[Assessment of effect of cognitive task on postural control in female patients with knee osteoarthritis]

Knee osteoarthritis is one of the most common musculoskeletal problems that can affect activity daily living of patients. Many studies have indicated postural control deficits in these patients; but the effect of dual tasking on postural control has not been examined yet. The aim of this study is to investigate the effect of cognitive task on postural control in the female patients with knee osteoarthritis. Postural stability in knee OA patients and healthy subjects [20 subjects in each group] in four positions was measured using the Force plate. Positions included double leg stance with closed or opened eyes with and without cognitive task. Area of COP and mean velocity [Vm] were measured for as static postural stability. Area under the curve increased in the double leg stance position in the patients significantly [P<0.05]. While mean velocity decreased by performing a dual task [P<0.05]. The response to dual-tasking was not significant between the 2 groups [P>0.05]. Postural control deficits and increased of center of pressure's sway were identified in participants with Knee osteoarthritis. Also performance of a cognitive task resulted in decrease of postural sway, but the dual- tasking did not change the postural performance of knee OA patients compared to healthy subjects

Effect of 2 different jump types on vertical leg stiffness and performance parameters in healthy young women

To investigate effects of 2 different jump types on vertical leg stiffness and performance parameters in healthy young women. People usually use various types of high jumping. It seems any model may have different effects on biomechanical parameters of the human body. Present study determined the effect of 2 jump types on performance parameters and vertical leg stiffness as a mechanical response of body to perturbations which occur during jumping. Vertical leg stiffness and performance parameters [jump height, flight time, contact time and power] were calculated in 25 healthy female subjects, under 2 conditions of Squat Jump [SJ] and Counter Movement Jump [CMJ]. Vertical leg stiffness [P= 0.028] and jump height [P= 0.039] were significantly higher in CMJ than SJ. Jump type has not any significant effects on the flight time [P= 0.1], contact time [P= 0.7] and power [P= 0.3]. Counter movement jump increases the muscle force production, work output and GRF and may cause improvement in jump performance. Increased vertical leg stiffness improves performance as well as the risk of injury

[ effect of soft cervical collar on movement response and anticipatory postural adjustment of postural muscle of neck following arm flexion during standing]

Neck pain is one of three common complains of neuromuscular system. There are three subsystem to maintain stability of spine: passive subsystem, active [muscles] subsystem and control subsystem. Detection of postural muscle response during postural perturbation like fast arm movement can be utilized to analyse of postural control. Wearing cervical collars is a way to prevent or cure cervical pain. The aim of the present study was to investigate the effect of soft cervical collar on movement response and duration of activity and recruitment pattern of cervical muscles. Twenty healthy young women participated in this study. They flex right shoulder in response to sound stimulus with and without wearing soft cervical collar. Surface Electromyography [EMG] used to assess postural muscle activity in following muscles: Deltoid, Trapezius, Cervical Erector spinae and Sternocleidomastoid. The effect of soft cervical collar on reaction time, onset and duration of activity of cervical muscles was calculated, Wearing soft cervical collar increased reaction time of arm flexion [P< 0.05] and decreased duration of activity of cervical extensor, trapezius and erector spinae [P< 0.05]. During shoulder flexion with additional load, onset activity of trapezius muscle was significantly earlier than other neck muscles but cervical erector spinae and Sternocleidomastoid exhibit coactivation pattern in response to perturbation. During fast arm movement that leads to postural perturbation, soft cervical collar alleviates the response and reduce activity of muscles. The strategy of motor control centers in response to perturbation in cervical spine is coactivation of flexor and extensor muscles to maintain stability

[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

effect of lifting on trunk muscles motor control in athlete and non-athlete subjects

