Electromyography and clinical neurophysiology最新文献

Many studies have shown an inverse relationship between axon length (or height) and nerve conduction velocity. A linear relationship was assumed, but there is no physiologic indication the relationship is linear. Furthermore, a linear relationship between height and velocity leads to implausibly low velocities for very long nerves. We propose that power regression analysis would produce more accurate results, in line with physiology. In a power regression the goal is to determine exponent x that best fits the curve V = kLx where k is a constant and L is nerve length. In a previous study, the authors established that the product of conduction time T and energy E or TE = kL3. Mathematical derivation from this relationship yields V2/V1 = (L2/L1)(-0.5), or, velocity V is inversely proportional to the square root of length. Data from 22 normal Ulnar Motor Nerve Conductions showed a very high correlation with this formula (exponent x = -0.529 SE = 0.21, theoretical value -0.5). Data from other researchers also supports this relationship. Overall, Ulnar Motor Nerve Motor Conduction Velocity appears to be inversely proportional to the square root of height. We believe this relationship holds for all long nerves.

The semitendinosus (ST) muscle has a tendinous intersection within the muscle belly that separates the ST muscle into distinct proximal and distal compartments. Thus far, no study has compared the electromyographic (EMG) activities between the proximal and distal compartments of the human ST muscle. This study aimed to investigate the intramuscular EMG activity patterns of the proximal and distal compartments of the ST muscle by altering the hip and knee joint positions. The study population comprised eight healthy male volunteers. They performed ramp isometric knee flexion tasks form the relaxed state to the maximal voluntary contraction (MVC) state with (1) the hip and knee at 90 degrees and 0 degrees, respectively (90-0 position), (2) both the hip and knee at 00 (0-0 position), and (3) the hip and knee at 0 degrees and 90 degrees, respectively (0-90 position). Fine-wire electrodes were inserted into the proximal and distal compartments of the ST muscle and the individual EMG activities were recorded. In the 90-0 position, the EMG activity of the distal compartment was higher than that of the proximal compartment at 60%, 80%, and 90% MVC. Moreover, in the 0-90 position, the EMG activity of the proximal compartment was higher than that of the distal compartment at 60% MVC. These results indicated that the lengthened or shortened muscle conditions induced regional differences in the EMG activity patterns, while the two compartments showed equivalent activity when the muscle length was moderate.

To clarify that the mixed nerve silent period (SP) and H reflex from soleus muscle may become an index expressed neuro-muscular function after reconstruction of anterior cruciate ligament (ACL), we studied the alteration of SP and H reflex from the soleus muscle in the patient with ACL reconstruction. Subjects were three patients with after ACL reconstruction, who were two male athletes (case A and B) and a female aerobics instructor (case C). Recording of SP and H reflex was performed longitudinally from one month post operation to six months post operation. As a result of this study, in case A, following findings were appeared; shortening of duration of SEP increasing the coefficient of variation of SP and increasing the amplitude ratio of H/M in non-operative side at the same time when his overusing activity of non-operative side. With case B, an appearance of long latency reflex (LLR) and an increase of coefficient of variation of SP in the operative side were verified in the period when many assists were required in order to correct motion image in rehabilitation. Concretely, from after the reconstruction over 5 months, LLR was appeared in SP of operative side, and increases of coefficient of variation was most remarkably in 4 months after the reconstruction, amplitude H/M ratio of operative side showed high value in 4 months after the reconstruction. With case C, remarkable problematical point was not found at the time of activity of daily life (ADL) acquisition and occupation return. So, with case C, feature findings of both SP and H reflex were not appeared. The results suggested that SP and H reflex from soleus muscle have become an index expressed neuro-muscular function of lower extremity and supra-spinal function in the patient after reconstruction of ACL.

