ACL reconstruction (ACLR), patients often experience postoperative limitations. To our knowledge, there are no systematic reviews analyzing additional physiotherapy interventions implementing standard rehabilitation programs in the early postoperative phase after ACLR. The objective of this study was to analyze the additional physiotherapy interventions implemented in standard rehabilitation programs that improve early-stage ACLR rehabilitation. For this systematic review, we followed the PRISMA guidelines. In March 2022 we conducted a literature review using electronic databases. Primary outcomes were pain, edema, muscle strength, ROM, and knee function. The risk of bias and scientific quality of included studies were assessed with the RoB 2, ROBINS-I and PEDro scale. For the review, we included 10 studies that met the inclusion criteria (total n = 3271). The included studies evaluated the effectiveness of Kinesio Taping, Whole-body vibration, Local Vibration Training, Trigger Point Dry Needling, High Tone Power Therapy, alternating magnetic field, and App-Based Active Muscle Training Program. Most of the additional physiotherapy interventions improved pain, edema, ROM, knee muscle strength, or knee function in early-stage postoperative ACL rehabilitation. Except for one study, no adverse events occurred in the included studies, which demonstrates the safety of the discussed physiotherapy interventions. Further in-depth research is needed in this area.

Correlation Between Knee Muscle Strength and Maximal Cycling Speed Measured Using 3D Depth Camera in Virtual Reality Environment

Correlation Between Knee Muscle Strength and Maximal Cycling Speed Measured Using 3D Depth Camera in Virtual Reality Environment

Photobiomodulation Therapy Using Infrared (808 nm) Low Level Laser Therapy Associated with Strength Training in Knee Osteoarthritis: A Randomized placebo-controlled clinical trial

Mechanisms for significant clinical and statistical benefits of photobiomodulation (PBMT) in the treatment of knee osteoarthritis (KOA) include anti-inflammatory effects, optimization of tissue repair, improved muscle function and analgesia. The effectiveness of (PBMT) associated with strength training (ST), in the form of strength training, has been investigated in randomized clinical trials, but the results are not well clarified. The aim of this study was to evaluate the effects of ST associated with PBMT on joint pain intensity, range of motion, physical function and muscle strength of the quadriceps femoris and hamstrings in patients diagnosed with KOA. Twenty-eight adult patients of both genders with KOA were randomly distributed in 2 treatment groups, performed 3 times a week, for 6 weeks: ST Group (ST), submitted to stretching, self- mobilization, muscle strengthening and sensorimotor training and ST and STP Group (STP), submitted to the same program as the ST followed by infrared laser irradiation (Therapy XT, DMC, São Carlos, Brasil, l= 808 nm, P= 100mW, 5 points in the medial joint region and 4 points lateral, 3 J/point, 30 s/point). Blinded evaluators assessed pain at movent and no movement and range of motion using Analogic Visual Scale and goniometry, respectively. To assess physical function, the WOMAC questionnaire (Western Ontario and MacMaster University Osteoarthritis Index) and functional tests were used: Sit and stand test; 2 min-walk test. The muscular strength of the quadriceps and hamstrings were measured using an isometric dynamometer. The evaluations were performed in 4 moments: before (EV0), during (EV1: 3 weeks of treatment), at the end (EV2: after 6 weeks of treatment) and 30 days after the end of treatment (follow-up). The STP group showed a significant reduction in pain intensity at rest and at movement in EV1, as well as, significant improvement in relation to stiffness, total WOMAC and knee flexion amplitude, an improvement in physical function and an increase in muscle strength of quadriceps femoris when compared to ST group (p <0.05). In the assessment of the strength of the hamstring muscles, there was no significant difference between the groups at any time evaluated (p> 0.05). ST associated with PBMT had greater effects in reducing joint pain intensity, active knee flexion, physical function and muscle strength, especially in the quadriceps femoris, than strength training alone in patients with KOA.

