Relationships between Quadriceps:Hamstring Strength Ratio and Lower Extremity Injuries in Netball Players

Background: Netball is a popular sport. Due to high impact and quick movement, there is an enormous load on the lower extremities which increases the risk for injury. Aim: The aim of this study was to investigate the relationship between the quadricep and hamstring strength and the prevalence of lower extremity injuries in netball players. Setting: Twenty-five female netball players (age: 20.8 ± 1.4 years) voluntarily participated. Methods: The Cybex Isokinetic dynamometer was used to determine concentric knee torques. Quadriceps:hamstring strength ratio was determined. Occurrence of lower extremity injuries was documented bi-weekly. Results: Medium effect sizes were noted for flexion torque:work for the left leg and for the quadriceps:hamstring ratio (≥60%) for the right leg. All the other measured variables have a small effect size. 18.75% of lower extremity injuries and ConQ:ConH of Conclusion: Injuries to the ankle and knee are especially common among netball players. Hamstring and quadriceps muscle asymmetry (>10%) were found to be a potential indicator of lower extremity injury. Contribution: This study highlights awareness on lower extremity injuries and the strength ratio between the quadriceps and hamstrings. This can aid coaches and netball players to lower the risk for injuries and thus improve individual- and team performance.

Patellofemoral MRI Alterations Following Single Bundle ACL Reconstruction with Hamstring Autografts Are Associated with Quadriceps Femoris Atrophy

High incidence of patellofemoral pain and patellofemoral joint osteoarthritis was found following anterior cruciate ligament(ACL)reconstruction.The unstability of patellofemoral joint might be an important contribution factor.This study was designed to define the relationship between the unstability of patellofemoral joint and quadriceps femoris atrophy.Twenty patients underwent MRI scan before ACL reconstruction and every two weeks after surgery,until 12 weeks.The merchant’s patellar congruence angle,lateral inclination angle,and quadriceps femoris muscle cross-sectional area were measured and the relationship between the changes of angles and the ratio of quadriceps femoris atrophy was studied by multiple regression analysis.Significant quadriceps femoris atrophy was observed after ACL reconstruction during the follow-up period of 12 weeks.The merchant’s patellar congruence angle and lateral inclination angle significantly changed after surgery.The alterations of the merchant’s patellar congruence angle were significantly correlated with the atrophy ratio of vastus medialis(coefficient=-5.76)and vastus lateralis(coefficient=8.35)during the follow-up period of 12 weeks.The alterations of lateral inclination angle were significantly correlated with the atrophy ratio of vastus medialis(coefficient=20.62),vastus lateralis(coefficient=-11.38)and rectus femoris(coefficient=-0.469)during the follow-up period 12 weeks.To sum up,ACL reconstruction can alleviate the dysfunction of patellofemoral joint to a certain extent.But,the unbalanced atrophy of quadriceps femoris once again destroyed the stability of patellofemoral joint following the operation,which might be one cause of patellofemoral joint pain and early onset of osteoarthritis after ACL reconstruction.So,rehabilitation training that focuses on quadriceps femoris especially the vastus medialis shortly following operation is suggested.

Spontaneous and simultaneous complete bilateral rupture of the quadriceps tendon in a patient receiving hemodialysis: A case report and literature review

The spontaneous and simultaneous rupture of both quadriceps tendons is uncommon and has rarely been reported in the literature. The current case involves a 43-year-old man with end-stage renal disease requiring hemodialysis for the past 20 years. The patient experienced bilateral knee pain and swelling and was unable to bear weight. Physical examination revealed bilateral quadriceps tendon defect above the patella and loss of active extension. Although plain radiographs of both knees showed no fracture or widening of the joint space, an inferiorly positioned patella was observed. Ultrasonography of the knees revealed a quadriceps tendon defect at the upper edge of each patella, while MR imaging revealed a tear in each quadriceps tendon from the superior poles of the patella. The patient then underwent surgical correction wherein the tendons were repaired using sutures passed through drill holes in the patella. The knees were immobilized with splints for 4 wk before starting physiotherapy. The patient subsequently regained full functional activity within 1 year.

ANALYSIS ON THE CURATIVE EFFECT OF QUADRICEPS PLASTY

Three kinds of operations of quadriceps femoris plasty are disscussed in this article.29cases of operations of quadriceps femoris plasty were performed. 23 cases got excellent result andlimb condition of all cases was improved after operation.We think that the best operation method toperform the quadriceps plasty is transplanting the muscular biceps femoris and semitendinous.Theproper age for the operated patient is over 10 years old.The operative indication and complicationare disscussed too.At last four kinds of methods to fix the transplanted muscles or tendor to thepatella are recomended.

