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Background and aim: Knee osteoarthritis (OA) is one of the most common synovial joint diseases (i.e. weight bearing joints) of the human body. This problem probably is more common in Iranian society that is used to sit on the floor and carpet. Following knee OA, patients complain of pain, inflammation, decrease of range of motion and muscle weakness. Therefore, they can not independently do their activity of daily living (ADL). Consequently, the side effects of physical incapability may render to psychological problems and this in respect do affect on their quality of life.Various treatments such as pharmalogical, surgical and physiotherapy have been recommended at different stages of OA by specialist. In the present study, the effect of physical therapy agents (considering the point that physiotherapy has no or negligible side effects) have been studied on OA. 

Materials and methods: 40 patients participated in this study the patients were refereed by orthopedic surgeon to the physiotherapy clinic of the Faculty of Rehabilitation. University ethical committee approved the procedures. Patients were randomly divided in two groups and physiotherapy treatments were applied as following:

Group I.  Low Level Laser Therapy, heat, exercise.

Group II. Placebo (i.e. inactive Laser), heat, exercise.

Results: The result of current study shows that both methods of physical therapy were quiet efficient on 7 variables that measured in this study (p< 0.05).  However, the result of this study showed that in laser group, pain and speed of gait were more effectively influenced (p< 0.000 and p<0.048 respectively) in comparison with routine physiotherapy. Consequently, patients can fairly independently do their activity of daily living and this in respect may reduce the psychological side effects of illness. 

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Background and aim:The role of thoraco-lumbar muscles is important in spinal column stability. Following fatigue due to constant activity, these muscles encounter with variable control pattern and variations of median and mean frequencies are little in relation to torque of force. However these parameters are useful in the literatures, but due to complexity of neuromuscular interaction and variety of motor control, signal processing can determine a wide range of changes and measurements.     

Signal processing nonlinear techniques exploit in biologic signals. Variables of nonlinear techniques are recurrence, determinism, entropy and so on.

The purpose of this study was to determine changes of entropy as nonlinear parameter in comparison with linear parameter and applicability of entropic measurements of the erector spinae muscles during fatigue.   

Materials and methods: Ten healthy women and 6 women with nonspecific low back pain (NSLBP) with a range of 20-30 years old patticipated in this study. Surface electromyography of isometric activities recorded from trunk (T12), lumbar (L3) and biceps femoris muscles during modified Sorenson isometric fatigue test. Median and mean frequency and also nonlinear parameters such as entropy and trend measured in one second of muscles activities before and onset of fatigue. 

Results:  Following fatigue in healthy group, median and mean frequencies reduced at a range of 12-20% (p<0.05). This decrement in LBP group was little (4 - 20%, p<0.05). Entropy increased 120-200% and trend reduced 800-2000% in normal subjects (p<0.05), whereas subjects with LBP indicated increment of entropy 65-220% and decrement of trend 240-500% (p<0.05). Before and after fatigue there was a significance difference between two groups in entropy parameter (p<0.05), whereas median and mean frequencies differences were not significant.

Conclusion:Following static positions, fatigue occurred in three levels of above muscles particularly at lumbar region. Traditional fatigue indicators showed good differences, but percentage of variability was low in comparison to nonlinear parameters. It suggests that nonlinear variables especially entropy are more sensitive than traditional indicators and can explain these stochastic behaviors

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Background and aim: The presence of the flexion relaxation phenomenon (FRP) during trunk flexion represents myoelectric  silence consistent with increased load sharing of the posterior discoligamentous passive structures. A number of studies have shown differences in the FRP between patients with chronic low back pain and healthy individuals, Persistent activation of the lumbar erector spinae musculature among patients with back pain may represent the body's attempt to stabilize injured spinal structures via reflexogenic ligamentomuscular activation for protecting them from further injury and avoiding pain.

Materials and methods: Two groups of female subjects ((20 - 40 years old) were participated in this study. First group consisted of 10 subjects with chronic low back pain (CLBP) and second group consisted of 10 healthy ones as control group. Both groups have performed 5 cycles of trunk flexion - extension . The speed of the movement repetition controlled by an electronic metronome . The EMG signals recorded from T12 and L3 paravertebral muscles and bisepse femoris on the right side. The lumbar flexion motion degree has been measured by the digital flexible goniometry.  All subjects have done Sorenson Back Endurance test in prone laying position. The subjects have extended their trunk up to the horizontal position and sustained in this position up to fatigue level .The subjects leave the table and asked to do 5 more cycle of trunk flexion - extension.