Immunohistochemical analysis of the quadriceps femoris muscle before and after total knee arthroplasty

BackgroundThe number of total knee arthroplasties (TKA) has increased steadily with the aging of the population. This surgical procedure is recognized for its success in pain relief and restoration of knee function. However, decreased quadriceps femoris (QF) muscle strength after TKA is frequently observed but with unknown etiology. Evidence suggests that the location of the operative incision (i.e., surgical access) can influence QF muscle structure and function. The present study aimed to assess the fiber type composition, structure and assembly of the QF's vastus medialis (VM) and vastus lateralis (VL) muscles before and after TKA. MethodsMuscle biopsies (VM and VL muscles) were collected from patients previously submitted to TKA via the medial parapatellar route and undergoing TKA revision (main group, n = 9) and patients with osteoarthrosis (OA) who were due to undergo TKA (control group: n = 18). The biopsied muscle tissue was prepared, stored, and then sectioned in a cryostat at −25 °C. The tissue sections were evaluated using routine staining techniques in pathological anatomy and histochemistry. ResultsThe normal mosaic pattern of the medial and lateral knee muscles was observed in the main and control groups, with no evidence of peripheral nerve damage. Notably, 88.9 % of the patients exhibited mild to severe VL atrophy, while only 11.1 % of patients in the control group presented this feature (P < 0.001). ConclusionsThe medial parapatellar incision for TKA surgical access does not generate definitive morphological changes in the VM and VL muscle fibers but may contribute to VL atrophy.

Association Between Knee Extension Strength and Functional Capacity After Intensive Care Unit Discharge: A 6-Mo Prospective Cohort Study.

Assessing functional improvement after intensive care unit discharge is particularly challenging. The aim of this study was to measure the association between (1) changes in knee extension muscle strength or quadriceps femoris and rectus femoris muscle thickness and (2) changes in functionality/function-related measurements in post-intensive care unit patients. This prospective cohort study included adult patients without previous disability, consecutively selected after intensive care unit discharge. Some parameters, such as Short-Form 36, 6-min walking test, 1-min sit-to-stand, and Short Physical Performance Battery, were measured at baseline and 3 and 6 mos after discharge. Correlations were assessed and regression models were built to assess the association between evolution in knee extension strength or muscle thickness and evolution in functional tests. Thirty patients completed the follow-up. Moderate correlation was found between knee extension strength change and Short-Form 36 physical functioning (correlation coefficient [ ρ ] = 0.53), 6-min walking test ( ρ = 0.38), 1-min sit-to-stand ( ρ = 0.52), and Short Physical Performance Battery ( ρ = 0.38). Baseline values and changes in knee extension strength moderately predicted evolution in Short-Form 36 physical functioning ( r2 = 0.32, P = 0.006). Changes in muscle thickness were overall not associated with changes in functional variables. Changes in knee extension muscle strength may inform on functional progression over time after intensive care unit discharge, although confirmatory studies are needed.

Agreement Between Isokinetic Dynamometer and Hand-held Isometric Dynamometer as Measures to Detect Lower Limb Asymmetry in Muscle Torque After Anterior Cruciate Ligament Reconstruction.

Two commonly used instruments to assess muscle strength after anterior cruciate ligament reconstruction are the isokinetic dynamometer, which measures isokinetic torque and the hand-held dynamometer, which measures isometric torque. Isokinetic dynamometers are considered superior to other instruments but may not be commonly used in clinical settings. Hand-held dynamometers are small, portable, and more clinically applicable devices. The purpose of this study was to assess agreement between a hand-held dynamometer and an isokinetic dynamometer, used to assess lower limb symmetry in knee muscle torque one year after anterior cruciate ligament (ACL) reconstruction. Cross-sectional measurement study. Seventy-two participants who had undergone ACL reconstruction (35 men, 37 women; age= 25.8 ± 5.4 years) were included. Isokinetic muscle torque in knee flexion and extension was measured with an isokinetic dynamometer. Isometric flexion and extension knee muscle torque was measured with a hand-held dynamometer. Bland & Altman plots and Cohen's Kappa coefficient were used to assess agreement between measurements obtained from the instruments. Bland & Altman plots showed wide limits of agreement between the instruments for both flexion and extension limb symmetry index. Cohen´s Kappa coefficient revealed a poor to slight agreement between the extension limb symmetry index values (0.136) and a fair agreement for flexion limb symmetry index values (0.236). Cross-tabulations showed that the hand-held dynamometer detected a significantly larger number of participants with abnormal flexion torque limb symmetry index compared to the isokinetic dynamometer. The wide limits of agreements and Cohen's Kappa coefficients values revealed insufficient agreement between the measurements taken with the two instruments, indicating that the instruments should not be used interchangeably. The hand-held dynamometer was more sensitive in detecting abnormal limb symmetry index in flexion torque, which promotes the option of use of hand-held dynamometers to detect differences between the injured and uninjured leg after ACL reconstruction. 3b.

