Electromy ographic responses of vastus muscles to dynamic postural perturbations in athletes with patellofemoral pain syndrome

Background and Aim: Patellofemoral pain syndrome [PFPS] is among the most common musculoskeletal disorders in the athletes and active individuals

Observation of muscular responses to unexpected perturbations is one of the most common methods to evaluate the neural strategies. The aim of this study was to evaluate the EMG response of vastus muscles to dynamic postural perturbations in the athletes with PFPS

Material and Method: This study included 10 male athletes with PFPS and 10 healthy male athletes. NPRS scale was used to assess pain. EMG activity of VMO and VL muscles measured during dynamic postural perturbation. The EMG signals were collected using a 16-channel BTS-FREEEMG 300 system, manufactured in Italy. Independent-1 test was used for data analysis

Results: RMS values for VMO and VL muscles in PFPS group, were higher than the corresponding values of the control group by 33.59% and 33.35% respectively, in the forward postural perturbation. There was a significant difference in VL muscle RMS values between the two groups [P=0.04]

RMS values for VMO and VL muscles in PFPS group were higher than those of the control group by 38% and 49.52% respectively, in the backward postural perturbation and there was a significant difference in VL muscle RMS values between the two groups [P=0.04]

Conclusion: The results showed that valtus muscles were more active in response to dynamic postural perturbation in the athletes with PFPS in comparison to the healthy athletes

Patellofemoral pain syndrome and in general joint disorders can lead to dysfunction in the whole sensory-motor system

Therefore, instead of focusing on local symptoms we should examine the whole body in sensory-motor system dysfunction

[Knee extension syndrome: a focus on symptoms and treatments]

Anterior knee pain [AKP or AnKP] is one of the most common disorders of knee. Many studies have been implemented about anterior knee pain and effect of different treatments on this disorder. Todays, this general term has been divided and studied more closely. Knee extension syndrome is one of the common disorders in orthopedic and physical therapy that diagnosed with increased stiffness of quadriceps muscle and causes anterior knee pain. The purpose of this review article is to evaluate this disorder more closely. A literature search was carried out using MEDLINE and SCIENCE DIRECT cite and JOSPT journal database to assess existing literature about anterior knee pain. Furthermore, literatures about the different standpoints of anterior knee pain and effectiveness of different treatments and interventions of anterior knee pain and knee extension syndrome have been identified. Fifty articles have been surveyed: forty-two articles evaluated the effect of different treatments on anterior knee pain. Five articles evaluated the various aspects of anterior knee pain more closely and three ones related to knee extension syndrome. According to these studies results, the causes of anterior knee pain can be classified in two categories: 1] anterior knee pain associated with patellofemoral disorders and 2] anterior knee pain non-associated with patellofemoral disorders. The knee extension syndrome is the cause for anterior knee pain but non-associated with patellofemoral disorders. In this disorder, the tilt angle of patella could be increased and this factor can increase the patients' pain. In contrast to general belief that focuses on tensor fascia lata- ilotiobial band complex [TFL-ITB complex], the rectus femoris muscle stretching should be focused more, because the ilotiobial band has a less effect on patellar tilt

[Studying the effect of perturbation training on gait kinematics of patients with anterior cruciate ligament injury]

Anterior cruciate ligament [ACL] damage is the most common injury of knee. It can change gait kinematics. Neuromuscular training and perturbation treatment programs are supposed to be effective in modifying gait kinematics of patients with ACL damage. The purpose of this study was to determine the effect of modified perturbation training protocol on gait kinematics in ACL deficient patients. Ten professional male athletes, between 18 and 45 years, with at least 6 and at most 24 months history of unilateral ACL rupture were enrolled in the study. Kinematics data of hip, knee and ankle joints were recorded using electrogoniameter device during walking before and after ten sessions of perturbation training. IKDC Subjective and Lysholm questionnaires scores were analyzed before and after training. IKDC Subjective and Lysholm questionnaires scores significantly improved after treatment [P=0.005]. Hip range of motion [P=0.02], peak flexion of hip [P=0.02], hip angle at stance phase [P=0.02] and peak dorsiflexion of ankle [P=0.03] were significantly increased after training. Perturbation training probably affects neuromuscular control and modifies feed-forward control, thus it can improve compensatory patterns of ACL deficient patients during gait. ACL deficient patients may adapt their problem with further use of hip joint and increasing hip flexion

[Isokinetic extension torque summation of lower extremity and functional test in patients with anterior cruciate ligament deficiency]