Results:  In patients group there is an increment and significant differences in lumbar flexion degree at the time of muscle EMG off  in comparison with healthy subjects after fatigue test (p<0.05). In both groups, the myoelectric silence period showed a significant change with respect to the pre- fatigue (p<0.05). The median frequencies shifted to lower frequencies after fatigue protocol (p<0.05).

Conclusion: Muscle reflexive responses would change following fatigue protocol. Therefore, the muscle activity will increase after the fatigue period. In the other hand, in patient group the role of the muscles as a stabilizer seems to be increased to enhance the stability at the injured segment after fatigue protocol .This protects the segment against pain and disability.

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Background and Aim: Neck pain is one of the common diseases (66.7%), which contains different age's groups such as youn. Results of researches indicate prevalence of women neck pain is higher than men, so experiment in neck disease in female is more necessary. The aim of this study is to evaluate changes of postural stability in patient with muscular neck pain. 

Materials & Methods: Twenty patients and fifteen healthy subjects contribute in this study.  Postural sway in quiet standing was assessed in both limb stance (BLS), one limb stance (OLS) of dominant side, on a force platform with open eyes (rigid-open) and standing on a force platform with closed eyes (rigid-closed) and standing on the foam (10.5 cm-thick) with open eyes (foam-open) without shoes. All of above conditions were done with dual task. Mean changes of logarithmic displacement in medial-lateral and for- aft directions were calculated.

 Results: There are significant differences between two groups, especially following dual task, and difficult conditions of OLS and standing on the foam.

 Conclusion: Patients with neck pain have difficultly in postural control that need to attending in treatment and prevention of following damages.

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Background and Aim: Forces imposed on body members even on light working condition, may gradually result in damages caused by working. Persons engaged at goods sales centers including cashiers, may be to catch exhaustion and neuromuscular damage due to repetition of their wrist, elbow and shoulder joints movement. The aim of this research is to assess the relation between the work factors and personal characteristic in possibility of the above symptoms.
Materials and methods: The questioners form propounded at Stanford university question were asked and coded based on the target group, and having been reviewed and surveyed were later used in this research. This questioner included parts such as recording the personal characteristics, history of illnesses, clinical diagnosis and evaluation of the work environment and the hand tools. Selected individuals were randomly employed at goods sales centers from five geographical districts of Tehran.
Results: The most complaint of employees was pain and dysfunction in upper limbs, neck and shoulder. Half of subjects had carpal tunnel syndrome.
ength of work time and employment duration at sales centers increase probability of neck and shoulder pain.
Conclusion: The profession of cashiering at sales centers is one of the most stress causing jobs on the peripheral joints of upper limb, so that the lengths of working in this position and the amount of activity have a positive effect on the increase of neuromuscular disorder. Apply of correct pattern of using the tools and the equipment in this work environment could substantially control the negative effects of this type of job. The most of complains expressed by individuals taking part in this research have been related to sign and symptoms of involvement of median nerve in the wrist and referral pain in the neck, shoulder and arm.

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Background and aim: Proprioception is a main component of somatosensory system that plays a protective role in acute injuries through reflex muscular splinting. Proprioception reduction could be a source of deficits in reaction time, postural control and postural stability. In chronic low back pain  patients (CLBP) the proprioception is decreased and leads to dysfunction in motor control and increased the risk of injury. Evaluation the repositioning of lumbar region could be an indication to measure the lumbar proprioception . The purpose of this study was to compare the lumbar repositioning in CLBP and healthy females. 

Material and Methods: Eighteen CLBP (22.83 ± 2.93 years) and 18 healthy females (23.33 ± 2.19 years) participated in this study. Lumbar repositioning error in 30% and 60% of lumbar full flexion and neutral position with closed eye in standing was evaluated with electrogoniometer. Absolute and constant error for 3 repositioning points were obtained and analyzed.

Results: Absolute error in patients with low back pain was significantly higher than control subjects in all 3 position points (P<0.05). Constant error did not show significant difference between two groups. (P>0.05)

Conclusion: Increased in absolute error of females with CLBP in lumbar repositioning implies that some aspects of proprioception may lose in patients with CLBP.