A comparison of isokinetic muscle strength in patients with chondromalacia patella: a cross-sectional study.

Chondromalacia patella (CMP), which is one of the most common causes of anterior knee pain in young adults, is often accompanied by reflex inhibition of the quadriceps muscle. In this respect, a significant correlation between isokinetic parameters and knee muscle strengths would be expected. We hypothesized that an isokinetic dynamometer, which objectively evaluates muscle strength, may be an important guide in detecting muscle weakness in new-onset CMP and determining early treatment strategies. A total of 113 participants (mean age 30.33 ± 6.96 years, min: 18, max: 44) were recruited and divided into two groups, thus a CMP group (n=48) and a control group (n=65). The symptom duration of the CMP group and the demographic characteristics of all participants were recorded. Knee flexion and extension muscle strengths were measured at angular velocities of 60°/s and 180°/s [Knee extension Peak Torque at 60°/s (PTE60), Knee flexion Peak Torque at 60°/s (PTF60), Knee extension Peak Torque at 180°/s (PTE180), Knee flexion Peak at 180°/s (PTF180) respectively] (five sets) using an isokinetic dynamometer. We also recorded the total work done in flexion and extension (TWDF and TWDE). A modified MRI staging system based on the Outerbridge arthroscopy system was used to stage CMP. Isokinetic dynamometric parameters were compared between CMP patients and healthy volunteers. 59 healthy volunteers (90.8%) were right-side dominant and 6 (9.2%) left-side dominant. 33 CMP patients (68.8%) were right-side dominant, and 15 (31.3%) left-side dominant. 20 (41.7%) CMP patients were classified as Stage 1, 20 (41.7%) as Stage 2, and 8 (16.7%) as Stage 3. All the PTF60, PTE60, PTF180, and PTE180 values were significantly lower in the CMP group than in healthy controls (all p < 0.05). CMP symptom duration ≥ 6 months was associated with significantly lower knee muscle strength than with symptom duration < 6 months (p < 0.05). Also, a statistically negative correlation was found between MRI stages and PTE60 values (p < 0.05). In conclusion, our findings show that the isokinetic dynamometer reveals muscle weakness in CMP patients, and weakness in isokinetic parameters was negatively correlated with symptom duration and MRI stages. Isokinetic knee muscle strength testing, together with other functional tools, enables the assessment of muscle weakness and early rehabilitation planning for patients with CMP.

Do individuals with knee osteoarthritis walk with distinct knee biomechanics and muscle activation characteristics? An investigation of knee osteoarthritis, hip osteoarthritis, and asymptomatic groups

BackgroundBiomechanical markers including reductions in sagittal plane kinematics and moments, increases in knee adduction moments (KAM), and altered muscle activations have been identified as hallmark indicators of knee osteoarthritis (OA). However, it remains unknown whether these features of knee OA gait are exclusive to the diseased joint. Research questionTo determine whether specific gait outcomes previously linked to symptomatic medial compartment knee OA are unique to knee OA by concurrently investigating a group of asymptomatic individuals and those with hip OA. Methods16 individuals with moderate medial compartment knee OA, 16 individuals with moderate hip OA, and 16 asymptomatic controls were recruited. Participants walked on a treadmill while segment kinematics and ground reaction forces were recorded. Sagittal plane kinematics and sagittal and frontal plane moments were calculated. Surface electromyograms were recorded from lateral and medial hamstrings and gastrocnemius and vastus lateralis and medialis. Discrete variable analysis was used to investigate knee joint mechanics and muscle activation ratios. Analysis of Variance models using Bonferroni corrections determined between group differences (α = 0.0167). ResultsSagittal plane knee kinematics and moments were statistically similar among all groups (p > 0.0167). No differences were found for peak KAM and impulse between knee OA and asymptomatic groups (p > 0.0167) but peak KAM (p = 0.006 and impulse (p = 0.001) were greater in the knee OA group compared to hip OA. The hip OA group had a lower KAM impulse (p < 0.0167) compared to the knee OA and asymptomatic groups. A greater LH:MH activation ratio (p < 0.0167) was found in the knee OA group compared to hip OA and asymptomatic groups. No other activation ratio differences were found (p > 0.0167). SignificanceMedial and lateral hamstring muscle activation levels may provide utility as a knee OA gait biomarker compared to biomechanical outcomes, quadriceps and gastrocnemius activation, when differentiating knee OA from asymptomatic and hip OA cohorts.