Available H-reflex procedures do not allow a reliable or valid examination for the L5 radiculopathy. However, recording the gastrocnemius H-reflex may allow a reliable and valid method for examination of the L5 nerve root. Therefore, the purpose of this study was to examine the intersession reliability of the medial gastrocnemius (MG) and lateral gastrocnemius (LG) H-reflexes recordings during standing and lying postures at varied ankle positions in healthy participants. The MG and LG H-reflexes of eight healthy participants were elicited by stimulating the tibial nerve and recording the resultant muscle response using surface electrodes. The stimulation parameters were 1.0 ms, 0.2 PPS, with incremented stimulus intensity. Four traces of the maximum amplitude H-reflex and M-wave were recorded during lying and standing with the ankle in neutral, full dorsiflexion, and full plantarflexion over two consecutive days. The averaged traces were used to calculate the intersession intraclass correlation coefficients (ICC) among conditions. Intersession ICCs (2, 1) of MG and LG during standing and lying with varied ankle positions were moderate to high (ranging from 0.58 to 0.94). The MG was more stable than LG and the ICCs were greater during standing (ranging from 0.76 to 0.94) than during lying (ranging from 0.58 to 0.85), indicating higher sensitivity of the MG H-reflex when the limb is engaged in functional standing However, the LG H-reflex reliability was robust and, thus, could be recorded consistently in the examination of the L5 nerve root.

Background: Carpal tunnel syndrome (CTS) is the most common type of peripheral nerve entrapment and is a significant cause of morbidity. Carpal tunnel syndrome (CTS) has more incidences in diabetic patients. It has been suggested that insulin has an effect on nerve regeneration similar to that of nerve growth factor (NGF). Therefore, we aimed to evaluate the effectiveness of local insulin injection on the median nerve in patients with non-insulin-dependent diabetes mellitus (NIDDM) who have mild-to-moderate carpal tunnel syndrome (CTS).

Materials and methods: We carried out a prospective, randomized, single-blind, case-controlled study in these patients. We randomly selected 50 patients, 20 of whom had bilateral mild-moderate CTS. Therefore we had 70 hands and categorized them into two groups. At the baseline we injected NPH insulin (10U) directly into the carpal tunnel in group 1, and performed physiotherapy for the other group (group 2). Two weeks later, NPH insulin (10U) was injected into the carpal tunnel again and we continued physiotherapy for group 2. Electrodiagnostic study was performed for these two groups before treatment and 4 weeks after the last injection and physiotherapy. The patients were followed up for 6 weeks.

Results: In both groups decrement of distal motor latency (DML) of the median nerves statistically was significant. In both groups, the increment of the sensory nerve conduction velocity was statistically significant. Also the decrement of pain, paresthesia, numbness, weakness/clumsiness and nocturnal awaking was statistically significant in both groups. But there was no significant difference between the two groups.

Conclusion: Local insulin injection is an effective and safe treatment for carpal tunnel syndrome in NIDDM patients as physiotherapy

We often observe when workers lift objects, they tend to move their heads upward and back. Their movement may be an efficient habit, but little is known about control of the head while lifting. Our primary aim was to investigate the hypothesis that several repetitive liftings would lead to an increase in neck extension. Fifteen healthy male volunteers (20.9 +/- 0.8 years old) were asked to lift a case 10 times without instructions about the starting posture or lifting technique. Motion data and electromyography (EMG) signals were continuously recorded. The lifting time, angles of joints, and distance between the case and the malleolus lateralis at the moment of lifting were calculated from the motion data. EMG signals of the initial 1/10 phase of each lifting time were averaged and normalized to maximal voluntary contractions(% AEMG), and the mean frequencies were calculated by wavelet transform analysis. One-way analysis of variance and post hoc analysis were performed with Dunnett's test (p < 0.05). The cervical extension angle significantly increased, and the distance between the case and the malleolus lateralis significantly decreased for the later lifting times. The % AEMG of the gluteus maximus and the biceps femoris significantly increased for the later lifting times. A moving upward and back of the weight of the head, a decrease in the distance between the body and the case, and increases in tension of the hip extensor muscles could facilitate a righting movement to maintain balance. Therefore, paying attention to head control may be efficient while lifting.