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Background and Aim: Muscle fatigue is a factor that caused muscle injuries. Ability to perform movement without error and controllability has important role in reduction of injuries. Reproduce ability of motion is reduced after muscle fatigue. Evaluation of motor control can produce suitable conditions for assessment of these changes and help us treatment guide lines for prevention of injuries. The aim of this study was to evaluate motor control changes following onset of fatigue in patients with anterior knee pain as a physiological aspect.
Materials and Methods: Fifteen voluntary female (10 healthy, 5 patients with bilateral syndromes) participated in this study. During dynamic fatigue test (open and closed chain movements), muscle activities were recorded from bilateral vastus medialis, vastus lateralis and rectus femoris (20 healthy and 10 patients quadriceps muscles) by surface electromyography (sEMG). Five dynamic cycles of motions were selected before and immediately after fatigue and then average of three middle cycles were compared for Symmetry Index (SI) as motor control assessment.  Also Median Frequency (MDF) were computed as an indicator for onset of fatigue. 
Results: MDF reduced significantly in both groups. This reduction was markedly showed in patients group. Reduction of SI was significant after fatigue test. Comparison of SI between groups indicated that before fatigue there was significant difference but after fatigue test was not significant.  
Conclusion: Dynamic motions can produce muscle fatigue and reduction of MDF. High central control system used different synergies following pain and functional impairment. Synergy patterns change after dynamic motions fatigue and cause reduction of SI. This change is dependent to pain and functional impairment and has not a stable pattern. 

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Background and Aim: 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.

Materials and Methods: 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.

 Results: 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.

Conclusion: 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. 

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Background and Aim: Patellofemoral pain syndrome (PFPS) is a common musculoskeletal condition. Women with patellofemoral pain syndrome would present significant weakness in many of hip muscle groups when compared with the healthy group. The objective of the present study was to compare the strength of hip abductor, extensor and external rotator muscle groups in sedentary women with bilateral patellofemoral pain syndrome to a matched control group of sedentary women without patellofemoral pain syndrome. 

Materials and Methods: Twelve women with bilateral patellofemoral pain syndrome as experimental group and other twelve matched women as control group participated in this study. Maximum isometric strength for three hip muscles including abductor, extensor and external rotator muscle groups was measured bilaterally in all subjects using a dynamometer fixed on a platform and finally averaged between two limbs and compared with the control group.

Results: The hip abductor, extensor and external rotator muscle groups of experimental group were statistically weaker than that of the control group (p< 0.001).

Conclusion:  It seems that lower limb muscles including hip muscles of women with patellofemoral pain syndrome become weaker due to disuse conditions. 

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Background and Aim: Neck pain is one of the most common musculoskeletal disorders in industrial society. There are complex changes in motor control of cervical spine in neck pain patients. The aim of this study was to compare the latency of activation of neck muscles during upper limb movement between neck pain patients and healthy subjects.

Materials and Methods: Eighteen chronic non-specific neck pain patients and eighteen healthy subjects who were matched in age, weight and height participated in this study. Subjects were standing on the ground and performed flexion and abduction movement of the right arm until at least 90 degree in five trials and consequently surface electromyography of neck muscles was recorded. Activation time of neck muscles was determined in comparison with the activation time of deltoid muscle (as an event) and then compared between two groups.  

Results: Findings of this study showed that in patients with chronic neck pain and healthy subjects during upper limb flexion and abduction movements, the superficial neck muscles were activated after deltoid activation. As well as in the neck pain patients compared to the healthy subjects superficial neck muscles onset was significantly appeared with delayed (P<0.05).

Conclusion: In patients with neck pain compared to healthy controls, the neck muscles were significantly delayed in responses to the internal perturbations of fast upper limb movements. It may be to increase the risk of injuries of neck region during fast upper limb movements.

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Background and Aim: More recently, attention has turned to the role of proximal structures in function of lower limb. Decreased lumbo-pelvic (or core) stability has been suggested to contribute to the etiology of lower extremity sport injuries. This is largely due to the closed chain nature of athletic activities. Groin pain is a common complaint for athletes participating in sports such as soccer. Adductor-related groin pain was the most common primary entity in soccer players. Therefore, the aim of this study was to compare of core stability between male soccer players with and without hip adductors strain. Various studies have been done for treatment and prevention of recurrent of this lesion and the most important thing in these studies was to keep the integrity of  the core stability.
Materials and Methods: Fifty professional soccer players (25 healthy and 25 with adductors strain. mean age: 21.32±2.73) was studied. Core stability was compared among them by 5 endurance and functional tests. Endurance of back extensors, trunk flexors and lateral flexors were tested by Modified Biering-Sorensen and Mc.Gilltests.In current research, the Double Leg Lowering test is applied to measure the function of the oblique abdominals muscles and the Single Leg Squat test is applied to measure the function of hip abductor and external rotators muscles.
Results: Endurance of back extensors, flexors and lateral flexors were significantly lower in the injured soccer players in comparison with the healthy players. Significant decrease in the function of oblique abdominal muscles, hip abductor and external rotator muscles were founded in the injured players (p<0.05).
Conclusion: Decrease of endurance and function in the trunk muscles is probably an important risk factor for hip adductors strain injuries in the soccer players. Increasing the endurance of the core muscles can be reduced the occurrence of hip addactors strain. 

