Tehran University Medical Journal

Background: Low back pain (LBP) is a one of the most common symptoms of vertebral column diseases. Spinal muscles have a outstanding role in maintaining vertebral column function in daily life. But proper function and motion of hip and knee joints also has an important role in performing smooth, fine and nonstressed movements of lumbar spin. Where as accurate and fine motions of hip and knee joints in cooperate with lumbar spin can improve translation and summation of forces and increase performance of movements. The aim of this research is to indicate the amount of interventions of lower limb joints on lumbar spin function in patients with LBP, and attention to physical treatment (PT) of them.

Materials and Methods: Fifty females with LBP due to osteoarthritis ( OA) of lumbar spin participated in this study and divided in two groups randomly with similar number of cases: a) ordinary treatment or control group and b) complementary treatment group. Patients in control group treated by routine PT approach ( superficial heat, ultrasound, TENS, forward flexion and back extension exercises ) and patients in complementary or test group received routine treatment similar to control group and also strength and stretching exercises of hip and knee joint muscles ( latisimous dorsi, gluteous maximus, iliopsoas, quadriceps and hamstring ) bilaterally. Range of motion (ROM) of lumbar, hip and keen joints by valid goniametere and pain of lumbar in motions at all of axis by visual analog scale measured before, after five and ten sessions of treatments in both groups.

Results: In control group with non parametric tests there was not significant difference of MMT of muscles and ROMs of hip and knee joints. Lumbar pain in motion after ten sessions of PT in this group reduced significantly ( P< 0.05 ). Increase of lumbar motion in all of axis after PT was significant at this patients ( P< 0.05 ). In second group that received complementary treatments ROM of joints, lumbar pain had significant differences between onset of treatments and five and ten sessions later ( P< 0.05 ), but there was not significant findings in MMT of muscles. There were significant differences between percentages of reduce of pain and increase of ROM in comparison of two groups ( P< 0.05 ). Where as patients that received ordinary PT and strength and stretching of muscles around of hip and knee indicated better recovery signs.

Conclusion: Reduce of lumbar pain with improve of motion and flexibility of muscles such as quadriceps, hamstring, gluteus maximus, iliopsoas and latisimous dorsi in a complete physical therapy approach indicate there are a great correlation between lumbar pain and functionality of lower limb joints. Therefore concentration to flexibility and extensibility of muscles of lower limbs is a basis aim in treatment of patients with lumbar OA.

Background: Joint trauma and injury are the most common causes of dynamic instability. Dynamic instability has a great effect on the lumbar spine, due to its three-dimensional motions. The greatest amounts of compression and shearing force are imposed at the points of maximum torque and velocity. The changes in these phase angles upon bearing various loads can cause some pathologic conditions. In this study, we examined the phase angle at maximum torque and velocity in the three planes of movement and then estimated their displacement upon external loads.

Methods: Using the B200 isoinertial dynamometer, 13 subjects were tested in three stages as follows: 1) Familiarization with tests and apparatus. 2) Warm-up and three maximum isometric tests, with a rest interval between each test, in the three axes of lumbar motion including: flexion/extension, rotation to right/left, lateral flexion to the right/left. 3) Five dynamic tests in these three axes of motion without load, with 25% maximum voluntary torque, and with 50% maximum voluntary torque. Special software was used to analyze the raw data and detect the occurrence of maximum torque and velocity in the dynamic range of motion at each of the three axes.     

Results: When the load was increased, the maximum dynamic torque in each of the three axes increased (P<0.05). The increase in load shifted the phase angles toward the maximum torque and velocity (P<0.05), with a positive correlation between changes in torque and velocity phase angles (P<0.05).

Conclusions: Rather than being a function of the biomechanical pattern, the changes in maximum torque and velocity of the phase angles following an increase in motion resistance to the outer range of the three axes are actually a control behavior in the motion processing system in dynamic movement.

Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Muscle weakness and fatigue are two factors that cause muscle injuries. The roll of motor control is important in regulation and reduction of this effect. Repetition of motion after muscle fatigue is due to the significant role of motor control system. The aim of this study was to evaluate the quality of roll control of central nervous system following fatigue in order to answer primary questions in therapeutic exercises.
Methods: Twenty voluntary healthy subjects participated in this study. Dominant abductor policis brevis after surface electromyography (SEMG) of maximal voluntary contraction (MVC) fatigued by maximum three minutes isometric contraction in specific hand splint monitored by dynamometer until reduction of activities to 50% MVC. Before and immediately after fatigue test, 5 dynamic full range of motion in abduction direction performed without resistance and muscle activities recorded by SEMG. Three middle muscle activities selected for comparison of Symmetrical Index (SI) as specificity of motor control assessment. Fatigue indicators were percentage of reduction of MVC and median and mean frequency of power spectrum of MVC before and after fatigue test.
Results: Significant reduction of MVC (46.77%), median (13.03%) and mean (12.20%) frequency were showed (p=0.001), whereas significant increase of SI (10.76%) appeared (p=0.000), following fatigue test.
Conclusion: Fatigue reduces muscle contraction velocity, therefore median and mean frequency decrease. Also after muscle fatigue reduces of muscle proprioception sense appears, that can cause slow dynamic joint motion. Upper central control systems try to correct this situation by involving new motor units and changes of muscle timing. Synchronization of primary and new motor units plays an important role in increase of SI.