Fibrosis of the Quadriceps Muscles Secondary to Sickle Cell Disease: A Case Report

The musculo-skeletal system is commonly affected in sickle cell disease, manifesting itself as bone infarction, femoral head osteonecrosis, osteomyelitis, myonecrosis, myofibrosis and fascitis. Myositis and fasciitis are observed during a vaso-occlusive crisis in 4% of patients. Pain and swelling of bilateral proximal groups of muscles of upper and lower limbs are common presenting complaints due to prolonged sickling crises [1]. We report a case of 30-year old known HbSS patient with bilateral knee stiffness of two months duration, with associated swelling and warmth of both thighs. No preceding history of trauma. He was said to suffer at least two sickling crises in a month with the last one occurring one week prior to presentation. X-ray of the thigh showed no calcification in muscle groups. He was commenced on flexion-extension exercises.

DETERMINATION OF QUADRICEPS FORCES IN SQUAT AND ITS APPLICATION IN CONTACT PRESSURE ANALYSIS OF KNEE JOINT

While the quadriceps muscles of human body are quite important to the daily ac-tivities of knee joints,the determination of quadriceps forces poses significant challenges since it cannot be measured in vivo.Here,a novel approach is presented to obtain the forces in squat through the combination of motion photography,force transducers measuring,multi-rigid-body theory and finite element analysis.Firstly,the geometrical and angular data of human for squat process were obtained through the analysis of photographed pictures for human squat with cam-era.At the same time,force transducers were used to measure the reaction forces from feet and to determine the center of gravity for identical squat process.Next,based on the multi-rigid-body dynamics,a mathematical model for human right leg and foot was established in order to determine the quadriceps torques under different squat angles.Then,so as to determine the quadriceps forces along with varied squat angles,a simplified three-dimensional finite element model was built,including tibia,fibula,patella,patella ligament and quadriceps tendon.Finally,the contact pressure of knee joint was analyzed for the squat with the established model of knee joint involving the obtained quadriceps forces from finite element analysis.And it showed that in the 0-90 degree squat process,the peak value of contact pressure of articular cartilages and menisci is increased with the increased squat angle.This study can be referenced for further un-derstanding of the biomechanical behaviors of knee,contact pressure effects of daily activities on knee,and is significantly instructive for sports rehabilitation.

Quadriceps strength assessed by magnetic stimulation of femoral nerve in patients with chronic obstructive pulmonary disease

Background Skeletal muscle dysfunction is one of important systemic manifestations of chronic obstructive pulmonary disease （COPD） and is associated with mortality in patients with COPD, thus quantifying its strength is of great clinical interest and of particular value. Quadriceps maximal volitional contraction （MVC） is often used for the routine measurements of this muscle＇s strength; while twitch tension （TwQ） evoked by magnetic stimulation of the femoral nerve has been employed for measurement of quadriceps strength non-volitionally. We aimed to investigate the prevalence and severity of skeletal muscle dysfunction in COPD patients by measurement of quadriceps strength with volitional and non-volitional techniques, and to probe into some methodological issues. Methods We recruited 71 COPD patients and 60 control subjects. Quadriceps strength was measured with both maximality of TwQ and MVC force. The reproducibility for TwQ and MVC was investigated using within-occasion variability from three repeated maneuvers. Results Maximal TwQ was achieved in 121 participants at a mean of 90% of the stimulator＇s maximum output. The mean maxmality of TwQ was decrease by about 44%-47% in COPD patients as compared with controls （P 〈0.05）, so was MVC. There was a significant correlation between quadriceps TwQ and MVC, and the mean ratio of TwQ/MVC was 0.29 in controls and 0.33 in patients. The coefficient of variation showed that TwQ yielded lower within-occasion variability than MVC in both groups. Conclusions Quadriceps strength is commonly and substantially impaired in patients with COPD, in terms of MVC as well as TwQ. The magnetic stimulation of the femoral nerve presents a higher reproducibility and is a better technique for measurement of quadriceps strength for the general population, especially for those who are too unwell to perform a full MVC; while it may not be applied to subjects who are over-weighted.