An Ensemble Machine Learning Technique for Detection of Abnormalities in Knee Movement Sustainability

The purpose of this study was to determine electromyographically if there are significant differences in the movement associated with the knee muscle, gait, leg extension from a sitting position and flexion of the leg upwards for regular and abnormal sEMG data. Surface electromyography (sEMG) data were obtained from the lower limbs of 22 people during three different exercises: sitting, standing, and walking (11 with and 11 without knee abnormality). Participants with a knee deformity took longer to finish the task than the healthy subjects. The sEMG signal duration of patients with abnormalities was longer than that of healthy patients, resulting in an imbalance in the obtained sEMG signal data. As a result of the data’s bias towards the majority class, developing a classification model for automated analysis of such sEMG signals is arduous. The sEMG collected data were denoised and filtered, followed by the extraction of time-domain characteristics. Machine learning methods were then used for predicting the three distinct movements (sitting, standing, and walking) associated with electrical impulses for normal and abnormal sets. Different anomaly detection techniques were also used for detecting occurrences in the sEMG signals that differed considerably from the majority of data and were hence used for enhancing the performance of our model. The iforest anomaly detection technique presented in this work can achieve 98.5% accuracy on the light gradient boosting machine algorithm, surpassing the previous results which claimed a maximum accuracy of 92.5% and 91%, improving accuracy by 6–7% for classification of knee abnormality using machine learning.

On the Optimal Whole-Body Vibration Protocol for Muscle Strength

The application of Whole Body Vibration (WBV) has been demonstrated to be effective in improving muscle strength/power by a number of studies, but an optimal training protocol has never been established. This paper presents a review of studies on the effects of WBV on muscles and an analysis of data to identify the optimal protocols for the most beneficial neuromuscular responses in terms of vibration frequency, amplitude, knee flexion angle, body posture (standing, sitting, supine, prone), muscle type (quadriceps, hamstrings), and vibration mode (superoinferior, anteroposterior, rotational). Ninety articles were selected for final review from initially selected 2093 articles using PRISMA guidelines. The findings suggest that the beneficial effects of WBV increase with frequency and amplitude but the optimal frequency and amplitude have not been established. The effect of the knee flexion angle is not clear. The optimal WBV protocol should be determined by considering the adverse effects of WBV on all parts of the human body including that related to head acceleration. WBV in sitting or lying positions may provide a better muscle response than standing. Directions for future research are discussed with regard to establishing the optimal WBV protocol as a safe and effective therapeutic/exercise modality for improving muscle strength and health.

Brain and spinal cord paired stimulation coupled with locomotor training facilitates motor output in human spinal cord injury.