Spinal injury especially during occupational lifting is one of the most common neuromuscular disorders in the general population of the world. Asymmetric motions of trunk frequent bending and twisting, lifting and forceful activities contribute to spine disorders. Sport as a comprehensive activity might be able to cause less force to the spine and decrease spinal injuries. The purpose of present study was to determine the effect of lifting on motor control pattern during combined symmetric and asymmetric trunk motions on athlete and non-athlete subjects. Seventeen non-athlete female subjects and seventeen athlete female subjects performed to lift four loads [5,7,9, 12 kilogram] at symmetric and asymmetric conditions. Under each condition temporal parameters of motor control were measured on flexor and extensor of trunk muscles. In two groups of athletes and non-athletes with increasing load, muscles begin their activity faster [P<0.05]. No significant change was found at asymmetric condition. Also, in athletes premotor time of muscles during lifting was less than non-athletes. With increasing load, according to the feed forward control mechanism and awareness of subjects from amount of loads, muscles quickly prepared to contract for starting the movement. It seems that the response of movement on the neuromotor system of athletes is preprogrammed and automatic due to sport experience. Actually muscles have anticipation activity

Changes of flexion relaxation pattern following rhythmic motion and fatigue during neck flexion

Cognition of fatigue effects on motion response can improve treatment approaches. Determination of mechanism [maximal voluntary contraction and repetition of movement] that cause change of central responses and neuromuscular transmission have specific emphasis in evaluation and treatment of patients. Following fatigue it is arguable which is more important, neural or osteo-ligamental components. Behavior of para spinal muscles due to their roles in control of posture and spinal alignments are more importance. Gesture and motion pattern of neck and lumbar column following fatigue is due to accession of disorder in neuromuscular junction [NMJ] or limitation in reflex response at this system. Reflex influence is not just for muscle fatigue but also it appeared in synergic muscles. It is clear that stimuli and inhibitory ways have important role in this process. Twenty normal subjects [10 female and 10 male] contributed in this study. Tests were including: 1- Training and warm up 2- Placement of recording electrodes on neck extensor muscles at second and forth spinal vertebra of dominant side. 3- Five motion of neck flexion and extension in sitting position at full range without external load. 4- Fatigue test, contain; A- Maximal isometric contraction at middle range about 3 minute, which were controlled by a dynamometer until onset of fatigue. B- Fifty dynamic and cyclic motions of neck flexion and extension in full range of it. 5- Perform five motions similar stage 3 immediately after muscle fatigue. Three middle cycles were chosen for evaluation. Degree of off activities in flexion, degree of onset of activities in extension, silent period and mean of muscles activities [RMS], before and after fatigue selected for analysis. Comparison of two type of fatigue indicated that there are significant differences between them. Range of motion and eccentric activity were similar for two conditions. Isometric fatigue showed more effect than cyclic condition. In neck motions flexion relaxation occurred. Dynamic motion and isometric activities caused muscle fatigue and changed silent period. This period reduced and it means that onset of extensor muscle activities occurred very soon and moved to middle and outer ranges. In this manner, naught privilege mechanical of non contractile elements in neck region is cause of this reduction. On the other hand extensor muscles have more responsibility for control and preservation of posture. Comparison of two approaches indicated that isometric activity produce more fatigue and spectral indexes such as median and mean frequency reduced markedly

effects of palmar static splint on hand function, spasticity and wrist and elbow range of motion of 8 to 12 years old spastic cerebral palsy children

Upper limb dysfunction is a common and disabling consequence of cerebral palsy. Any functional disorder in the hand can cause a person's independence to be disrupted and therefore his or her social independence is threatened. The purpose of this study was to determine the effects of volar static splint on hand function, spasticity and wrist and elbow range of motion of 8 to 12 years old spastic children. The design of this study was clinical trial and before after. Fourteen 8 to 12 spastic cerebral palsy children that have the inclusion criteria of study were selected from rehabilitation clinics of Tehran. The patient used a volar static splint [10 degree of wrist extension, full extension of fingers and abduction and opposition of thumb] for 2 mounts [2 hours during day and 4 to 6 hours at night]. In this study Jebsen Taylor Hand Function Test was used to evaluate hand function. Modified Ashworth Scale was used to evaluate spasticity. A Goniometer was used to measure range of motion. The results of this study showed significant improvement in hand function [P<0/001] Significant reduction in wrist spasticity [P<0/001] and elbow spasticity [P<0/009] and significant increase in wrist range of motion [P<0/001] The data did not show any significance in elbow range of motion [P<0/336]. Our findings suggested that 2 months using of volar static splint in children with spastic cerebral palsy can improve hand function, wrist and elbow spasticity and wrist range of motion

