مجله پژوهش در علوم توانبخشی
سال چهارم شماره 2 (پاییز و زمستان 1387)

Human motor system is organized for execution of various motor tasks in different and flexible ways. This is mainly achieved by the way that central nervous system (CNS) uses the redundancy in musculoskeletal system. The kinetic redundancy in human musculoskeletal systems is a significant property by which central nervous system achieves many complementary goals. In this study, by explaining the definition and role of uncontrolled manifold for movement kinematics, the kinetic redundancy concept is explored in mathematical terms. The null space of the kinetically redundant system when certain joint moment and/or stiffness are needed is derived and discussed. In this paper, the mathematical methods have been developed for a simpler planar biomechanical model with 3 muscles in which the explained concepts have been utilized.

Patellofemoral pain syndrome (PFPS) is one of the most common musculoskeletal disorders affecting adults. Patellar taping provides an effective treatment in alleviating the symptoms of a high proportion of subjects who present with PFPS. The mechanisms of pain reduction have not completely been established, although it may be related to alteration in the kinetics of patellofemoral joint following taping. A Case-control study was designed to examine the effects of patellar taping on the biomechanics of the patellofemoral joint in subjects with PFPS. Patellofemoral joint reaction force (PFJRF) of eighteen subjects with PFPS and the similar number of healthy controls were assessed using a motion-analysis system and one force plate. This procedure was performed on the affected knee of subjects with PFPS, before, with and finally after patellar taping during the eccentric phase of single leg squatting. Unaffected knee of subjects with PFPS and both knees of control group were also undergone the similar procedure. The result revealed that the mean values of PFJRF prior to taping (2025 ± 347 N) had decreased significantly following a period of taping and exercises (1720 ± 303 N) (P < 0.05). The PFJRF values of affected knees of subjects with PFPS before application of tape, and healthy controls (1922 ± 398 N) were not significantly different (P > 0.05). The corresponding decrease of pain level accompanied with the decreased kinetics, may explain the mechanism of pain reduction following patellar taping in subjects with PFPS

Chronic anterior knee pain is one of the most common complaints, especially in our society. It consists of a large number of patients in orthopedic clinics. This pain might have serious negative effects on students’ educations, on the other hand, limits their physical activities that is essential for their age. In contrast to adults, such pain etiologies may vary in many ways for teenagers. Some are easily curable and others not. In time evaluation and diagnosis can lead to a faster and more efficient treatment. The aim of this study was to evaluate chronic anterior knee pain in Iranian teenagers. In this cross-sectional study, among patients referred to Isfahan Hospitals from December 2005 to December 2007, 198 teenagers (8 to 18 years-old) who suffered from untreated chronic anterior knee pain were enrolled. All of them were examined by an orthopedic specialist. The patient's demographic information such as age, sex, physical activity type, underlying diseases if any, knee trauma history if any, pain duration, laboratory and radiological findings, and other diagnostic findings and the final diagnosis were recorded in questionnaires. Then, the relations between disease etiology and these factors were sought. Chronic anterior knee pain was more frequent in boys compare with girls (53.1% vs. 46.9%). At the ages around puberty, chronic anterior knee pain was more common. The most prevalent etiologies were patella-femoral dysplasia, malalignment of lower limbs, knee menisci and ligaments tearing, osgood-schlatter disease, juvenile rheumatoid arthritis (JRA) and osteochondritis dissecans, respectively. In our study like many other ones, patella-femoral dysplasia and malalignment of lower limbs are the most prevalent causes among other etiologies. Such causes like malalignment of lower limbs and JRA are found more in girls and osgood-schlatter disease and osteochondritis dissecans are more common in boys. JRA and osteochondritis dissecans were considered as rare causes for chronic anterior knee pain; however in our study they played an important role. Finally we can diagnose these causes and treat them properly by this mean, we’ll be able to teach the patients how to prevent such diseases