Combined interventions for neuromodulation leading to neurorecovery have gained great attention by researchers to resemble clinical rehabilitation approaches. In this randomized clinical trial, we established changes in the net output of motoneurons innervating multiple leg muscles during stepping when transcranial magnetic stimulation (TMS) of the primary motor cortex was paired with transcutaneous spinal (transspinal) stimulation over the thoracolumbar region during locomotor training. TMS was delivered before (TMS-transspinal) or after (transspinal-TMS) transspinal stimulation during the stance phase of the less impaired leg. Ten individuals with chronic incomplete or complete SCI received at least 20 sessions of training. Each session consisted of 240 paired stimuli delivered over 10-min blocks for 1 h during robotic assisted step training on a motorized treadmill. Body weight support, leg guidance force and treadmill speed were adjusted based on each subject's ability to step without knee buckling or toe dragging. Most transspinal evoked potentials (TEPs) recorded before and after each intervention from ankle and knee muscles during assisted stepping were modulated in a phase-dependent pattern. Transspinal-TMS and locomotor training affected motor neuron output of knee and ankle muscles with ankle TEPs to be modulated in a phase-dependent manner. TMS-transspinal and locomotor training increased motor neuron output for knee but not for ankle muscles. Our results support that targeted brain and spinal cord stimulation alters responsiveness of neurons over multiple spinal segments in people with chronic SCI. Noninvasive stimulation of the brain and spinal cord along with locomotor training is a novel neuromodulation method that can become a promising modality for rehabilitation in humans after SCI.

Effects of Knee Extension Joint Angle on Quadriceps Femoris Muscle Activation and Exerted Torque in Maximal Voluntary Isometric Contraction.

Simple SummaryFor human movement to occur, the neural system needs to activate muscles. Muscles then pull the bones that rotate around the joints. As the joint angle for the movement initiation changes, the mechanical conditions for the muscle force production also change, as does the exerted torque (i.e., maximal endpoint force). However, it is unclear whether different joint angles produce different muscle activation in maximal voluntary isometric contraction. This study investigated the effects of knee joint angle on muscle activation, produced torque, and whether the knee angle affects the muscle activation–torque ratio. Participants were instructed to produce maximal isometric knee extension in joint angles of 80, 90, 100, 110, 120, and 130°, while their muscle activation and torque output were assessed. The results confirmed the dependence of torque on knee angle, while muscle activation remained unaffected. While the trend could be observed, significant effects did not occur in muscle activation–torque ratio for lateral and medial quadriceps heads. The investigated range of knee joint angles seems to provide optimal conditions for maximal muscle activation but not for the torque output, hence for the ligament loading and joint contact forces. Therefore, clinicians and sports coaches should carefully set the training goals and choose the knee joint angles accordingly.This study investigated the effects of knee joint angle on muscle activation, exerted torque, and whether the knee angle affects the muscle activation–torque ratio. Nine healthy adult male participants participated in the study. They performed maximal voluntary isometric contraction (MVIC) at six (80°, 90°, 100°, 110°, 120°, and 130°) different knee joint angles (i.e., angles between the thigh and shin bones). Their maximal torque was assessed utilizing an isokinetic chair, while their muscle activation (root mean square [RMS]) was assessed using an eight-channel single differential surface EMG sensor. For the purposes of the torque–knee angle relationship and muscle activation–knee angle relationship, the torque and RMS were normalized relative to the maximal value obtained by each participant. To evaluate the muscle activation–torque ratio in function of knee angle, RMS was normalized relative to the corresponding torque obtained at each knee angle. Repeated measure analysis of variance was used to investigate the effects of knee angle on muscle activation, torque, and muscle activation–torque ratio. There was a significant effect of knee joint angle on normalized torque (F = 27.521, p < 0.001), while the activation of vastus lateralis and vastus medialis remained unchanged. The changes in knee angle affected the muscle activation–torque ratio of vastus lateralis (Chi-square = 16.246, p = 0.006) but not the vastus medialis. These results suggest that knee joint angles from 80° to 130° provide a stable milieu for muscle electrification, while mechanical factor such as knee joint angle (i.e., lever arm length) affect the torque output when one needs to contract quadriceps maximally during the isometric contraction.