Assessment of balance impairments in patients with knee osteoarthritis

Knee osteoarthritis is one of the most common musculoskeletal problems, can affect on patient's daily activity and produce dependency in their daily activity and functional disability; The aim of present study is to compare static balance in patients with knee osteoarthritis and healthy subjects using force plate. Postural stability in knee OA patients and healthy subjects [each group 20 subjects] were measured by force plate. Two positions were selected double stance with closed or opened eyes. Range of fore/aft [Rfa] and Range of side ways [Rsw], were measured as static postural stability. Rsw increased significantly in the double stance position in patients group [P<0.05]. Also in both groups, Rsw and Rfa in the double stance with closed eyes were more than of open eyes position [P<0.05]. Postural control deficits and increase of center of pressure's sway were identified in participants with knee osteoarthritis. Therefore, one of the most important goals of rehabilitation is to improve balance control in knee OA patients

effects and maintenance of constraint-induced therapy on spasticity and function of upper extremity in hemiplegic cerebral palsy children 6 to 12 years old

Cerebral palsy is a non progressive disorder and the most common movement problem in children. Many children with cerebral palsy are of hemiplegic type. One of the important problems of this children is unilateral upper limb dysfunction, that not using the affected side causes forgetfulness and more problems on this side. In this study, effectiveness of Constraint-Induced Therapy [CIT] and the maintainance of this technique on spasticity and performance of upper extremity in hemiplegic cerebral palsy children 6 to 12 years old have been investigated. In this pretest - posttest quasi experimental study, 20 cerebral palsy hemiplegic children 6 to 12 years old [15 boys and 5 girls] with 8.7 years mean age were selected. Interventions were performed about 8 weeks and patients were followed for 4 weeks. Spasticity on the affected side in wrist and elbow were tested by Modified Ashworth Scale and upper extremity function by the Box and Block test. The data were analyzed with the Wilcoxon and paired t- tests. Constraint-Induced Therapy in the affected limb decreases significantly the spasticity of wrist [p = 0.00] and elbow [p = 0.005] and significantly increases performance score [p = 0.00], and the recovery significantly maintained one month after the interventions. Constraint-Induced Therapy of affected upper extremity could possibly decrease limb spasticity and increase function with two mechanisms: Fierstly, The reduction of not using the plegic side and secondly, neuroplasticity in CNS. This improvement may remain viable in the affected limb

[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

[Comparison of concentric isokinetic dominant shoulder internal and external rotator torque between professional female volleyball and tennis players]

The purpose of this study was to measure isokinetic maximum and average peak torque of internal and external rotators of glenohumeral joint in volley ball and tennis players This study was performed on 17 professional female athletes [7 tennis players and 10 volleyball players] with age ranged 18-28 years. The subjects had played in a skilled team for more than 3 years. They were free from injury to their dominant shoulder in the past year. Subjects performed a five minute warm up by shoulder wheel and Maximum average Peak Torque [APT] were obtained unilaterally by a Biodex System 3 with the arm of players in 90 degree abduction at 120,180 and 210 o/s. Players performed five trails of concentric movements with 30 second rest between them. Maximum and average of maximum torques of shoulder rotator, in both groups, expect for internal rotators of tennis players, reduced by increase of movement speed [P<0.05]. There are not significant difference between two groups in maximum, average of maximum torques and normalized data [ratio of maximum torque to weight]. There is significant difference between two groups in percentage of APT of External rotator / Internal rotator ratio at 210 o/s [P<0.05]. Volleyball and tennis have no effect on isokinetic strength of shoulder rotators. In high speed, ratio of External rotator / Internal rotator is reduced. This indicates that increase in movement speed increase internal rotator in comparison to external rotator in these professional female athletes