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Background and Aim: This study was performed to compare the stiffness of hamstring and rectus femoris muscles in subjects with anterior knee pain and normal subjects.

Materials and Methods: In this non experimental and case-control study, 20 persons with anterior knee pain were selected simply from convenient sample and 20 healthy persons were selected by matching method. proximal and distal stiffness of hamstring and rectus femoris muscles were measured using an isokinetic device in the passive mode. Also, maximal concentric peak torque during flexion and extension movements of hip and knee, in two groups were compared by independent T-test and correlation analysis.

Results: There was no significant difference between anterior knee pain and proximal compartment of rectus femoris(P=0.320) and hamstring(P=0.125) stiffness, but there was significant difference between anterior knee pain and distal compartment of rectus femoris and hamstring stiffness (P<0.001). Significant relationship was found between anterior knee pain and muscles strength (P<0.001). No correlation was found between strength and stiffness of rectus femoris (P=0.356) and hamstring muscles (P=0.643) in patients group, but in healthy subjects this relationship was found (P<0.001). 

Conclusion: In patients with anterior knee pain, hamstring and rectus femoris muscles stiffness increased and muscle strength decreased. Increasing of muscle strength was effective on stiffness in healthy subjects, but there was no relation between them in patients group. Also rectus femoris and hamstring muscles possibly have different proximal and distal neuromuscular compartments.

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Background and Aim: Osteoarthritis is the most common joint disease in adults around the world and plays a great role in inducing disability in elderly. Patients suffering from severe knee osteoarthritis usually complain of pain and severe functional disability. For these patients, conservative treatments are often induces least remedy for pain and improvement of functional ability. This study evaluates the effects of knee mechanical traction on pain, edema, range of movement and functional ability in patients with severe knee osteoarthritis.

Materials and Methods: In this clinical trial, forty women with severe knee OA (grade 3 & 4 on the Kellgren-Lawrence grading scale) were recruited and randomly divided into two groups with different treatment protocols (common physiotherapy treatment and common physiotherapy treatment accompanied by knee traction). Functional capacity and level of pain were assessed by 6-minute walking test and visual analog scale respectively. A goniometer was used to measure knee range of movement and edema was also evaluated by use of measuring tape.

 Results: Common physiotherapy treatment accompanied by knee traction compared to common physiotherapy treatment leads to significant decrease in pain (P<0.01) and increase in functional capacity (P<0.05).

Conclusion: Common physiotherapy treatment accompanied by knee traction is a more effective treatment than common physiotherapy procedure in patients with severe knee osteoarthritis.

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Abstract Background and aims: One of the complications of breast cancer treatment is ipsilateral upper extremity lymphedema. Secondary lymphedema is a chronic condition that leads to loss of function and disorder of Quality of life. The aim of this study was to evaluate the effects of Complex Decongestive Physical Therapy (CDP) on pain severity and quality of life in patients with secondary upper extremity lymphedema after breast cancer treatments. Material and methods: A total 30 women (age 29-70 yrs.) with secondary lymphedema after breast cancer treatments participated in this study. They were referred by general and cancer surgeons to Physical Therapy clinic based on inclusion and exclusion criteria. They were treated with complex decongestive physical Therapy. This protocol comprises of manual lymphatic drainage (MLD), compression garments, remedial exercise and skin care for 4-weeks, once per day, 5 days per week. Quality of life and severity of pain were evaluated before and after treatment. The quality of life was assessed with QLQ-C30 questionnaire. The severity of pain was also assessed by Visual Analog Scale (VAS). Results: After 4 weeks treatment severity of the pain are decreased after treatment. The physical and social roles of quality of life (QLQ-C30) were significantly increased (p<0000). Conclusion: Based on the results of this study, utilization of complex decongestive physical therapy (CDP) In upper extremity lymphedema is a useful method for pain relief and increment of quality of life. Keywords: Upper extremity lymphedema, Complex decongestive physiotherapy (CDP), Severity of pain, Quality of life

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Background and Aim: Some of the patients with chronic low back pain commonly do not experience full recovery with the conventional physical therapy. It is revealed that may be there are some items in subjects with low back, which are not studied well till now. Since there are some evidences about breathing pattern disorder in low back pain patients, the purpose of this study was to compare between some important breathing pattern index in non-specific chronic low back pain and healthy subjects .