The technique of utilizing a single gracilis functional muscle transfer to restore quadriceps function following sarcoma surgery

Aim:Quadriceps strength and knee extension,the most important factors limiting the ability to rise from a chair,are crucial for walking at an appropriate speed,ascending and descending stairs,and performing activities such as running,dancing,and jumping.Resection of the anterior compartment of the thigh,including all four quadriceps muscles,for the treatment of a sarcoma is uncommon;however,when necessary,it is very debilitating and adversely affects a patient's quality of life without functional reconstruction.Currently,there are a limited number of complex and difficult reconstructions to restore quadriceps function that have been described with variable outcomes.We describe a simple technique that employs a single gracilis functional muscle transfer to replace essential quadriceps function.Methods:This is a case series describing the use of either a free or pedicled single gracilis muscle to restore quadriceps function following sarcoma resection.Results:Four patients underwent an anterior compartment sarcoma resection that resulted in a large segmental defect and/or denervation of all four quadriceps muscles such that no quadriceps function would remain without reconstruction.All four patients underwent a functional reconstruction using a single gracilis.Three of the living patients achieved British Medical Research Counsel Grade 4 strength,can achieve full knee extension,are able to navigate stairs,and are able to ambulate without a brace.The fourth patient unfortunately was deceased in under three months following his tumor resection.Conclusion:Despite its small size in comparison to the quadriceps muscles,with physiotherapy and training,the gracilis muscle demonstrates the capacity to hypertrophy and replace quadriceps function following limb salvage surgery.

Acute exercise in ozone-polluted air induces apoptosis in rat quadriceps femoris muscle cells via mitochondrial pathway

Ozone(O_(3))pollution can decrease sport performance and induce respiratory toxicity,but relatively few studies have investigated its effects on skeletal muscles.We randomly assigned rats to the following groups based on a 2×4 two-factor factorial design:Air+0,Air+10,Air+15,and Air+20,O_(3)+0,O_(3)+10,O_(3)+15,and O_(3)+20.The rats in the+0 groups rested,whereas those in the+10,+15,and+20 groups ran on a treadmill(in clean air for Air groups and in air polluted with 0.14 parts per million[ppm]O_(3)for O_(3)groups)at speeds of+10,+15,and+20 m/min,respectively,for 1 h.Thereafter,key enzyme activities involving the tricarboxylic acid cycle,oxidative phosphorylation,adenosine triphosphate(ATP)content,histopathological changes,oxidative stress,inflammation factors,and apoptosis were assessed in the rat quadriceps femoris samples.Ozone reduced key enzyme activities and ATP contents in the quadriceps femoris regardless of whether the rats exercised.Pathological changes,inflammatory factors,oxidative stress,and mitochondria-dependent apoptosis were only evident under conditions of exercise combined with ozone and increasingly worsened as exercise intensity increased.These findings suggested that acute exercise under ozone exposure could induce damage to the quadriceps femoris,which would negatively affect sport performance.Ozone-induced disrupted energy metabolism might be an early event that becomes more critical as exercise intensity increases.Therefore,care should be taken when exercising in polluted air,even when ozone pollution is mild.

Effectiveness of exercise for osteoarthritis of the knee:A review of the literature

Osteoarthritis(OA)of the knee is the most common type of arthritis and the major cause of chronic musculoskeletal pain and mobility disability in the elderly.The objective of this paper is to discuss the effectiveness of exercise for OA of the knee based on a review of the literature.We reviewed the relevant literature,i.e.systematic reviews and meta-analyses searched using PubMed.Muscle strengthening and aerobic exercises are effective in reducing pain and improving physical function in patients with mild to moderate OA of the knee.

Sonographic muscle mass assessment in patients after cardiac surgery

BACKGROUND Patients undergoing cardiac surgery particularly those with comorbidities and frailty,experience frequently higher rates of post-operative morbidity,mortality and prolonged hospital length of stay.Muscle mass wasting seems to play important role in prolonged mechanical ventilation(MV)and consequently in intensive care unit(ICU)and hospital stay.AIM To investigate the clinical value of skeletal muscle mass assessed by ultrasound early after cardiac surgery in terms of duration of MV and ICU length of stay.METHODS In this observational study,we enrolled consecutively all patients,following their admission in the Cardiac Surgery ICU within 24 h of cardiac surgery.Bedside ultrasound scans,for the assessment of quadriceps muscle thickness,were performed at baseline and every 48 h for seven days or until ICU discharge.Muscle strength was also evaluated in parallel,using the Medical Research Council(MRC)scale.RESULTS Of the total 221 patients enrolled,ultrasound scans and muscle strength assessment were finally performed in 165 patients(patients excluded if ICU stay<24 h).The muscle thickness of rectus femoris(RF),was slightly decreased by 2.2%[(95%confidence interval(CI):-0.21 to 0.15),n=9;P=0.729]and the combined muscle thickness of the vastus intermedius(VI)and RF decreased by 3.5%[(95%CI:-0.4 to 0.22),n=9;P=0.530].Patients whose combined VI and RF muscle thickness was below the recorded median values(2.5 cm)on day 1(n=80),stayed longer in the ICU(47±74 h vs 28±45 h,P=0.02)and remained mechanically ventilated more(17±9 h vs 14±9 h,P=0.05).Moreover,patients with MRC score≤48 on day 3(n=7),required prolonged MV support compared to patients with MRC score≥49(n=33),(44±14 h vs 19±9 h,P=0.006)and had a longer duration of extracorporeal circulation was(159±91 min vs 112±71 min,P=0.025).CONCLUSION Skeletal quadriceps muscle thickness assessed by ultrasound shows a trend to a decrease in patients after cardiac surgery post-ICU admission and is associated with prolonged duration of MV and ICU length of stay.