Knee joint has a major role in various lower extremity activities. Among different elements of knee joint complex; more interest was seen to anterior cruciate ligament because of its alignment, structural complications, more nerve receptors and susceptibility to injury. After injury of this ligament, knee extensor torque decreases but it is believed that this decrease compensated for by muscles of hip and ankle joints. This suggestion has not investigated by isokinetic studies. Therefore, the aim of this research was that if quadriceps muscle torque decreases in spite of rehabilitation process and if this decrease compensated for by hip extensors and ankle plantar flexors? 10 healthy men [age: 22-35 years old] and 10 patients with ACL deficiency [age: 23-42 years old] participated in this study. Plantar flexor muscle strength, quadriceps muscle strength and hip extensor muscle strength were tested by Isokinetic Biodex System 3 at 60 and 180 degrees of angular velocities. Also functional vertical jump test was done for each lower extremity. Will coxson test and Spearman correlation coefficient were used. Results showed that there was no significant difference between mean strength of gastrosoleus, hip extensors and sum of mean strength of gastrosoleus, quadriceps and hip extensors of patient's injured and sound limbs [P>0.05]. Results showed that there was significant difference between mean strength of quadriceps of injured and sound limbs [P> 0.01]. There was no relationship between gastrosoleus, quadriceps and hip extensor summation and vertical jump functional test in the patients and normal subjects [P>0.05]. The results show that compensation occurs in the ankle plantar flexors and hip extensors of injured lower extremity. Thus in spite of significant decrease in quadriceps strength in the injured limb, sum of mean strength of gastrosoleus, quadriceps and hip extensor muscles between injured and sound limbs was not statistically significant. Also there was no relationship between functional test and isokinetic parameters. Thus functional vertical jump test can not be used instead of isokinetic test

Reliability of center of pressure measures during dynamic balance performance

Few studies have assessed the reliability of postural balance measures during dynamic balance performance that introduce additional challenging to postural control system. In addition sometimes in the static conditions some deficiencies of the postural control system may not be revealed obviously therefore the aim of this study was to assess the reliability of postural control parameters during functional performance on force plate in healthy subjects. Ten healthy male subjects [mean age: 25.4 years, weight: 68.2 kg height: 176.9cm] participated in this study. None of the subjects were involved in sport activities. Every subject performed three ISseconds trials of eyes open single leg stance on a force plate during dynamic balance task. Participants grasped object with hand at their waist level and release it at above shoulder level. The reproducibility of the center of pressure [COP] deviations [average speed and length of path] was assessed. All participants were tested on 2 sessions with an inter-measurement interval of 7 days. COP data was collected for each trial. The intraclass correlation coefficient [ICC] was used as parameter of intra-session and inter-session [Test-Retest] reliability. The ICCs for intra-session reliability of average speed and length of COP path were 0.89 and 0.91 respectively. The ICCs for inter-session reliability were 0.95 and 0.96 respectively. The study showed high and very high reliability for center of pressure measures during dynamic balance task. Therefore this dynamic performance can be used as a balance pattern in postural control assessment.. These can be used as reliable parameters in dynamic postural control assessment due to high reliability of average speed and length of COP path

relationship between isokinetic squat and vertical jump in anterior cruciate ligament reconstructed patients

For the rehabilitation program of the anterior cruciate ligament reconstructed patients [ACLR] strength and functional assessment and comparing with the uninvolved side is in great importance. Strength plays an important role in performing vertical jump moreover. It is performed in closed kinetic chain. Despite this importance, no information exists regarding the relationship on peak force of linear isokinetic and vertical jump score. The purposes of this study werel- To determine correlation between isokinetic squat and vertical jump in healthy and ACLR patients. 2- Comparing the peak force and vertical jump between the involved and uninvolved side of the ACLR patients. Twenty two ACLR patients with 6 months post-surgery and 16 healthy men participated in this study. Their isokinetic squat strength at the testing velocity of 25.4 cm/sec and vertical jump was measured. ACLR patients' peak force and vertical jump were significantly different between the involved and uninvolved side P<0.05. The findings showed low relationship [r=0.425] at the involved side between the vertical jump and peak force of squat, however, there was no relationship in the uninvolved side and the control group. Findings of this study indicate no relationship between vertical jump and peak force of squat. Both testing methods should be used since strength not always correlate strongly with physical performance. Closed kinetic chain isokinetic testing should be used for testing lower extremity strength, while vertical jump should be used to determine performance levels

Temporal stability of torque parameters and induced perception following muscle fatigue