  

Materials and Methods : In this descriptive analysis study, there were 16 patients with chronic non-specific low back pain and 16 healthy subjects. Both groups were matched and selected by some of the demographic characteristics. Respiratory data including respiratory rate, volumetric, time depended and chemical index were calculated by K4b2 instrument.

  

Results: They have significant differences in some of the respiratory parameters including respiratory rate, inspiration and expiration times and total time of respiration between two groups, whereas inspiration total time ratio, volumetric and chemical index do not have significant differences.

  

Conclusion: Existence of disorders in some parameters of respiratory patterns in patients with low back pain are revealed that survey of respiratory system in patients with chronic non-specific low back pain can be effective in diagnosis and treatment process in physiotherapy centers.

  

Keywords: Low back pain, Breathing, Respiratory chemistry.

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Background and Aim : Hemiplegic shoulder pain is a common problem that its prevalence varies from 48% to 84%. This disorder limits the patient’s ability to achieve the optimal function. The objective of study was to assess the relationship between hemiplegic shoulder pain with neuromusculoskeletal disorders in post stroke hemiparesis

  

Materials and Methods: This study was an observational-analytic that fullfilled on fifty patients with acute stroke. The post stroke period was 28 days. The following items were evaluated:shoulder subluxation with X-ray, shoulder spasticity with Modified Modified Ashworth Scale (MMAS), soft tissue injury with orthopaedic tests and RSD with clinical features.

 

Results: Hemiplegic shoulder pain was present in 28 patients(56%). Seventeen patients (85%) showed shoulder subluxation, 18 patients (72%) had supraspinatus tendonitis ,13 patients (65%) had biceps tendinits, 4 patients (14/2%) had ACJ involvement, 3 patients (10/7%) had elbow flexor spasticity, 2 patients (7/1%) had shoulder adductor spasticity ,2 patients (7/1%)had shoulder internal rotators spsticity , 4 (14/2%) patients had RSD.

  

Conclusion: Results from this study show that one factor does not play role in causing hemiplegic shoulder pain and this disorder is multifactorial. Prevention of shoulder pain and performing appropriate physiotherapy can play a role in improving stroke patients’ function.

 

Keywords: Stroke, Shoulder pain, Sublxation, Muscle tone, Shoulder –Hand syndrone

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Background and Aim: Low back pain (LBP) is the most common and expensive musculoskeletal problem in industrialized societies. One in ten people suffers from LBP once in his life. It is self-limited up to 90%, but it is common to repeat. By the way, sacroiliac joint (SIJ) is the origin of low back and pelvic pain in many cases and one of the most important elements in normal musculoskeletal function during gait cycle. Muscles are important to stabilize this joint plus to bones and ligaments. Some of the muscles (Gluteus Maximus, Biceps Femoris, Multi Fidus, Erector Spinae) contributing in gait cycle are important to transfer load through SIJ. The aim of this present study is to compare muscle activity timing during initial and mid stance phase of gait cycle.

  

Methods and Materials: Sixteen low back pain cases and fifteen healthy subjects participated in this study. A footswitch is placed beneath foot at the suffered side in LBP cases and dominant foot in control group. Two markers were on the 5^th metatarsal bone and lateral maleolus. Electrodes are placed on selected muscles according to SENIAM. Digital camera and EMG Datalink were turned on simultaneously and subject started to walk with his own favorite speed in a specific direction and path. Onset and time to peak of selected muscles were recorded during gait by Datalink and processed by its software.

  

Results: Low back pain cases showed delayed muscle onset, although it was not significant (P=0.4). Time to peak of all selected muscles in loading response event in LBP group was longer and significant (P=0.01). There was also significant difference in time to peak of all selected muscles during mid-stance event (P= 0.005) except biceps femoris muscle.

  

Conclusion: Delayed onset and longer time to peak during initial and mid stance phase of gait can be interpreted as a compensatory strategy to control trunk movements effectively, provide sufficient stability and transfer load to lumbar area efficiently.