Can infrared thermography be used to monitor fatigue during exercise? A case study

Background: Infrared thermographic imaging(IRTG) is a safe and reliable technology used to monitor skin temperature. The main aim of our study was to evaluate the relationship between skin temperature changes and muscle fatigue in order to answer the main research question if IRTG can be used to monitor muscle fatigue.Methods: This was a case study performed on a 23-year-old trained middle distance runner. After warm-up the subject was exercising on the dynamometer for 7.5 min at 120?/s performing only concentric contractions of quadriceps. At the same time IRTG recording of both(exercising and non-exercising) quadriceps was performed.Results: A correlational analysis that was performed in order to quantify the relationship between power and temperature change over time has shown that there is a significant negative correlation between skin temperature increase and power decrease(r = -0.543, p = 0.036) of exercising quadriceps. In linear regression model the exercising quadriceps power could be predicted from skin temperature. No such relationships were noted for the non-exercising limb that served as a control.Conclusion: We believe that correlation between skin temperature change and muscle power output as described in this case study deserves further analysis on the larger sample including subjects of the different ages, health status, and physical abilities in order to create a new tool for monitoring the muscle fatigue.

The anatomical,electrophysiological and histological observations of muscle contraction units in rabbits:a new perspective on nerve injury and regeneration

In the conventional view a muscle is composed of intermediate structures before its further division into microscopic muscle fibers.Our experiments in mice have confirmed this intermediate structure is composed of the lamella cluster formed by motor endplates,the innervating nerve branches and the corresponding muscle fibers,which can be viewed as an independent structural and functional unit.In this study,we verified the presence of these muscle construction units in rabbits.The results showed that the muscular branch of the femoral nerve sent out 4–6 nerve branches into the quadriceps and the tibial nerve sent out 4–7 nerve branches into the gastrocnemius.When each nerve branch of the femoral nerve was stimulated from the most lateral to the medial,the contraction of the lateral muscle,intermediate muscle and medial muscle of the quadriceps could be induced by electrically stimulating at least one nerve branch.When stimulating each nerve branch of the tibial nerve from the lateral to the medial,the muscle contraction of the lateral muscle 1,lateral muscle 2,lateral muscle 3 and medial muscle of the gastrocnemius could be induced by electrically stimulating at least one nerve branch.Electrical stimulation of each nerve branch resulted in different electromyographical waves recorded in different muscle subgroups.Hematoxylin-eosin staining showed most of the nerve branches around the neuromuscular junctions consisted of one individual neural tract,a few consisted of two or more neural tracts.The muscles of the lower limb in the rabbit can be subdivided into different muscle subgroups,each innervated by different nerve branches,thereby allowing much more complex muscle activities than traditionally stated.Together,the nerve branches and the innervated muscle subgroups can be viewed as an independent structural and functional unit.This study was approved by the Animal Ethics Committee of Peking University People’s Hospital(approval No.2019 PHE027)on October 20,2019.