Normative values and changes in range of motion, strength, and functional performance over 1 year in adolescent female football players: Data from 418 players in the Karolinska football Injury Cohort study

ObjectiveTo study normative values of range of motion (ROM), strength, and functional performance and investigate changes over 1 year in adolescent female football players. DesignCross-sectional. Participants418 adolescent female football players aged 12–17 years. Main outcome measuresThe physical characteristic assessments included (1) ROM assessment of the trunk, hips, and ankles; (2) strength measures (maximal isometric and eccentric strength for the trunk, hips, and knees, and strength endurance for the neck, back, trunk and calves), and (3) functional performance (the one-leg long box jump test and the square hop test). ResultsOlder players were stronger, but not when normalized to body weight. Only small differences in ROM regarding age were found. ROM increased over 1 year in most measurements with the largest change in hip external rotation, which increased by 6–7° (Cohen's d = 0.83–0.87). Hip (d = 0.28–1.07) and knee (d = 0.38–0.53) muscle strength and the square hop test (d = 0.71–0.99) improved over 1 year. ConclusionsNormative values for ROM and strength assessments of neck, back, trunk, hips, knees, calves and ankles are presented for adolescent female football players. Generally, fluctuations in ROM were small with little clinical meaning, whereas strength improved over 1 year.

Zoledronic Acid for prevention of bone and muscle loss after BAriatric Surgery (ZABAS)-a study protocol for a randomized controlled trial

BackgroundBariatric surgery has adverse effects on the muscular-skeletal system with loss of bone mass and muscle mass and an increase in the risk of fracture. Zoledronic acid is widely used in osteoporosis and prevents bone loss and fracture. Bisphosphonates may also have positive effects on skeletal muscle. The aim of this study is to investigate the effects of zoledronic acid for the prevention of bone and muscle loss after bariatric surgery. Methods/designThis is a randomized double-blind placebo-controlled study. Sixty women and men with obesity aged 35 years or older will complete baseline assessments before randomization to either zoledronic acid (5 mg in 100 ml isotonic saline) or placebo (100 ml isotonic saline only) 3 weeks before surgery with Roux-en-Y-gastric bypass (RYGB) or sleeve gastrectomy (SG). Follow-up assessments are performed 12 and 24 months after surgery. The primary outcome is changes in lumbar spine volumetric bone mineral density (vBMD) assessed by quantitative computed tomography (QCT). Secondary bone outcomes are changes in proximal femur vBMD assessed by QCT. Changes in cortical and trabecular bone microarchitecture and estimated bone strength will be assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). Cortical material bone strength at the mid-tibia diaphysis will be assessed using microindentation and fasting blood samples will be obtained to assess biochemical markers of bone turnover and calcium metabolism. Secondary muscle outcomes include whole body lean mass assessed using dual-energy X-ray absorptiometry. Dynamometers will be used to assess handgrip, shoulder, ankle, and knee muscle strength. Short Physical Performance Battery, 7.6-m walking tests, 2-min walking test, and a stair climb test will be assessed as biomarkers of physical function. Self-reported physical activity level is assessed using International Physical Activity Questionnaire (IPAQ).DiscussionResults from this study will be instrumental for the evidence-based care of patients undergoing bariatric surgery.Trial registrationClinicalTrials.gov NCT04742010. Registered on 5 February 2021.

VP.34 Two-year follow-up of muscle strength and function in patients with glycogen storage disease type IIIa

Glycogen storage disease type IIIa (GSDIIIa) is an autosomal recessive disorder caused by mutations in the AGL gene coding for the glycogen debranching enzyme. The symptoms start in childhood with liver involvement and progress at adulthood with skeletal muscle weakness. With imminent therapeutic trials, quantitative documentation of disease progression is essential. The objective of this study is to identify the most affected skeletal muscle measures over 2 years of follow-up. The 6-minutes walk test (6MWT), knee (Biodex torquemeter) and ankle (MyoAnkle dynamometer) flexion/extension torques, as well as muscle function measure (MFM) were performed at 2 years interval. Forty-one patients aged from 10 to 66 years old (28±15 y), 59% females, were included. At baseline, the 6-minute walk distance (6MWD), knee and ankle flexion/extension torques, expressed as a percentage of predicted value (%pred), as well as the 3 dimensions of the MFM (D1, D2, D3) and the MFM total score, were all significantly lower than the maximum score of 100% (P<0.01). This reflects significant impairment in walking, knee and ankle joints muscle strength, standing and transfers (MFM D1), axial and proximal (MFM D2) and distal (MFM D3) motricity. After 2-years of follow-up, only MFM D1 and the MFM total score were slightly but significantly reduced (paired Wilcoxon test, P=0.016 and P=0.010, respectively). Because the age of onset of MFM D1 degradation was previously established around 35 years (Decostre 2017), the paired Wilcoxon test was performed only for patients aged at least 34 years (n=15). In this small sample, MFM D3 and knee extension strength were significantly impaired (P<0.05), but not MFM D1 (probably because 2 patients improved their MFM D1 score). In conclusion, the MFM and the knee extension strength are the most promising outcome measures for this slowly progressive disease. A longer follow-up is ongoing.