Muscular fatigue is common problem that an athlete faces repeatedly during sport competition or therapeutic exercise. Undoubtedly, fatigue affects the precision of subjects' performance and limits the range of physical and sport activities. Muscle fatigue advantages and disadvantages have been reviewed in many previous studies. To challenge this controversy fatigue evaluation requires reliable, stable and precise methods of analysis itself. Researches on muscle strength and subject's perception of fatigue have been done in many studies. Therefore; researchers in this study focus on temporal stability of both subjective perception of fatigue and produced muscle torque after fatigue. Fifteen healthy female between 20-30 years of age, who at least had some non-professional light sporting activities once a week, volunteered in this research. Each of volunteers was evaluated in 3 different sessions. The first session was to familiarize the volunteers with the Isokinetic tests. For the main test, each of the volunteers was evaluated once and then after one week interval. At each session after warm up, perceived fatigue was measured using Visual Analog Scale. Then Average peak torque and average power maximal concentric Isokinetic of quadriceps were measured at the velocity of 60 degrees per second. To perform the fatigue protocol, subjects were asked to perform successive maximal quadriceps contractions until the three subsequent quadriceps torque output drop below 50 percent of maximal torque output. Afterwards, for re-measurement average peak torque, average power and perceived fatigue were evaluated similarly. The interaclass correlation coefficient [ICC] of average peak torque, average power and visual analog scale before performing fatigue protocol were calculated%81.6,%87.4 and%47.9 respectively. The repeated ICC after fatigue has estimated%59.9 >%64.4 and%96.6 respectively. This research demonstrated that Isokinetic temporal stability parameters were high before fatigue. In other words, both torque and power are reliable in two repetition times in a session, as well after one week interval between. After fatigue; the stability rate of torque and power recorded by Isokinetic were repeatable and this repeatability has been moderate to high. However; VAS showed a completely opposite results, in which before fatigue the stability of imagined local fatigue perception has been very low and was not significant, although after fatigue the VAS showed high repeatability

Reliability and minimal detectable change of foot arch height index device

This study was aimed to examine the reliability of a developed device measuring [arch height ratio] index. 40 feet [the right and left foot of 20 subjects] were measured. Foot length was measured from posterior aspect of calcaneus to the tip of longest toe and dorsum height was measured at the midpoint of total foot length. All measurements were assessed in three weight bearing conditions of 10, 50 and 90 percent of total body weight on three occasions [10 minutes and five days after the first measurement] by a single rater. Finally the arch height ratio index was calculated. The ICC values in different conditions of 10, 50 and 90 percent of total body weight in 10 minutes after the first measurement were calculated 0.96, 0.97 and 0.92 and in five days after the first measurement were calculated 0.97, 0.97 and 0.91. Minimal detectable change values of arch height ratio index in all conditions of measurement were 0.01. Simplicity of usage, low cost and high reliability of this device is highly recommended for clinical and research use

[Shigella spp frequency, serotyping and antibiotic resistance pattern in acute diarrheic patients in Zanjan Shahid Beheshti hospital, during 2003-2007]

Gastroenteritis is one of the most important diseases in the world. This disease is more critical among children, people with immune deficiency and the sufferers from mal-nutrition. Shigella spp. as the most important cause of dysentery, causes much mortality around the world. Increasing antibiotic resistance is one of the major health problems. This research aimed to study the pattern of antibiotic resistance of Shigella spp. In Zanjan Shahid Beheshti Hospital. Shigella spp. was isolated from stool samples of diarrheic patients during 2003-2007 using common microbioloyic methods. They were examined for serotyping and antibiogram using disc diffusion method. Shigella spp were found in 134 out of 682 [19.6%] diarrheic stool samples. They comprised of 53% males and 47% females. The highest number of positive samples was found in August and the lowest number was seen in March. The shigella species isolated from 134 positive cultures, identified as sh.flexeneri [62.7%], sh.boydii [20.1%] and sh.dysenteriae [17.2%]. In the antibiogram, ciprofloxacin was the most sensitive antibiotic [88.8%] and Ampicillin showed the highest resistance [100%]. Due to irregular use of antibiotics and increasing antibiotic resistance to Shigella species it can be suggested that some of antibiotics can be omitted from the list of drug choice

[Functional outcome of lower limb following anterior cruciate ligament reconstruction; a prospective clinical study]

Both isokinetic testing and functional tests are commonly used to evaluate anterior cruciate ligament reconstructed [ACLR] patients. The object of this study was to evaluate motor performance of the knee and determine the relationship of isokinetic test scores to scores on a variety of lower extremity functional tests. Ten healthy subjects and eleven ACLR patients at least six months after surgery performed the following: knee isokinetic tests at 60 and 180 deg/sec; three functional tests including leg vertical jump, single hop, and triple cross-over hop for distance. The International Knee Document Committee Subjective Knee Evaluation Form [IKDCSKEF] was used to score the self-assessment of each study participant. Paired T-test was used to compare the involved and uninvolved knee. Pearson correlation coefficients were used to determine the relationship between the scores on the isokinetic test and functional tests. Significance was determined by P<0.05. IKDCSKEF score was significantly lower in patients than control subjects. Quadriceps peak torque and functional test scores were significantly lower in the involved knee of the ACLR subjects compared to the uninvolved knee. Correlation coefficients of isokinetic peak torque to body weight and functional testing were not significant in patients or control subjects, whi1e the limb symmetry index [LSI] of the quadriceps isokinetics peak torque to body weight and the LSI of the functional tests were significant [r = 0.54 to 0.97]. These results indicate a significant relationship between the LSI of various functional tests and the LSI of isokinetic testing among ACLR patients. Thus, in situations where an isokinetic dynamometer is not available, the LSI of functional tests can be used to estimate quadriceps deficiency for ACLR patients