Membrane and Subcellular Muscle Injury Are Induced by Single or Multiple Exposure to Cigarette Smoke

Cigarette smoking is the main cause of chronic obstructive pulmonary disease (COPD). Diaphragm injury is observed in patients with COPD. However, the potential role of smoking in triggering or perpetuating muscle injury is unknown. The present study was aimed at evaluating the potential role of commercial tobacco smoke as a direct cause of skeletal muscle injury in experimental conditions. Seventy Wistar rats (170 - 250 g) were assigned to smoking (n = 49) or non-smoking (n = 21) groups. The smoking groups were submitted to a single or multiple (i.e., five or thirty) daily sessions of cigarette smoking in an inhalatory chamber (time length: 2 h each session). The level of exposure was constant and assessed by CO concentrations (50 ppm) and serum cotinine analysis. Animals submitted to a single smoke exposure and the corresponding controls were euthanized in groups at 0 h, 2 h, 4 h, 24 h or 48 h after completing the exposure. Animals submitted to multiple exposures were euthanized at 0 h after smoking. Samples from vastus lateralis muscle were obtained and processed for assessing cell injury and selected protein expression. Monoclonal anti-albumin antibodies were used to identify muscle fibers with sarcolemmal (membrane) injury. Subcellular muscle injury was assessed using transmission electron microscopy (EM). MyoD, myogenin and α-tubulin were immunodetected using western blot techniques. Exposure to cigarette smoke associated with significant membrane damage (mean relative difference (MRD) with controls: +181%, p = 0.004) and sarcomere disruptions (MRD: +226%, p = 0.001). Expression of MyoD and myogenin (normalized to α-tubulin) were significantly increased at 4 h and remained increased at 48 h post-exposure. We conclude that not only a single but also consecutive exposure to tobacco smoke have acute deleterious effects on peripheral muscle structure. A rapid induction of subrogate markers of skeletal muscle stress and repair processes associates to sarcolemmal and sarcomere damage.

Anatomic Dissection of the Femoral Vein at the Bamako Anatomy Laboratory

Objectives: The purpose of this work was to measure the dimensions of the femoral veins, to describe the affluent and the variations of the femoral veins. Methodology: Twenty-four femoral veins of 12 fresh adult cadavers were dissected and photographed. Results: The diameter of the superficial, deep and common femoral veins was respectively 8.75 mm;7.60 mm and 13.95 mm. The common femoral vein was 80.70 mm long. At the level of the superficial vein, the modal disposition was noted in 79.17%;as anatomical variations, it was split in 2 cases, the presence of a collateral canal in 1 case and in 2, and it received a quadricipital muscle vein. At the level of the deep femoral vein, the modal disposition was noted in 16.67%, and the anatomical variations were noted in 83.33% where it received no affluent in the femoral trine. The modal disposition was noted in 91.67% at the level of the mode of birth of the common femoral vein, in 16.67% at the level of its tributaries. The anatomical variations were noted in 8.33% in the mode of birth of the femoral vein, in 83.33% in which the common femoral vein received, in addition to the large saphenous vein, other tributaries, the most frequent of which were the quadricipital veins and the circumflex femoral veins. Conclusion: The diameter of the femoral veins is important. The main tributaries of the common femoral vein are GVS, VQ and circumflex femoral veins. The femoral variations are numerous and important to know to avoid a possible misdiagnosis in case of their thrombosis.

Should proximal ruptures of the anterior rectus femoris muscle be treated surgically?

Purpose:No therapeutic consensus has been established about proximal ruptures of the rectus femoris muscle.The objective of this literature review is to determine a therapeutic course of action.Methods:We conducted a literature review on the PubMed database using the following keywords(in French and English,respectively):"quadriceps/quadriceps","droit antérieur/rectus femoris","proximal/proximal","chirurgie/surgical","avulsion/avulsion".We collected 266 articles,36 of them were selected,which were related to our topic:proximal rupture of the anterior rectus femoris.Patients with a proximal rupture of the rectus femoris,minor or major patient of traumatic origin were included in this study.Patients injured at another lesion level,or non-traumatic lesions of the proximal rectus femoris(tendinitis without ruptures,tumor or others)were excluded.For each patient,the indications,the type of treatment and the functional result were analyzed,with the time to recovery and the level of recovery from sports and professional activities(same sport/profession or not,same level or not)as the main criterion of judgment.Fisher exact test was used for statistical comparison.Results:The aims of conservative treatment are to be pain free for the patient,to fight hematoma and to rehabilitate the injury as quickly as possible.The surgical techniques are varied,with most consisting of either a reinsertion of the musculo-tendon stump or a resection of the scar tissue with myo-tendinoaponeurotic suture in place.The functional results are good for the majority of the treatments proposed,but the conservative treatment has a shorter recovery time(3 months vs.4 months for the best surgical results).Highly displaced bone avulsion is the only indication for first-line surgical treatment.Conslusion:The main disadvantage of conservative treatment is the risk of residual pain beyond 3 months(10%),justifying an MRI to guide secondary surgical treatment.We propose a treatment plan for proximal rupture of the proximal rectus femoris rupture.