  

Key words: Muscle activity, Low back pain, Gait, Trunk muscles, Lower Limb Muscles

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Background and Aim: Regarding to high prevalence of low back pain (LBP) in athletes and its effect on their athletic function, an accurate evaluation before planning the rehabilitation program seems necessary in athletes with LBP. It should be considered that human movements are like as a kinetic chain. It means that any problems in every parts of this chain can cause dysfunction in the other parts of the chain. Not taking attention to the relationships between different parts of this chain may result in suboptimal rehabilitation. Therefore, focusing treatment on the entire parts of the kinetic chain besides the injured part, may prevent recurrenceof the dysfunction. Since in the kinetic chain hip muscles act as a link between lower extremities and trunk, the purpose of the present study was to evaluate and compare muscles strength of hip joint in female athletes with and without non-specific chronic LBP.

  

Materials and Methods: Fifteen healthy female athletes and 15 female athletes with non-specific chronic LBP participated in this study. Their age was between 18-30 years. Hip extension, abduction and external rotation strength in all participants were measured. A hand-held dynamometer (HHD) was used to measure muscle strength. Since fixing HHD by examiner’s hand is fraught with error, it is fixed by a stable frame.

  

Results: The maximum strength value of hip extension and abduction in female athletes with LBP were significantly lower than these measures in healthy group (P < 0.05). No significant differences were seen in the maximum value of hip external rotation strength between two groups (P > 0.05).

  

Conclusion: The results of the present study show that hip extension and abduction strength in female athletes with LBP were lower than these measures in healthy group. Therefore, hip strength measurements besides the examination of the spinal column seem to be necessary in evaluation and rehabilitation of the patients with LBP.

  

Key Words: Non-Specific Chronic Low Back Pain, Hip Muscles Strength, Athlete

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Background and Aim: Low back pain (LBP) is the most common and expensive musculoskeletal problem in industrialized societies. One in ten people suffers from LBP once in his life. It is self-limited up to 90%, but it is common to repeat. By the way, sacroiliac joint (SIJ) is the origin of low back and pelvic pain in many cases and one of the most important elements in normal musculoskeletal function during gait cycle. Muscles are important to stabilize this joint plus to bones and ligaments. Some of the muscles (Gluteus Maximus, Biceps Femoris, Multi Fidus, Erector Spinae) contributing in gait cycle are important to transfer load through SIJ. The aim of this present study is to compare muscle activity timing during initial and mid stance phase of gait cycle.

  

Methods and Materials: Sixteen low back pain cases and fifteen healthy subjects participated in this study. A footswitch is placed beneath foot at the suffered side in LBP cases and dominant foot in control group. Two markers were on the 5^th metatarsal bone and lateral maleolus. Electrodes are placed on selected muscles according to SENIAM. Digital camera and EMG Datalink were turned on simultaneously and subject started to walk with his own favorite speed in a specific direction and path. Onset and time to peak of selected muscles were recorded during gait by Datalink and processed by its software.

  

Results: Low back pain cases showed delayed muscle onset, although it was not significant (P=0.4). Time to peak of all selected muscles in loading response event in LBP group was longer and significant (P=0.01). There was also significant difference in time to peak of all selected muscles during mid-stance event (P= 0.005) except biceps femoris muscle.

  

Conclusion: Delayed onset and longer time to peak during initial and mid stance phase of gait can be interpreted as a compensatory strategy to control trunk movements effectively, provide sufficient stability and transfer load to lumbar area efficiently.

  

Key words: Muscle activity, Low back pain, Gait, Trunk muscles, Lower Limb Muscles

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Background and Aim: The calculated parameters of the center of pressure (COP) are suitable indicators for evaluating balance in patients after rehabilitation. Therefore, determining the reliability level of each parameter is a matter of great importance. This study tried to determine the reliability of some parameters of the COP sway in patients with myofascial neck pain in different postural situations.

  

Materials and Methods: The present study is a test-retest reliability design. Twenty patients with myofascial neck pain performed a single and a double leg test with open and closed eyes on a force plate and with open eyes on foam in three sessions with a 30 minute intervals for 30 seconds. Antero-posterior and medio-lateral sway range, mean velocity and mean area of sway were calculated.

  

Results: The mean velocity showed high reliability (0.98) in all situations, but the other parameters were variable in different situations.

  

Conclusions: The results showed that some COP parameters are highly reliable in assessment of patients with myofascial neck pain.

  

Keywords: Reliability, Myofascial neck pain, Center of pressure, Force plate