Morphology of the rat knee joint after intraarticular injection of hydroxymethyl-quinoxaline dioxide

Topical antiseptics are widely used in orthopedics and traumatology. However, studies highlighting the effects of antiseptics during long-term use on joint tissues are limited. In the performed work, the peculiarities of the structure of intra-articular tissues of the knee joint and muscles in rats in two series of experiments were noted: control group (saline injection into the joint) and experimental group (hydroxymethyl-quinoxaline dioxide injection into the joint) daily for 5 days. Histological methods with semi-quantitative assessment of articular cartilage and synovial membrane were used. During the first day after the drug administration, similar reactive changes to the injection of saline and hydroxymethyl-quinoxaline dioxide were observed in the joint tissues of the two groups of rats. The synovial membrane of the capsule was thickened, and synoviocytes were hypertrophied. The articular cartilage contains single cells with dense nuclei only in the superficial parts, but in general, the cytoarchitectonics of articular cartilage was preserved. In 5 days after injection, no statistically significant differences between saline and hydroxymethyl-quinoxaline dioxide were observed for the study periods. According to the studies the safety of long-term use of the drug as an antiseptic for articular tissues was confirmed.

Isometric Knee Muscle Strength and Patient-Reported Measures Five Years after Anterior Cruciate Ligament Reconstruction: Comparison of Single versus Dual Autograft Hamstring Tendon Harvesting.

There is some controversy regarding the use of one or two hamstring tendons for anterior cruciate ligament reconstruction (ACLR). In this study, two cohorts of 22 male patients underwent an ACLR with hamstring tendon autografts. One cohort was reconstructed through an all-inside technique with the semitendinosus tendon (ST group) and the other with the semitendinosus and gracilis tendons (ST-G group). Anterior tibial translation (ATT), Lysholm, and IKDC scores were assessed preoperatively and five years postoperation. Additionally, isometric knee muscle strength was manually measured in both groups and in another cohort of 22 uninjured control male subjects five years after the operation. There were no significant differences in ATT and Lysholm scores between the operated groups. The IKDC score was lower in the ST-G group than in the ST group—9.57 (CI 14.89–4.25) (p < 0.001). No significant differences between injured and uninjured knees were detected in hamstring to quadriceps ratio strength and quadriceps limb symmetry index of the two operated groups, but the hamstring limb symmetry index was significantly lower in the ST-G group than in the ST and control groups. This study shows that using an ST-G autograft for ACLR yielded less flexor strength and worse results in some patient-reported outcome measures (PROM) than using an ST autograft five years after the operation. The observed results let us suggest that the use of one autograft hamstring tendon for ACLR is clinically preferable to the use of two hamstring tendons.

A novel home-based rehabilitative knee brace system is a viable option for postoperative rehabilitation after anterior cruciate ligament reconstruction: a report of 15 cases