The every possible attempt in voice disorders assessment is to gather samples which represent individuals’ actual voice in the daily speech. The researchers have found that voice characteristics in reading a passage are closer to daily speech. Making texts has been started since early 20th century. The lack of suitable text in Farsi language makes it difficult to conduct requisite researches and present documentary results of interventions. Researchers believe that Sara lip reading test which had been used for voice studies in Farsi language is not appropriate. The goal of this study is to make an appropriate text for assessing the voice characteristics which is also effective for both research and clinical goals. The required text was made by the study of the characteristics of used texts in other languages, considering the Dr. Speech software limitations in analyzing duration of stimuli and the results from investigations used Sara lip reading test. The content validity of this text was assessed. Its reliability was determined by test-retest method. The content validity of the text was confirmed by the university professors. In examining the reliability, it was indicated that measuring the studied characteristics has a high reliability. There was a general consensus among university professors about the text validity. In examining the reliability, Cronbach′s alpha was more than 0.7 in studied variables. Considering the confirmed validity and reliability, it can be concluded that this text can be used for assessing voice characteristics in voice studies in normal sample

Previous studies on chronic low back pain (CLBP) have addressed the biomechanical performance of trunk, including its mobility, and the static balance performance in the related population. However, the onset of low back pain is commonly linked with dynamic activities and therefore, the evaluation of the balance performance in dynamic condition would be clinically important. The objectives of this study were to assess the dynamic postural control and its relationship with trunk mobility in chronic low back pain patients. Twenty-four female patients with chronic low back pain and 24 able-bodied females, all between 25 to 45 years old, voluntarily participated in this study. Dynamic postural control, lumbar mobility and back pain were measured by a Biodex system, Schober technique and Quebec questionnaire, respectively. Multivariate analysis of variance (repeated measure) and Pearson correlation coefficient were used for data analysis (α < 0.05). Chronic low back pain patients had greater dynamic postural sway (P < 0.0001). In chronic low back pain, the function of lower limbs and the trunk’s proprioception were affected. This deficit was better observed in closed eyes condition. Lumbar mobility was significantly reduced in chronic low back pain group, However there was no significant relationship between the lumbar mobility and the postural control (P < 0.001). Chronic low back pain is associated with greater postural sway and reduced lumbar mobility. These variables are independent and should be considered in both detection and treatment process separately. More studies are sequined to determine if these parameters are primary or secondary

Introdaction: The spine is an important part of the human skeletal system. The objective of this identify was to study the effects of weight, gender and number of pregnancies (in females) on low back pain and the lumbar total and segmental lordosis. Seventy five subjects (41 males and 34 females) aged between 18 and 62 years were randomly selected. The subjects had not any previous history of back–pain or related surgery. Lateral X-ray in standing position followed by the cobb method was used to evaluate lumbar total and segmental lordosis. Variables such as subjects age, weight, height, gender, body mass index (BMI) and number of previous pregnancies (for the females) were obtained and recorded on a data sheet. In this study, pain scores were evaluated by a pain ruler. For the statistical analysis of the date, the ANOVA, tokey post hoc test and sample t-test were applied by the meaningful statistical level of less than 0.05. The amount of lumbar total lordosis was greater in females compared to the male subjects. Lumbar segmental lordosis in various parts were as follow: L1-L2 (4 in men, 6 in women), L2-L3 (8 in men, 9 in women), L3-L4 (8.7 in men, 9.5 in women), L4-L5 (12 in men, 14.6 in women), L5–S1 (23 in men, 18 in women). The degree of lumbar lordosis (upper part) was greater in obese females compare to normal weights. The number of pregnancy was in correlation with the increase in the degree of lumbar total lordosis in female subjects. Women had more pain than men. It can be concluded that obesity, gender, body mass index and multiple child birth have significant effects on low back pain and lumbar total and segmental lordosis

The aim of this study was to assess the prevalence of kyphosis disorders in students. Five hundred and two students in three levels including primary (99 girls, 99 boys) guidance (47 girls, 57 boys), and high schools (100 girls, 100 boys) participated in this study. Frontal Cobb angle was measured by flexi curve ruler. Data were analyzed by chi square. After collecting the data, subjects were classified in 4 categories includeing flat back, normal, kyphosis, and hyperkyphosis. In all 256 boys, 2% had flat back (2%), normal (76.6%), kyphosis (21.4%) and in 256 girls (4.5%), showed flat Bach, flat back normal (80%), kyphosis (15%), but there were significant differences between their disorders (P > 0.05). There was significant difference between boy and girls in elementary school (P < 0.05). In guidance and high school boy and girls, there were significant differences between their spinal deformities (flat back, normal and kyphosis). We concluded that reducing improper habits and familiarized the children with proper way of carrying her or his bags and performing proper activities such as sitting, sleeping and also participated in regular training, can reduces the risk of spinal deformities.