The purpose of this study was to use a wavelet analysis designed specifically for surface mechanomyographic (MMG) signals to determine if the % myosin heavy chain (MHC) isoform content affected the shape of the MMG frequency spectrum during isometric muscle actions. Five resistance-trained (mean +/- SD age = 23.2 +/-3.7 yrs), five aerobically-trained (mean +/- SD age = 32.6 +/- 5.2 yrs), and five sedentary (mean +/- SD age = 23.4 +/- 4.1 yrs) men performed isometric muscle actions of the dominant leg extensors at 20%, 40%, 60%, 80%, and 100% of the maximum voluntary contraction (MVC). Surface MMG signals were detected from the vastus lateralis during each muscle action and processed with the MMG wavelet analysis. In addition, muscle biopsies were taken from the vastus lateralis and analyzed for % MHC isoform content. The results showed that there were distinct differences among the three groups of subjects for % MHC isoform content. These differences were not manifested, however, in the isometric force-related changes in the total intensity of the MMG signal in each wavelet band. It is possible that factors such as the thicknesses of the subcutaneous adipose tissue and/or iliotibial band reduced the potential influence of differences in % MHC isoform content on the MMG signal.

Recent researches are trying to rebuild an important human history of its posture and march from the anatomic function evolutions of the skeletal muscle (10, 11, 9, 2). The aim of this study is to verify electromyography data of muscles recto femoris, iliocostalis, gluteus maximus, erector spinae, semitendinosus during human locomotion in two different treadmill protocols (Naughton and Bruce). Data analyses, such as mean was calculated on the Word Office Excel. For electromyography data Aqdata program was utilized. Muscles rectus femoris, iliocostalis, gluteus maximus, erector spinae, semitendinosus were studied using electromyography analyses during human locomotion in treadmill. A number of six individuals was selected for this research. For the Bruce test all individuals ended there participation in the test on the fourth or fifth stage. For the Naughton test all individuals completed the 21 minutes walking. For the Bruce test all the muscle had higher RMS mean when compared with Naughton test, due the effort level for each test.

The present paper explains how an 18 year-old boy, who suffered an incomplete spinal cord injury (SCI) at the Cervical 5/6 levels, could achieve a near-complete recovery within 3 years of coordination dynamics therapy (CDT). The anatomically incomplete SCI was evident on MRI (Magnetic Resonance Imaging) which showed that 50% of the cord tissue was destroyed at the injury site. The administered CDT included the training of crawling, walking, running, jumping, and exercising on special CDT devices. Now 21 years old, this chronically injured young man cannot only walk independently, but he can also run and jump. He has attained full bladder control and is off all medications. The underlying mechanism contributing to this excellent recovery will have to be explained in the framework of the System Theory of Pattern Formation. In this framework the clinical improvement can be quantified in terms of coordination dynamics values, behavioural description of movement performance, analysis of motor patterns, and surface electromyography (sEMG) recorded during the movements. The impaired ability of the injured nervous system to self-organize is evidenced by deteriorated motor programs recorded with sEMG, unstable movement performances, and asymmetric attractor layouts in coordination dynamics recordings. On the other hand, the improvement of motor programs after CDT could also be measured by surface EMG, including measurements of antagonistic action of muscles and also by the improvement of the mean stability of motor patterns. These indicators of improving motor programs could be correlated with clinical improvement in certain motor performances like running and jumping. The recovery could mainly be achieved through a functional reorganisation as was indicated by the absence of significant improvement in the power of the quadriceps femoris muscles. The performances of turning on the special CDT device against high loads were diagnostic for the extent of repair of the integrative functions of the CNS. The cure of urinary bladder function is probably attributable to learning transfer from stereotyped, coordinated, integrative movements to the neural networks involved in bladder control. Since the patient received sub-optimal CDT, it took more than 3 years for the recovery. It appears that the repair of the integrative functions of the CNS need longer periods of time. But training such integrative movements is pivotal in inducing learning transfer from motor patterns to autonomic functions that resulted in the cure of urinary bladder function.