PurposeTo investigate the functional outcomes for patients who used a novel home-based rehabilitative system during the postoperative period after anterior cruciate ligament (ACL) reconstructions.MethodsPatients undergoing ACL reconstruction surgeries were prospectively enrolled. A home-based rehabilitation system, which is composed of a knee brace with a motion tracker, a mobile app, and a web portal, was applied. Patients could complete the rehabilitation exercise through the audio guidance and the real-time tracking system which displayed the achieved motions on the user interface of the app. Feedbacks from the patients, including the International Knee Documentation Committee (IKDC) scores, were collected and uploaded to the web portal. Each patient would meet a specialized physical therapist face-to-face once a month. At postoperative 6 months, every patient received a GNRB arthrometer examination and a Cybex isokinetic dynamometer examination.ResultsA total of 15 patients (10 males and 5 females) were enrolled and followed for at least 6 months. The mean time of return to full knee extension was 1.5 months.The mean difference in laxity measured by GNRB arthrometer at 134 N significantly improved at postoperative 6 months (1.8 ± 1.6 mm) compared to that measured preoperatively (3.4 ± 1.9 mm) (p = 0.024). The peak torques of flexor and extensor muscles measured by Cybex isokinetic dynamometer remained unchanged at postoperative 6 months (p = 0.733 and 0.394, respectively). The patients’ IKDC score became smaller at postoperative 1 month (p = 0.011) and significantly improved at postoperative 6 months (p = 0.002).ConclusionUsing a home-based rehabilitative knee brace system after ACL reconstruction is a viable option as patients maintained their knee muscle strengths maintained their muscle strength and achieve similar or better knee range of motion six months postoperatively.

Does ipsilateral and bilateral knee strength status predict lower extremity injuries of elite judokas; a prospective cohort study

ABSTRACT The association of pre-participation knee muscle strength status with lower limb injury occurrence was investigated. Knee extensors and flexors muscle strength status including the traditional hamstrings/quadriceps (H/Q), Q/Q, H/H, and the non-dominant H/Q: dominant H/Q, HQ:HQ, ratios were recorded before the 10 month judo activity. Fifteen lower limb sport injuries were recorded for 53 judokas during the follow-up questionnaires. Significant accuracy of dominant H/Q ratio 60º/s (AUC 0.702, 95% CI 0.520 to .883, p = 0.023), as well as HQ:HQ ratios 300º/s (AUC .318, 95% CI 0.138 to 0.497, p = 0.040), and 60 º/s (AUC 0.311, 95% CI 0.130 to 0.491, p = .033) were revealed discriminating between injured and uninjured judokas. The optimum cut-off of dominant H/Q ratio associated with belonging to uninjured judokas group was 43.2% (sensitivity, 0.974; specificity, 0.533). Isokinetic knee muscle dynamometry is useful for predicting the likelihood of lower limb injuries in professional judokas during competitive activity.

Muscle architecture in patients with primary Sjögren syndrome.

This study aims to investigate skeletal muscle architecture and strength in patients with primary Sjögren syndrome (pSS). Between July 01, 2017 and November 30, 2017, 19 pSS patients (19 females; mean age: 54.1±6.6 years; range, 42 to 62 years) and 19 age-, body mass index-, and sex-matched healthy controls (19 females; mean age: 53.2±6.7 years; range 42 to 61 years) were included. Sjögren symptoms were assessed with the European Alliance of Associations for Rheumatology (EULAR) Sjögren's Syndrome Patient Reported Index (ESSPRI). Muscle thickness, pennation angle, and fascicle length were measured at quadriceps femoralis, gastrocnemius and soleus muscles. Isokinetic muscle strength tests were performed at 60 and 180°/sec for knee and at 30 and 120°/sec for ankle. Anxiety and depression evaluated with the Hospital Anxiety and Depression Scale (HADS), fatigue with Multidimensional Assessment of Fatigue scale (MAF), and functionality with Health Assessment Questionnaire (HAQ). In the pSS group, the mean ESSPRI was 7.70±1.17. The mean scores of depression (10.05±3.09 vs. 4.47±2.29; p<0.0001), anxiety (8.26±4.28 vs. 3.79±2.42; p<0.0001), functionality (0.94±0.78 vs. 0.22±0.26; p<0.0001), and fatigue (37.69±5.47 vs. 17.69±5.26; p<0.0001) were significantly higher in patients with pSS. Only, the pennation angle of vastus medialis in dominant leg was significantly greater in healthy controls (p=0.049). Peak torques/body weight of knee and ankle muscles were found to be similar. Excluding a minor decrease of the pennation angle at vastus medialis, muscle structure of lower extremity of pSS patients were similar to healthy controls. In addition, isokinetic muscle strength did not significantly differ in patients with pSS compared to healthy controls. In patients with pSS, disease activity and fatigue level were negatively correlated with isokinetic muscle strength measurements.